How to Monitor Your Engine's Email this article | Print this Condition article With a few extra simplechecks before, during, and after each flight, you can gain a broader picture of your engine's health, and increase your confidence in your aircraft. February 5, 1996 by John Schwaner This article is Copyright © 1995 by Sacramento Sky Ranch Inc. All rights reserved. Preflight: About the Author ... 1. Inspect the aircraft's John Schwaner is AVweb's belly. On most powerplant expert. John is a aircraft, any fluid leaks world-class authority on piston from the engine aircraft engines, and a specialist compartment ends up on the in the engineering analysis of belly. Fresh oil is a sign of an oil engine failures. John runs leak. Dark soot is a sign of rich Sacramento Sky Ranch, Inc., a engine mixture or increased leading distributor of aircraft combustion gas leakage past the and engine parts, and probably piston rings. Fuel dye is a sign of the foremost aircraft hose shop a fuel leak. One quick look at the and magneto overhaul facility in belly and you know whether the U.S. John and his wife live in there are any leaks in the engine Sacramento, California. compartment. John has also written two 2. Take your finger tip and touch superb technical books: Sky the inside edge of the exhaust Ranch Engineering Manual and pipe. If your engine's mixture The Magneto Ignition System. and oil consumption are normal, Both can be previewed in and then your finger should be clean, ordered from the AVweb or possibly have a slight tan ash Online Bookstore. deposit. If your finger tip has dry black soot on it, then your engine at a rich fuel/air mixture. If your finger has oily black soot, then your engine's burning too much oil. 3. Smell inside the engine compartment for any fuel smells. Small fuel leaks evaporate fuel as they leak and may not be enough to drip. Leaks may occur at primer fittings, hose connections, or the hose itself. One sniff in the engine compartment and you've checked all of the fuel connections for leaks. 4. Check the color of the oil on the dipstick. If it looks like black lacquer then the piston rings are leaking combustion gas into the oil. Start: 1. Listen for any out of the ordinary noises as the starter turns your engine. You should hear the starter, the clanking of the impulse couplings, and no wheezing of air out the engine breather or intake. 2. On your Continental 6-cylinder engine, does the propeller turn with the starter? If the starter turns but the propeller sometimes doesn't, then the starter adapter is slipping and needs to be repaired. 3. On Lycoming engines if the starter turns but the propeller doesn't then the starter Bendix is starting to stick. Usually cleaning and silicone spraying the starter Bendix shaft fixes the problem. 4. Does the engine kickback when starting? If it does, then you have a problem with the magneto impulse couplings, engine timing, or the starter vibrator. 5. If the engine's getting hard to start then your magnetos probably need repair. Idle: 1. Many engine problems are first noticed during idle. Engine roughness, caused by carbon fouled spark plugs, lead fouled spark plugs, a sticky valve, or a hydraulic lifter not operating properly are more common at idle. 2. A carbon fouled spark plug clears when you increase power, a lead fouled spark plug does not clear when you increase power. A carbon fouled spark plug indicates a spark plug that is not firing constantly or that the engine is operating at a too rich fuel/air mixture. Lead fouled spark plugs indicate a rich fuel mixture or that the power is being increased too rapidly at takeoff. 3. Bad hydraulic lifters are more noticeable during idle then during flight. A worn hydraulic lifter that leaks oil causes rocker arm to valve clearance. The rocker arm strikes the valve tip instead of pushing the valve open, resulting in a tapping noise. The noise goes away as the cold engine oil flows into the hydraulic lifter. Cold oil, being more viscous, doesn't leak out the hydraulic lifter as fast as hot oil. This causes the hydraulic lifter to pump up, closing the tappet clearance and causing the tapping noise to go away. This is fine and should not be a concern if the noise goes away shortly. If tappet noise occurs regularly then replace the hydraulic lifters. Worn or defective lifters cause the valve to pound against the seat, possibly causing valve breakage. 4. Is the oil pressure at its normal position? Low oil pressure at idle and high oil pressure during flight is caused by leakage in the oil delivery system and cannot be fixed by adjusting oil pressure. Takeoff: 1. Is takeoff rpm lower then normal? If takeoffs are getting longer and climb performance is getting worse, then suspect that a camshaft lobe is flattening out. Damaged camshaft lobes cause a gradual decrease in takeoff rpm in an otherwise smooth engine. 2. If takeoff rpm is low on a constant speed engine then the problem may be in the governor and not in the engine. Check to see if you can reach redline rpm in cruise flight. If a constant speed propeller airplane won't reach redline rpm in cruise, then the propeller governor is holding back the propeller and your 3. problem is not low engine power. In cruise flight or descent, even an engine with low power will turn a propeller past red line because of the low engine loading. 4. Monitor for engine smoothness and power. 5. Is vacuum pump pressure normal? As the vacuum pump starts to fail it often produces lower suction for a flight or two before failure. Cruise: 1. Magneto problems often cause a slight roughness as you climb to altitude. The roughness may go away when you reduce power to cruise. High manifold pressure requires more voltage from the magneto to spark the plugs then lower manifold pressure. Therefore, if you can turn the engine roughness on and off by changing the manifold pressure, then the magneto is at fault. 2. The higher the altitude the less resistance to arching within the We found him disarmingly frank in discussing a variety of issues from competition to Cessna's chances.The optimum idle setting is one that is rich enough to provide a satisfactory acceleration under all conditions and lean enough to prevent spark plug fouling or rough operation.magneto. The relationship is not linear and sometimes may not exist. Does the engine cutoff evenly? If not. only to clear up when you reduce power or descend to a lower altitude. A rise of 25-50 rpm will usually satisfy both conditions. Boob has been at Lycoming since 1985. To some degree oil pressure follows oil temperature and oil temperature follows cylinder head temperature. Therefore. 3. 3. the idle cutoff circuit is leaking. Check the aircraft belly again. If the propeller has more than 100 hours on it and is starting to sling oil onto the windshield then its time to send it off to a propeller shop. This causes oil temperatures to rise without a corresponding increase in CHT temperature. 4. Future of the Piston Aircraft Engine: An Email this article | Interview with Lycoming's CEO Print this article During one of our three visits to Lycoming. oil pressure goes up. He worked in sales and marketing before being . You should get no more than a 100-rpm increase when going to idle cutoff. increased heat transfer from the cylinders to the oil occurs when the piston rings start leaking hot combustion gas into the oil. As cylinder head temperature goes up. As oil temperature goes up. oil pressure goes down. 2. For example. This can be used as a crosscheck of proper gauge operation. a marginal magneto often causes slight engine roughness during the climb. the company's chief executive. Any more than 50 rpm means that idle mixture is too rich. having spent 17 years in sales at Piper Aircraft before that. we spent a couple of hours with Phil Boob. Shutdown: 1. 500-hour ATP and CFIA/CFII/CFIME. Part 2: A Visit to Lycoming Supplemental Feature: Future of the Piston Aircraft Engine: An Interview with . Articles in This Series Future of the Piston Aircraft Engine. 1995 by Paul Bertorelli This article originally appeared in THE AVIATION CONSUMER and is reprinted here by permission.. About the Author . Paul Bertorelli is a professional aviation journalist and editor.. He's Editorin-Chief of The Aviation Consumer and editorial director of AVweb and Belvoir Publications' Aviation Division. Part 1: A Visit to TCM (Teledyne Continental Motors) Future of the Piston Aircraft Engine. He's a 4. He owns a Mooney 231. November 9.appointed CEO in 1986. our engine business is good. Lycoming's CEO Why would a sane and profitable multi-national conglomerate like Textron want to mess around with engines for little airplanes? Because as long as we return to the shareholder the profits they expect. there's no problem with this division. in parts and in overall engines. too. If it gets to the point that an investor could say "Textron. we've got the competition from the PMA guys. Even so. More parts go into overhauls than into repairs. We realized they were just going . We're 30 percent of the overhaul market now and obviously 100 percent of the new engines for replacement.AVweb's comments are in red. I don't know if I could get into this or not. That was our whole thrust on the cylinder-kit program. Our business in total and our dollars in total have been stable and in fact. That includes overhaul.: In parts. We wouldn't sell the rest of the stuff to go along with it. gee. And we have been able to do that. slightly better this year than last. because you can't get them anywhere else. parts and entire engines? Yes. Still. Then we had the PMA guys. coming in with their valves and rings and pistons and so forth. We finally recognized that for years. we were trying to sell a cylinder. what we call a stud assembly. which was just the cylinder. we'll be in the engine business. the reason I don't own your stock is that you've got too many of these divisions that aren't returning a profit. We did $20 million in that segment last year and we only have about a third of the market. even not counting our windfall from Chevron." Textron would look at it differently. We're measured by Textron as a stand-alone business. In that case. But the real growth opportunity is in the overhaul business and if you get that. And I can tell you that as a stand-alone business. Do you see any way to eke some growth out of a market that's declining at a percent or more a year? Our business is not declining. you automatically get the spares. Our real growth opportunity is in the aftermarket business. it's obvious from our tour that the factory is a shadow of its former self. you might look at the shrinking market and the liability costs and say. That's different than saying if they didn't own it already would they go out and invest in it. You haven't mentioned Continental as a competitor. You're looking at in excess of a millionand-a-half dollars to do that. Say you want to put a Continental engine in a Saratoga. You have to remember that 75 percent of our business is aftermarket and the parts aren't interchangeable with Continental engines. what would the price to the consumer be if he bought a cylinder from us and went to Superior and bought all the valves and rings and so on? What would it cost? We got that number and decided we had to sell our cylinder kit at X dollars. We put this program into place and we haven't sold less than a thousand a month since we started. So I can only assume that either they believe they know how to make the 2000 work and the economics are driven on that. Can they be profitable at that volume? Cessna has run the economics on this thing. None of them are big. probably half of the two thousand. Do you consider them competition? No. particularly in the international market. You're not a proponent of the pent-up demand theory. So we just said. so we'll sell 50 engines here and 50 engines there. I give my predecessors the credit for this. or. one of the reasons I flinch so much on that is because it's not Like you . Somebody had to make a decision to go back into business. At the outside. Back in the 1970s. it's difficult to make financial sense out of changing from one manufacturer's engine to another. then? Well. they've got to factor down to some level and still have it make sense. I don't see it as sustainable. I think we're benefiting from that today. Other than new OEM. Lycoming took a different approach. when Continental didn't want you as a customer unless you'd buy thousands of engines. When I look at the OEMs (original equipment manufacturer) we have a list of 40 customers all over the world. Why would you do it? How much better do these things have to be before the consumer is willing to pay the additional rnoney? Are Cessna's plans to make 2000 airplanes a year by 1997 or 1998 sustainable? No.to keep picking away at our business. unless you're having significant product problems or customer acceptance problems. We had been selling about a thousand stud assemblies a year. Use the yacht and the airplane as a comparison. how many Lexus's were sold last year. you don't have an industry. furniture. They haven't done that. I don't need to know a . " Are you guys telling me. airplanes or cars. I get a knot in my stomach. look. how many yachts.000 Cessna 172. houses. I don't care if you're selling automobiles. it's impossible that you couldn't sell an additional 2000 airplanes. When you start thinking about cost you gotta say. how many skiing packages? People are spending money. if you can't get the younger people interested. Now if you said they figured out some magic way to come to the market with a $70. how many Cadillacs. I remember sitting with Tom Gillespie at Piper towards the final days of the Cheyenne program when he challenged the whole sales force sitting around the table and said.can't today go buy a new airplane comparable to the new 172 for a comparable amount of money. I think some people are saying that i n the entire world today. you gotta get on the phone. If they don't work. file a flight plans get a clearance. Put money in the bank and they can rub my nose in anything they want to. go whatever direction or whatever route somebody tells you to as opposed to the route that you'd really like to go. Do you think the lack of interest in flying or ownership is cost driven or is it some other factor? It's maybe not so much cost as much as the hassle with the activity. Don't these generate interest and demand among young people? Certainly those are excellent programs." When I sit back and look at the fact that you can go buy new airplanes today and I consider that the prices aren't going to be that much different and I look at the lack of student starts. But it's the right kind of thing to do. Meaning that if you wake up tomorrow morning and look out the bedroom window and it's a foggy day. then I don't know. You mentioned student starts and the lack of new pilots. But I hope Cessna is right. I hope I'm so wrong that they rub my nose in it forever. But I don't know how to measure their success and I don't think anybody else knows what the impact of programs like these could be. What do you think of the AOPA Mentor Program and EAA's Young Eagles. I'd change my answer real quick. that in the whole damn world we couldn't sell one Cheyenne in the last three months?" And the answer was "you bet. check the weather. before you can back your car out to go to work. Now. We basically didn't see any change in our costs in 1995 as a result of that. And it will be a financial benefit. At Oshkosh this year. it'll make a difference. The airframe manufacturers should see it earlier. it's not very impressive to buy an airplane and go down and sit in it Friday night and have drinks.000. there seemed to be a general euphoric feeling that the industry is on the comeback. We've already had it happen to us. I said how to use it-because it's not very impressive sitting on the ramp. if somebody says when you're done with this. At any given time we've got about 175 suits working. Given what appears to be fierce competition from engine shops. And probably it's going to allow us to make increases below the inflation rate. tie it up to the dock. Now.000 engine and be able to sell it for $14. win or lose. You may win the suit.damn thing about a yacht to impress you with it. How many engines are 18 years old that don't have some parts replaced? And a good trial lawyer is just going to zero right in on those replaced parts. Somebody has to know how to use that airplane-I didn't say how to fly it. your avowed promise to improve efficiency and perhaps with a declining cost for product liability. For the last 10 years or so. but it'll be several years before that manifests itself . On the engine side of it. you're gonna take that $16. I'm inclined to believe that what's missing is disposable time as opposed to disposable income. there's constant replacement going on. is it realistic to expect engine prices to actually decrease? I can say almost with certainty what we're doing here will cause the price to not increase at the rate that it has over the last 10 years. Some people argue that the statute of repose is responsible for this. All I need to do is buy it. I don't know yet. Then it really won't make the difference some people think it will? No. is $300. by the way. take you down and throw my cocktail party on Saturday night and I've impressed all my friends. it's been just the opposite. I think it's just a piece of the solution that may eventually revitalize the industry. But the engine manufacturers and the component manufacturers are going to be the ones to see the direct benefit last. but you spend about the same amount for defense costs to win as to lose. . Our average defense cost. What's Lycoming's view? I think that's an exaggeration.000 per suit. . He's a 4. Part 1: A Visit Email this article | to TCM (Teledyne Continental Motors) Print this article We expected our recent visit to the Teledyne Continental Motors factory in Mobile to be depressing.But if I can do that and at the same time increase the overall business and make a profit that makes sense. Future of the Piston Aircraft Engine. About the Author . About the Author . but we came away feeling surprisingly upbeat about the future of TCM. I will.500-hour ATP and CFIA/CFII/CFIME... 1995 by Paul Bertorelli and Mike Busch This article originally appeared in THE AVIATION CONSUMER and is reprinted here by permission. Paul Bertorelli is a professional aviation journalist and editor... November 9. He's Editorin-Chief of The Aviation Consumer and editorial director of AVweb and Belvoir Publications' Aviation Division. He owns a Mooney 231. Mike Busch is editor-inchief of AVweb. Mike and his wife Jan reside on the central coast of California in a semi-rural area where he can't get DSL or cable TV.000-hour commercial pilot and CFI with airplane. which he maintains himself. he's owned and flown a Cessna T310R turbocharged twin. a member of the technical staff at Cessna Pilots Association. For the past 14 of those years. instrument and multiengine ratings. A 6. Articles in This Series Future of the Piston Aircraft Engine. In his never-ending quest to become a true renaissance man of aviation. and in a prior lifetime was a contributing editor for The Aviation Consumer and IFR Magazine. Mike has been flying for 36 years and an aircraft owner for 33. Mike's on the verge of earning his A&P mechanic certificate. Part 1: A Visit to TCM (Teledyne . we've been touring the country talking to as many engine experts as we could find." Fortunately. It took nearly six months of dogged persistence before TCM agreed to our visit in mid-May. Part 2: A Visit to Lycoming Supplemental Feature: Future of the Piston Aircraft Engine: An Interview with Lycoming's CEO The visit that almost wasn't When we first called TCM's public relations office last winter to arrange a plant tour and management interview. Even then. we were told that we would not be permitted to take photos or use tape recorders. . we talked at length with Lewis and all of the other top TCM managers. During the next day and a half. This is the second article in a periodic series on the current state and future of the engine business. we were able to arrange a breakfast meeting with TCM president Brian Lewis and persuade him that we weren't there to do a hatchet job on his company. it became quickly obvious that the company wasn't exactly thrilled with the idea.Will the piston engines of tomorrow incorporate new technology of will they just be more of the same? Do piston aircraft engines even have a future? To answer these questions. Lewis reluctantly but graciously relaxed most of the restrictions originally placed on us. and that management interviews would be strictly "off the record. Continental Motors) Future of the Piston Aircraft Engine. The second article in this series recounts our visit to Textron-Lycoming and our revealing one-onone interview with Lycoming's CEO. and saw as many parts of the manufacturing operation as time allowed. TCM prospered during the heyday of general aviation in the 1970s. Continental's original factory was in Ohio. the firm was turning out more than 10. a diversified conglomerate with operations ranging from weapons and aerospace to shower heads and Water-Piks. and to transform itself from a manufacturer of new . The company expanded into its current Alabama location starting in 1966 when the Air Force decided to close down Brookley AFB (now Mobile Downtown Airport) and Continental was able to lease the old hangars and buildings for a song. The A40 was the first of a long series of Aseries engines that culminated in the A225 engines that powered early Beech Bonanzas in the late 1940s. The 1980s was a traumatic decade for TCM. we were pleasantly surprised by much that we saw and heard at TCM. The company was forced to downsize drastically. The TCM workforce reached 950 people. And TCM's reluctance to let us visit made us suspicious about just what they were trying to hide. Given this background. In the early 80s. TCM's rollercoaster ride Continental has been building piston aircraft engines for 65 years. The A-225 was the progenitor of today's big-bore 470.To be honest. and the company expended into virtually every available building at the Brookley site. the market for new TCM engines vanished. In 1969. and 550 Continentals. Cessna (TCM's biggest customer) shut down piston production altogether. We'd heard rumors that Teledyne was on the brink of shutting down TCM and getting out of the piston aircraft engine business.000 engines a year. Beech. mostly new engines for Cessna. Then disaster struck. the general aviation industry experienced a devastating downturn. we arrived in Mobile with some preconceived notions about what we would find there. and other OEM customers. 520. Continental Motors Corporation was acquired by Teledyne. The A40 evolved into the O200 and O300 engines used in the Cessna 150 and 172. By 1979. Virtually overnight. and other manufacturers slowed to an insignificant trickle. Teledyne acquired additional space at Brookley and relocated all TCM operations to Mobile. In 1930 Continental introduced the A40. New piston aircraft production virtually ceased. We'd been told horror stories about quality assurance problems at TCM. a 38horsepower 4cylinder horizontallyopposed air-cooled engine used in the Piper Cub and Taylorcraft. TCM is down to about 600 employees. and quality circles reminiscent of a Japanese car company. and a new top management team tasked with repairing the company's relationship with its workforce. One legacy of the strike was a customer perception of poor quality control that persists to this day. If the court approves the buyout plan. the other half of the business is in selling replacement parts to overhaul shops and other field maintenance facilities. Teledyne brought in a new TCM chief executive. He sees positive signs for the first time in fifteen years. solving the quality problems. TCM's new realities Today.600 engines a year. TCM is the dominant engine supplier for the . TCM is the lead member of a creditor group that is attempting to acquire Piper and bring it out of Chapter 11. and anticipates slow but solid growth for some years to come.engines into a supplier of parts and rebuilt engines to the aftermarket. The remaining 85% are remanufactured engines for the aftermarket. Cessna's decision came as no big surprise. With Cessna resuming piston aircraft production. TCM will become the largest shareholder of the new Piper. Mooney. Lewis's comment: "we're disappointed that Textron made its decision along corporate lines. and re-engineering the company in response to TCM's different and downsized market. Only about 15% of those are new OEM engines. These engines represent about half of TCM's revenues. Since Cessna and Lycoming are both divisions of Textron (another 1960s-vintage conglomerate). Brian Lewis." Piper is a different story. TCM's future OEM business won't come from Cessna. Brian Lewis is convinced that TCM's worst years are behind it. manufacturing cells. TCM became a giant overhaul shop The trauma was compounded in 1989 when TCM's management and labor union reached an impasse in contract. In essence. The company was reorganized into business units. Lewis expects the market for new OEM engines to revive. In the aftermath of the strike. Piper expected to exit bankruptcy soon. and several overseas manufacturers. TCM's other OEM customers include Beech. and the kitplane business growing rapidly. and produces about 3. and would presumably become Piper's primary engine supplier. In addition. resulting in a long and bitter strike that crippled TCM's production. who stated that engines for its new piston production would be 100% Lycomings. In contrast. TCM intends to keep and enhance its reputation as the most innovative company in the piston engine market. The innovative geared high-RPM Tiara engine that TCM developed the '70s appeared briefly on one agplane and then disappeared into oblivion. Nevertheless. and tends to make engineering changes very rarely and only when absolutely necessary. Questair Venture. Continental has a much bigger R&D budget. TCM's promising liquid-cooled "Voyager" engine developed in the '80s has yet to surface except in a relative handful of RAM-converted Cessna 414As. We talked at length with TCM's engineering chief. Although he doesn't see the OEM business returning to the heady levels of 1979. TCM holds an STC to install liquid-cooled IO-550 engine in the Beech Bonanza.). etc. . Brian Lewis made it clear that he considers innovation to be a key factor in providing tomorrow's OEMs and converters a reason to choose TCM rather than Lycoming. Also. TCM expects to start shipping engines using the new Slick LASAR electronic ignition system as soon as Unison can get FAA certification. about what the TCM engines of tomorrow would look like. Some of their "improvements" have not worked out well in the field (such as Nitralloy exhaust valve guides and cast steel-belted pistons). Take a side-by-side look at engine parts catalogs sometime: a TCM parts catalog is dominated by hundreds of change pages. Barton's roadmap includes lots of small product improvements. Engineering innovation For decades. and is trying to get it to market via a licensing arrangement with a (yet unnamed) airframe converter. which TCM expects to become an increasingly important segment of the OEM market.high-performance kitplane market (Lancair IV. and makes changes much more frequently. For example. But TCM's predisposition toward innovation has been a two-edged sword. reman engines by the end of the decade if all goes well. while a Lycoming parts catalog has hardly changed in years. Lycoming spends relatively little on R&D. Lewis thinks that TCM's business might reach a 50-50 ratio of new vs. Continental has pioneered many important engineering innovations like fuel injection and turbocharging. And the company has spent many millions on R&D programs that have not paid off. Continental and Lycoming have displayed very different attitudes toward innovation. TCM's enthusiasm for R&D seems undiminished. several new but evolutionary engines. John Barton. and a major thrust to incorporate electronics into TCM engines. Finally. basically a four-cylinder version of the current IO360. Expect to see this occur in small increments. finely-balanced. We saw a new line of rocker cover and accessory gaskets that have an integral raised rubber-like bead to improve sealing and eliminate pesky oil leaks. dubbed the IO-520-LW. And we looked at a brand new clutchless starter that TCM is introducing to replace the old and failureprone O200 starter. TCM is developing a pair of new high-power geared engines. Ultimately. John Barton still believes that they were both steps in the right direction. the turbocharged model will be rated at nearly 500 hp. a normally aspirated GIO-550 and a turbocharged GTSIO-550. At the opposite end of the horsepower scale. liquid-cooled engine with variable-timing electronic ignition. to power trainers and mediumsized kitplanes. TCM is creating a new 125 hp IO240 engine. capable of operating on low-octane unleaded fuel. Although TCM's geared high-RPM Tiara engine was a commercial failure 20 years ago and its liquid-cooled Voyager engine has yet to gain much acceptance. a lightweight 250 hp version of the IO-520 is in development. high-RPM. TCM engineers are focused on the increased application of electronics to the piston aircraft engine. most likely the Slick LASAR system. We examined a new O200 cylinder assembly that incorporated dozens of significant improvements. . His long-term vision of TCM's piston engine of the future (what he calls the "Advanced Core Engine") is a geared. Barton showed us a number of new product improvements in his engineering lab. electronic mixture control. Future engineering direction Barton's engineers are working on several new engines to meet specific needs. but it gives a good indication of where TCM engines are most likely headed. TCM's goal is a single power lever system that reduces pilot workload while assuring optimum power and mixture settings. TCM is investigating an electronic fuel control unit that would provide optimum mixture control. The first use of electronics will be variable-timing electronic ignition. much as the auto industry did a decade ago. There's no target date for such an engine. and a single power-lever control. Longer term. electronic instrumentation. TCM is also working on an electronic engine instrumentation package to replace the traditional steam gauges we now use. the retooling allowed TCM to cut the price of new cylinder kits by 30% to 40% last year. The first portion of the factory to be retooled was the cylinder