CF34-Engine survey

CF34-8EFlight Operations Seminar February 2004 GE Aircraft Engines Flight Operations Support • Established within the GE Customer and Product Support Operation to: – Interface with customer and airplane manufacturer flight operations – Represent their viewpoint within GE – Provide flight operations feedback to GE • Staffed with pilots with airline, military, flight test, training, and engineering experience • Specific tasks: – – – – Conduct engine systems/operations briefings and seminars Perform operations surveys Research engine operations questions from customers and aircraft manufacturers Issue and maintain engine operations documents: • Specific operating instructions • Operations engineering bulletins – Maintain selected airplane flight/operations manuals – Provide pilot support to GE Flight Test Operation – Participate in accident/incident investigations involving GE powered airplanes -8EFLIGHTOPS.PPT Contact Information: NOTES Walt Moeller Technical Pilot GE Aircraft Engines 111 Merchant Street Cincinnati, OH 45246 Phone: (513) 552-6602 [email protected] 3 Outline • • • • • • • • Program Overview Technical Features Operational Characteristics Testing Normal Operating Considerations Reduced Thrust Erosive FOD and Volcanic Ash Inclement Weather Operation -8EFLIGHTOPS.PPT NOTES 5 . . PPT NOTES 7 .Program Overview -8E FLIGHTOPS. CF6. CF6) 8 .Commercial Engines Small Large CFM56-2 CFM56-3 CFM56-5A CT7 shaft CT7 prop CFM56-5B CFM56-5C CFM56-7B T58 T64 CF6-6 CF6-50 CF6-80A T700/CT7 CF34-1/-3/-8/-10 CF6-80C2 CF6-80E1 GE90 -8EFLIGHTOPS. NC: Small and Large Commercial Turbo Fans (CF34. GE90) • Evendale. OH: Large Commercial Turbo Fans (CFM56) • France (Snecma): Large Commercial Turbo Fans (CFM56. Mass: Small Commercial Turboprop and Turbo Shaft • Durham.PPT GE and CFM engines are built at the following locations: NOTES • Lynn. PPT NOTES 9 .CF34 Engine Family CF34-3 CF34-8 CF34-10 -8EFLIGHTOPS. PPT NOTES 10 .’86 1991 1995 1999 .000 Lbs • Improved SFC • Flat Rated to 86°F • Growth Capability to 22.2003 2004 EIS -8EFLIGHTOPS.500 lbs class • Thrust Capability to 20.CF34 Family Evolution Military Service Corporate Service Regional Jet and Corporate Service CF34-8C/D/E/C5 CF34-3B/-3B1 CF34-3A1 TF34 CF34-1A/3A • Long Life Materials • Reduced Noise • Serpentine Cooled First Stage Turbine • Improved Materials • Modularity USN USAF S-3A A-10 • Boroscope Ports • New Ignition System • New Low Emission Combustor • Hot Day Performance • Higher Flow Compressor • Improved Cruise SFC • Higher Climb/Cruise Thrust CF34-10 • 50% Thrust Increase 14.000 lbs + • FADEC equipped • Reduced Parts Count • Improved Flat Rating • Improved Maintainability • Containment • High/Hot Performance 1975 1982 . CF34-8E Technical Features -8E FLIGHTOPS.PPT NOTES 11 . ) 128 128 128 Weight (lbs) 2.PPT NOTES 12 .470 2.200 Length (in.170 13.470 2.0 52.2 46.) 52.800 APR thrust (lbs-SLS)* 13.) 46.2 46.CF34-8E Specifications Engine parameter -8E2 -8E5 -8E5A1 EMBRAER 170/175 EMBRAER 170/175 EMBRAER 170/175 ISA+15 ISA+15 ISA+15 Normal takeoff thrust (lbs-SLS)* 12.XXX 13.0 52. Bleed Off -8EFLIGHTOPS.200 14.470 Maximum diameter (in.000 14.2 Fan bypass ratio 5:1 5:1 5:1 Overall pressure ratio 28:1 28:1 28:1 Compressor stages 10 10 10 HPT stages 2 2 2 LPT stages 4 4 4 Aircraft Flat rating temp (oC) *Installed.0 Fan diameter (in. Power to drive accessories is extracted from HPC front shaft and mechanically transmitted through drive shaft to accessory gearbox 13 .Annular combustor with 18 fuel nozzles .Variable inlet guide vane assembly .CF34-8E Propulsion System Cross Section Spinner design (“coniptical”) optimized for inclement weather 2 Stage High Pressure Turbine 4 Stage Low Pressure Turbine 10 Stage Compressor Chevron Exhaust Nozzle Engine control Wide Chord Fan Blades • Full Authority Digital Engine Control (FADEC) Accessory Gearbox -8EFLIGHTOPS.5 variable stator vane assembly .2 stage HP turbine •The accessory drive system .Single stage fan coupled to 4 stage low pressure turbine NOTES •The high pressure system .PPT •The low pressure system .10 stage HP compressor rotor . PPT NOTES 14 .CF34-8E Propulsion System -8EFLIGHTOPS. PPT NOTES 15 .CF34-8E Nacelle and Thrust Reverser Thrust reverser Hurel Hispano Fan cowl Aermacchi Inlet cowl Aermacchi Aft core cowl Hurel Hispano EBU systems Aermacchi -8EFLIGHTOPS. CF34-8E Powerplant Airflow Primary Airflow Secondary Airflow Parasitic Airflow -8EFLIGHTOPS. Secondary is used as fan bypass and parasitic for customer and component requirements. Primary is used by the core engine.PPT The airflow paths are divided into primary. and parasitic. NOTES 16 . secondary. PPT Innovative design of nacelle shape and transcowl deployment: •Transcowl naturally blocks bypass duct when deployed •No need for blocker doors •Improved reverse thrust efficiency •Common left hand and right hand nacelle NOTES 17 .CF34-8E Thrust Reverser Reverse Thrust Forward Thrust -8EFLIGHTOPS. CF34-8E Nacelle – Left Side Access FADEC & T2 Access Panel Operability Bleed Valve Exhaust Inlet & Piccolo Tube Inspection Panel Pressure Relief Door -8EFLIGHTOPS.PPT NOTES 18 CF34-8E Nacelle – Right Side Access Oil Servicing Door Inlet & Piccolo Tube Inspection Panel IDG Sight Glass Door Inlet Anti Ice Exhaust & Piccolo Tube Inspection -8EFLIGHTOPS.PPT NOTES 19 CF34-8E Engine Bearing Structure N1 ROTOR #1 BALL BEARING Single Stage Fan Rotor Four Stage Low Pressure Turbine #2 ROLLER BEARING #5 ROLLER BEARING -8EFLIGHTOPS.PPT NOTES 20 CF34-8E Engine Bearing Structure #4 ROLLER BEARING #3 BALL BEARING N2 ROTOR Ten Stage High Pressure Compressor Two Stage High Pressure Turbine -8EFLIGHTOPS.PPT NOTES 21 PPT NOTES 22 .CF34-8E Engine Sump Structure A Sump Located in Compressor Front Frame B Sump Located in Combustion Chamber Frame C Sump Located in Exhaust Frame -8EFLIGHTOPS. PPT NOTES 23 .5 INTER TURBINE TEMPERATURE P3 COMPRESSOR DISCHARGE PRESSURE T2 FAN INLET TEMPERATURE -8EFLIGHTOPS.CF34-8E Engine Aerodynamic Stations T4. CF34-8E Fan Rotor BALANCE WEIGHTS FAN BLADE AFT SPINNER RETAINING PIN FAN DISK #1 BEARING #2 BEARING FORWARD SPINNER -8EFLIGHTOPS.PPT • The spinner is a hybrid shape of conical (to minimize ice accretion) and elliptical (to reduce ingestion into the core engine of rain and hail) NOTES • Wide chord fan blades 24 . PPT • The fan case is lined with acoustic panels for noise reduction NOTES • The fan case also serves as a blade containment system 25 .CF34-8E Fan Stator FAN CONTAINMENT CASE TIE ROD FAN SPEED SENSOR OUTLET GUIDE VANE COMPRESSOR FRONT FRAME #1 BEARING #2 BEARING -8EFLIGHTOPS. PPT NOTES 26 .CF34-8E High Pressure Compressor Rotor STAGE 1 – 2 BLISK FORWARD SHAFT STAGE 4 – 10 SPOOL STAGE 3 BLISK -8EFLIGHTOPS. PPT • The variable inlet guide vanes and four variable stator vane stages serve to match airflow of the forward and aft compressor stages NOTES • The variable IGVs and VSVs are controlled by the FADEC • At low N2 speeds they are closed and move toward the open position with increasing N2 speed • Malfunctioning or off schedule VSVs can cause stalls or slow acceleration • Fourth stage compressor air is extracted for sump pressurization • Sixth stage is extracted for air conditioning. nacelle anti-ice. nacelle anti-ice and wing anti-ice 27 . wing anti-ice • Tenth stage is used for air conditioning.CF34-8E High Pressure Compressor Stator VARIABLE GEOMETRY ACTUATING ARMS STAGE 4 BLEED MANIFOLD STAGE 6 BLEED MANIFOLD INLET GUIDE VANES VARIABLE GEOMETRY VANES FIXED STATOR VANES -8EFLIGHTOPS. PPT • Fuel is supplied to the combustor by 18 fuel nozzles equally spaced around its circumference NOTES • ignitors are located within the combustor at the 4 o’clock and 8 o’clock positions 28 .CF34-8E Combustor OUTER LINER STAGE 1 HIGH PRESSURE TURBINE NOZZLE NOZZLE SUPPORT SWIRLER INNER LINER -8EFLIGHTOPS. Plugging cooling holes and changing the aerodynamics of the HPT nozzle area 29 .CF34-8E High Pressure Turbine STAGE TWO NOZZLE STAGE TWO SHROUD STAGE ONE SHROUD STAGE TWO BLADES STAGE ONE BLADES STAGE ONE DISK OUTER TORQUE COUPLING HPT SHAFT STAGE TWO DISK -8EFLIGHTOPS.PPT • The HPT nozzle diverts combustor exit gas to the HPT rotor NOTES • A serious effect of flight through volcanic ash is that the ash melts in the combustor then solidifies and creates a ceramic coating on the HPT nozzle vanes. PPT