fabrication facility. however. and were able to retire almost 75 ancient manually-operated machines. Cylinders are now manufactured with greater consistency and less dimensional variation than before. TCM's vice-president and general manager of operations. The company is investing big bucks to retire decades-old manually-operated machine tools and to replace it with state-of-the-art computerized numerically-controlled (CNC) equipment. New CNC machines will replace old tooling wherever it is advantageous to do so. In contrast. took us through the cylinder shop and showed off his expensive goodies. smelly. gang-boring crankcase halves with custom-built boring jigs is both faster and more reproducible than drilling holes sequentially with a CNC rig. and has almost twice the production capacity of the old facility. laboratory clean. and surprisingly small (perhaps 1. Next in line for retooling at TCM are the crankshaft and crankcase production areas.") TCM's modern Mori Seiki CNC machines are the same kind we saw when we visited the Dallas production facility where Superior's Millennium cylinders are built. Such equipment was conspicuously absent during our visits to Lycoming. Final assembly When Atwood took us though the area where final assembly of engines is performed. final assembly is done in a separate room that is air conditioned. Some of the old equipment will remain. Nevertheless.000 square feet). Most importantly. because CNC isn't always the best solution. Most of the TCM factory looks like a gigantic machine shop: huge. sprawling. brilliantly lit.Major retooling Meantime. The new cylinder shop is one-third the size it used to be. Atwood expects to achieve significant productivity increases and cost savings when the crank and case cells are retooled. Over the past three years. TCM is making major changes to their manufacturing operation. TCM has installed four new Mori Seiki CNC machines that cost $1. with row after row of big metalworking machines. hot. (We discuss the new economics of cylinders in "The Jug Jungle. For example. requires substantially fewer workers. dark. . Every TCM engine is built in this one little room. it was not quite what we expected. Howard Atwood.5 million. ) Production control TCM has also created major new data processing systems to support its manufacturing operation. showed us how the new system works. The test cells are old and low-tech. (Lycoming uses a similar scheme. (This differs from Lycoming.) The assembly dollies allow the engines to be assembled with the crankshaft horizontal. detailed procedures. These all move down the line together as engine assembly progresses. the assembly manual for each engine is customized for each particular engine serial number. Caton told us that this system proved invaluable during production crunch following the recent Chevron fuel contamination crisis when demand for . Pivots on the dolly permit the assembler to turn the engine on its side or even upside-down for easy access during various assembly steps. using steam-gauge instrumentation and manual logging of results. (TCM has one high-tech computer-instrumented test cell that is used by engineering. Production and materials control are now computerized with an order-driven scheduling system. Because TCM builds such a wide variety of engine models and spec numbers. We saw a mixture of old-style (text only) and new-style (text plus graphics) manuals when we visited. every field overhaul shop we've visited assembles engines with the crankshaft vertical and supported by the propeller flange.Every engine has its own assembly dolly. each engine is wheeled to an instrumented test cell where it goes through a test run that normally lasts 45 to 60 minutes. and its own serial-numbered assembly manual. its own parts cart. where new and rebuilt engines are built on separate parallel assembly lines. If an urgent situation arises (such as an AOG order). After final assembly is complete. There is just one assembly line that every engine traverses. TCM's manager of production control. and so forth. If any of the required parts are in short supply. the computer instantly allocates all necessary parts based on the proper bill-of-materials for that particular engine model and spec number. corrective action can be taken immediately so that production is not impacted. TCM is in the process of digitizing their assembly drawings so that the computer can incorporate graphics into these manuals. whether new or reman. itemizing each individual assembly step. When an engine order is received. Ron Caton.) In contrast. torque values. The manual contains hundreds of pages of computer printout. the computer is smart enough to realloate parts from lower-priority orders. Thornbury explained that TCM's emphasis is on monitoring and improving each manufacturing process so that problems can be caught and corrected long before out-of-spec parts start appearing.reman engines and parts suddenly went ballistic. One out of every 25 engines that comes out of final assembly and test-cell run is pulled off the line and subjected to a complete teardown inspection. At the opposite end of the Q/A spectrum is engine audit inspections. The audit engine then goes back through final . and surface roughness testers. Red flags go up any time variation exceeds one-half of the allowable inspection tolerances. So we sat down with Bill Thornbury. he graciously started over in plain english. vice-president of quality assurance. Although detailed inspection is the last line of defense against out-of-spec parts. Thornbury started out with a highly technical presentation that was frankly over our heads: Cpk=2. Questions about quality Innovative engineering and efficient manufacturing may be well and good. Special emphasis was given to certain critical measurements such as the roughness of cylinder microfinish which TCM considers critical to proper break-in. The use of these fancy new instrumentation was particularly in evidence when we visited the cylinder cell. TCM is now phasing in state-of-the-art measurement tools that we'd never seen anywhere else in our travels. all with digital outputs to permit direct computerized logging of measurements. A long list of critical dimensions—Thornbury called them "key characteristics"—are measured and logged. but what customer care about more than anything else is quality. SPC analysis. In support of this kind of analysis. It was impossible for TCM to keep up with the unexpected order surge. The computer allowed TCM to provide fairly accurate delivery time estimates to customers during the Chevron crunch so that they knew how long their aircraft would be down and could make alternate plans. Thornbury showed us electronic torque wrenches. When he noticed our eyes starting to glaze. depth gauges. Prior to our visit. micrometers. and asked him to give us a detailed show-and-tell about TCM's approach to Q/A. 6-sigma. Critical dimensions are logged and analyzed to determine whether dimensional variations are random or whether a trend can be detected. but things would have been a whole lot worse if the new scheduling system hadn't been in place. we'd heard numerous stories about the poor quality of the engines coming out of Mobile. go public with it. . TCM was in the throes of a labor dispute that severely disrupted its manufacturing operations and had devastating impact on product quality.S. and started to build excellent cars that were every bit as good as what the Germans and Japanese were making. updated their tooling. These folks meet to evaluate a quality problem and decide how to deal it. auto industry. The U. But it took many years before the stigma associated with poor quality American cars was erased from the mind of the consumer. no matter how remote or improbable it might be. automakers redesigned their cars. Superior. As a result of this policy.S. Barton." To deal with such problems when they arise. A piston aircraft engine has an average life of about ten years before it is majored or replaced. We suspect that the same phenomenon is partly responsible for the perception of poor TCM quality. or any of the overhaul shops we visited. and droves of Americans started buying Toyotas and BMWs instead of Chevys and Dodges. TCM has created a "Product Integrity Council" which includes Atwood. What happened? Did it occur in-house or at a supplier? Have any defective parts or engines reached the field? Can we identify precisely which serial numbers are affected? Is a service bulletin or airworthiness directive required? Is priority notification required? How can we ensure that it doesn't happen again? A basic ground rule of this Council is: if there's any safety issue involved. Detroit developed a reputation for building terrible cars. overhauled their Q/A procedures. sometimes "stuff happens. Thornbury. But we have our own theories. and various other key managers. Perception versus reality We came away with the vivid impression that TCM is working both harder and smarter to assure product quality and consistency than what we saw at Lycoming.) No matter how thorough a company's Q/A procedures are. (Lycoming uses a similar procedure. In this regard. Perception seems to lag years behind reality in this business. So why does TCM have such a bad reputation for quality in the field? Neither Thornbury nor anyone else at TCM could give us an answer. it's similar to what happened to the U.assembly and gets another test-cell run. This means that an average owners' last contact with the factory was about five years ago. TCM sometimes finds itself getting bad press when another company faced with the same situation might have elected to say nothing. And five years ago. More than a decade ago. and Archer . and to obtain price and availability information. Archer has been tasked with re-inventing his department so that it serves the customers of today: the aircraft converter. this change is very welcome and about a decade overdue. those shops are doing a far better job at telling their story than the factory is. and Victor come to mind. TCM-NET is presently being used by 70% of TCM's distributors. TCM is in the midst of a major reorganization of its customer service department that at last recognizes the realities of today's market. These firms used to compete with TCM on the basis of price.) And frankly. Consequently. the distributor. We spoke with Tim Archer. we'd feel just fine about buying a TCM factory reman. they have a vested interest in making TCM remans look bad. Since many of them make more profit selling an overhaul than they do selling a factory reman. We can't help but conclude that this is a factor in perpetuating the perception of inferior quality from TCM. and provide field support. and aircraft owner. but with today's aggresively-priced remans this is no longer possible. director of sales and service. Based on what we saw in Mobile. a miniscule fraction of TCM's product goes to OEMs. TCM appears to be working harder on product quality than anyone else in the industry. and has invested heavily in automation of his department.Also. In our judgement. Contrary to widespread perception." Today. the FBO. deal with warranty claims. he deployed TCM-NET—a PCbased system providing 24-hour on-line dial-up access to TCM's distributor network. (Capehart. the word "customer" in the TCM lexicon was defined as "airframe manufacturer. These are the folks that process orders. there's a love-hate relationship between TCM and many of its distributors. Prior to the Great Downturn. to submit and track warranty claims. Last year. A number of high-profile shops are quite overt in marketing their overhauled engines as better than what the factory turns out. RAM. Consequently. and with several of Archer's managers. Customer service The last department we visited at TCM was customer service. TCM seems to have come light years from the bad old days of '89 and '90. The system allows distributors to place and track orders for engines and parts. Archer is a big believer in computers. it is an irony of today's market that TCM's principal customers (authorized distributors of TCM reman engines) are also TCM's principal competitors (overhaul shops). FBO-LINK will be introduced later this this to a hand-picked group of large FAA repair stations. We've found them to be technically sharp and good folks to work with. The system has eliminated most of the access problems associated with time-zone differences. export documentation is now handled by one person working half-time. The . and showed us a demo). a Chadwick-Helmuth balancer. The next phase of the automation initiative is called FBO-LINK. particularly for overseas distributors.expects the number to reach 99% by year-end. We have first-hand experience dealing with a few of these TCM field reps. is TCM's "Gold Medallion Club. Overall. FBOs will have 24-hour on-line access to warranty status. Archer used to have four full-time people preparing export documentation. warranty claim tracking. In addition to the headquarters support organization. With the advent of TCM-NET. Owners will have online access to warranty status. A couple of the reps who serve geographically-large territories also have company airplanes. FBOs may be able to use their PC to videoconference with factory support experts (Archer is experimenting with this right now. but ultimately should become available to any field maintenance shop that wishes to participate.S. and now (since the advent of TCM-NET) a laptop computer. plus 2 international reps. a fancy digital thermocouple test set." This is a version of TCM-NET that will be available to aircraft owners who have new or reman TCM engines. TCM's customer support headcount decreased from 48 to 36 over the past few years. Each rep is equipped with a borescope. modem. A third phase of this program. These are the guys your mechanic calls for technical help or warranty support when you have an engine problem. service bulletins. but the number of people in direct customer-contact roles increased from 23 to 27. and is basically a version of TCM-NET designed to allow field maintenance shops to have direct access to TCM factory support. Eventually. and cellular phone. Each regional rep is an experienced A&P with extensive expertise in troubleshooting TCM engines. and has produced a tremendous savings in paperwork. and technical briefs. and tech briefs. This program should provide yet another incentive for owners to choose a factory reman over a field overhaul. About 30% of TCM's business is overseas. but that business involves vastly more paperwork than does domestic business. slated for rollout next year. and a broad range of troubleshooting help. TCM has 10 field technical reps—8 regional reps in the U. service bulletins. are coming ten years too late. If there's anything that TCM isn't doing well. what we saw in the course of our visit to TCM was what we expected to see: a big. After a decade of denial following the precipitous industry downturn of the early '80s.biggest problem is that they travel a lot and are not always easy to reach on short notice. TCM is investing millions in state-of-the-art machine tools and computer systems. TCM today has a teriffic story to tell. Also contrary to common perception. TCM seems to be doing everything right in the area of quality assurance. TCM's advertising is ineffective. smelly factory packed with hundreds upon hundreds of antiquated metalworking machines operated by hundreds of sweaty machinists. They're clearly working harder at Q/A than anyone else we visited (including Lycoming). but it's doing a lousy job of telling it. TCM is clearly a company undergoing profound change. There's no queston that TCM had big problems 5 or 6 years ago during the period of labor unrest. dark. although certainly welcome. it would be this: go hire a topnotch Vice President of Corporate Communications. geared. TCM can be expected to be the engineering frontrunner in liquid-cooled. and they are making the R&D investment that they think is needed to give the airframe builders of tomorrow a good reason to select TCM engines rather than Lycoming. and electronically-managed engines. Their public and press relations stink. and is a prototype for what TCM will be doing to the rest of the factory during the remainder of the decade. TCM management believes that the OEM market for piston engines will rise again. And their new customer support initiatives. TCM definitely is not behaving like a company on the brink of getting out of the business. and most of the surprises were pleasant ones. And yet we saw lots of things that we found suprising. it's communicating with the world outside of Mobile. If we had one piece of advice for Brian Lewis. as rumors might have you believe. Overall impressions In one respect. In our judgement. TCM has brought in a new management team and appears to be turning the company around and doing almost all of the right things. The new cylinder cell has yielded impressive results in productivity and cost-cutting. turbocharged. old. But today we're inclined to think that most of the horror stories about TCM's poor quality are outdated and a bum rap. We think TCM's public . . Lycoming should soon be top dog of the OEM engine market. About the Author . But while they're busy gearing up for Cessna. Future of the Piston Aircraft Engine. . He owns a Mooney 231. November 9. the company still plans to expand its overhaul and parts business. Part 2: A Email this article | Visit to Lycoming Print this article With Cessna back in the new piston airplane business... He's Editorin-Chief of The Aviation Consumer and editorial director of AVweb and Belvoir Publications' Aviation Division. Paul Bertorelli is a professional aviation journalist and editor. He's a 4.. About the Author .500-hour ATP and CFIA/CFII/CFIME. 1995 by Paul Bertorelli and Mike Busch This article originally appeared in THE AVIATION CONSUMER and is reprinted here by permission.image is way past TBO and needs a major overhaul. In his never-ending quest to become a true renaissance man of aviation. and in a prior lifetime was a contributing editor for The Aviation Consumer and IFR Magazine. A 6. Mike's on the verge of earning his A&P mechanic certificate. which he maintains himself. a member of the technical staff at Cessna Pilots Association. For the past 14 of those years.Mike Busch is editor-inchief of AVweb. he's owned and flown a Cessna T310R turbocharged twin. Part 1: A Visit to TCM (Teledyne . instrument and multiengine ratings. Mike has been flying for 36 years and an aircraft owner for 33. Articles in This Series Future of the Piston Aircraft Engine.000-hour commercial pilot and CFI with airplane. Mike and his wife Jan reside on the central coast of California in a semi-rural area where he can't get DSL or cable TV. Will the piston engines of tomorrow incorporate new technology of will they just be more of the same? Do piston aircraft engines even have a future? To answer these questions." While that admonition proved to be an exaggeration. during the heyday of general aviation manufacturing in the U. Continental Motors) Future of the Piston Aircraft Engine.S. The first article in this series recounts our visit to Teledyne-Continental Motors. too. The plant is a working monument to the term "sunset industry. a determined company can prosper at a volume of business that would have seemed preposterously low by 1970s standards. Lycoming has survived by brutally downsizing itself . As has Continental. we've been touring the country talking to as many engine experts as we could find. a mechanic we know advised us to brace for a shock when our travels took us to Textron Lycoming's plant in Williamsport. A companion piece presents our long and revealing one-on-one interview with Lycoming's CEO." he said." but it also shows that even in the midst of a declining market. Lycoming's aviation engine business is a fraction of what it was in the late 1970s. there's truth to it. "It's like a ghost town. "You won't believe that place. Part 2: A Visit to Lycoming Supplemental Feature: Future of the Piston Aircraft Engine: An Interview with Lycoming's CEO When we embarked upon our grand tour of engine plants and shops last fall. This is the second article in a periodic series on the current state and future of the engine business. Pennsylvania. Auburn and Duesenberg and before that.) What limited R & D money it has goes into improved and more efficient manufacturing processes and—an industry buzzword these days— "enhanced customer service. thus Lycoming will soon be far ahead of Continental in new engine sales. As we reported in the August Aviation Consumer. highly specialized assembly operation whose competition is field overhaul shops and the companies that make engine parts. any euphoria over a glorious recovery is tempered by the trauma of cutbacks that seem all too recent. Yet even though Lycoming execs seemed happy with this development. manufactured auto engines for the Cord. seemingly but a generation beyond the days when factories ran on steam-driven lineshafts. the Lycoming Company. The Old Line A visitor to Lycoming's Williamsport plant is struck by one thing: the place is old. Continental is investing substantial money into clean-sheet engine designs while Lycoming intends only incremental improvements. the plant is evolving into a large. Lycoming will continue to shrink its Williamsport workforce and to outsource most of its primary manufacturing. Lycoming's "modern" history—meaning the manufacture of airplane engines—dates to early 1920s. Cessna announced that all of its new production will use Lycoming engines." Shortly after our third visit to Lycoming. (The company files still contain spec sheets and price lists for the sewing machines. evidently. the R-680. on the same site it now occupies. But unlike Continental. Before that. before turning to engines. we sensed that at Lycoming. they weren't exactly dancing in the streets at Williamsport. when it produced a nine-cylinder radial. with no revolutionary products in the works. which plans to capitalize on what may be a modest recovery by investing in new plant. which powered such aircraft as Stinsons and Stearmans.) In 1932. (At least none that they would tell us about. Cessna hasn't ordered production-run engines yet and in general. Lycoming (then called Demorest Fashion and Sewing) achieved no small success in the sewing and garment industry. In effect. it made a successful line of sewing machines.during the late 1980s and by ruthlessly cutting costs. Lycoming got gobbled up by the Aviation Corporation (Avco). which . 000 to barely 3500 in 1982. Lycoming had been going great guns through the 1970s. the factory runs on the tools it had 20 or 30 years ago. some dating to the 1940s and 1950s. but that business was sold to Allied-Signal and now all that remains are a few pieces of advanced CNC machinery. The engine industry practically went down the tubes with the OEMs. it built aircraft engines of all designs (including radials) and. turning out 1500 new engines a month. old-style industrial buildings. Fokker and several airlines. Through the 1930s and 1940s. including Fairchild.. with high ceilings dimly lighted with fluorescent tubes and populated by rows of old machine tools. Lycoming laid off workers and did away with defunct and unused machinery. Lycoming built a high-output line for connecting rods and a fully automated crankcase machining line that trundles cases from one machining operation to the next on a little trolley. with production at or above the 300-engines-a-month level and plenty of additional capacity.nothing. Two years from now. Lycoming had three shifts of workers. In 1986.. down from a peak of about 1800 during the heyday. it will decline to 300 or so. The crash of 1980-81 changed all that.already consisted of 81 companies. but generally. In little more than three years. There was no need to bother with remans or overhauls in those days. Large areas of the plant floor are given over to. having been bought from General Dynamics. we were shown some machine tools upgraded with numerical controls. During the early 1970s. Avco was bought (including Lycoming) by Textron. During our tours. On the Factory Floor The downsizing is obvious to even a casual observer touring the Williamsport plant. Until recently. At its peak production. yet another oldline industrial conglomerate that evolved from the New England textile industry (hence the name). The workforce stands at just less than 600. Like Continental. It . eventually. Now the output hovers between 300 and 400 engines a month. The industry seemed to accept periodic downturns but everyone assumed the inevitable rebound would yield yet ever higher demand for engines. As production plummeted. the Williamsport plant made parts for the turbine division in Bridgeport. tank and turbine engines. Lycoming's CEO. according to Phil Boob. Cessna wound up in the Textron fold in 1992. piston production sagged from a high of 17. most of them remans and factory overhauls. Bendix. The factory is a complex of classic. also outsources but it has aggressively invested in modern machinery. The Quality Issue For all its benefits. There's just tremendous excess quality machining all over the world and in the U. The reason is that other people have already made that investment in modern equipment that's being under utilized. "I'm wondering what the financials are going to look like when they start getting hit with the depreciation on that equipment in a skinny market. If the vendors aren't competent the quality will suffer and if they aren't reliable. a strategy that Boob says Lycoming considered but rejected. the customer doesn't care who makes it. Five years from now. if only in terms of the sheer volume of vendors. Instead." meaning that 25 percent of what goes into a Lycoming engine arrives at the factory in finished condition. are they going to wake up and find that the company can't be profitable because of the depreciation? One of us is gonna be right and one of us is gonna be wrong. It hasn't been for years. "We are in the position to invest. Within two to three years.was state of the art for its day and still holds its own." Continental. of course. Why fight the world?" Managers at Lycoming are fond of the phrase "added value" and throughout our tours. that number will be closer to 95 percent. The factory will require a fraction of the floor space it now occupies and the workforce is expected to stabilize at about 300 workers. We were told that incremental improvements are made on machining and tooling processes. with no need for the factory to do anything but install it. Lycoming admits that this has been a problem in the past.S. the parts won't arrive on time. About 75 percent of its manufacturing is "value added. but no capital-intensive upgrades of the sort we saw at Continental are planned. outsourcing has its problems. the Holy Grail at Lycoming is outsourcing." says Phil Boob. "but that would be the wrong answer for us. The world isn't going to vertical integration anymore. But it has far more capacity than Lycoming has orders. As long the quality is there in the finished product. we were shown operations in which Lycoming workers were machining or processing parts which had originally been produced by another manufacturer. but it chooses not to. Lycoming insists that it's more than profitable enough to invest in new plant. . 80 companies alone supplied fasteners and hardware. each engine is inspected for critical items such as cylinder-bolt or rod-bolt torque. Lycoming performs an instrumented test-cell run on every engine and documents the results. the vendor list had been winnowed to 130 and eventually. As does Continental. (Continental doesn't offer factory overhauls. we saw a QC program built on periodic inspections of each process and part and Lycoming does the same.) At various points in the Lycoming assembly process. a vendor's quality is at the point where we wouldn't catch any problems unless we inspected every part. They hope to rapidly move toward a system of certified vendors. whereby companies supplying the parts demonstrate they can produce quality work and inspect parts in their own plants before shipping them." On the engine assembly line itself. At Continental. most of Lycoming's outside work and parts will be supplied by fewer than 100 companies. the company was dealing with some 300 vendors. differentiated only by the color of the serial number plate." says Moffett. Exchange overhauls are done in the factory while customer overhauls are completed in a small shop at the Williamsport Airport. Lycoming operates two distinct lines. for example. Slowly. "It just adds cost. he says. By this summer. these assembly manuals are being tied into computer tracking systems. There's no particular magic in either number. but no value." Instead.) At Continental. (Continental strips every 25th engine. This is in contrast to Continental. although we have to say Continental's QC systems appear to be . it's just the inspection procedure the FAA happened to have approved for each factory. Quality control is one reason for this. we were shown detailed manuals that list standardized assembly procedures for each engine as it moves down the line.Engineer Rick Moffett told us that as recently as a year ago. one for new engines and one for remans and overhauls. "At some point. although each engine is accompanied down the line by inspection sheets that ultimately form a paper trail of its history. It also disassembles every 20th engine of each type after the test cell run to inspect for damage or unusual wear. at least for now. By comparison. "It makes no sense to inspect parts over and over. Curiously. just remans. Lycoming is just beginning to develop this sort of computerized documentation. where all the engines move down the same line. overhaul shops can still undersell the factory. from field overhaul shops. Lycoming seems to earn acceptable although not perfect grades for quality. Until Cessna ramps up (and assuming it really meets its projected sales volumes). we receive far fewer complaints of poor quality slipping through the cracks at Lycoming. but the price spread is less than it used to be and factory engines always include new cylinders. its prices didn't lure much business away from traditional overhaul shops. high prices on engine parts that make it difficult for them to compete with the factory's economics. "the competition is fierce and the margins tend not to be what we would like. Lycoming would have little incentive to price its engines and parts competitively." All that's changed." says Boob. a significant incentive for some customers. "Right now. In our informal surveys of engine shops and from letters we receive from owners and operators. the leading supplier of aftermarket engine components and Lycoming's chief competition. Indeed. "In 1976. of course. Without Superior and other PMA houses. What complaints we do hear often concern lagging parts shipments and. we didn't really sell engines. you knew where to find us. marginal field shops have been driven out of the business and those that remain are finding a tougher go of it. As both Lycoming and Continental have lowered their costs and learned to live by thinner margins and with Lycoming offering factory overhauls. say many field shops. 70 percent of Lycoming's dollar output is either parts or remanufactured/overhauled engines." says Peter Bates. . Despite the Cessna orders. who handles international marketing. Getting the Business But Lycoming does have the competition and having watched its new engine business dwindle." When Lycoming first got into the overhaul business.more state-of-the-art. "if you wanted an engine. almost the entire stockroom was filled with boxes from Superior Air Parts. But if we get our cost structure in line—and we have been doing that—then there's no reason that we shouldn't own a minimum of 60 to 75 percent of that worldwide market. On many engines. the company has filled the void by going after the bread and butter of the field overhaul shops. we expect Lycoming will continue to go after the replacement market. at one engine shop we visited. the plant would inventory parts for each engine. used to require six basic crankshafts in 29 variations. the process was wasteful of time and money. on the other hand. for exampleùare kept "inflow" and can supposedly be shipped within two weeks on an exchange basis. the differentiation amounting to a hole bored here instead of there. work would halt until a new run of parts could be made. The O-320. when volumes were high. is obsessive about retaining what works. But because Lycoming builds so many variants of only five engine families (more than 600). Lycoming had trouble matching even those schedules. Lycoming. if an engine assembler ran out of cranks or some other part. Continental touts itself as a hightechnology engine company. More of the Same Another stark contrast between Lycoming and Continental is the corporate attitude toward innovation and risk. Lycoming uses a variation of the "just-in-time" inventory method pioneered by Japanese auto plants." he says. field overhaul shops are bad enough but until recently. Now. such that engines for popular airplanes—an IO-360 for a Mooney. for example. Inventories of major parts are tracked by demand and then advanced through manufacturing only to the point where commonality with other engines in the family ends. Moffett says it took a fundamental reshaping of factory culture that's still ongoing. but it surely eased the pain of equipping an overhaul with new jugs instead of reconditioning the old ones. the factory has put in place a four-tiered delivery schedule. Now. This development didn't kill the re-conditioned cylinder market overnight. . Worse. says Moffett. thus the plant ties up less money in inventory but can still meet short delivery schedules. with hopes that its clean-sheet designs will lead the way to the future.In 1992. Lycoming essentially cut the cost of its cylinder kits by half on the most popular engines. Although delivering an overhaul or reman in two weeks sounds like a trivial accomplishment. With five to eight week lead times common. In days of yore. The factory had always been at a disadvantage in service and engine delivery times. Now. there are three basic cranks and finish work on the part doesn't happen until just before it's due to go into the engine. "Being good at building new engines doesn't mean you're worth a damn at overhauls. It also made factory overhauls yet more competitive. Few field shops can match that. Well." In Boob's mind. More important. or you could get more per engine. above all.30 fuel specifics. "I was vice-president of sales at the time. Conclusion . neither Deere nor Lycoming found any takers. But if I'm going to replace a 540 with a rotary at the same numbers. "If all I'm doing is replacing engines that I'm selling anyway." recalls Phil Boob. But if you're looking for a new-age powerplant with 400 horsepower and . That was Cessna. The engine proved to be an embarrassment for both Lycoming and Cessna. "We found just one airframe manufacturer willing to sign a memorandum of understanding to go forward with that engine. The engine was supposedly an improved variant of what had been a virtually bulletproof powerplant for Cessna. that didn't stop Lycoming from teaming with John Deere in the mid1980s to build a revolutionary new aircraft rotary engine. In recent history. one of Lycoming's more painful forays into innovation was the O-320-H2AD engine that powered the Cessna 172 from 1977 to 1980. why am I going to do it? Why would anyone do it?" That's not to say Lycoming won't improve its engines incrementally. how does it make sense to develop new engines? Now if you could increase the market. but the experience reinforced the company's instincts to stick with the tried and true. they found one. Some complain that Lycoming is too conservative and waits too long to correct design or production flaws. avoiding disastrous service problems that alienate customers and strain the warranty budget. It suffered premature camshaft and valve train wear. actually.making tweaks in production processes and. it starts to make some sense. it won't come from Williamsport. Still. They signed the memorandum on Monday and made the announcement on Friday that they were getting out of the light airplane business. It plans to make available the new Slick LASAR electronic ignition system and doubtless numerous other minor improvements. After sinking millions into the project. the current market—probably even a revitalized market— isn't demanding nor will it support revolutionary engine designs. obviously. or increase the total number of units you could sell. it gave Lycoming an opportunity to tailor the engine to its new automated crankcase line. Lycoming eventually cured the H-engine's ills. not to mention failures due to sheared oil pump drives. but not necessarily standard. With Cessna's restart on the horizon. Lycoming appears to be in a superb position to grab more of the overhaul and reman market. Cessna asked Lycorning for a 300plus HP bed-mounted engine for the 206 and Lycoming proposed a new . with outside companies building the parts and pieces. no one at Lycoming thought Cessna would drop the Continental IO-520 in favor of a Lycoming engine but that's exactly what happened. Although Lycoming's customer service network is not yet as sophisticated as Continental's—its plans for computer on-line access to maintenance data are a year or more away—the company has added service reps in the field and doubled the number of people available to help customers over the phone. however. Lycoming won't need much investment to service what could be a huge inflow of business. add shifts and go at the job hammer and tong. Despite the fact that the 172. The parallel-valve IO-360 to be used in the Cessna 172. although we have some concerns that if predatory pricing drives too many field shops out of business.182 and 206 will be getting engines they've never had before. Even if Cessna fizzles.Of all the companies we've visited recently. a major new order for powerplants meant the factory would staff up. lack of competition will cause engine prices to spiral upward again and service quality may decline. is virtually the same engine used in the Cutlass RG. Although it has hired on some additional engineering help. Gearing Up For Cessna In the old days. ostensibly to reduce the likelihood of carburetor ice.) When we visited the plant last winter. Lycoming will stick to its corporate philosophy of using only the tried and true. At this point. And despite complaints. for example. We see this as generally positive news for aircraft owners and operators. Lycoming seems the best positioned to benefit from any GA recovery. that seems unlikely to happen in the near term future. Given the health of the PMA industry. Lycoming doesn't suffer the bad quality rep that seems to perpetually dog Continental. Lycoming will fill Cessna's orders mostly with the workers it already has. it looks like Slick's LASAR electronic ignition system will be an option on this engine. or at least as much of it as the customer will accept. although it will have fuel injection instead of a carburetor. (It hasn't been certified yet. Not anymore. and how to get rid of it. crankshaft. The IO-580 will have top-mounted induction and a bottom-mounted exhaust. cam) will be essentially the same as that used in the 540-series engines. Licking Alternator Whine Email this article | Print this article Is that whine in your earphones driving you nuts? It might well be alternatorinduced radio noise. and probably the foremost aircraft hose shop and magneto overhaul facility in .model called the IO-580. John runs Sacramento Sky Ranch. The biggest difference may be in external appearance. and a specialist in the engineering analysis of engine failures. About the Author . what causes it. with the additional displacement coming from boring of standard 540 cylinders. rods. 1996 by John Schwaner This article is Copyright © 1995 by Sacramento Sky Ranch Inc. The heads will be retreads. John is a world-class authority on piston aircraft engines. whereas Lycoming has generally located the intake plumbing on the bottom of the engine. John Schwaner is AVweb's powerplant expert. The IO-580 will have 310 HP and a turbocharged version-using a new model Garrett turbocharger-is in the works. February 5. Inc.. The power section (crankcase. a leading distributor of aircraft and engine parts.. Here's how to identify alternator and regulator noise. But even this engine is new only by degree. too.. All rights reserved. having been used on the TIO-540-V2BD used in the Piper Mojave 15 years ago. That engine had less than a stellar service history but its problems weren't related to heads and cylinders. After the diodes rectify the three AC phases and sum them all together. The best way to detect ripple voltage on the electrical bus is with an oscilloscope. the corresponding pair of diodes becomes forward biased and allows alternator current to pass. (Some meters do this automatically when you select AC volts. and the other three are connected to the negative (ground) terminal. You will need to do comparison readings with other aircraft to determine . width-modulated field control system can also create a whine in the radios. ordered from the AVweb Solid state regulators that use a pulseOnline Bookstore. Another method is to use an ordinary volt-ohmmeter (VOM) set to measure AC volts. the combined result is a DC voltage with only a slight amount of AC ripple voltage remaining. master switch off also turns off the radio Both can be previewed in and noise. so the voltmeter reading you see is the amount of AC ripple voltage on the bus. Turning the alternator The Magneto Ignition System. You may have to connect a capacitor in series with the positive meter lead to block out the DC voltage so that only the ripple voltage gets to your meter. Regulator-caused whine can be distinguished from the alternator-caused whine in that the intensity and pitch of regulator-induced noise changes with changing current load at a constant engine speed. turning on the landing lights won't increase alternator whine but will increase regulator whine. John and his wife live in Alternator induced radio noise Sacramento. Three diodes are connected to the positive output terminal of the alternator. As the voltage of each stator winding increases. Each of the three stator windings is connected to a pair of diodes.Identifying the problem the U. but diodes convert it from AC to DC before it leaves the alternator. How the alternator works Current generated in the alternator stator windings is three-phase alternating current. Thus. Six diodes are required to rectify the three stator phases.) The capacitor is an open circuit to DC but passes AC.S. California. Which stator winding and diode pair is conducting at any moment depends upon rotor position. is a high pitched whine whose John has also written two pitch and intensity increases superb technical books: Sky and decreases with changes in Ranch Engineering Manual and engine speed. These meters were originally sold as the Ward Aero Alternator Tester model 647. as model 10-647-01. and infinite resistance in the opposite direction. the low impedance of the battery keeps . especially at the battery. Circuit causes Alternator whine can also be caused by poor electrical connections.what AC voltage level is normal. the amount of ripple voltage increases markedly. Now reverse the test probes and repeat the test. Two test methods can be used to test the alternator without disassembly. The diodes should show low resistance in one direction. Calibrate the VOM on the R x 1 multiplier range scale so that there is zero reading with the VOM leads shorted together. but not the same as in the previous step. Alternator whine can be a symptom of a bad alternator diode. Checking the diodes With the alternator apart. there is not enough ripple voltage to cause radio noise. What causes alternator whine? Normally. The second test method is to use an oscilloscope to check the alternator output for excessive voltage ripple or rectifier spikes caused by a bad diode. Then reverse the leads and check again. Normally. Note the three ohmmeter readings: they should be identical. If an alternator diode fails. the diodes can be checked with a VOM set to measure ohms. Repeat the same test procedure for the three diodes on the negative rectifier plate. You need to unsolder the stator leads from the each diode. Note the three ohmmeter readings: again they should be identical to each other. These are diode failure and increased circuit impedance. A bad diode will show up on the meter. They are currently sold by Support Systems Inc. Connect one test probe to the alternator's positive output terminal and touch the other test probe to each of the three solder terminals of the diodes mounted to the positive rectifier plate. There is a hand held unit with a probe that clamps over the alternator output wire. But. This test makes sure that each diode conducts in only one direction. Three of the ohmmeter readings should show a low resistance reading of approximately 6 to 20 ohms and three should show an infinite reading (no meter movement). connecting one test probe to the negative output terminal and checking all three diodes with the other probe. there are two conditions that can cause an increase in ripple voltage sufficient to create radio noise. or blocking the voltage ripple so that it cannot pass. Although DC resistance as measured with an ohmmeter may still be low. The ideal low-noise circuit would have the alternator power output going directly to the battery's positive terminal. including the engine grounding strap. Flat braided ground straps are ideal for grounding the airframe to the engine mount. Circuit impedance can be lowered by making sure the battery posts are clean and making good contact. In the real world. Filter capacitors There are two methods of filtering ripple voltage: bypassing the ripple voltage back to the source. firewall. the aircraft battery acts as a big ripple absorber. the greater the ripple voltage on the bus and the more whine you hear in your radios. alternator noise could not occur. Capacitors bypass noise currents back to the alternator return path . Flat braided straps are used because impedance is less with a braided. Also check the alternator ground connections.) Any AC ripple voltage in the aircraft bus is absorbed by the battery.the aircraft's electrical circuits at a DC potential. The amount of voltage ripple at the bus depends upon the impedance between the bus and the battery. a short-circuit for AC current). The radio power lead would also go directly to a pure DC source. flat conductor than a round wire conductor. But the lower it is. If the alternator power lead and the radio power lead connects to a bus.01 ohm. This dumps ripple voltage into the battery. then voltage ripple can go from the alternator to the radio power lead. Thus.. and through the fuselage to the battery.e.. DC resistance between the alternator and the negative post of the battery terminal should be as low as possible. If the battery provided zero impedence (i. Let's assume that the battery positive terminal is corroded. The return path is from the alternator to the engine.. engine mount. the less ripple voltage there will be.virtually zero. the battery. Capacitors are used to bypass ripple voltage. where it is absorbed. there will always be some impedance. The higher this impedence. the highfrequency resistance (i. DC resistance should be less than 0. The most effective approach depends primarily on the circuit impedance.e. whereas inductors are used to block noise currents.. (Impedence is simply resistance to an AC current. This impedance is higher than at the battery. These connections should have low resistance. impedence) may be very high. Inductive filters . The effectiveness of using a capacitor as a noise filter depends upon matching the capacitance rating of the capacitor to the frequency of the noise currents. But with 1 inch leads. this is high-frequency and the capacitor should be in the picofarad range. To be effective. Capacitor resonance can be approximated with the following formula: resonant frequency (in MHz) equals 1/2 pi times the square root of lead length times capacitance.5 to 50 microfarad capacitor. Cessna has a 5. Consequently. The capacitor is installed with one lead connected to the power output and the other lead to ground.72 microfarad capacitor filter available as part number S1915-1. then this is low-frequency and the capacitor should be in the microfarad range. So capacitor lead lengths used in filter circuits should be kept as short as possible. so that it is in parallel with the circuit. The best types of capacitors for filtering are ceramic and tantalum capacitors. The correct size capacitor is one where the frequency we wish to bypass is the same or less than the resonant frequency. This is the resonant frequency. The frequency at which the capacitor's capacitance and inductance are equal is where it has the lowest impedance and the best filtering. Electrolytic capacitors are relatively poor noise filters. For DC voltages the capacitor forms an open circuit (high impedance) and doesn't allow any current to pass. and also have a short life. For example. ceramic for the picofarad range and tantalum for the microfarad range.(commonly referred to as ground). a capacitor must have a low impedance path back to the alternator. while larger size capacitors (microfarad range) are effective at lower frequencies. an alternator filter uses a . If you're filtering conducted interference (as you are in an alternator). a 500 pf capacitor with 1/4 inch leads resonates at 100 MHz. a filter capacitor must be mounted as close to possible to the alternator. Typically. In this manner we have formed a low-pass filter. At noise frequencies the capacitor forms a short circuit (low impedance) and bypasses noise currents back to the alternator. Notice that lead length has a significant effect on the capacitor's resonant frequency. it resonates at 50 MHz. If you're filtering radiated interference (where the conductor is acting as an antenna). Smaller size capacitors (picofarad range) are effective at high frequencies. 1998 b Mike Busch y This article originally appeared in the December 1998 issue of CESSNA PILOTS ASSOCIATION . and to use a filter capacitor at the alternator output terminal. To be effective. knowing the symptoms that often can be tip-offs to what's wrong. It is best to install ferrites on the radio power input leads.The other way to filter radio noise is to block the ripple with a series inductor. Troubleshooting the Turbo-System Email this article | Print this article Turbocharging problems seem to be among the most elusive for A&Ps to find and fix. This magnetic field raises the impedance and effectively blocks noise currents. So alternator voltage ripple is usually bypassed to ground by use of a capacitor. ferrite impedance must be larger than circuit impedance. at least judging from the feedback we get from aircraft owners. Ferrites are effective on radio power input leads and strobe power input leads. and using a logical troubleshooting strategy. The most common style of inductor for noise filtering is a ferrite core. However. plus a step-bystep checklist for diagnosing those turbo gremlins. and in the second case they prevent noise currents from exiting the strobe. creating an inductor in series with the circuit. ferrites are simple to use and have an amazing filtering ability. Ferrites are best used in low impedance circuits whereas capacitors are best used in high impedance circuits. AVweb editor Mike Busch offers all that. The keys to success include having a thorough understanding of the system. DC current passes through the core but high frequency currents induce a magnetic field in the ferromagnetic material of the core. To filter the output of an alternator would required an impractically huge ferrite core. In the first case they prevent noise currents from entering the radio. December 25. These come in many different styles but typically the wire with the noise currents is wrapped around the core. a description of the symptoms provided by the Mike's on the verge of earning owner or pilot. I advise that it's almost never a good idea to instrument and multiengine "throw money at the problem" until sufficient ratings. that description his A&P mechanic certificate. a member of One of the most perplexing the technical maintenance problem areas that staff at Cessna owners of high-performance piston Pilots aircraft have to deal with is the Association.. In most cases. Mike has been flying for troubleshooting has been done to identify the 36 years and an aircraft owner actual cause of the problem. and that instrument provides only a very indirect Turbocharging Basics What Really Happens What Can Go Wrong? A Troubleshooting Strategy About the Author . 6.MAGAZINE. the mechanic has no choice but to rely entirely on renaissance man of aviation. and are sometimes quite quest to become a true erratic or intermittent. which he maintains himself. I often hear from lifetime was a contributing unhappy owners who have already incurred editor for The Aviation considerable expense in overhauling or Consumer and IFR Magazine. Furthermore.000-hour commercial pilot and CFI with airplane. Turbo problems generally show up on the Manifold Pressure gauge. . for 33. We don't have a turbocharger spindle speed gauge or a wastegate position indicator on the panel. As always. Mike and his wife Jan reside on is often incomplete or misleading because the the central coast of California in owner or pilot doesn't really understand what a semi-rural area where he the mechanic needs to know to diagnose the can't get DSL or cable TV. problem correctly. there's precious little cockpit instrumentation that offers any direct measurement of what the turbocharging system is doing. Mike Busch is editor-in-chief of AVweb. he's owned and flown a mechanics to troubleshoot. They're hardly ever Cessna T310R turbocharged reproducible on the ground. A replacing costly turbo-system components without having resolved the trouble. Unfortunately. In his never-ending quite high altitudes. and in a prior turbocharging system. often occur only at twin. For the past 14 of those There are very good reasons that turbocharging problems tend to be difficult for years.. Turbocharging Basics The basic principles of turbocharging are quite simple. faster turbocharger speed. Nevertheless. often leaving pilots blissfully ignorant that mechanical problems are developing until those problems get quite serious. the system would "run away" and very possibly exceed maximum engine operating limits. which would increase the compressor speed and therefore the manifold pressure.indication of what's going on with the turbocharging system. and a centrifugal compressor impeller mounted on the other end. hg. known as turbonormalizing. Without such a control system. if the owner or pilot understand how the system works and knows that to look for. In either case. higher manifold pressure. it's usually possible to isolate turbocharging problems problem without having to resort to the "shotgun approach" of replacing or overhauling one component after another until the problem finally disappears. the turbocharging system needs to include a means of controlling the turbocharger's compressor output pressure. One.000 RPM). producing more exhaust volume. For example. thereby eliminating the progressive horsepower reduction that occurs with normally-aspirated engines as the aircraft climbs. The turbocharger itself consists of exhaust-driven turbine wheel mounted on one end of a shaft. hg. known as turboboosting. which is used to boost the pressure of the engine's induction air and therefore increase the engine's power output. which would otherwise simply be wasted energy.) to provide increased sea level horsepower. the fundamental design of the automaticallycontrolled turbocharging systems used on most high-performance and pressurized aircraft tends to compensate for-and therefore conceal-problems with the engine and turbo-system. such as reduced compression ratio and intercooling. Boosted engines normally employ some means to provide adequate detonation margins. boosts manifold pressure to a value significantly higher than sea level ambient (usually 35 to 45 in. This drives the compressor. . Engine exhaust gases. are used to spin the turbine at very high speed (typically 50.000 to 100. etc.) at altitude. and if the mechanic employs a logical procedure for troubleshooting the system. The other. To make matters even worse. a small increase in engine power would result in a small increase in exhaust volume. This would result in an additional increase in engine power. In other words. is used to maintain sea level manifold pressure (roughly 30 in. Turbocharging can be employed in two ways. a turbocharged engine would be fundamentally unstable. This would cause the turbocharger to spin faster. a decrease in turbocharger speed. the engine would be nearly impossible to control. almost all of the exhaust bypasses the turbocharger. If the wastegate is fully open. (A few aircraft such as the Mooney 231 and Piper Seneca use fixed wastegates. Automatic control Most high-performance turbocharged aircraft (including all pressurized piston models) employ an automatic wastegate control system to regulate the turbocharger. if it is fully closed.Likewise. and so forth. In short. The way turbocharger output is regulated is by means of a butterfly valve called a "wastegate" which allows a certain amount of exhaust gas to be vented overboard without going through the turbocharger. a small decrease in engine power would cause a reduction in exhaust volume. a reduction in manifold pressure. while Cessna's T182/TR182 and some older aftermarket turbo . virtually all of the exhaust must go through the turbocharger. a further decrease in engine power. This causes more exhaust to pass through the turbocharger. The pressure controller monitors the output of the turbocharger's compressor (also known as "upper deck pressure" or UDP).) The automatic system employs a hydraulic wastegate actuator and an pressure controller to maintain turbocharger output at the desired pressure. The more oil pressure is applied to the wastegate actuator. decreasing the oil pressure in the wastegate actuator and allowing the wastegate to open a bit. If the turbocharger output is less than the set-point of the controller. Most unpressurized turbos use an absolute pressure controller (APC) set to maintain turbocharger output at a few inches over engine red-line. and should be adjusted so that application of full throttle produces the proper red-line manifold pressure for takeoff. Thus. the aneroid expands and closes the poppet valve. turbocharger output rises above the set-point of the controller. The difference between an APC and VAPC is that the VAPC's set-point is varied by means of a cam connected to the throttle control. on the other hand. slowing it down and decreasing compressor output. and increasing the compressor output. the more the wastegate closes until. This lets more exhaust gas bypass the turbocharger. The wastegate butterfly is normally held in the full-open position by a strong spring. the VAPC works just like an APC (and is adjusted to produce proper full-throttle MP in the same fashion). the VAPC set-point is reduced so that the turbocharger doesn't have to "work so hard" when the pilot throttles back to . forcing exhaust gas to go through the turbocharger. allowing exhaust gas to bypass the turbocharger. Here's how it works. Engine oil pressure applied to the wastegate actuator causes the wastegate butterfly to close. At full-throttle. If. equilibrium is quickly reached whereby the turbocharger output stays right at the set-point of the controller and the system remains stable. spinning it faster. The controller set-point is easily adjustable by screwing the controller's poppet valve seat in or out. Most pressurized piston aircraft use a variable absolute pressure controller (VAPC). at about 50 PSI. increasing the oil pressure in the wastegate actuator and causing the wastegate to close. But at partial throttle settings. The controller is a simple device that consists of an aneroid and a poppet valve. and regulates the oil pressure to the wastegate actuator to hold the turbocharger output constant.conversions use manually-controlled wastegates. the aneroid contracts and opens the poppet valve. the butterfly is fully closed. reduced manifold pressure. and reducing RPM from 2700 to 2350 reduces the exhaust flow even more. so the wastegate remains fully closed throughout the taxi and probably even during the runup. However. let's follow it through an actual flight profile and see what it actually does. As the engine develops more and more power. fullthrottle manifold pressure at takeoff never quite reaches sea level ambient (around 30"). The APC sees that the turbocharger output is less than its set-point of 35" so it closes its poppet valve to call for wastegate to close. for a turbocharged airplane to achieve rated red-line MP on takeoff. causing the turbo to spin back up to the point where UDP is steady . the controller opens its poppet valve to relieve