NOTES 30 .CF34-8E Low Pressure Turbine STAGE 3 – 6 NOZZLES LOW PRESSURE TURBINE STATOR CASE LOW PRESSURE TURBINE SHAFT STAGE 3 – 6 ROTORS -8EFLIGHTOPS. CF34-8E Accessory Gearbox -8EFLIGHTOPS.PPT • The AGB is a cast two-piece housing. Drive pads allow for the mounting of the accessories on the forward and aft faces of the gear box. Intermeshed gears are located in the housing. Power is taken form the core rotor of the engine and transmitted to the engine accessories by the gear box NOTES • The AGB provides support and drive for all mechanical accessories needed to supply the engine with fuel, lubrication and electrical power. The top of the AGB serves as the oil reservoir. 31 CF34-8E Accessory Gearbox – Aft View Oil Reservoir Fuel pump PMA Starter Air Valve Starter Integrated Drive Generator (IDG) -8EFLIGHTOPS.PPT NOTES 32 CF34-8E Accessory Gearbox – Forward View Oil Pressure Switch Chip Detector Hydraulic Pump Oil Filter Lube and Scavange Pump -8EFLIGHTOPS.PPT NOTES 33 CF34-8E Engine Airflow A SUMP PRESSURIZING PRESSURIZING VALVE B SUMP PRESSURIZING C SUMP PRESSURIZING 4 6 10 BLEED AIR FOR AIRCRAFT 4TH STAGE SHUTOFF VALVE HIGH PRESSURE SHUTOFF VALVE PRESSURE REGULATING SHUTOFF VALVE -8EFLIGHTOPS.PPT • ECS Bleed Pressures and Temperatures NOTES •(Maximum values at ATTCS (APR) thrust) •6th Stage Bleed •Pstatic = 153.6 psia •Temperature = 758 F •10th Stage Bleed •Pstatic = 374.3 psia •Temperature = 1064F 34 The FADEC enhanced engine is not only more powerful and efficient than its mechanically controlled counterpart. more precise. and provide more capability than the older mechanical controls.PPT FADEC is Full Authority Digital Engine Control. NOTES 35 . and easier to maintain. They also integrate with the aircraft onboard electronic operating and maintenance systems to a much higher degree. It is the name given to the most recent generation of electronic engine controls currently installed on a variety of high-bypass turbofan engines. it is simpler to operate. FADEC systems are more responsive. monitoring and feedback – Cables and connectors • More than just fuel control functions – – – – – Start Ignition Variable geometry (VSV’s) Reverse thrust Fault detection -8EFLIGHTOPS.CF34-8E FADEC • Full Authority Digital Engine Control – No mechanical connection cockpit to engine – Analogous to “fly by wire” aircraft control system • Consists of – Dedicated alternator and power supplies – Sensors for control. FADEC Control System • Improved operational characteristics – – – – – – Reduced ITT thermal overshoot Full flight regime thrust management Uniform engine response times Automated starting Built-in thrust ratings Idle speed control for aircraft bleed requirements • Improved aircraft .engine integration – – – – Auto-thrust system features and compatibility Less hysteresis Digital aircraft interface Better informed cockpit -8EFLIGHTOPS.PPT NOTES 36 . Ignition System 115V 400Hz A Ign A Plugs B Ign B • Features – Two independent systems per engine • Automatically alternated every start – – – – – – Either channel can control both ignition boxes Ignition off when N2 >50% Auto relight if “flame-out” sensed Pilot can select continuous ignition Both ignitors on for all air starts If FADEC detects a missed light-off during a ground start attempt the other ignitor will be energized – Ignitors located at the 4 and 8 o’clock position on combustion case -8EFLIGHTOPS.PPT NOTES 37 . PPT NOTES 38 .VSV Control Feedback Closed FADEC A VSV actuators FMU VSV B Transient Schedules Steady state Open N2K • • • • • Match airflow of Fwd/Aft compressor stages Electrical vs mechanical schedule Steady state schedules maximize efficiency Transient schedule improves stall margin Controlled by FADEC through FMU servo valves -8EFLIGHTOPS. • Once filtered. meters flow to the fuel injectors through the manifold.CF34-8E Fuel System -8EFLIGHTOPS. passes through the fuel/oil heat exchanger and then flows to the FMU where it enters the fuel filter. where it mixes with compressor discharge air and is burned. using commands from the FADEC.PPT • Fuel supplied by the aircraft fuel tank(s) flows to the centrifugal boost stage of the