the oil pressure to the wastegate actuator. Climbing out of 1000' AGL. causing UDP to increase until it reaches the controller set-point of 35". but the controller immediately notices the resulting decay of UDP and closes its poppet valve to command the wastegate to close and force more exhaust through the turbocharger. At that point. This causes the turbocharger to start slowing down. but tops out at a few inches less than that due to unavoidable pressure losses in the induction system. Now we taxi onto the runway and slowly apply full throttle for takeoff. let's suppose we're flying an unpressurized airplane like my T310R that uses a simple absolute pressure controller. Likewise. Let's start the engines and taxi to the runup area. the wastegate (which is spring-loaded to the full-open position) will close all the way. allowing the wastegate to open as necessary to stop the turbocharger from spinning up any faster and thereby holding UDP right at 35" (and indicated MP right at the 32" redline). the exhaust flow increases dramatically and spins the turbocharger faster and faster. and the APC set-point is adjusted to about 3" higher (about 35") to produce red-line MP on takeoff. As soon as engine oil pressure comes up. My T310R's manifold pressure red-line is at 32". Throttling back to 29" MP reduces the exhaust flow from the engine. the APC set-point must be a few inches higher to compensate for induction system losses. we reduce to 75% cruise-climb power (which in my T310R is 29" MP and 2350 RPM). To make things simple.) You've probably noticed that when flying a normally-aspirated airplane. there's not enough exhaust flow to spin up the turbocharger enough to produce 35" of UDP. since the engine is at idle. What Really Happens To gain a better understanding of how the system works. (The differences when flying a pressurized airplane with a VAPC are minor and not really significant for purposes of this discussion. the controller closes the wastegate further and further in order to compensate for the reduced exhaust . and the controller were to keep closing the wastegate more and more to compensate for the decreased ambient air pressure. Now that we're trimmed for level cruise at FL180. If we were to keep climbing higher and higher. Climb As we climb on up to the Flight Levels. this occurs at around FL220. the ram air effect causes a small increase in induction air pressure and a corresponding (somewhat larger) increase in UDP. This all happens so quickly that we're never aware that it's going on.000' of climb. outside ambient pressure decreases by about 1" per 1. As we do this. which is the bottom of the green arc on my T310R. Again. eventually we'd reach a point where the wastegate was fully closed and the controller was no longer able to maintain 35" of UDP. In the cockpit. This decreased pressure would normally cause a corresponding decrease in UDP (and therefore MP).at 35". without the inch-per-thousand-feet drop-off that we'd expect in a normallyaspirated airplane. the engine is said to be "bootstrapping" because the system is unregulated (and therefore unstable) and large MP variations may be observed. Cruise But we don't want to go that high today. In my T310R at 75% cruise-climb power. and commands the wastegate to open a bit in order to slow down the turbocharger and hold UDP right at 35". this can't go on forever. Let's suppose we level off at FL180 and let the airplane accelerate to cruise speed. the controller notices this happening. Of course. causing the turbocharger to spin slower and reducing UDP. we slowly pull back on the prop controls to reduce RPM from 2350 (top of the green arc on the tach) to 2250 RPM. The controller reacts by commanding the wastegate to close in order to spin the turbo back up and restore 35" UDP. exhaust volume is also reduced. At this point. As the airspeed increases. when the wastegate is fully closed and the automatic control system is no longer able to maintain constant UDP. it occurs somewhat higher (FL250 or more). Suppose we continue to reduce RPM gradually from 2250 to 2100 RPM. while in many other turbocharged aircraft. forcing more and more exhaust through the turbocharger and spinning it up faster and faster as required to maintain UDP at a constant 35". we notice that MP is staying more-or-less right where we set it (at 29"). As we reduce engine RPM. but once again the controller compensates for this decay by gradually closing the wastegate more and more as we continue to climb. but the controller sees this and opens the wastegate enough to hold UDP steady. We switch off altitude hold on the autopilot. we've had enough fun. It stays there until we throttle way back for our final descent and landing. Eventually. all we see is that MP remains rock steady at 29". of course. But at some point around 2150 RPM. outside ambient increases by about 1" per 1. right where we set it. As we descend.000'. at which point engine oil pressure goes away and the wastegate returns to its spring-loaded full-open position. the wastegate is most of the way open. Descent Okay. The wastegate remains fully closed as we turn off the runway and taxi in to the ramp. It remains fully closed until we pull the mixtures to idle cutoff. By the time we get down to pattern altitude. What Can Go Wrong? The preceding discussion is all predicated on an engine and turbo-system that is working properly. A wide variety of mechanical ailments can interfere with the proper operation of the system. even fullclosed wastegate is not enough to maintain 35" UDP because the idling engine is hardly putting out any exhaust volume at all. and roll in enough nose-down pitch trim to start a 1. As our indicated airspeed rises from its cruise value of 160 KIAS to around 200 KIAS.flow and maintain 35" UDP.000 FPM descent out of FL180. so the controller must continually open the wastegate more and more to prevent UDP from rising. we increase RPM by 50 or so and see that the bootstrapping stops. as we close the throttle all the way prior to touchdown. and the controller has to close the wastegate to make up for it and maintain 35" UDP. These include: Induction leaks Exhaust leaks Internal engine problems Wastegate problems Controller problems Turbocharger problems All of these problems can result in improper operation of the turbocharging system. and it's time to head back to the barn. When we do that. Upon observing the onset of bootstrapping. the wastegate will reach the fully closed position and any further reduction in RPM will cause the engine to bootstrap (indicated both by loss of MP and instability of MP readings). the reduction in engine power causes exhaust volume to fall. increased ram air tries to increase UDP above 35". but each one tends to produce symptoms that are subtly different in . In the cockpit. More and more induction air escapes through the leak. helping a member troubleshoot his Cessna T310 in which it turned out that an engine control cable had been chafing against the engine's induction manifold in a hard-to-see location. or at least rule out some of the possibilities and help narrow the search. So relatively little induction air escapes through the leak. At 1. the induction leak becomes a total irrelevancy. But since-as we noted earlier-most turbo problems show up only at high altitudes and seldom on the ground.) Manifold pressure inside the induction manifold is at red-line (32"). Consider what happens during a full-power takeoff at or near sea level. (Once again. let's assume the airplane in question is my Cessna T310R so we can use the same numbers as we did before. The pilot squawked the problem when he notice a significant manifold pressure "split" between the two engines while cruising at the Flight Levels. a careful analysis of the symptoms can often help pinpoint the cause of the problem. As we continue to climb at 29" MP.000'? About 29"! So now. I recall. creating a fairly significant induction system leak. but that's only a trifle greater than outside ambient pressure (around 30"). the turbo controller senses this loss and keeps closing the wastegate and cranking up the turbo output to compensate for it. that's not surprising.character. In the cockpit. The problem only showed up when the airplane was flying up high. The engines appeared to be operating normally on the ground. From the cockpit point of view. for example. However. during takeoff. and the controller will cause the wastegate to close just a trifle. and when operating at low and middle altitudes. it's often up to the pilot (rather than the mechanic) to make critical observations of the symptoms and decipher what they mean. If you think about the consequences of an induction leak. compensating for the small loss and effectively concealing the problem. . What's the outside ambient pressure at 1. Eventually the steel cable wore a slot all the way through the wall of the cast aluminum induction pipe. outside ambient decreases by about 1" per 1. Induction leaks One of the most common causes of turbo-system problems are leaks in the induction system. both MP needles are right where they should be and everything appears nominal. since the pressure inside and outside the induction manifold are virtually identical.000' so the pressure differential between inside and outside the induction manifold increases steadily.000' we throttle back to 29" MP for cruise-climb. Therefore. What little loss there is will be sensed by the turbo controller as a loss of UDP. and so there's no loss of pressure through the leak at all. loss of MP and MP regulation) at higher altitudes. The controller. closing the throttle butterfly and choking off most of the available induction air. this shows up as a higher-than-normal MP indication at idle…perhaps 17" instead . and the turbocharger on that engine is spinning faster than it should be. and the premature onset of bootstrapping (i. (It's called a throttle because it chokes off the engine's airway!) The result is a significant vacuum in the induction manifold. But suppose there's a substantial leak in the induction plumbing somewhere between the throttle and the cylinders. What happens? Ambient air rushes in through the leak because of the vacuum in the induction manifold. is that the pressure differential across induction leak has become so great (about 15" now) that even the maximum output of the turbocharger can no longer keep up with the loss. of course. but the engine is running just fine and there's no cockpit instrumentation to provide the slightest clue that something's awry. The engine is "trying to breathe" but the throttle is retarded to idle. has commanded the wastegate to go fully closed.g.. exhaust leaks) that can produce the same symptoms.e. The pilot's first indication of a problem comes as the airplane climbs through 15. or even leaving the ground at all! The tip-off is higher-thannormal MP when the engine is throttled back to idle. Consider an engine idling on the ground. In the cockpit. In the cockpit. Best of all.the MP needle never wavers from 29" and so the pilot remains blissfully unaware of the problem. The wastegate on the leaky engine is closed more than it should be. What's happened. it its now-futile attempt to compensate for the leak. there are other kinds of problems (e.000' and the MP on the troubled engine starts to fall and become erratic. this symptom is one that can be checked without having to take the airplane up to high altitude. as the engine consumes the air in the induction manifold but the closed throttle butterfly blocks the inflow of air to take its place. These are the classic symptoms of an induction leak problem: normal operation at takeoff and low altitude.. this shows up as a very low MP reading (typically. So how can you be sure? Good question! It turns out that there's another symptom-one that the owner of this aircraft missed-that can often be used to distinguish an induction leak problem like this one from various other kinds of turbo-related problems. Unfortunately. something on the order of 12" to 15") far below outside ambient (around 30" at sea level). while the MP on the other engine remains rock-solid at 29". and the engine has started to bootstrap…something that should normally not happen until the airplane climbs well into the Flight Levels. the symptom can be produced by other things besides an induction leak (e. The service manual has tables that establish how much MP you should be able to obtain at these benchmark altitudes under specified conditions of RPM. leaks in the upper deck portion of the system prior to the throttle body). Some induction leaks won't produce this symptom (e. a non-firing cylinder or a badly misadjusted idle mixture).g. All that's required is to pressurize the induction system with a few PSI of air-one good way is simply to pump air into a cylinder as if you were doing a compression check. a simple pressure check may be in order. High MP at idle isn't a perfect tool for diagnosing induction leaks. If you suspect an induction leak (based on the observed symptoms).. looking for leaks that reveal themselves by blowing bubbles. around the throttle shaft. But certainly if you see both abnormal bootstrapping at altitude and high MP at idle. and the MP readings are recorded. and consists of a test flight at altitude in which certain power settings are established at certain altitudes. the first step should be to confirm the diagnosis by performing a critical altitude check. to a lesser extent.g. Also. fuel flow and temperature. then you can be sure you have a problem…and odds are that it's an induction leak (although there are other possibilities that we will discuss later on).. and that's probably the first place you should look for trouble. The engine will also be idling leaner than usual-since the leak lets in more air but not more fuel-so the engine may tend to stumble a bit when you throttleup for taxi (at least if the leak is big enough). If you can't find anything obviously wrong after careful visual inspection of the induction system. Exhaust leaks . but the rest of the induction system should be completely airtight. If your engine falls significantly short. certainly the odds favor an induction leak. but rotate the prop so that the cylinder's intake valve is open-then close the throttle and go over the entire induction system with a soapy water spray. The procedure is described in detail in your aircraft service manual.of 14". Some leaks are expected at the induction system drains and. If the aircraft is a twin. (Unlike a lower-deck induction system leak. an exhaust leak will not affect MP at idle. All turbocharged aircraft should have their exhaust systems meticulously inspected for leaks every 50 hours. and should put the airplane on the ground at the earliest possible moment. The pilot of a turbocharged aircraft who experiences a sudden unexplained loss of manifold pressure in-flight should assume that an exhaust failure may have occurred.) Exhaust leaks are inherently much more dangerous than induction leaks. Because the exhaust system operates under extreme heat and pressure. so the symptoms generally won't show up until the airplane is at high altitude. and this is required by Airworthiness Directive for certain aircraft such as the Cessna T210 and all turbocharged twin Cessnas. the pilot should consider the possibility of shutting down and securing the engine to minimize the threat of in-flight fire.An exhaust leak can produce similar symptoms to an induction leak-the onset of bootstrapping at a lowerthan-normal altitude-because any exhaust that escapes through a leak bypasses the turbocharger just as if it escaped through an open wastegate. I have done extensive investigation of exhaust failures in turbocharged aircraft. I don't mean to frighten you with this statement. exhaust leaks are usually a lot easier to detect because they typically leave brightly-colored exhaust stains (and sometimes also obvious heat damage) that can be detected visually during an engine-compartment inspection. Fortunately. and has concluded that . the turbo controller will try to compensate for (and thereby cover up) the problem by commanding the wastegate to close. and because exhaust gas is so very corrosive. because of the very serious threat of in-flight fire. exhaust leaks can sometimes develop suddenly (a "blowout") rather than gradually. Just like with an induction leak. but this means that the wastegate will go full-closed at a lower-than-normal altitude. If you see it. you're very likely not even to notice the loss of one cylinder…particularly in a twin where any roughness or loss of power is masked by the other engine. You'd think that a six-cylinder engine that was firing on only five cylinders would be very obvious to the pilot. Internal engine problems A third possible cause of bootstrapping at a lower-than-normal altitude is an internal engine problem that prevents one or more cylinders from firing. a zero-compression cylinder will generally cause the same abnormally high MP at idle as an induction leak. As usual. This would most likely be something that reduces the compression of a cylinder to near-zero (such as a valve that's badly burned or stuck open). This is a symptom you should watch for before every flight. wouldn't you? Well. A non-firing cylinder reduces the exhaust output of the engine by onesixth (assuming a six-cylinder engine). because it performs such an unenviable job: regulating the flow of incredibly hot and corrosive exhaust gases. . it's usually a tip-off that something significant is wrong.the risk of an in-flight exhaust failure (particularly one of the "blowout" variety) is extremely remote on aircraft whose exhaust systems have been properly maintained and inspected. By the way. you've probably found your culprit. besides induction leaks. and this means less flow through the turbocharger. or something that prevents both spark plugs in the cylinder from firing (such as severe lead fouling of both plugs). the controller will try to compensate (and cover the problem up) by closing the wastegate. If so. I can tell you from firsthand experience that unless you have a probe-per-cylinder EGT system that shows one cylinder running ice cold. It makes perfect sense that the wastegate would be one of the most problematic parts of the turbocharging system. Wastegate problems The other most common cause of turbo-system problems. are problems with the wastegate and wastegate actuator. Trust me on this one! So if you notice bootstrapping at unusually low altitudes but can't seem to find any leaks in the induction and exhaust. it's definitely worth doing a compression check and having a look at the plugs to make see whether one cylinder is not firing and/or operating at near-zero compression. The vast majority of in-flight blowouts and exhaustrelated fires involved exhaust components with very high time and usually ones with poor-quality weld repairs that failed. reaching its fully-closed position when the pressure reaches around 50 PSI. especially during periods of constant wastegate movement such as climb. and which can be made to disappear at will by increasing RPM a bit or descending a bit. carbon and sulfur) to the point that it no longer opens and closes smoothly when commanded to do so by the wastegate actuator. Simply remove the oil line that runs from the engine oil pump to the wastegate actuator.Most wastegate problems are of the "sticky wastegate" variety in which the shaft on which the wastegate butterfly pivots gets "coked up" with byproducts of combustion (a nasty concoction of lead. If the wastegate appears to be sticky. O-ring deterioration. As air pressure reaches 15 PSI or so. and airspeed (all times when wastegate adjustments are most likely to be commanded by the controller). The result shows up as abnormal MP fluctuations. Whatever the exact cause of the sticky wastegate. If you suspect you might have a sticky wastegate. and are most obvious during changes in altitude. and flight in turbulent air. Another somewhat less common cause of "sticky wastegate syndrome" occurs when the wastegate actuator itself starts to bind as a result of the accumulation of oil-borne deposits. Also make sure the wastegate butterfly opens and closes fully. power settings. it's possible that you might be able to "rescue" it by giving it a good soak overnight in a strong penetrant like Mouse Milk . descent. a total movement of approximately 90 degrees of shaft rotation. Any tendency to stick should be obvious during this test. erratic MP fluctuations due to a sticky wastegate generally occur at various altitudes and RPM settings. it's easy to check in the shop. Watch for any signs of jerkiness or binding as you exercise the wastegate in this fashion. It's easy to confuse the erratic MP fluctuations caused by a sticky wastegate with the unregulated MP fluctuations caused by bootstrapping. Now simply watch the wastegate assembly as you slowly and repeatedly vary the air pressure from zero to 50 PSI and back. Bootstrapping (due to a fully-closed wastegate) is a condition that predictably occurs at high altitude and low engine RPM. but they're really quite different if you know what you're looking for. the result is that the constant series adjustments commanded by the turbo controller-which are normally executed so rapidly and smoothly that they are unnoticeable to the pilot-become jerky and erratic. Hook a source of adjustable air pressure to the oil inlet port of the actuator-an ordinary cylinder compression tester is ideal for this purpose. On the other hand. the wastegate should open smoothly. As you back the pressure down towards zero. the wastegate should start to close smoothly. and/or scoring of the actuator cylinder. ) If the problem follows the controller when you swap sides (twins only) and a simple cleaning doesn't resolve the problem (singles or twins). too. But don't count on it. it might just be that the poppet valve is sludged up. It spends its life in almost air-conditioned luxury.) The controller's upper deck air reference line and inlet port should contain nothing but air. and it's an unfortunate fact that lots of perfectly good controllers are sent out for overhaul in the course of "shotgunning" turbo system problems. purge the line with solvent and shop air. If you see any. pilots and mechanics alike have a tendency to name the turbo controller as prime suspect. it's time to yank the wastegate and send it out for overhaul. Disconnecting the oil lines and shooting a few shots of shop air into the oil return port might dislodge the gunk and fix the controller problem. Disconnect the line and inspect for any signs of liquid contamination (fuel or oil). Before you send the controller out for overhaul (which doesn't come cheap). there are a few things you should try first: If you're flying a twin. If I had to come back as a turbo-system component in my next life. and there's not a whole lot that can go wrong with it. (That's a whole lot less scary than it sounds. and disassemble the controller's aneroid chamber and clean it out. only that it's one of the system last components you should suspect. the controller is hardly ever the culprit.or AeroKroil. (At least it worked for me last time I tried it. try swapping the left and right controllers and see if the problem changes sides or stays put (or goes away altogether). The turbo controller is seldom the culprit for two reasons: it has a terribly easy job. only then should . and regulating oil flow to the wastegate actuator at the other. The swap generally takes less than an hour and could save you many hundreds of bucks and a week or two of downtime. If a penetrant soak doesn't result in silkysmooth action. Expect to pay around $400 for the overhaul. Make sure that the overhauled wastegate is installed with the proper high-temp attaching hardware and new gaskets. watching upper-deck pressure at one end. Think about it for a minute: the controller never sees hot exhaust gases or high engine temperatures like other turbo-system components. In fact. Controller problems When the turbocharging system starts acting up. If the controller is at fault. I'd almost surely apply for the job of turbo controller! That's not to say that the controller cannot cause turbo problems. plus a couple of hours of labor to remove and reinstall. Turbocharger problems Of course. If it leaks into the turbine. A less spectacular failure mode occurs when the turbocharger center section wears out. Turbochargers have several failure modes. . not because it seldom fails. If oil leaks into the compressor. Time to yank and overhaul the beast. A visual inspection of the turbocharger will confirm oil where it doesn't belong. it will result in an abnormal accumulation of oily deposits on the tailpipe and belly. and often excessive play when the shaft is wiggled. oil being pumped into the hot exhaust). and your mechanic doesn't have much difficulty figuring out what to do next. turbocharging problems can also be caused by-ta da!-the turbocharger itself. but because when it does fail.000 RPM or so. generally resulting in engine oil winding up where it doesn't belong: in the compressor and/or turbine portions of the turbo. I'm listing this component last. turbos sometimes fail catastrophicallythe engine suddenly goes normallyaspirated (or quits from over-rich mixture) and the aircraft starts trailing black smoke (actually. or chunk of exhaust valve) that damaged the compressor or turbine wheel. For example.you consider sending the thing out for overhaul. most of which are more-orless self-diagnosing. alternate air door hinge. the tower rolls the equipment. often because the turbo ingested some foreign object (like a nut. You put the airplane on the ground fast. bolt. and sometimes oil dripping from the tailpipe after shutdown. the failure is more or less obvious. it will result in oil-soaked induction plumbing (you'll likely see oil dripping from an induction system drain) and oil-fouled spark plugs. While a turbocharger can last a full engine TBO if the engine is operated with sufficient TLC. A catastrophic failure like this generally stems from a turbocharger that suddenly develops a serious out-of-balance condition while spinning at 50. it's certainly not unusual for a turbo to need a midterm overhaul. easiest and cheapest troubleshooting steps. cracked induction coupling. Visually inspect the induction system looking for any sign of a leak (chafedthrough manifold. Visually inspect the exhaust system looking for any sign of a leak (tip-off is usually brightly colored exhaust stains).A third turbocharger failure mode is a bit more subtle. .). By all means do a "critical altitude check" as documented in the service manual for your airplane. but here's a starting point: The first step in any turbo troubleshooting strategy should be a thorough test flight to document the exact symptoms. It's impossible for me to suggest a one-size-fits-all strategy. If nothing suspicious is found. time-wasting "shotgun" approach is to devise a logical troubleshooting strategy. If nothing suspicious is found. it's overhaul time. and then gradually works towards rarer failures and more difficult and costly actions.000 RPM. to determine if you have a premature bootstrapping problem and to quantify just how serious it is. and/or airspeed changes (indicative of a sticky wastegate). If it is noted. descents. A Troubleshooting Strategy If you have a turbo-system problem. while the metal loses much of its strength at the white-hot 1600°F temperatures at which the turbine operates. pressurize the induction system and use soapy water to search for leaks. the best way to avoid falling victim to the expensive. and stems from the fact that the turbine wheel operates under tremendous centrifugal forces as it spins at 50. or if they occur primarily during climbs.000 to 80. Be sure to note whether any erratic or abnormal MP indications occur only at high altitudes and/or low RPMs (indicating bootstrapping). The turbo should be inspected for signs of blade scrape at each annual (and any other time the tailpipe is removed). Also note whether MP at idle is higher than normal (indicative of an induction system leak). loose hose clamp. Your strategy should seek to find or rule out potential causes in a sequence that starts with the most common failure areas and the quickest. The result is that the turbine blades develop a very gradual "stretch" over the life of the turbochargerparticularly if it's run hot and hard-and ultimately they can stretch enough that they actually start to scrape on the turbine housing. Do a quick compression check and spark plug inspection to determine whether you have a cylinder not firing or with near-zero compression. etc. and the consequences of neglect can be devastating. June 5. Connect a source of variable regulated shop air (such as a cylinder compression tester) to the oil inlet port of the wastegate actuator. AVweb's Mike Busch explains how mags work. If any of those problems are noted. Remove the oil lines from the turbo controller and blow shop air through the poppet valve to dislodge any sludge. try an overnight penetrant soak. Check the turbocharger for signs of FOD. pull the turbo for overhaul. what can go wrong with them. Remove the air reference line and inspect for any signs of fluid contamination. what preventive maintenance they require. and what to do about it. and turbine blade scrape. and exercise the actuator by repeatedly varying the air pressure between 0 and 50 PSI.. In a twin. But mags need regular maintenance. try exchanging the two controllers to see whether the problem moves with the controller. . If the wastegate is sticky.. If it does. pull the wastegate and have it overhauled. watching for any sign of sticky operations. probably because they're so reliable and our engines have an "extra" one. oil in the compressor or turbine. About the Author . 1999 by Mike Busch This article originally appeared in the May 1999 issue of CESSNA PILOTS ASSOCIATION MAGAZINE. and if cleaning the controller doesn't help. If that doesn't free it up. Mag Check Email this article | Print this article Magnetos are frequently-neglected items. send it out for overhaul.pressurize the exhaust system and use soapy water to search for leaks. excessive center section play. The fact that mags his never-ending quest to can continue to function in the face of become a true renaissance man such neglect is a testament to their of aviation. deafening silence). of earning his A&P mechanic As we'll discuss shortly. Mike has every 100 hours and a major disassembly been flying for 36 years and an inspection. Occasionally. highwhere he can't get DSL or cable altitude misfire. mag certificate. Aviation Consumer and IFR Many owners aren't aware (and an Magazine. which is a in a prior lifetime was a relatively significant item on a twin contributing editor for The because there are four mags to do. The 500past 14 of those years. he's hour major maintenance is frequently owned and flown a Cessna neglected.. nasty the technical surprises). as well as several member of significant unscheduled items (i. Mike and his wife performance deteriorates significantly if Jan reside on the central coast this routine maintenance isn't done. Mike's on the verge inherent reliability. In having been removed.000-hour alarming number of A&Ps conveniently commercial pilot and CFI with forget) that both Bendix (TCM) and Slick airplane.g. deterioration of engine efficiency. the result is much more serious (e. This of California in a semi-rural area usually shows up as hard starting. A 6. instrument and (Unison) mags need a minor tune-up multiengine ratings.My recently-completed annual Mike Busch inspection of my Cessna is editor-inT310R included a considerable chief of amount of scheduled AVweb. For the adjustment every 500 hours. and it's not unusual to see an T310R turbocharged twin. One of the scheduled staff at maintenance items this year was 500Cessna Pilots Association.e. engine reach TBO without the mags ever which he maintains himself. What Makes 'Em Tick? A magneto is a self-contained ignition system that converts mechanical rotation into high-voltage pulses that are used to fire the spark plugs. and does so without the need for external power from a battery or electrical . and/or general TV.. lubrication and aircraft owner for 33. a maintenance work. cleaning. and hour magneto maintenance. its rotor gradually loses magnetism. For years. The amount of energy generated in the primary coil winding is a function of how rapidly the magnetic field across the primary changes. the rotor can be re-magnetized and this is typically done at major overhaul of the mag. and how fast it turns. so its ability to generate energy weakens. The Coil and Breaker Points . Like any alternator. This powerful than other models. mags generate their maximum energy when turning at full operating speed. it Bendix S-1200 mags are larger and more turns 1. more powerful magnets. Big mags (like the Bendix S-1200) generate more energy than do little ones (like the Slick 6300 or the Bendix D-3000 dual-mag) because their rotors have bigger. The Rotor The term "magneto" comes from the permanent magnet rotor which is spun by the engine's accessory gearing. magnetos have been the ignition system of choice for aircraft engines because they continue to function perfectly even in the face of a total electrical failure. This varies with two things: how strong the rotor's magnet is. Fortunately. Equally important as the strength of the rotor's magnetism is its rotation speed. In a fourcylinder engine. As a mag gets older. the rotor turns at engine RPM — in a sixcylinder engine. Each full rotation of the rotor induces two waves of electric current in the primary coil.5 times crankshaft speed. and put out a lot less energy at slow RPMs (such as idle). of opposite polarity. function as a specialized alternator which generates alternating current flow in the primary as the rotor turns.system. magnetized rotor. together with the primary winding of the magneto's coil. the breaker points are closed.000 volts. but it's not even close to enough voltage to jump the gap of a spark plug. The collapse of the core's magnetic field induces a large voltage spike in the primary. Now. The two coil windings act as a special sort of step-up transformer. Normally. while the other end is hooked to the high-tension terminal of the coil. interrupting the flow of current in the primary coil winding. and causing the magnetic field in the coil's core to collapse quite suddenly. At the moment of ignition. The secondary winding of the coil consists of a very large number of turns of very fine magnet wire — perhaps 20.000 to 30.000 or so — wound around the same core as the primary. This current flow produces a powerful magnetic field in the coil's iron core. around and around the coil. that's enough voltage to give you a nasty jolt if you grabbed a hold of the magneto's low-tension terminal while the engine was running. One end of the secondary winding is grounded. while the other end is connected to a set of cam-operated breaker points similar to those used in automotive distributors in the pre-electronic-ignition era. Now that is enough to produce a nice. One end of the coil is permanently grounded to the case of the magneto. That's where the coil's secondary winding comes in. hot spark! . Since the secondary winding has something like 100 times as many turns as the primary. the magneto's cam opens the breaker points.The primary winding of the coil consists of 200 turns or so of heavy-gauge copper wire wound around a laminated iron armature. grounding both ends of the primary coil and allowing current induced by the rotor magnet to flow continuously Basic magneto schematic diagram. which may be as high as 200 or 300 volts. the 200to 300-volt spike produced in the primary when the breaker points open induces a voltage 100 times as large in the secondary: 20. Such arcing at the breaker points is a Bad Thing for two reasons. By the time the capacitor is charged. At the moment of point opening.The Capacitor One little fly in this ointment has to do with what happens at the breaker points at the moment they're opened by the cam. oil. . It is essential that the inside of the distributor block remain scrupulously clean and dry. Here's how it works. arcing causes a tiny amount of metal transfer from one breaker point to the other. and therefore a weaker spark at the plugs. the cam has separated the points far enough that the 200. arcing won't be effectively suppressed. The size of the capacitor is critical. arcing causes the magnetic field in the coil to collapse more slowly. the coil's field will collapse so slowly that the magneto's voltage output will be seriously reduced. The magneto accomplishes this by means of a mechanical distributor.or 300-volt spike in the primary coil cannot jump the gap. Second. passing in close proximity to individual electrodes connected to the four or six or eight spark plug lead wires. or dirt — can impair the dielectric properties of the block and allow internal arc-over between distributor block terminals. if it's too large. Since the points are being opened by mechanical action of the cam. If it's too small. During the first microseconds that the cam is opening the points. To solve these two problem. mags are equipped with a capacitor connected across the breaker points. First. The slightest bit of contamination — moisture. The high-tension lead of the coil is connected to a rotating wiper electrode on a large distributor gear that turns at half crankshaft speed inside the mag's distributor block. The distributor block is made of insulating (dielectric) material capable of withstanding tens of thousands of volts. The Distributor The high-voltage pulses produced by the secondary winding of the coil must be directed to the spark plug of each cylinder in sequence. it's obvious that the process of point opening isn't exactly instantaneous. resulting in a lower voltage induced in the secondary. On the other hand. The result is a nice. and if left unchecked would cause the points to erode and pit quite quickly. the initial voltage spike charges the capacitor for 50 microseconds or so instead of arcing across barely-separated breaker points. they're still so close together than the 200volt spike in the primary coil winding can arc across them. predictable waveform and much longer-lasting points. (The "P" stands for "primary. A broken P-lead center conductor results in a dangerous "hot mag" condition in which the ignition switch is unable to shut off the magneto. Once such arc-over occurs.causing engine misfire. External timing is performed with the mags mounted to the engine. Mag Tune-Up Tuning up the magnetos for optimum performance involves two sets of adjustments: internal timing (point gap and E-gap) and external timing (or "timing the mag to the engine"). Broken P-leads are a frequent problem.. Shielding of the P-lead is essential. facilitating subsequent arc-over events. and should be checked . making the mag incapable of generating a spark. since the lead is exposed to engine heat and vibration and air blast. it tends to leave a carbonized track in its wake. A broken P-lead shield usually causes radio interference which disappears when he particular mag is shut off with the ignition switch. The P-lead is normally a 16-gauge shielded wire..") Its purpose is to allow the ignition switch to disable the magneto by grounding the hot side of the Slick 6300-series mags are compact and reliable. The P-Lead The "P-lead" is a wire that runs from the ungrounded end of the magneto coil's primary winding to the cockpit ignition switch. and should be performed at least every 500 hours of operation. As long as the P-lead is grounded through the ignition switch. primary. the breaker points are unable to interrupt the primary current flow. because an unshielded P-lead acts as an antenna that radiates the ignition pulses generated by the magneto and creates interference with aircraft radios.particularly at high altitudes. The internal adjustments require that the mags be removed from the engine and opened up. with the shield grounded to the magneto case. every 100 hours or at annual inspection.g. These adjustments are essential to ensure that the magneto is able to generate enough energy to produce a hot spark. 10 degrees +/. so the "E-gap" adjustment is made by adjusting the breaker points. Once the point gap is correct. On the big Bendix S-1200 and dual Bendix D2000/3000 mags. The number of degrees of rotation from neutral to point opening is called the "E-gap" and needs to be set to a specified value (e. Then the point gap is measured with an ordinary wiretype feeler gauge. External Mag Timing . Now. rotate the rotor slowly until you can feel a "magnetic detent. and rotating the cam until the "E-gap" is correct.2) so that the points open exactly when magnetic field induced in the coil by the rotor is at its maximum.018 inch for Bendix mags). If the "E-gap" drifts out of limits." This is known as the "neutral position" of the rotor. To do this. First. with a timing light ("buzz box") attached across the breaker points.. the mag will continue to work but the spark it produces will be weak. rotate the magneto until the points just start to open." The point gap should be set first. the drive shaft of the magneto is rotated to the position at which the cam has opened the breaker points to the maximum extent. Internal Mag Timing There are two internal adjustments that must be set correctly for a magneto to operate properly: point gap and "E-gap. The points are then adjusted until for the specified gap (normally about . this adjustment is made by loosening the screw that attaches the cam to the rotor shaft. Other magneto models have non-adjustable cams. the "E-gap" can be set. The drift can be in either direction.) causes the points to open earlier. The usual procedure is to loosen the magneto hold-down clamps and to "bump" the mag a little bit to bring the timing back to specifications. You see. etc. Bumping The Mag When ignition timing is checked routinely at 100-hour or annual inspection. and should be re-checked every 100 hours. one of the spark plugs in the #1 cylinder is removed and the crankshaft rotated until the #1 piston is at top-dead. the magnetoes must be mounted on the engine and ignition timing set correctly. External timing is critical to proper engine operation. Wear on the rubbing block causes the points to open later. advancing the timing. The base clamps are tightened and the timing is re-checked. To do this. The problem comes when mechanics fail to keep track of how far the magneto timing has been "bumped" in the course of successive inspection intervals. each magneto is adjusted so that its breaker points open precisely at this desired firing position. the same factors that cause the external timing to drift (rubbing block wear and point erosion) . The adjustment is made by loosening the two magneto base clamps and rotating the entire magneto on the engine mounting pad until the points just start to open (as shown by the timing light connected to the mag's P-lead terminal). This procedure is fine so far as it goes. retarding ignition timing. Using an ignition timing light ("buzz box").Once these internal adjustments have been made. It should be within a degree or so of spec. center position. Once this TDC position is established.Checking external mag timing with a timing light. Erosion of the breaker points themselves (due to arcing. it's not unusual to find that it has drifted off-spec by a degree or two. the crankshaft is rotated to the specified firing position (typically 20° before TDC). drift beyond that should be considered a "red flag" that it's time to pull the mag and re-adjust the internal timing. Then there's the problem of timing. say. If you crank an engine at 20 RPM and a spark plug fires 20° before the corresponding piston reaches the top of its compression stroke. and even at that speed. Naturally. But there's no way that an engine is going to start with ignition timing like this. while it's certainly okay to bump the mag timing by one or two or even three degrees to correct timing drift. But. the spark would be marginal at best. Starting the engine is another matter altogether.also cause the magneto's internal timing to drift away from the correct Egap. our electric starters Slick 6300 mag. the engine will backfire — .) Getting Started Once the engine is running. (One more reason for including more detail in your maintenance log entries. unless you keep track of each time you bump the mag timing. 150 RPM (referred to as the mag's "coming in speed"). exploded view. a magneto is not capable of generating enough energy to fire a spark plug at less than. which degrades the quality of the spark that the mag produces. you have no way of knowing the cumulative amount of timing drift that has occurred since the E-gap was last set. So. typically at something like 20° BTDC (before top-deadcenter). There are two major obstacles to starting a magneto-ignition engine. Magneto-ignition aircraft engines have fixed ignition timing. a properlyadjusted magneto does a fine job of providing the required ignition. crank the engine at very low speed — typically 10 to 20 RPM. This setting is a compromise between takeoff and cruise (where we'd really like the ignition timing to be advanced even more) and idle (which would be a lot smoother if the timing was retarded). For one thing. When the starter cranks the engine.guaranteed. Which you use depends on what kind of airplane you fly. then you have impulse couplings. and employ an ignition switch . As the engine continues to turn. while most Cessna twins and many Beech Bonanzas use the electrical method (retard breaker). an impulse spring in the hub is wound up for 25° to 35° of engine rotation (the "lag angle") until a drive lug on the coupling body trips the flyweight. When this happens. Here's how it works. At this point. and if you hear "snap snap snap" just before your engine stops at shutdown. disengaging it from the stop pin. to have a prayer of getting our engine started. It's easy to tell whether or not your engine uses impulse couplings. If you hear a loud "snap" when you pull the prop through by hand. and the magneto rotor is turned fast enough to generate a decent spark. Two rather different methods are commonly used to accomplish these things — one mechanical. Some installations provide an impulse coupling on both magnetos. This has precisely the two effects desired: the ignition timing is retarded (by lag angle of the coupling). centrifugal force causes the spring-loaded flyweights in the impulse coupling to retract so that they no longer catch on the stop pin. the engine drives the magneto directly and timing returns to its normal setting of 20° BTDC or whatever. and (2) figure out a way to retard the spark enough to ensure that the engine won't backfire during cranking. Impulse Coupling The impulse coupling is an extraordinarily clever mechanical solution to the starting problem. Neat trick. we need to do two things: (1) figure out a way to coax the magneto into generating enough energy to fire the spark plugs at slow cranking speeds. eh? Once the engine starts. This stops the magneto shaft from turning further. and the other electrical. a spring-loaded flyweight in the magneto drive hub catches on a stationary stop pin mounted on the magneto case. Others use an impulse coupling on only one mag. So. It's a mechanism that's contained within a hub that attaches to the magneto's drive shaft and is driven in turn by the engine. the wound-up impulse spring "snaps" the magneto through its firing position at a speed much faster than cranking speed. Most Cessna singles use the mechanical method (impulse coupling). causing catastrophic destruction of the engine. So be sure your impulse couplings are not worn excessively and that all applicable ADs are complied with. but nowadays both Bendix and Slick make retard-breaker mags. the fact remains that the magneto is still turning too slowly to generate the energy required to fire a spark plug. Unison Industries introduced a product called SlickSTART. which is really a solid-state replacement for the old starting vibrator used in the . aircraft battery power is converted into pulses by a starting vibrator — basically. however: You can't start the engine with a dead battery. the retard-breaker mag makes use of a second set of breaker points to generate a spark at retarded ignition timing during engine start. Because impulse couplings have moving parts. only the left mag has the extra breaker points. It also produces easier starting because the spark plug fires a dozen times or so during each ignition event. it saves a little weight. While the extra set of points solves the problem of retarding the spark for starting. and starting is done with the right mag disabled in this scheme. inducing high-voltage pulses in the secondary winding that do contain sufficient energy to fire the spark plug. Generally. and some failure modes can cause parts of the impulse coupling to drop into the engine gearbox.) Finally. the "Shower Of Sparks" trademark that Bendix uses for this system. This scheme has some advantages. (Hence. there have been a lot of Airworthiness Directives against impulse couplings in recent years — both Bendix and Slick — and these have to be taken very seriously. SlickSTART In 1997. As the name implies.that grounds out the P-lead of the non-impulse mag during the start. rather than just once. There is one big disadvantage of the retard-breaker ignition system. a little electric buzzer — and those pulses are fed to the magneto coil's primary winding via the P-lead. Retard Breaker An alternative solution to the starting problem is the retard-breaker magneto. Don't bother trying to hand-prop a twin Cessna unless you're simply looking for a new and different kind of aerobic workout. In addition. they need to be disassembled and inspected carefully during each 500-hour magneto maintenance cycle. To deal with this problem. This was first pioneered by Bendix in its "Shower Of Sparks" system. It eliminates the mechanical risks associated with worn impulse couplings. An impulse coupling failure inflight can result in total engine failure. Flying High Starting is one phase of operation that is especially challenging to the magneto ignition system. and also got approval for use with impulse-couplingequipped mags as well as the retard-breaker kind." To ensure that the spark occurs where we want it to occur. Flying at high altitudes is another. Here's the problem: Air is a pretty good electrical insulator. If we set our spark plug electrode gap to 0. or inside one of the ignition harness wires. and is far better at firing carbon-fouled plugs. we must make sure that the spark plug represents "the path of least resistance" for the high-voltage pulse generated by the magneto. On the other hand.018 inch. In fact. but its insulating capability (dielectric constant) varies with pressure. the better it insulates — the lower the pressure. Unison got the SlickSTART approved for use with both TCM/Bendix mags as well as their own Slick mags. etc. (Note that nothing can help if the plugs are lead-fouled. if you're not having any problems with starting. The higher the pressure of the air. however. just about the only engines that the SlickSTART is not approved for are those that use the Bendix D-2000 or D-3000 dual magneto. High-Altitude Misfire . then we can be pretty certain that the spark will occur at the spark plug electrodes. it's an excellent idea. for example. we want that pulse to create a spark inside the cylinder by jumping the air gap between the electrodes of the spark plug. The SlickSTART produces a much hotter spark for starting than either a starting vibrator or impulse coupling. What we don't want to happen is for the spark to occur anywhere else — such as inside the magneto distributor block. When a magneto generates a high-voltage pulse. the easier it is for electricity to pass through it (in what we call a spark).) Is it worth retrofitting your engine with the new SlickSTART system? If your engine is hard to start or you operate in frigid temperatures. Such an undesirable spark is called an "arc-over" and results in what we call "misfire. or between the ignition harness wire and a nearby piece of the engine.retard-breaker system.018 inch. there's probably no reason to make the change. particularly when we're talking about turbocharged engines and flight-level flying. and make sure that any place else in the ignition system that the spark could jump is a whole lot bigger than 0. Interestingly enough. other than removing and cleaning the plugs. thanks to the compressive effects of the turbocharger and the compression stroke of the piston. and "high-altitude misfire" begins to occur. So the spark plug gap is the path of least resistance and that's where the spark occurs. so that air isn't nearly as good an insulator. a great deal longer than the spark plug gap. you should probably have a mechanic open up the mags and inspect the inside of the distributor blocks for carbon tracking. This will reduce the combustion-chamber pressure in the vicinity of the spark plug electrodes. and make it easier for the spark to occur where it's supposed to occur. thereby increasing the air pressure inside the magneto and thereby raising the breakdown voltage. the first thing you should do is throttle back. The air in the vicinity of the spark plug remains at high pressure. making it easier and easier for arc-over to occur there. the air pressure in the vicinity of the spark plug electrodes is quite high (since it has just been compressed by the piston). When you get back on the ground. The air pressure inside the magneto is outside ambient. At the moment of ignition. so it's a pretty good insulator. At some altitude. But the air pressure inside the magneto decreases with altitude. Your next move should be to descend to a lower altitude. Preventing Misfire . Such conductive deposits produced by previous arc-over events can make it much easier for subsequent arc-overs to occur. which is considerably lower. Let me tell you from firsthand experience that this will really get your attention! If you ever experience high-altitude misfire in flight. But the air gaps inside the magneto are at least several tenths of an inch wide. Now suppose this airplane starts climbing up to a cruising altitude up in the flight levels. the breakdown voltage inside the magneto becomes lower than at the spark plug electrodes.Imagine a turbocharged airplane departing a sea level airport. and should be cleaned off. There are basically two fundamental strategies for preventing such highaltitude misfire: make it easier for the spark to occur where it's supposed to. For example. the gaps increase as the spark plugs wear.2 inches apart. How can you make it harder for arc-over to occur inside the magneto? There are two ways. so part of their cost is offset by less frequent plug maintenance. but they tend to hold their gaps much longer. The specs Spark plug gaps are critical for high-altitude say that a RHB32E flying. reducing the chance of internal arc-over between the widelyspaced electrodes. the huge TCM/Bendix S6-1200 mags that I use on my airplane have distributor block electrodes that are spaced 1. Fine-wire plugs are more than twice as expensive.019 inch. Fine-wire plugs also last a good deal longer than do massives.016 inch to gain increased margin against high-altitude misfire. One is to use magnetos that are as physically large as possible. . so they're much more resistant to high-altitude misfire than the smaller Slick 6300 mags that are also approved for my engines. or make it harder for it to occur where it's not. Of course.016 and 0. and perhaps even every 50 hours if you have a history of high-altitude misfire. One obvious way to make it easier for the spark to occur where it's supposed to (at the spark plug electrodes) is to tighten up the spark plug gap. so it's important to clean and re-gap the plugs on a regular basis: at least every 100 hours. I gap mine to 0. Many operators who fly regularly at high altitude prefer to use fine-wire spark plugs instead of the usual massive-electrode type. spark plug should be gapped to between 0. for example.The other way to minimize the chance of arc-over is to pressurize the mags by pumping bleed air from the turbocharger into them. and change the filter in the magneto pressurization line often. As a result. however. Putting It All Together .). TCM has an improved large green pressurization line filter (p/n 653386) that is more effective than the small. If you do have pressurized mags installed. make sure they receive frequent maintenance. etc. Pressurized mags are a mixed blessing. In fact. While they certainly produce an adequate spark. RAM Aircraft also sells an improved filter. a pressurized version of the big Bendix S-1200 mag — the S1250 — is available. and used by RAM on their GTSO-520 engines used on the Cessna 404 and 421. it also creates a new problem — internal contamination of the magneto — New-style pressurization line filter helps keep particularly when moisture out of pressurized magnetos. pressurized mags need to be opened up and cleaned a lot more frequently than do non-pressurized ones. Although the pressurization is an effective way to eliminate the highaltitude misfire problem. RAM Aircraft. Slick Service Bulletin SB1-88A recommends a teardown and internal inspection of pressurized mags every 100 hours (compared with 500 hours for nonpressurized mags). fits pressurized Slick mags on all its TSIO-520 engines. Both of these filters provide a sump and drain line for moisure. The smaller Slick pressurized mags also do not produce nearly as energetic a spark as do the big TCM/Bendix S-1200s. they have less margin for misadjustment (E-gap drift. For really high altitudes. clear ones at removing moisture from the pressurization air before it reaches the magneto. flying through moisture (rain or clouds). If you fly at high altitudes (especially if turbocharged). consider simply exchanging the mags at 500 hours for reconditioned units from Unison. or pressurized Slicks with the big green TCM or RAM line filters to keep moisture out of the mags. Continental's Cram Course: TCM's Aviation Technician Advanced Training Program Email this article | Print this article . it's easy enough to perform the 500-hour inspection and adjustment procedure locally. If the timing has drifted off by more than a degree. Keep track of how far the timing has been "bumped" at each inspection. even if the normal 500-hour maintenance interval hasn't yet arrived. remove the mags from the engine for major maintenance.) If your engine uses impulse couplings. For TCM/Bendix mags. you should be using either the big TCM/Bendix S-1200 mags.e. I recommend John Schwaner's book The Magneto Ignition System. Every 500 hours. For even more information about magnetoes. external timing) with a magneto timing light. For high-altitude operations. and replace the wear-prone parts (points. consider installing the SlickSTART solid-state unit. "bump" the mag to return the timing to specifications. (Slick tends to discourage field maintenance of their mags by setting parts prices high and offering very reasonable prices for overhauled-exchange units. Cumulative "bumping" of more than about three degrees is good reason to remove the mags from the engine and readjust the internal timing. be sure to inspect them very carefully for excessive wear. and make sure all ADs have been complied with. carbon brush. If hard-starting is a problem.. and distributor block). check ignition timing (i. you need to take extra precautions to prevent high-altitude misfire. For Slick mags. Clean and gap your plugs frequently (every 50 to 100 hours) and keep the gaps at the low end of the allowable range. which will work with almost any installation except for the TCM/Bendix dual-mag. Consider using fine-wire spark plugs.Every 100 hours or annual. and in which direction. he's owned and flown a Cessna T310R turbocharged twin... and in a prior lifetime was a contributing editor for The Aviation Consumer and IFR Magazine. a member of the technical staff at Cessna Pilots Association.000-hour commercial pilot and CFI with airplane. and $750 in tuition.. A 6.How would you like to learn more about your TCM piston aircraft engine than 99% of your fellow Continental owners will ever know .. Mike Busch is editor-inchief of AVweb. For the past 14 of those years. AVweb editors Mike Busch and Jeb Burnside (both of whom fly behind Continentals) recently went through TCM's Aviation Technician Advanced Training Program and lived to tell about it.. December 23. instrument and multiengine ratings. Ala. and maybe even more than your A&P knows? All it takes is five days in Mobile. Mike has been flying for 36 years and an aircraft owner for 33. 