fuel pump. • The flow leaves the pump and returns to the FMU. Upon exiting. • The fuel pump provides the controlling fuel flow to operate the OBV based on commands from the FADEC 39 . The 18 fuel injectors deliver atomized fuel into the combustion chamber. One flow passes through the secondary highpressure gear stage of the pump and then goes back to the aircraft as motive flow. The FMU. the flow divides into two paths. the flow leaves the FMU and returns to the fuel pump where it enters the primary high-pressure gear stage. NOTES • The second flow exits the pump. PPT • The lubrication system provides the following functions: oil storage and delivery. to the heat exchanger for cooling. lubrication/protective barrier against wear and corrosion of internal components. 40 . • Vent air is removed from the sumps and scavenge oil.CF34-8E Lube System Schematic -8EFLIGHTOPS. or the deaerator in the oil reservoir. is pressurized by the supply element of the Lube & Scavenge pump. by the air/oil separator on the AGB. pressurization and vent. and then returns to the reservoir. and then to the engine bearings. flows past the chip detector. and vented overboard through the drain mast. to the deaerator. • The scavenge oil is removed from the sumps and the AGB by the scavenge elements of the L&S pump. NOTES • Oil from the system reservoir. sent to the filter. heat and contamination removal. CF34-8E Operational Characteristics -8E FLIGHTOPS.PPT NOTES 41 . PPT NOTES 42 .Ratings Transients Operating Limits Exceedances -8EFLIGHTOPS. for example Not agency certified Specified by aircraft/engine manufacturers Reflected in aircraft power management Basis of aircraft climb.Ratings Versus Thrust Limits • Ratings – Takeoff and MCT – Agency certified • Thrust limits – – – – – – – MCL. cruise performance Prolong engine life (versus MCT) MCT intended primarily for engine out operation -8EFLIGHTOPS.PPT NOTES 43 . MCR. Flat Rate Concept • All GE/CFMI engines • Power managed for – Constant thrust independent of ambient temperature up to “flat rate” temperature – Decreased thrust above flat rate temperature to maintain a constant ITT – Flat rate temperature defined as ISA +∆T (for example ISA + 15oC) • N1 schedule reflected in – Thrust Rating Computer (TRC). Flight Management System (FMS) – Graphic or tabulated data in operations publications -8EFLIGHTOPS.PPT NOTES 44 . To meet aircraft performance requirements.PPT I. Any deviation from N1 power management will result in corresponding deviations in ITT. the engine is designed to provide a given thrust level to some “Flat Rate” Temperature (FRT). NOTES II. thrust decreases and aircraft performance is adjusted accordingly. Constant thrust N1 Decreasing thrust TAT Constant thrust FRT III. ITT increases with OAT to FRT. This applies to positive deviations of N1 (overboost) as well as to reduced thrust operation. TAT Decreasing thrust FRT ITT Red Line ITT Increasing ITT TAT Constant ITT FRT -8EFLIGHTOPS. III. Thrust II. N1 for takeoff power management schedule increases with OAT (up to FRT) to maintain constant thrust. 45 . then remains constant.Engine Parameters at Takeoff Thrust I. power management N1 (and thrust) decreases. At temperature above FRT. After FRT. Altitude Variation SL Thrust Increasing altitude OAT FRT Increasing altitude N1 SL OAT FRT ITT Increasing altitude SL OAT FRT -8EFLIGHTOPS.PPT NOTES 46 . Additionally. NOTES 47 . As a result of this increased efficiency.PPT The power management function on FADEC engines consists of controlling N1 (rather than N2) to produce thrust requested by the thrust lever position.Typical FADEC Transient Characteristics thrust lever angle N2 ITT N1 thrust lever set Time -8EFLIGHTOPS. total pressure and ambient pressure) and engine bleed requirements to calculate N1 based on a thrust lever position. FADEC modulates the variable stator vanes to maximize engine efficiency during transient and steady state operations. The FADEC uses the ambient conditions (total air temperature. the ITT bloom and droop are reduced. N1. allow higher power management with lower potential for limit exceedances -8EFLIGHTOPS.PPT NOTES 48 . N2 red lines • Based on the capabilities of hot section and rotating parts • Limits must be compatible with transient characteristics • FADEC engines.Operating Limits • ITT. with lesser transients. ITT on a zeromargin engine will reach the ITT redline at takeoff thrust.ITT Margin ITT Redline Margin Deterioration ITT TAT OATL FRT -8EFLIGHTOPS. 