2000 by Mike Busch About the Author . which he maintains . (Chris actually holds an A&P certificate. Mornings are devoted to classroom discussion. Ala. I'm Not An A&P (But I Play One On The Internet) Although TCM designed the ATATP syllabus primarily for professional aviation maintenance technicians. However. writer of maintenance-oriented articles.) himself. extremely worthwhile and highly recommended. surrounded by disassembled engines. they encourage maintenance-involved aircraft owners like Jeb and me to attend. and generally come back with a definitive answer after lunch or the next day.. and member of the technical staff at Cessna Pilots Association. so I had modest expectations for what I would derive from the class. I must say that I was pleasantly surprised. while afternoons are mostly spent performing hands-on activities ranging from changing cylinders to adjusting fuel injection systems to setting magneto e-gap. I arrived in Mobile knowing a fair bit more about TCM engines than your average A&P. and came away learning a good deal more than I anticipated. All in all. they have ready access to the appropriate expert. and Jeb does a lot of the work on his — and all of us found the program to be a fascinating and highly educational week of total immersion into TCM piston aircraft engines. Mike's on the verge of earning his A&P mechanic certificate. Welcome to Mobile . A great advantage of holding the course at the factory is that all the technical resources of TCM are near at hand. it was a terrific week. components and cutaways. where I spent a full week at the Teledyne Continental Motors factory going through TCM's Aviation Technician Advanced Training Program (ATATP).) Participants spend a full week being taught by TCM subject matter experts. In his never-ending quest to become a true renaissance man of aviation. but we try not to hold that against him. The course is held during the last full week of every month at the factory — located at Mobile Downtown Airport — and tuition is $750 for the week. (You might want to bookmark this URL. As a an active wrench swinger. I attended the course with AVweb Executive Editor Jeb Burnside (who owns a TCM-powered C33A Debonair) and my good friend Chris Wrather (who owns a TCM-powered V35 Bonanza). as well as exploration of offsyllabus subjects. Program details and enrollment instructions can be found on the TCM Link Web site. The classes are small — limited to about 15 students — providing plenty of opportunity for Q&A with the TCM instructors. since it's not particularly easy to find from the TCM Link home page. Mike and his wife Jan reside on the central coast of California in a semi-rural area where he can't get DSL or cable TV.I recently returned from Mobile. If a question comes up in class that the instructors can't answer. All three of us are very maintenance-involved aircraft owners — Chris and I do virtually all the maintenance on our respective airplanes. A rental car is a must. specializing in extended-stay business travelers. About 20 minutes later (after missing our off-ramp and having to double back). and consumed in the classroom. A friendly (but well-armed) security guard directed us to the classroom facility. the three of us headed for the hotel. including riverboat gambling in nearby Biloxi. But you can pretty much find any sort of food that strikes your fancy — we had marvelous steaks one evening at Ruth's Chris. For a small city. the first order of business was to find a place for dinner. Jeb. The emphasis seems to be on fresh seafood and New Orleans-style cuisine. After transferring our bags from the 310 to the car. Jeb and I all found the accommodations there to be more than adequate. Mobile has a remarkable variety of places to eat. we met up at the rental car to head for our first day of training. parked in the small visitors parking area just outside the main entrance to the plant. located in an undistinguished industrial-looking building adjacent to the factory. for example. Miss. however. since it's roughly a 15-minute freeway drive from the hotel to the TCM factory (which is located on-airport at BFM). and signed in at the guard building. we arrived at the TCM factory.. The locals assured us that there was plenty to be had. students attending the ATAP are responsible for transportation and lodging costs.Chris and I flew from California to Alabama in my Cessna 310. TownePlace is an attractive hotel located about halfway between MOB and BFM airports. we'd allowed some . and we chose the Original Oyster House on Mobile Bay for our arrival night dinner. The course was sufficiently intensive that none of us mustered the energy to check out the nightlife during our weeklong stay in Mobile. and the price unbeatable. catered lunches are provided by TCM each day of class. We decided to take their word for it. and our late-night prowls were pretty much limited to the Krispy Kreme doughnut shop near our hotel. arriving at Mobile Downtown Airport [BFM] on Sunday afternoon. After checking into the hotel.m. Let's Get Started Bright and early at 7:30 a. who'd flown commercially to Mobile International [MOB] because his Debonair was in the avionics shop. and some interesting Nouvelle Mexican cuisine another. TCM has made hotel arrangements with the TownePlace Suites at an astonishingly low room rate: $40 per night. In addition to the $750 course tuition. was there to meet us in a rental car. Chris. Suffice it to say that none of us lost weight during our week in Mobile. The former Brookley AFB is now Mobile's GA reliever and home to the TCM factory (see diagram). In the interests of time. Fortunately. and our class was full (as is usually the case).extra time for getting lost. including a production test cell technician and a specialist from the marketing department. former ATATP lead instructor. head of tech support for TCM's ignition systems division (formerly Bendix/Scintilla). and all were extremely well-prepared. Class size is limited to approximately 15 students. Also participating as students were a couple of TCM employees. . long-timer in manufacturing at TCM.m. I was impressed that each instructor made a point of giving us their email addresses and telephone extensions. Most of the attendees were full-time professional AMTs attending the course at their employer's expense. Don taught the fuel injection system segment of the course. now works for TCM marketing and in charge of the TCM Link program. it was a rather diverse and interesting group. nine years with TCM. Five TCM instructors participated in our seminar: Billy Beam. Some had traveled a long way to attend. Bob Robbins. Billy Beam anticipated our concern. The first session started off with some introductions of both instructors and students. All were very knowledgeable and personable instructors. inviting us to contact them directly should we have any questions after the course was over. Don Fitzgerald. Training Materials: Worth The Price of Admission The next order of business was a quick overview of the course organization and a walk-through of the training materials furnished by TCM to each ATATP student. Tim Davis. and quickly assured us that TCM would arrange to pack and ship the materials to us at the end of the class. The training materials are extensive — most of our group agreed they alone were worth the $750 tuition — and their sheer weight and volume caused many of us to express concern about how we would manage to get them home after the course was over. so we didn't embarrass ourselves by arriving late. who taught the ignition systems segment. lead ATATP instructor. and runs until 4:30 p. Pat Pierce. founder of ATATP and longtime TCM engineer. prior to which he owned an overhaul shop for five years.m. with the hands-down prizewinner being a delightful fellow from a GA maintenance facility in Finland. Together with we three amateur wrench swingers. who conducted the factory tour segment. Class begins each day at 8:00 a. was founded in 1905 in Muskegon. illustrated parts lists. . containing detailed study text for each technical topic covered by the course. Continental introduced its first "flat" aircraft engine. and — perhaps the most heavily used of all during the course — an official TCM-logo coffee mug. fuel injection system adjustment and cylinder installation. we also received a compact binder containing a series of handy "ready reference guides" covering TCM engine specifications. Their initial product was a four-cylinder. service bulletins and application data for all TCM/Bendix magnetos. In 1929. Continental Motors introduced its first clean-sheet-design aircraft engine. This was the "bible" for the fourth day of the course. Ross Judson (who provided the engineering knowhow) and Arthur Tobin (who provided the seed money). instructors would often pose questions from the workbook to check our comprehension and see if any subjects needed repeating. instructor Billy Beam provided a brief but fascinating history of the company. which was devoted to the care and feeding of Bendix mags and related ignition components. Before getting into the meat and potatoes of the current TCM engine product line. and although it was pretty primitive by today's standards. four-cycle automotive engine featuring an in-line. a seven-cylinder radial dubbed the Model A70. when many small companies were going out of business. We found ourselves referring to this binder frequently throughout the course. The third binder contains the TCM Ignition Systems Master Service Manual. an assortment of TCM decals. torque specifications. a detailed discussion of what should be covered during 100-hour/annual inspections. ignition switches and starting vibrators. and that was not an original design but rather a converted Wright nine-cylinder radial. The second binder contains a complete compendium of all TCM aircraft engine service bulletins filed in reverse chronological order (newest first). and a workbook section containing a series of study questions. four-cylinder. together with a very useful set of cross-reference indexes that make it easy to locate the service bulletins that relate to any particular subject. by two brothers-in-law. Mich. L-head configuration patterned after the European auto engines of the time — hence the name "Continental Motors. Continental.. horizontally-opposed engine with bolt-on heads and a single ignition system. harnesses... In addition to these three big loose-leaf binders. (While there are no formal exams or quizzes during the course. Two videos are also furnished: one covering cylinder removal/replacement and the other fuel injection system adjustment. TCM Engines. more than 90 11x17-inch foldout diagrams (many in color). Then. we learned. The first of these is the ATATP Training Manual." It took 22 years before Continental produced its first aircraft engine in 1927. singlecamshaft.Most of the course materials were organized into three mammoth 8.) Also included in the Training Manual are model-by-model engine installation procedures. the Model A40. This was a 40horsepower. Also provided are a TCM Link CD-ROM. including overhaul manuals.5x11-inch loose-leaf binders. including a particularly fascinating one from Glacier Vendervell on bearing failure analysis. in 1931. One of these original A40s was on display in the classroom. Two years later. and an assortment of reprinted technical briefs from various engine component vendors. stroked (creating the IO550). . In 1939. and GTSIO series. 470/520/550 "permold" series. The "sandcast" and "permold" families of big-bore engines employ surprisingly different lubrication systems — the sandcast engines (front-mounted oil cooler) use an asymmetrical oil system in which oil flows forward through ." In 1970. and geared (creating the GTSIO-520). For instance. but by 1980 the Michigan facility was history.And Now The balance of Monday and the first part of Tuesday were devoted to an in-depth discussion of TCM's current engine product line. the six-cylinder E-185 developed to power the original Beech Bonanza. Despite external appearances that are fairly similar. it introduced its first "big bore" engine. the opposite of Lycoming). Continental adapted its air-cooled aircraft engines to power British and American tanks. when TCM was looking for space to expand. Then. 360 series. in 1945. while the other models all have integral wet-sump oil pans. the 240 series has kidney-shaped wet sump mounted directly underneath the engine crankcase. The 240 and 360 series use a separate bolt-on accessory case and a front-mounted fuel pump. The move from Muskegon to Mobile was made in incremental steps (the union local in Muskegon wasn't exactly thrilled). the company was acquired by Henry Singleton's Teledyne Corporation. black means new.. We first reviewed some basics that apply to all TCM engines: model nomenclature (GTSIO520 means geared turbo-supercharged fuel-injected opposed 520 cu.the resemblance to the later A-50 and A-65 and C-90 engines (used in Piper Cubs and Taylorcrafts) and the O-200 and O-300 (which power Cessna 150s and older 172s) is obvious. while in the big-bore engines (470/520/550) the accessory section is an integral part of the crankcase casting and the fuel pump is mounted to the rear of the engine. turbocharged (creating the TSIO-470. silver means a "Platinum-series" or "Raytheon Special Edition" engine). data plates (blue means rebuilt. we started dissecting each of the five engine series in TCM's current product line: 240 series.).. and -550). The IO-470 was later bored (creating the IO-520). the City of Mobile made the company an offer it couldn't refuse: all the space TCM could possibly ever need at the recently-closed Brookley AFB (now Mobile Downtown Airport) on a 99-year lease at the rate of $1 per year. and numbering of cylinders and crankshaft cheeks and journals (all numbered from back to front. the first American "conglomerate. -520. each of these five engine series has quite profound differences. The "new" TCM plant isn't much to look at — mostly huge old WWII-vintage hangars that look like Quonset huts on anabolic steroids — but there's lots of space and it's hard to beat the rent. Along the way. Then. with the addition of fuel injection. 470/520/550 "sandcast" series. the IO-470 used in the Cessna 310 and Beech Bonanza. in. The E-series engines evolved into the O-470 used in the Cessna 182 and. to the Precision/Bendix fuel injection system used on injected Lycomings). etc. or look at an oil cooler and tell whether it was a standard or non-congealing design. The latter design provides several advantages. Jeb's Debonair and Chris's Bonanza) use an updraft induction system. was our guide for this segment. While TCM's older designs (including the engines used on my Cessna 310. There was lots of kibitzing and swapping of favorite hints and kinks among the students and instructors that I found very useful. volumetric efficiency. There were also a few comments about how much easier it is to change a jug on a stand-mounted engine in the classroom than in an actual airplane. The fuel pump output ("unmetered fuel") then goes to a fuel control unit ("FCU") consisting of two metering valves. Before we knew it. the GTSIOs. and the like. say. we found that we'd learned the various TCM engine models so thoroughly that we could pretty much draw the lubrication schematics and drive train configurations from memory. Fuel Injection System Wednesday was devoted entirely to the TCM continuous-flow fuel-injection system. and scavenging. pushrod tube spring compressors.) and set about doing some actual cylinder R&R under the watchful eyes of instructors Billy Beam and Bob Robbins. the TCM fuel injection system is very simple (compared. The TCM system begins with an engine-driven fuel pump whose output pressure is basically a function of engine RPM. As before. which I found to be one of the most interesting and useful parts of the course. After reviewing the TCM video on how to remove and reinstall a cylinder. we practiced measuring cylinder fits and limits. We also reviewed the two basic induction system configurations used on TCM engines. we got to our first hands-on session. This was starting to get scary! After lunch on Tuesday. 4:30 had arrived and it was time to quit for the day. where small details like baffles and cowlings get in the way. while the permold engines (front-mounted alternator) use a hollowed-out camshaft as the main oil gallery. 360s and some 550s use a top-mounted induction system with cross-flow cylinder heads. TCM's Don Fitgerald. And so forth. By lunchtime on Tuesday.the main gallery in the right case half and then rearward through the main gallery in the left case half. We could look at an oil pump and tell whether it was from a sandcast or permold engine. 240s. Conceptually. one controlled by the cockpit-mounted mixture control . ring compressors. we broke up into teams. measuring ring gaps. rounded up the necessary tools (cylinder base wrenches. In addition to yanking and hanging jugs. a very gifted instructor. the segment began with a theoretical overview of the system that applies to all fuel-injected engines. including improved mixture distribution. In addition to its basic role as a four. Conceptually simple. one for naturally-aspirated engines and the other for turbocharged ones. There's a lot more engineering wizardry in the various fuel injection system components than meets the eye. with the high-pressure output controlled by an aneroid referenced to upper-deck pressure.and 360-series engines use special versions of these fuel pumps in which the mixture-metering valve is part of the pump assembly rather than the FCU. plus a third for an altitude-compensating schedule controlled by an aneroid referenced to ambient pressure. It takes a bunch of moving parts — a spring-loaded poppet valve and a spring-loaded diaphragm — to accomplish this function. ah. and the proper size to use depends on the particular engine model and which flavor of manifold valve is installed. it was time to move on to the practical matter of how to adjust the system. the devil is in the details.and the other controlled by the throttle (along with the induction system throttle butterfly). but as usual. throttle position. Once we felt we understood how the fuel injection system works. In addition to the training manual diagrams. including cutaways of the fuel system components. As if this were not enough. and mixture setting — then goes to a manifold valve that divides it into four or six equal parts and sends it to continuous-flow injector nozzles located in the intake port of each cylinder. The fuel nozzles come in two basic varieties. The basic difference is that the former has air bleeds vented to ambient air. The nozzles incorporate tiny air orifices that mix air with the fuel at reduced throttle settings. the 240. The latest vintage IO-550s use yet a third pump with three adjustments — the usual two for high and low RPM. but there's nothing like fondling the parts in your hands to ensure you understand how they are constructed and how they work. The nozzles are available in a wide range of orifice sizes.. while the latter has air bleeds plumbed to upper-deck pressure. the back of the ATATP classroom is taken up with tables covered with various TCM engine parts. the manifold valve is responsible for providing a clean fuel cutoff when the mixture control is retarded to the idle cutoff position. yes . A different pump is used for turbocharged engines. Diagrams are great. improving atomization. There's your basic pump for naturally-aspirated engines — it has two adjustments: one to set the maximum fuel pressure at takeoff RPM and another to set the minimum fuel pressure at idle RPM.or six-way flow divider. The manifold valve is also a lot trickier than it looks. Proper fuel system adjustment is a major bugaboo of TCM engines — it's . Turns out that there are at least five different varieties of fuel pumps used in TCM fuel-injected engines.. The output of the FCU ("metered fuel") — which is therefore a function of engine RPM. he's lived and breathed magnetos since puberty. It's imperative that the adjustment be performed on the airplane. This is a special room built specifically for testing and calibrating fuel injection components. starting vibrators. manager of technical support for TCM's Bendix division. rough idle.astonishing how many engines in the field were not properly adjusted when they were installed. and have never had the adjustment checked since. the class adjourned to TCM's fuel system test cell for some hands-on practice. and misadjustment can cause hard starting. Jeb. we didn't get any photos of the test cell — for some reason. the room contains all sorts of OSHA-required protective devices to eliminate the risk of electrical sparks that might ignite fuel vapors. Chris and I couldn't wait to slap some gauges on our airplanes and tweak the fuel injection systems into perfection. There are four different adjustments to make — two fuel pressure adjustments on the fuel pump (high and low RPM). TCM frowned on our request to use flash photography. ignition switches. the cell uses pressure transducers connected to a PC that displays digital pressures and RPMs and logs and graphs the data. getting a good feel for the adjustment sensitivities (PSI change per turn of the adjustment screw) and how the adjustments interact with one another. Each of us took turns adjusting the high and low fuel pump adjustments. Basically. plus two adjustments on the FCU (idle mixture and idle RPM).) After reviewing the adjustment procedure in detail on paper. Tim teaches with a laconic delivery that sounds precisely like Jimmy Stewart (it helps to close your eyes. By the time the day was done. This course segment was taught by Tim Davis. (For IO-550-powered aircraft with the altitude-compensating fuel pump. and there's nothing about TCM/Bendix mags that he doesn't know. alternators and starters. The adjustment procedure requires that accurate pressure gauges be teed into the fuel system in two places — at the fuel pump output (unmetered pressure) and at the manifold valve input (metered pressure). which manufactures magnetos. The fuel pump is driven by a variable-speed electric motor that can simulate any desired engine RPM. These adjustments interact with one another. since he looks nothing at all like Jimmy Stewart). Since actual avgas is used for these procedures. premature exhaust valve failure. and then to re-check them iteratively until all are within required specifications. a fifth adjustment is required. ignition harnesses.) The test cell contained an actual TCM fuel system. and an extinguishing system that can fill the room instantly with carbon dioxide should someone be foolish enough to ignore the no smoking signs and flick his or her Bic. etc. Ignition Systems Thursday was ignition system day. so it's vital to make them in the proper order. Tim also has an extraordinarily dry and subtle wit that . and must be made by reference to test flight results at altitude. (Regrettably. Tim previously worked for Bendix/Scintilla prior to its acquisition by TCM about 1980. Instead of typical pressure gauges. TCM Service Information Directive SID97-3 is the definitive reference for making these adjustments. a mag needs to be turning at least 150 RPM to generate the 10. The permanent-magnet alternator induces a modest alternating voltage (on the order of plus/minus 20 volts) in its primary coil. Each of these mag families uses significantly different construction. a step-up coil. He covered the electrical properties of matter (such as insulators vs. We started off with an hour-long short course in the basic physics needed to achieve a first-principles understanding of how a mag works.000 volts) in the secondary step-up winding (typically a 75-to-1 turns ratio to the primary). For one thing. they present some unique problems during engine start.consistently had us in stitches throughout the day. The other is electrical: a retard breaker and starting vibrator usually referred to by the Bendix trademark "Shower of Sparks. There are three basic families of TCM/Bendix mags: the compact S-20/200 series. and magnetic properties such as flux density and retentivity). making what sounded like it might be a dry subject anything but. conductors). starting requires that the spark occur at approximately TDC. Tim also taught us how to disassemble. Next. The interrupter (cam. Tim used these principles to explain the operation of an aircraft magneto. and the unique D2000/3000 dual mag (providing two independent magnetos in a single package with a single drive shaft).) . points and capacitor) interrupts the current flow in the primary coil and causes its electromagnetic field to collapse suddenly." Each scheme has its advantages and disadvantages. and the basics of electromagnetic induction.000 volts that is the minimum needed to produce a decent spark — unfortunately. The collapse generates a high-voltage pulse (up to 35. Also. inspect and reassemble an impulse coupling. The jump-gap distributor sends this high-voltage pulse to the appropriate spark plug lead. Tim passed around an assortment of TCM/Bendix magnetos and watched over us as we disassembled and reassembled them. and a jump-gap distributor. the starter motor turns the engine at only a small fraction of this speed. but elicited lots of colorful verbiage when we tried it. The mag consists of four basic components: a permanent-magnet alternator. rather than the usual 20° to 24° before TDC to which mags are normally timed. and by the time we were done. the big S-1200 series (a favorite for turbocharged aircraft because of its outstanding high-altitude performance). Since this was stuff that most of us hadn't thought about since our high school days (and promptly forgot after finals). Two alternative approaches are used to solve these problems. and we discussed them. we found it to be an excellent and interesting refresher. The session next transitioned from theory to practice. One approach is mechanical: the impulse coupling. each of us had the chance to take each of these mags apart and put it back together again at least once. While magnetos provide a highly reliable ignition source independent of the aircraft electrical system. the inverse square law. an interrupter. lines of flux. the fundamentals of magnetism (magnetic poles. (Reinstalling the impulse coupling spring was easy for him. until the particular journal is within the required dimensional specifications. When all the journals have finally been coarse-ground to the proper dimensions. TCM purchases various other engine components. but those tours had been limited to an hour or so and only hit a few highlights.. each operation performed by a skilled operator at a grinding machine. We practiced the internal timing procedure under Tim's watchful eyes. and some gears. Before we knew it. using a "buzz box" and timing gauge. Factory Tour The fifth and final day of the course was largely devoted to a factory tour. (In contrast. I'd toured the TCM factory several times before. or contamination inside the distributor cap. the crankshaft repeats the whole sequence on a succession of fine grinding operations to obtain the final dimensional tolerances. Never file tungsten points when they get pitted . This tour was completely different. Pitted points often indicate that the capacitor is bad and needs replacement. camshaft and connecting rod forgings and rough crankcase. building these engines remains an amazingly labor-intensive process. and resetting the internal timing ("e-gap") and point gap. Tim provided a constant stream of hints and kinks. cylinder barrel and cylinder head castings arrive from TCM's forging and casting suppliers. High-altitude misfire can be caused by excessive e-gap.. in fully finished form. always replace them. measures. The crankshaft is also gun bored on a horizontal boring machine to provide the required hollow center. I took lots of notes.. grinding and polishing steps in the TCM factory to produce finished parts ready for final inspection and assembly. 4:30 had arrived and it was quitting time. Then the crank is . such as pistons. We also practiced timing the mags to the engine. grinds and re-measures. Conn.All TCM/Bendix magnetos require 500-hour major maintenance that includes lubricating the internal gears and bushings. Despite TCM's huge investment in modern computer-controlled (CNC) machine tools. The tour began at the beginning — in the receiving area. The operator grinds.) We must have spent at least an hour following the various steps required to produce a crankshaft. for example. hydraulic tappets. excessive spark plug gap. The rough crankshaft forging must go through stage after stage of coarse grinding to create each main journal and rod journal. and the counterweight hanger blades are machined and drilled. Each of these major engine components goes through literally dozens of separate machining. pushrods.) before inserting them into spark plugs make them much easier to extract next time the spark plugs are removed. where crates of raw crankshaft. And we learned how to use a harness tester to identify a faulty ignition lead. We literally got to see every step involved in the creation of a new TCM engine — and the number of discrete steps required to make a crankshaft or connecting rod or cylinder assembly is truly mind-boggling. Throughout all this. Danbury. Spraying ignition harness "cigarettes" with an aerosol release agent called MS-122/22 (Miller-Stephenson Chemical Co. manually balanced on a computerized balancing machine, with metal ground off the crank cheeks as necessary to achieve the required balance. Once the machining is completed, the crank goes to the nitriding ovens where it's baked in hot ammonia gas for some 40 hours to harden its surface. After nitriding, the crankshaft goes through several stages of cleanup and polishing. The counterweight hanger bushings are inserted, and the crankshaft goes to final inspection (where a surprisingly low number wind up being rejected and scrapped). And that's just for one engine part ... the crankshaft! Camshaft production is a similar, but somewhat less tedious and more automated process. At the time of our tour, roughly half of TCM's camshaft production was being done on a brand new state-of-the-art CNC machine that TCM acquired just this year, while the other half was still being done on a pair of vintage mechanical cam grinding machines. Once cam production is completely converted over to CNC, we were told, TCM will be making some engineering improvements to their cam lobe contours that could not be accomplished using the old equipment. After grinding and polishing, the camshafts are case-hardened (carburized) in an oven, then cleaned, polished, and coated with manganese phosphate for corrosion protection. Production of connecting rods — among the most highly stressed components of the engine — was particularly interesting. Each con rod starts out as a single rough forging. The crankshaft end of the rod is sawed in two to separate the rod cap. Then semicircular sections are "hogged out" of both the rod cap and the big end of the rod on a giant vertical mill to rough out the big-end bore. The rod and cap are then reassembled, the rod bolt holes drilled, the rod and cap mated up, and then the bores are precision milled, chamfered and polished. Again, it was surprising to learn how many individual machining steps are required to produce a finished connecting rod. The story was much the same for cylinders and crankcases, except that TCM has pretty much fully converted to modern CNC equipment for machining case halves, cylinder barrels and cylinder heads. One of the most mesmerizing sights, however, was to watch the heads and barrels being mated together in decidedly low-tech fashion. A factory worker wearing protective gloves removes a hot cylinder head assembly from the oven and quickly places it in a fixture. The worker then inserts chilled intake and exhaust valve seats into the head before it begins to cool. (As the head cools, it creates a permanent interference fit with the barrel and valve seats.) Then, he positions the cold barrel against the hot head and spins it to mate the threads. We just couldn't get enough of watching this particular factory worker's rhythm as he processed about one new cylinder assembly per minute. (Later, we were sad to learn that TCM was about to reassign the job of inserting the valve seats to a new CNC machine. The result will undoubtedly be more consistent positioning of the seats, but it'll sure take away the romance.) After many fascinating hours spent watching how these various engine components are produced, we proceeded to final assembly where the engines are actually built up. A job in final assembly is perhaps the most prized position to which a TCM factory worker can aspire, in large measure because the final assembly area (which occupies only about 2,000 square feet of TCM's enormous plant) is one of the very few places in the factory that has air conditioning. Half of the final assembly area is devoted to a classic production line, in which engines move from station to station and as buildup progresses. There is only a single assembly line that accommodates all engine models, new and rebuilt alike. (I found this to be a marked contrast to Lycoming, where new and rebuilt engines are built on two separate lines.) The other half of the final assembly room consists of small assembly bays accommodating one engine each. If assembly of a particular engine is delayed due to parts availability, for example, it will be pulled off the assembly line and moved to one of the bays so as not to hold up the rest of the engines on the line. The same is true of any engine that requires special attention for whatever reason — such as the special one-of-a-kind ultra-highhorsepower TSIO-550 engine that TCM built up for use at the Reno National Air races. Our tour ended at TCM's production engine test facility, where is run through a programmed series of test procedures. The bays, and the test sequences are controlled and monitored by technicians who use mouse clicks rather than knob twists to Each cell is monitored both by computer instrumentation and computer readouts are also piped to a central control room can keep track of the goings on in all six cells concurrently. This was a genuinely fascinating day for all of us, and we came just how much effort goes into the production of a piston aircraft engine ... and why they cost as much as they do. every engine that comes off the TCM line facility contains six computerized engine computers and supervised by test regulate what's going on in the test cells. by closed-circuit TV. The TV pictures and where the production test supervisor away with a far better appreciation of Time To Go Late Friday afternoon, as we said our goodbyes to our instructors and fellow classmates and packed up our precious course materials to be shipped home, Jeb, Chris and I compared notes. We all agreed that the course had been extraordinarily worthwhile, and that we'd learned far more than we'd expected. Beyond the formal curriculum, we remarked on how valuable it was to have the chance to get to know so many subject matter experts at the factory on a first-name basis. The week had been educational, stimulating, fascinating and fun, and we were all sorry to see it come to an end. Without question, we all felt it was time and money well spent. If you'd like to become a real expert about your TCM powerplant and can find the time to spend a week in Mobile, I can't recommend this course highly enough. If you can drag your favorite mechanic along, so much the better. I promise you won't be sorry. The ATATP classes are typically booked up months in advance, and pre-registration is a must. Contact Billy Beam at 1-334-436-8660 or by email at
[email protected]. Getting Good Paint Email this article | Print this article Two top rated shops tell us what separates the average paint job from the exception. As Paul Bertorelli reported in Aviation Consumer, here's what you should expect. December 24, 2001 by Paul Bertorelli This article originally appeared in the January 2002 edition of AVIATION CONSUMER, and is reprinted here by permission. About the Author ... Paul Bertorelli is a professional aviation journalist and editor. He's Editorin-Chief of The Aviation Consumer and editorial director of AVweb and Belvoir Publications' Aviation Division. He's a 4,500-hour ATP and CFIA/CFII/CFIME. He owns a Mooney 231. The Aviation Consumer a handful of shops consistently draw rave reviews with not so much as the slightest complaint about quality. a mess up close.) Over the years. a well-detailed master work from what one shop owner we visited recently calls a “50-footer. Aviation Consumer readers have heaped praise on Dial Eastern almost to an embarrassing degree. the customer might not appreciate the work because many owners have never seen a good paint job. we recently decided to visit two of those shops—Dial Eastern States Aircraft Painting in Cadiz.Painting anything well— especially an airplane—is as much art as science. the things most owners consider important. Ohio and Reese Aircraft at Trenton-Robbinsville. in the end. (Even that’s a tight fit. he was operating his own aircraft repair facility called Dial Aircraft and merely combined the two into Dial Eastern States. It takes experience and skill to get it right and. just southwest of the New York City area. not exactly something you’d draw out of a hat. Given the length of the runway and the size of the two-bay hangar—it’s small—Dial Eastern handles only singles and twins up to about the size of a Cessna 421.” glossy at a distance. Words like “superb” and “true . When Guenther bought it about 12 years ago. Dial Eastern First. New Jersey. West Virginia. Over the years we’ve been doing our periodic aircraft paint-shop surveys. Yet it doesn’t take a trained eye to separate good paint from bad. that odd name. The shop is located at Harrison County Airport. Dial Eastern’s Dick Guenther told us that the shop was first established in the late 1980s by another owner under the name Eastern States Aircraft. just across the Ohio line from Wheeling. Armed with the question: what goes into a good paint job?. warranty or customer service. scheduling. “the owner is in New York or D. Chris Hollis. to walk us through the typical Dial Eastern paint job. We asked Dick Guenther and his shop liaison. putting them on higher side of average. something that’s often not done. inspected and. Guenther and better shops insist—rightly—that controls be removed. just for reference.” Photos of hidden damage or proposed items to be fixed are e-mailed and the shop consults with the owner. digital photos.000 and $20. the shop pays attention to detail. Not every shop does this but a savvy owner might do it for himself. On some controls—Bonanza ruddervators and Mooney ailerons—this is a critical task and shouldn’t be skipped. What exactly is Dick Guenther doing out there to merit that sort of adulation? In short. But it should still be standard on all . or somewhere and he can’t come out here to look at what we find. Dial Eastern wants between $7000 and $11. according to our surveys. sometimes.000.C. lavishes time and effort on prep work. stripped. Next comes what Guenther and Hollis say is a must for any paint job.) We were a little surprised to learn the job starts with a detailed inspection and. rebalanced after painting. whether premium-priced or not: All control surfaces should be removed. sure proof that the controls hadn’t been removed during our last paint job. quite a bit higher than average. Indeed. (That's Dick on the left and Chris on the right in the above photo. We figured the pictures would come later. from start to finish.000. For singles. stays on schedule— something owners consider important—and charges a fair price.craftsmen” come frequently to mind. The shop paints twins for between $13. after our shop tour. And that’s not to say cheap. Hollis inspected the company Mooney and within seconds noted a telltale wedge of overspray behind an aileron.” says Guenther. most important. “Half the time. aircraft. Stripping: Chemicals vs. the actual laying on of the color-is the quickest part of the process. Guenther goes so far as to record the balance data in the aircraft logbook. arguably the most tedious and time-consuming . But their work will only be as good as what's under the paint and that's where prep work comes in. Blasting Painting an airplane-that is. specifically stripping. along with the signoff for the paint itself. a couple of good spray techs can base coat an airplane in under an hour. " . wing compartments. Ken Reese told us that in the early days. "There were stories about blasting holes through the skins and that just never happened. Various schemes-mostly chemical-have been tried but these days. they'll turn up inside the cabin. The Robinsville shop strips chemically. Before blasting was refined. it doesn't return to its original tautness. extremes in temperature and the abrasive effects of rain in flight. Reese Aircraft is unique in that it does both chemical and bead blasting. Reese has two shops. it's tough stuff and equally tough to remove from aluminum. The latter paints mostly turboprops and jets and strips via blasting. When it first emerged nearly two decades ago. Although the process "cuts" the paint off with tiny plastic beads that are softer than both the paint and the underlying metal. a few aircraft were seriously damaged by the process. one in Robbinsville and a second at Stewart Airport in Newburgh. New York.aspect of the job. Since aluminum has a high coefficient of expansion." Reese says. but it was never as bad some claimed. Considering that aircraft paint has to withstand exposure to sunlight. the process inevitably creates friction and heat. instruments and everywhere else they don't belong. no question. most shops rely on either chemical stripping or bead blasting. a mild abrasive method using plastic media blasted onto the surface with compressed air. mostly related to operator error and a tendency to use too much air pressure. "You heard the horror stories about blasting. there were problems with bead blasting. heating aircraft skin causes it to pucker and once distorted. we published a couple of horror stories about bead blasting gone bad. A second significant problem with bead blasting is that those little beads-like dust-go everywhere and if the aircraft isn't sufficiently protected. which goes quicker thanks to the paint two methods of being loosened first. methylene chloride mixed with a soap or wax carrier. he says. measured for wear. Reese once commissioned a lab test several in which increasingly large amounts of blasting beads were products injected into greased bearings. we can't" says Reese. it’s not corrosive. That’s certain not to be the case if the aircraft was stripped with acid stripper. chemical Not that blasting media is especially damaging if it does stripping. so benign. Although methylene chloride is considered hazmat and requires special disposal methods. then clears the paint away there are with bead blasting. no stripper can be entirely flushed— especially from laps—and if it’s not removed. airplane. get into moving parts. we think. That means the airplane's blasting.Stripping Blasting is a skill akin to painting itself and Reese says it's As noted in critical to keep the blast nozzle moving over the painted the surface being stripped. acid stripper will cause . you find a slippery. openings are sealed. causing the bearing to dry some not fail. should anyone contemplating industrial having an aircraft bead blasted by a knowledgeable shop. Reese says the plastic blasting media some caused no wear until so much of the stuff was injected benign and that it displaced the grease. neither. "Do we keep every little grain of media out of the chemical airplane? No. Guenther tells us he’s re-painted his own work on a number of aircraft in which stripper found its way either between lapped skins or inside a structure but wasn’t entirely flushed out." he adds. including blasting. "We do keep it out of and bead critical areas. the engine is wrapped and the glass And within and fiberglass are masked before blasting begins. In that case. At least some blasting media does find its way into the stripping. with a chemical stripper first. Reese says he doesn't stay up Dial nights worrying about blasting media contamination and Eastern given the utter lack of complaints we hear about the uses plain process. which some shops still use because it’s faster than any other method. waxy coating but no corrosion. which were then spun and are used. However. With proper precautions. Reese actually treats the surface sidebar. have any engine .” Sand-and-sprays might last but many don’t and later. “Stripping the paint down to bare metal is the only chance we’re going to get to see what’s under the old paint. if there’s enough of it on the surface. It had a sand-and-spray and where the paint had worked around the rivets. according to Hollis and Guenther. It’s a warranty issue. sometimes enough to cause expensive damage that won’t be obvious for years to come. this is a sore point with most paint shops. The other thing is that when you paint over someone else’s work. for any foreign material will complicate the laying on of color and may ultimately cause adhesion problems later on. don’t have it treated with anti-corrosion compound for at least six months before. including Dial Eastern. the airplane has to be exhaustively pressure flushed and cleaned of even the tiniest contaminants. he can tell war stories about blowing blasting media out of the airplane years after it was stripped and painted by another shop. “the controls need to be removed and balanced. the paint will form little non-adhering craters called fish-eyes.corrosion. Anti-corrosion compounds such as ACF-50 and Corrosion-X are generally seen as a good thing. that’s one thing. in short. so any weeping of stripper or anti-corrosion compound is removed. a mess. you’re counting on a mechanical bond not a chemical bond between the two paints. A year would be better. And while you’re at it. it’s often due to what’s done—or not done—at the next stage. we’ll want to do it before we put color on. “If you even think you’re going to get your airplane painted. unless you run a paint shop. too. Guenther says he has no beef with bead blasting and believes it will produce as good a job as chemical stripping in the hands of the right shop.” Spotless Guenther believes that when a paint job has problems. On the other hand. Hollis showed us a Bonanza that had been flown in for an estimate. like most shops. If anything needs to be fixed. the top coat was peeling away from the older paint. Following stripping. Which led us naturally to this question: How about forgetting stripping and just scuffing up the paint and spraying on a fresh coat? Will Dial Eastern do that as an alternative to an expensive strip and paint? “No.” says Guenther. Speaking of the latter. Careful attention is paid to skin laps. It was.” he says. The stuff weeps out of rivet holes and between laps and no matter how careful the shop is. late of PPG but recently bought by Sherwin Williams. primed and painted.” even new ones. When we bounced that observation by Ken Reese. they use Bondo. treating the surface with a mild solution of phosphoric acid to thoroughly clean the metal deep into its surface structure. non-corrosive abrasives to do the etching. At Dial Eastern. albeit a specialized polyester type mixed with an aluminum paste. (Some say especially new ones. Three hundred miles to the east at Reese Aircraft in Trenton-Robbinsville. Guenther uses stainless brushes and mild. dent and blemish filling and fine sanding. the aircraft is alodined. specifically Imron over Variprime primer and. the better the airplane will be protected. the next operation is etching. which is priming and painting. he agreed. When it’s applied correctly. I’ll . leading us to conclude that which one a shop uses revolves more around customer service and convenience than quality issues. As we reported on our paint shop survey article in the November issue of Aviation Consumer. a tough epoxy primer called Corlar. the shop can move on to the next step. Having heard from hundreds of readers and dozens of shops. shops tend to pick a paint system they’re comfortable with and stick with it. Following a short curing period.) Body work is similar to what goes on in the auto industry. Guenther uses DuPont products. followed by more flushing. you’ll never know it’s there. Contrary to popular belief. At Dial Eastern. We’re told that alodining is a routine process by most shops but we’ve also heard that some shops skip this step. we don’t see much difference between the quality of the major paint systems. but added this: “If a customer asks and the airplane is going to be outside. it’ll be confined mostly to the belly. a so-called chromate conversion process that serves as both a base corrosion protector and an adhesion improver for subsequent coats. A “leaker” can fill the skin laps with oil. in demanding applications where oil or corrosion compound seepage might cause adhesion problems. Each speaks highly of the other product line. Ken Reese uses JetGlo. airplanes get their share of “body work. True. Etching. Priming Following stripping and flushing. And yes. but the better the paint adheres everywhere. causing the same problems. After body work.oil leaks taken care of. We think it’s worth asking about and that it should be done. To Reese’s eye. the surface should be evenly glossy and wet looking. an indication that the shop thought no one would ever look underneath. says Guenther. It goes without saying that you shouldn’t see any runs. If there’s stripper burn around the window edges. And every contrasting surface should be free of overspray.recommend AcryGlo over JetGlo. the shop wasn’t very good at masking. they should be fair and smooth. with no quick turns. you’ll see it and it’s the kiss of death against a quality paint job. lift the control surfaces and look around the counterweights. sags. moldings and other contrasting surfaces. is more resistant to hydraulic fluid and jet fuel and the wide temperature swings jets see in normal operations. meaning the gear wells should be shipshape-and-bristol and there should be no sign of painted over grease blobs or corrosion. meaning that it retains the total wet look high gloss of a fresh paint job. Some paint jobs look good on top or at a distance—what Dick Guenther calls “a 50-footer”—but a quality job should look just as good on the belly. What are we looking for. “Get it into a hangar lit with sodium vapor or fluorescent and grab a towel and wipe it down.” Huh? That’s right. horns and control rod ends. The Extras Most reputable shops—and both Dial Eastern and Reese qualify—will firmly . Bright sunlight will hide every flaw and it’ll look great. Look for crispness around stripping. is an acrylic urethane with better UV protection than JetGlo. says Reese. also in the Sherwin Williams line. thus the fresh paint wasn’t worked into the wet stuff on the surface.) As Chris Hollis noted. (Nonetheless. If the control surfaces weren’t removed during painting. if you really want to see the details of another guy’s paint work. however. don’t do it outside. Eyeballs On Which leads us to ask Reese how he judges a good paint job. If the airplane has curved stripes. on the other hand. fish-eyes or orange peel in an otherwise pristine surface. with no dull spots. eyeball the entire surface of the aircraft as you wipe it down. we still do. “If you really want to examine a paint job. the shop may have been working with a single spray man who couldn’t keep up with the paint. Check details such as window glass. with no paint built up along the edges or roughness where the rules were masked.” says Reese.” AcryGlo. “holds out” better. exactly? Viewed obliquely. JetGlo. JetGlo. If you see the latter. corroded fasteners back on? Guenther also recommends replacing any worn control parts. it doesn’t make sense to go through all that again just to put in new nuts later. Here's what you're really getting for your flying dollar. but you may want them done so get a price. On a twin.kdaviation. If nothing else. for example. we can recommend either without reservation. At Dial Eastern.com. Generally they aren’t. Reese or any other shop. “You’ve got the controls off." As Coy Jacob explained recently in Aviation Consumer.com. anything beyond that is an extra and extras can add up. Contact Dial Eastern States at 740-942-2316 or www. that can cost a couple of thousand bucks. why put the old. 2002 by Coy Jacob This article originally appeared in the March 2002 edition of AVIATION . Reese Aircraft is at 609-586-9283 and www. Having visited both these shops.” he says. some external fasteners are included in the price of the job but many customers—especially those driving high-zoot singles and twins—opt to replace everything with new stainless steel. The Zero-Time Myth Email this article | Print this article Only the factories have the legal right to declare an engine "zero time. But whether you go with Dial Eastern. such as rod ends or the nylon locking nuts.insist on certain details and will recommend others as nice-to-haves. But if you’re spending 10 times that on paint. Also ask if door jambs. that doesn't mean all new parts. we also recommend a visit for a walkthrough of the shop’s process. you get a base color and two stripes.desapi. baggage doors and other quasi-interior elements are included in the paintwork. March 11. you’ll educate yourself in what goes into a good aircraft paint job. Both Reese and Guenther advise asking the shop about what exactly the price includes. A zero-time engine can contain used parts — perhaps many used parts of unknown service history. At Dial Eastern. CONSUMER and is reprinted here by permission. the FAA also allows the original equipment manufacturers (OEMs) to label their rebuilt engines "zero time. But if you think you're getting something you're not. of course. All the parts will be factory new. "zero time" versus "stated total time" may make little difference in the outcome. it might not have all new parts. What's in a name? Or a label? About the Author ." a minor sleight of the pen that has some field overhaul shops fuming. excluding test-stand time. a simple label — or. what you think. the zero-time is thought to be a better engine. a field overhaul could have more new parts than a zero-time factory engine. new recently manufactured engines are fairly and properly termed zero-time. Obviously. Hands down.. Please . notation — can carry an impressive formerly the Mooney Mart. in reality. He more properly. We don't blame them. in cache that. editor to Aviation Consumer. since it has all new parts. When it comes to aircraft Coy Jacob is a contributing engines. OEMs Only. However. a logbook operates the Mod Squad. In some cases. A case in point is the value a buyer or owner puts on a "zerotime" engine as opposed to a freshly overhauled powerplant from a field shop. the term is misleading at best. As far as engine longevity.. Except. frankly. may not mean Venice. Florida. " Lycoming. article. even if the scope of work done on the engine by a field shop is exactly the same as the factory's rebuild process. FAA-blessed right to term any engine zero time. while Continental sells new and remanufactured engines only. A terminology note here: FAA regs don't recognize the term "remanufactured" but use the term "rebuilt. The Canadian Aviation Regulations don't have an equivalent to our FAR 91. of course. the rules are a little different.421. So in Canada. which allows "zero time" to be recorded for a factory rebuilt engine. One industry activist. In Canada. For years." In this Click on photo for larger image. believes that zero-timing is paramount to false advertising and has officially . Even though the factory's actual remanufacturing/rebuilding process may be functionally identical to what most competent engine shops offer on new limits overhauled engines. the actual time or the term of prior duty time is considered "total time unknown. even the OEM's own overhaul shops can't call their overhauled engines "zero time. Bill Schmidt of Cincinnati-based Signature Engines. That's simply not the case. buyers seem enamored with the idea that a zerotime engine from the factory contains all new parts. offers factory overhauls and new engines. field shops have complained about this practice — an "exalted privilege granted from on-high" — as one engine shop owner puts it. Actually." Only a new engine is zero time. we have used the terms interchangeably.No one but the OEMs have the official. Having the production drawings is a nice technicality but unconvincing as basis for building a better engine. How It Works From the FAA's point of view. says that. critical when building new engine components from scratch. Engine modifier Terry Capehart of High Performance Engines Ltd. Except under the most unusual of circumstances. (The same is true of field overhauls.petitioned the FAA to change the rules. Arkansas and Zephyr Engine's Charlie Mellot in Zephyrhills. but some even consider it blatant false advertising. everything any competent shop needs to know about how to overhaul the engine is contained in the OEM Service and Overhaul Manuals.stopzerotime. for all to see. just as overhaul shops do. Jimmy Broad. In fact. Most reputable engine shops not only believe the term "zero time" means nothing. In other words. He even has his own Web site to carry the cause forward. . say there are instances in which internal components involved in sudden stoppages or accidents have found their way into zero-time engines. Just why did the FAA allow this practice to get started? Probably because. we're told by industry insiders that the drawings are rarely used anyway. The site includes Schmidt's petition to the FAA.com. The typical independent shop may actually have a better handle on the past history of the engines they offer than does the factory. since the principal specifications are in the overhaul manuals. by the way. the OEMs have access to the original production drawings. which receives cores by the pallet load. the factories do inspect the parts for wear and damage before reusing them. Drawings are.) At present. Florida-based JB Aircraft Engines Services. there's no legal obligation for anyone turning an engine in for a core charge to inform the factory of such abuse. Of course. while the OEMs may not admit to it. thus they can theoretically attest that each engine component conforms to new specs during the rebuilding process. of Sebring. how important are these production drawings? Not very. in our estimation. your "zero-time" crankshaft can legally be undersize due to wear but still treated like new because the factory allows it. Florida. In practice. however. in Mena. www. it's entirely possible for a factory zero-time rebuilt engine to contain parts having more total time than the engine it's replacing. whether it's a new part or one with 2000 hours of flight time. the factories declared the standard and passed it down to the field shops doing overhauls. cases. the factories went after the overhaul business with two distinct advantages: the economy of scale conferred by volume and the cache of holding the engines' birthright. That said. In fact. as exchange cores are passed through the rebuilding process. When the factories began overhauling and remanufacturing. However. this makes sense. nor do they typically make any effort to do so. if you opt to have your engine overhauled by Lycoming and you specifically decline an exchange. the end result would bear little resemblance to any specific run-out engine from whence the parts came. Similar parts were then sorted as being within OEM new specs. plus any new parts installed during the overhaul. When the new engine business declined. Keeping a group of non-serial numbered parts together can be a logistical nightmare and. the engine could be composed of used core parts of widely varying times. with minimal FAA oversight. . is logical. This. Because any future re-assembly into engines could actually be somewhat of a mix of used and new parts. individual engine components are typically not kept together as a functioning parts group. It's not uncommon to see gaps of thousands of hours in an aircraft's history. the engine makers only built new engines. the OEMs claim they can't keep track of every used component's total time in service. disassembled and parts inspected. sans those components replaced by new parts. Our audits of engine and airframe logbooks turn up all kinds or errors. In other words. Volume. which was discarded. you'll get your own serviceable core parts back. exchange engines were returned to the factory. Major components such as crankshafts. given the sloppy state of paperwork that passes for logging these days. If you opt for an exchange overhaul from Lycoming. even if you could do it. serviceable. how would you log the time for each component and what meaning would that have? The part total time designation loses its value unless all the components are kept together as one functioning engine. too. gears and so on are typically re-used if they meet specs. They left overhauls to field shops. great and small. sorted and put into bins of identical parts to be reassembled later.until about the late 1980s when new airplane production was less anemic than it is now. Numbers From a volume/manufacturing standpoint. or outright junk. any part that failed before the replacement time could be construed as being officially okayed by the factory. rebuilt." But this might also increase the company's liability exposure. we're sure the lawyers have some stake in the "zero-time" argument as well. who oversees the Mattituck operation. Click on photo for larger image. In effect. in general aviation recips. Although it wasn't mentioned specifically in our conversations. thus there's no mechanism in place to keep track of the duty times of internal parts. Lycoming's VP and Chief Engineer Rick Moffit argues that. in 1999. Continental bought Mattituck Aviation Corp. TCM says the drawing requirements are increasingly controlled by a computer system . is no different than any other field shop. This means that while the "parts bin" argument may have had some merit in influencing the FAA some years ago. although manufacturers do publish recommended TBOs which are mandatory only for for-hire operations. a respected overhaul shop. Teledyne Continental's chief engineer John Barton and Jay Wickham. Lycoming says the company does enjoy advantages over overhaul shops. Were they to publish specific accepted minimum times for components. both of whom obviously have a different take on the zero-time issue. we contacted Continental and Lycoming. per se. the notion of time-limited parts doesn't exist. field shops might then be able to call their engines "zero time. in FAA parlance. What the Factories Say For the OEM view. especially as it relates to the factories' publishing minimum/maximum time specifications for certain parts. the need to track duty time of reinstalled components is neither necessary nor perhaps meaningful. And while it's true that the drawing themselves aren't always on the factory floor. Mattituck does sell overhauls and. It sells new and remanufactured engines or. As we've reported. support the view that having production drawings gives the factories a meaningful advantage. in that sense. For its part.Continental doesn't overhaul.. Lycoming doesn't serialize the majority of its parts. If field overhaul shops provide this service. sees both sides of the argument. CEO of Engine Components. Further. the zerotime privilege for the factories was set in stone four decades ago and it would take an act of Congress to change it. it relies on distributors and shops with potentially conflicting sales interests to sell its products. reworked crankshafts are examined and undergo the same 40-hour nitriding process that all factory new crankshafts get. is that parts used in zerotime engines are subjected to the rigorous requirements of factory new components. it's not likely to be the same process the factory uses. But. say Wickham and Barton. Continental says one of its rebuilt engines is likely to contain more new parts than a field overhaul. says Garvins. the CAPPS system contains the latest drawing revisions.") What Garvins and engine shops object to is that OEMs are essentially . the deception. Indeed. says TCM. Since the factory doesn't sell direct. The PMA Market Gary Garvins. The confusion — and to a degree. false advertising at worst. TCM's Wickham notes that many facilities that compete with Continental use intentional "factory disparagement" to create favorable buyer impression of their products. (One engine shop owner told us. says TCM. Many rejected parts may in fact meet service limits overhaul requirements but not new requirements. For example. "if the FAA could drop the zero-time issue without un uproar. This system makes dimensions and requirements readily available in the factory to a level of detail not included in overhaul manuals. which overhaul manuals may not. it would. a way of work that may be effective for shops but would prohibit Continental from factory authorizing such a shop. is there for the taking by all parties — over the "zero-time" issue.called CAPPS for computer aided process planning system. it's not unusual to find factory overhaul manuals not in evidence at an overhaul shop. legally or not.. He agrees with the Lycoming line of reasoning but he also agrees with shop owners who believe the zero-time claim is misleading at best. a major PMA house. thus a detailed understanding of what goes into a zero-time engine is not necessarily conveyed to the potential buyer. Inc. TCM says that during its rebuilding process. it routinely destroys all cylinders and many other components that might otherwise find their way into overhauled engines. Of more material import. He says there are many quality engine shops fully capable of assembling engines equal to or better than anything turned out by the factories. To some buyers. one engine" build-up method used by field shops has the advantage of allowing closer inspection and checking of each phase of the overhaul. worked for Continental for years." This would alert the buyer to the fact that the engine is not zero time since new but contains used parts. Tim Archer. After all. says Archer. He says the real issue shouldn't be the logbook verbiage but what it implies. by the way. The engine factories. it's important to know this. these are their drawings and I can't blame them for not wanting to release them. To be fair. Zephyr's Mellot argues simply for more truth in advertising: "My suggestion would be to allow the factory to use the term 'zero-time since remanufacture' due to the fact that they're the only ones with the proprietary manufacturing drawings. don't look for anything to change soon. In fact. do you want to know the history of all the parts used in building up your rebuilt/overhauled engine or not? The OEM's would have us believe that they're the only ones who can accurately determine if the used parts should be reused and that they have unique inspection ability. like the airframers. who is senior vice president for Superior Air Parts. Archer. In other words. But is that true in the real world? Archer says no. In researching this article. Our view is that many buyers don't make the distinction. the "one man. are struggling to retain profitability and we doubt the FAA is going to propose rulemaking to make the job any harder.allowed to "throw away the logbooks" on used but serviceable components and then to use the zero-time claim in advertising. we sensed that this issue is a hot potato that the OEMs and the FAA would very much like to ignore. says there are more issues at stake than just the zero-time claim. What It All Means Even though engine shops chaff at the advantage enjoyed by the OEMs and Bill Schmidt is trying to get his Zero-Time Coalition off the ground. the engine factories do retain the mother lode of detailed information on the engines they build and are often the only source of information critical to overhauling an engine correctly. so he has seen the argument from both sides of the fence. Both Lycoming and . another big PMA supplier. which gives them a distinct advantage in the minds of buyers. This isn't a bad thing. If all new parts are important. nor does it mean the engine is blemished. Both engines will have used or reconditioned parts. there's little difference between a zero-time overhaul from the factory and an overhaul from a reputable field shop. Perhaps many used parts of unknown service history. you won't. buy a new engine. To us. building or buying a hangar might be an option. the best field shops have been doing nothing but overhauls for decades and we know from experience that they know tricks the factories don't. because building an engine is not the same as overhauling one. The bottom line? When you see a logbook with a claim of a zero-time engine. don’t count on it. But a good investment? As AVweb's Paul Bertorelli wrote in Aviation Consumer. The cold reality is that. A Hangar of Your Own Email this article | Print this article If you can’t find a rental. know that. additional inspection processes. Given the product recalls from the factories — mostly recently on Lycoming crankshafts — we don't think either OEM is in a position to claim the high ground on superior quality control. It is true that a zero-time engine is different from an overhauled engine. unless it's a factory-new engine. in terms of durability. January 19. but only by a degree determined by how many new parts it might have and. On the other hand.Continental rightly point out that their factory drawings contain information not found in overhaul manuals. the more critical factor is how the builder supports its work with warranty performance. it contains used parts. as TCM says. safety and value. But if you buy an engine labeled "zero time" and expect to get all new parts. 2003 by Paul Bertorelli Editorial Director About the Author . either because none exist at their home airports or because they’ve grown weary of the ramp riffraff. Yes.500hour ATP and CFIA/CFII/CFIME. He's Editor in Chief of The Aviation Consumer and editorial director of AVweb and Belvoir Publications' Aviation division. No Way. say others. Welcome to the real world of aircraft ownership. Yet as the boomer generation ascends into financial security. if we’re lucky. say some hangar dwellers. a surprising number of owners are seizing the day.This article originally appeared in the March 2001 edition of Aviation Consumer. has a thin veneer of pavement over the mud. But what are the particulars here? Do the numbers work in favor of buying or building a hangar? No way. we recently interviewed more than a dozen owners and builders of hangars. No How Paul Bertorelli is a professional aviation journalist and editor. . where most of us tough it out in a tiedown that. buying or building their own hangars. He owns a Mooney 231. Maintenance Definition of a crying shame: returning home from the refurb shop with your $9000 paint and upholstery redo only to lash the thing down in a mudhole masquerading as a tiedown. absolutely. if you can both find and afford one. Herewith is their advice on investing in a barn for the baby. a hangar would be ever more preferable. He's a 4. To sort out the arguments pro and con. It’s simply more convenient. rare indeed is the airport that has any hangars available at all. but . in our view. The standard assumption that hangaring retains value is a straw man. Although a hangar will protect the paint and keep the upholstery spiffier. Every owner desperately wants a hangar and the reasons for that are obvious and compelling. the phrase “always hangared” ranks with “the check’s in the mail” and “I’m sure I put the gear down. in our view: group hangaring that requires line-crew towouts.” No. major and minor. causing all sorts of mayhem.Hank Galpin’s $400. let alone a ready surplus. Owners who have gone this route tell us it’s not a question of if you’ll suffer hangar rash. Waiting lists for hangar space are common across the country.000 big box includes a furnished apartment. Unfortunately. no hot sun blistering the paint nor rain sopping the innards. according to our survey. the real reason you hangar is pure convenience and nothing more. No ice and snow to remove. The most widely available type of hangaring is also the least desirable. On airport property. individual condo-style boxes that are rented or bought outright. broaddoored behemoth of a structure often capable of accommodating two or more aircraft. Plusses: lots of room and amenities. almost favorable. group hangars are often heated. if heated. Moreover. Subject to zoning laws and bank lending restrictions. the airport may provide some services.when. literally. Next on the pecking order are t-hangars. such as snow plowing. Owners quoted group hangar rates between $300 and $1200 a month. which is generally “fee simple” ownership. Buy one for $10. Minuses: tight fit in some increases hangar rash risk. with the lowest about $125 and the highest in the $600 range. in colder climes. Last. which is nice. We would characterize some as benign.000 up. and there’s not much room for the extraneous airplane junk for which most owners want a hangar in the first place. T-hangar plusses: They’re cheaper to buy and less involved than box hangars.usually the airport owner or town -. for the aircraft owners while others clearly favor the airport owner or developer of the hangar complex. But not with hangars. you don’t exactly own a hangar in the same way you own a house.000 to $40. They’re sometimes standalones or in condo arrangements. Leasehold arrangements vary all over the map. An example of the former is the arrangement Paul Thomas has on his home . The Land Deal Unless you live on an airport residence arrangement. no hangar rash worries.000. depending on size and location. these are generally in “leasehold” ownership. which means someone else -. which isn’t nice. For that fee. depending on location and aircraft size. you can do what you like with fee simple property. These hangars are more the province of owners than renters and cost from $20. putting them within reach of many owners.has fee simple title while you merely have a long-term right to use the land for an agreed-upon monthly or yearly fee. Average rental rates seem to hover around $200. a high-ceilinged. with some kind of lease arrangement with the airport for the land they occupy. but this comes at a high cost. good resale value. usually. pricey to maintain through a winter. water and sewer and electrical hook-up. the best of all worlds: the so-called box hangar. Or maybe not. Minuses: large box hangars can be expensive and. whether you build or buy. ” Nonetheless. Conn. Okay. but then. that’s not a bad one. “It would have been better if we owned the hangars free and clear at the end of the 30 years. As deals go. they’re satisfied if not happy with the deal. Less attractive are the long-term leasehold arrangements that revert the hangar ownership status back to the airport.” Obviously. Presumably. is that the longer he stays in the hangar. the problem with this deal. we must. How Much Money? Scott Witschger’s box hangar was erected near Albuquerque. he can sell the hangar for market value or move it somewhere else. Should the lease terminate. “We do not actually ‘own’ the hangars. This means that the hangar has good residual value for about 15 years or so. another owner or the hangar developer. We found a number of those.. N. in our view. sell the hangar back to the FBO for a dollar. including one that Saratoga owner Brian Peck bought into in Oxford. He owns his $35.M. my resale market is restricted to guys who only have a decade or so of flying ahead of them.” says Peck. near Minneapolis. After 30 years. “Here’s the part that’s hard to swallow. the less value it has.airport at Anoka Country Airport. the new owner gets the same long-term leasehold deal. says Peck. by contract. and . “No 35-year-old rich guy is going to be stupid enough to plunk down whatever I’m going to ask when I’m 70 years old only to have the hangar yanked out from under him when he’s 50 years old. but the state didn’t see it that way. Thomas built his own hangar but leases the land for a nominal $200 a year long-term fee.000 40X60-foot hangar. say Peck and others who have entered into such arrangements.” Peck told us. which he bought already erected. Ark. heated. Since total construction costs vary with size and style of hangar. -Rick Rodkin Rogers.to well over $100.25 per sq/ft. we think estimating average hangar costs at $22 per square foot is realistic. no insulation in leasehold ownership: $34. including considerable paving outside the hangar. insulated roof and wall for shop. bi-fold door. insulated with heat and bi-fold door in leasehold ownership: $23. insulated and heated: $148. • 50X60 box hangar.500 or $5. Here are some for-instances: •60X60 box hangar. although the costs will be much higher in some areas. Construction Notes Hangar construction options vary. insulated with roof skylights in fee simple ownership on an airpark: $69. Given the results of our survey. with two doors in leasehold ownership: $70.000 or $34. 920 square feet. insulated in 20year leasehold ownership: $400. leasehold ownership: $34. • 40X60 box hangar.800 or $13.000 for some of the finest ramp palaces imaginable.000 on the low end -. less the monthly leasehold arrangement. Fla. •50X50 box hangar with sliding door.80 per sq/ft.66 per sq/ft.. we think it’s useful to consider some average. steel with sheetrock finish inside. -Marshall Carter.000 for 2880 square feet.53 per sq/ft.600 or $9.44 per sq/ft. Minn. Ala. Plymouth.92 per sq/ft. • 48X90 steel hangar with doors at each end. not to mention region of the country. -Todd Underwood Muscle Shoals. Mont.000 or $19. -Joanne Arbaugh Pellston Regional Airport.50 per sq/ft.000 or $25 per sq/ft.000 or $42. -Paul Thomas Anoka County Airport.800 or $14. Mich.cost $60. in fee simple ownership on residential airpark: $28. per-square foot costs. Ark. but the most desirable new hangars are metal with concrete pads and aprons. -Jerry Jackson San Geronimo Airpark. Texas •50X50 box hangar. -Hank Galpin Glacier Park. • 60X60 steel box hangar. -Chris Kelly Pine Shadows Airpark.000 or $19. heat in floor. self-erected in fee simple ownership on private air park: $14. Some such hangars are merely metal . Mass.16 per sq/ft. -Mike Miles Little Rock. bi-fold door. • T-hangar. •75X125 box hangar with 60-foot bi-fold door. Buying or building a hangar can range from a moderate investment -$10. a sliding door is a good choice.” says one Vermont hangar owner. Speaking of snow shoveling. “Once you select the door and the building. a bi-fold is desirable because it pivots into the hangar initially. since generic steel building companies generally don’t make nested structures and thangars occupy the bottom price strata. Fla. Even in moderate climates with no snow. so you can open the door then ease a plow blade across the door threshold. Track doors with outriggers are even worse than nested sliders when a foot of snow hits the ground. Each has its pros and cons but aside from cost. bi-fold doors and swinging doors which pivot outward.say a Butler or a Mesco -. climate drives door design. it slides off and piles up in front of the door and now I’ve got four feet of snow to shovel. It seems a minor thing. several owners said that if they had it to do all over again. they would add an overhang to the front of the hangar to keep snow from butting against the door. the manufacturers of both have to talk to each other so the dimensions are right and the front wall is designed to accommodate the load. but owners say it makes a difference. Don’t Scrimp . FulFab or Port-a-Port are purpose-designed for airplanes. clearing the snow without heroic shoveling. Otherwise. such as Erect-A-Tube.” There are a handful of door designs but three are practical for small GA hangars: sliding doors with tracks. overhangs and/or gutters are advisable to keep moisture away from the base of the building. a building is a building and whether it houses airplanes or farm equipment is immaterial except in one regard: the door. you’ll need a load reaction data sheet from the door company.buildings -. Hangar owner/builders told us that door design dimensions are near the top of the list in hangar construction considerations. making winter pullouts a nightmare of shoveling and chipping. “I have a south-facing hangar. Where snow is a worry. The latter is important if an inexpensive t-hangar is your goal. Says Chris Kelly of Pine Shadows. In warm climates. since it’s the cheapest option if there’s no risk that snow and ice will clog the tracks.adapted for hangar use while others. so when the snow melts.. make sure the door company and building company are dancing cheek-to-cheek so that the building is engineered to support the door.80 per sq/ft. Others may provide only the crudest schematics. both the raw steel and labor to erect it.600 box hangar in Texas (bottom). progress can grind to a halt. Some steel building companies sell a complete package. Without this critical data. was closer to the norm. Or you can hire your own contractor to erect the structure. “One surprise for me was that I had to get a local architect to finish up the . say experienced hangar builders. find out how complete the building supplier’s drawings are. which local building departments will accept without question.. Mike Miles’ hangar (top) was the cheapest we found while Jerry Jackson’s $28. Are they good enough for the local building department to issue a permit? Some building companies will provide engineer’s stamps on the drawings. Moreover. usually a subcontract crew. In either case.At $5. a plus in hurricane country.” says Scott Witschger. which support the walls and roofs.plans. don’t go cheap on the steel sidewall sheeting. says Underwood. the hangar cost more than we figured. “because of footings. says Todd Underwood. Code dictates minimums but these can and sometimes should be exceeded. are often placed on 25-foot centers. Adding an additional main frame on 20-foot or less centers costs perhaps 10 percent more but pays off in a stiffer structure that’s more wind resistant. One owner told us the construction company that poured his slab failed to include a plastic vapor barrier: “Our floors are cracking and leaking and will have to be re-poured in the spring. a local architect or builder may have to be engaged to do drawings for concrete footings and pads. Scrimping on steel quality and construction may be shortsighted. Even if the drawings are complete. you’re going to have trouble fixing it. it represents a more significant portion of total hangar cost than some hangar builders expect. Adding these later if you need them may be costly or impossible. “Yes. get costs on the code-required basics first. too.” Some owners think it’s a good idea to be present when the concrete is poured.M. Speaking of concrete. For example. staining the sheeting with rust rivulets. who built a hangar near Albuquerque. which are quite large. I was off by a third on the concrete. fastened with long-life or stainless drill screws that won’t corrode. says Underwood.” says Scott Witschger.” Underwood told us. When specing the building.” Concrete specs are dictated by local code but most require 3000-pound mix poured at least four inches thick. with particular attention to the door hardware and function and anything that helps keep the hangar dry. “You can trade your car in for a new one every year but if you cut corners on a hangar. He recommends at least 26-gauge galvalum sheeting. then ask about additional structural and weather-resistance enhancements. with steel mesh reinforcing. Scrimping may cost money in the long run. <> From the things-I’d-do-differently file came these tidbits: • In a large hangar. the main frame uprights. install a door at both ends. who operates a steel building business and builds hangars throughout the southern tier states. which added cost. Underwood says sheeting pre-coated with polyester paint weathers well. N. The convenience of single- . Likewise. an always-open ridge vent will reduce condensation. install the plumbing anyway. •In a heated hangar. •Before signing a leasehold agreement. something which many hangar owners complain about.will eliminate condensation. In warm areas. •Even if you don’t plan a sink or bathroom at the outset. •Shiny gray epoxy floor finishes are nice but slick when wet. south/east facing will clear ice and snow from the door more readily. •Minimal roof insulation -. but the runoff will freeze at night. •For heated hangars. Avoid reversion deals that award hangar ownership to the airport. lower is wetter. then double it. wet area. ceiling fans will dramatically improve heating efficiency and comfort. install a closable continuous ridge vent.airplane pullouts without tedious repositioning of others is worth the cost. they’ll add natural light and save on lighting costs. roof and walls will have to be insulated. a south-facing hangar will be hotter to work in during the cool mornings. foundation drains may be the only way to keep the hangar dry. Installing them during construction will be cheaper than after the fact. Higher is dryer. Owners say there’s never enough lighting in hangars. Add grit to the paint or ask your concrete finishers about a smooth surface with some tooth.even in warm climates -. Some airports will be flexible. • Plan for as much lighting as you think you’ll need. Smart Money? . Aluminumfaced bats and panels are best. consider site orientation carefully. How are you going to change the lightbulbs? •Install as many skylights as you can afford. •If you have a choice. try some hardball negotiation for better terms. some won’t. •If the hangar is heated. In colder areas. You can always finish out the bathroom later. In warmer climates. •In a low. The same applies to electrical outlets. • Think about this: Hangars are high. can you get out of it whole? Not too surprisingly. . “An investment? Oh.” However. at the least. Mont.000. Fla. large hangars he’s built will be profitable because they’ll accommodate jet operators able to pay high rent in the hangarscarce Boston area. who built a 75X125 hangar at Glacier Park. Is a hangar a good investment or. “It’s kind of like owning a house. for $69.: “You’re not going to make a lot of money at the small end.Chris Kelly probably has good investment value in his steel box hangar built on Pine Shadows Airpark.. if any. a repository for your money without much growth. no” says Hank Galpin.” And from Marshall Carter. the bottom line. the owners we interviewed have no illusions about investment value of hangars. Mass. Finally. a banker and hangar developer in Plymouth. says Carter. A modest hangar on an airport with good demand for hangars will probably appreciate more than an expensive one, with limited market appeal. “If we sell, I think we’ll lose” said Joanne Arbaugh, who built a $148,000 hangar on a small regional airport. Nonetheless, there are success stories in hangar purchases and we wouldn’t call them rare, just not all that common. The best hangar investment scenarios seem to be in t-hangars bought five or 10 years ago and flipped for a 20 to 50 percent gain in value. These deals seem limited to airports with high demand but little supply. Otherwise, hangars may be more like equities than real estate. The longer you keep them, the higher the value but spikes and valleys in value may be determined by the national and local economy. Equivalent real estate purchase may be more stable. “Long term,” says Scott Witschger, “ I do think it’s a good investment. Absolutely. I do my own maintenance and in some rental hangars, you get a hassle for that.” Ultimately, our impression is that most owners who buy or build hangars consider it an emotional, “feel-good” purchase and don’t give a hang about the investment value. Besides, any savvy aircraft owner knows that if you’re interested in investment value, keep your money as far away from airplanes as possible. We like Brian Peck’s outlook best: “Obviously, if I had to depend on the resale value, I would not have bought the thing. But having my airplanes and tools and oil cans and rags in my very own hangar with a refrigerator full of Coke and beer makes me happy. There’s no reason not to buy a hangar, except money.” August 31, 2000 Email this article | Print this article The Aircraft Owner's Tool Kit It has been said that one of the most dangerous things in general aviation is an owner with a Phillips screwdriver. As a result of owner-performed preventive maintenance, technicians often find themselves working on something that an owner tried to fix, but only made worse. Clearly, some guidance for homebuilders and owners contemplating work on their aircraft is necessary. With that in mind — and with tongue firmly in cheek — AVweb presents this list of definitions for common tools that should be a part of every homebuilder's and owner's tool kit. August 31, 2000 by Peter Egan (?) Editor's Note: The following came to AVweb's attention without an author's attribution. Since publishing it, we've learned that Peter Egan of Road & Track magazine is possibly its author. AVweb regrets the oversight. Joseph E. (Jeb) Burnside Executive Editor HAMMER: Originally employed as a weapon of war, the hammer is used as a kind of divining rod to locate expensive parts not far from the object we are trying to hit. ELECTRIC DRILL: Normally used for spinning rivets in their holes until you die of old age, but it also works well for drilling mounting holes just above a fuel line. PLIERS: Used to round off bolt heads. HACKSAW: One of a family of cutting tools based on the chaos principle. It transforms human energy into a crooked, unpredictable motion, and the more you attempt to influence its course, the more dismal your future becomes. VISE-GRIPS: Used to round off bolt heads if nothing else is available, they can also be used to transfer intense welding heat to the palm of your hand. OXYACETYLENE TORCH: Used almost entirely for lighting various flammable objects in your hangar on fire. WHITWORTH (Metric) SOCKETS: Once used for working on older British engines and airplanes, they are now used mainly for impersonating that 9/16-inch or 1/2-inch socket for which you've been searching the last 15 minutes. DRILL PRESS: A tall upright machine useful for suddenly snatching flat metal bar stock out of your hands so that it smacks you in the chest and flings your drink across the room, splattering it against that freshly painted aircraft part you were drying. WIRE WHEEL: Cleans rust off old bolts and then throws the bolt somewhere under the workbench with the speed of light. Also removes fingerprint whorls and hard-earned guitar calluses in about the time it takes you to say, "Ouch!" HYDRAULIC FLOOR JACK: Used for lowering an airplane to the ground after you have installed your new tires, trapping the jack handle firmly under the landing gear leg. EIGHT-FOOT-LONG DOUGLAS FIR 2x4: Used for levering an airplane upward off a hydraulic jack. TWEEZERS: A tool for removing wood splinters. TELEPHONE: Tool for calling your neighbor to see if he has another hydraulic floor jack. TROUBLE LIGHT: The mechanic's own tanning booth. Sometimes called drop light, it is a good source of vitamin D, "the sunshine vitamin," which is not otherwise found under airplanes at night. Health benefits aside, its main purpose is to consume 40-watt light bulbs at about the same rate that 105-mm howitzer shells might be used during, say, the first few hours of the Battle of the Bulge. More often dark than light, its name is somewhat misleading. PHILLIPS SCREWDRIVER: Normally used to stab the lids of old-style paper-and-tin oil cans and splash oil on your shirt; can also be used, as the name implies, to round off Phillips screw heads. AIR COMPRESSOR: A machine that takes energy produced in a coal-burning power plant 200 miles away and transforms it into compressed air that travels by hose to a pneumatic impact wrench that grips rusty bolts last tightened 60 years ago, and rounds them off. . HOSE CUTTER: A tool used to cut hoses 1/2-inch too short.PRY BAR: A tool used to crumple the metal surrounding the clip or bracket you needed to remove in order to replace a 50-cent part.