49 . An engine with a negative ITT margin will reach ITT redline at some temperature less than FRT. The ITT margin decreases as engine components deteriorate. This is called the OAT limit (OATL). NOTES At temperatures at or above FRT.PPT ITT margin is the difference between the ITT redline and the ITT observed on a full thrust takeoff at or above flat rate temperature (FRT). PPT NOTES 50 .Contributors to ITT Exceedances • Engine deterioration • Engine hardware damage • Bleed air leak • Inappropriate selection of bleed air based on the thrust configuration -8EFLIGHTOPS. PPT FADEC will control the engine according to the above charts. Thrust II. Below FRT thrust would be maintained but N1 and ITT would be higher versus no inversion.Effect of Temperature Inversion at Takeoff I. some loss of thrust would occur (not deemed significant by the aircraft manufacturers) in terms of aircraft performance. Above FRT. NOTES 51 . Constant thrust N1 Decreasing thrust TAT Constant thrust FRT TAT Decreasing thrust FRT III. EGT Increasing EGT TAT Constant EGT FRT -8EFLIGHTOPS. . Testing -8EFLIGHTOPS.PPT NOTES 53 . Ground testing is primarily accomplished by GEAE’s Peebles Test Operation in Peebles. This presentation summarizes some of these tests and test facilities used. California. Flight testing is accomplished by GEAE’s Flight Test Operation in Mojave.PPT NOTES 54 .Overview • A variety of development and certification tests are conducted on GE/CFMI engines. Ohio and by comparable SNECMA facilities in France. -8EFLIGHTOPS. GE Peebles Outdoor Test Facility -8EFLIGHTOPS.PPT NOTES 55 . NOTES Shown above is GE90 engine.Crosswind Testing • Objectives – Demonstrate engine operability in crosswinds and tailwinds • Location – Peebles Test Operation -8EFLIGHTOPS. crosswind and tailwind conditions.PPT A bank of electrically driven fans can rotate 360º around the engine to create headwind. We look at start characteristics with tailwinds in excess of 50 knots as well as the engine’s resistance to instability during acceleration and high static thrust operation in high crosswind conditions. 56 . spinner and booster/HPC stators. NOTES Ice is allowed to build up at various power settings. 57 . an ice slab is fired into the engine to simulate the shedding of ice that was allowed to build up on the engine because of late or no actuation of inlet anti-ice. then shed by centrifugal force and temperature rise during engine acceleration.Cold Weather Testing • Objectives – Demonstrate engine operability in a heavy ice environment for certification and engineering evaluation – Demonstrate a “cold” start • Location – Peebles Test Operation -8EFLIGHTOPS. In another test (not shown here).PPT These tests evaluate impact on hardware and operability of ice build up on non-anti-iced engine components such as fan blades. Shown above is GE90 engine. In this case.PPT Normally. NOTES 58 . test stand scheduling and ambient temperature conditions precluded outdoor testing.Icing Tests in Climatic Hangar (CFM56-3 Upgrade) -8EFLIGHTOPS. Outside temperatures were approximately 30 deg C while temperature in the hangar were in the –15 deg C range. where the tests were performed with the engine installed on a leased B737-300 in a temperature controlled environment. Ohio outdoor test facility. icing tests are run at our Peebles. CFM fabricated a portable version of the Peebles test set-up and shipped it to the USAF climatic hangar in Florida. ) and medium birds (up to 2 ½ lbs.Bird Ingestion Testing • Objectives – Evaluate impact on engine hardware and operability of bird ingestion • Location – Peebles Test Operation -8EFLIGHTOPS. NOTES Shown above is CFM56-7 engine.) are fired into the engine while it is operating at takeoff thrust.PPT Large birds (up to 8 lbs. 59 . Erosive FOD Testing • Objectives – Evaluate ingestion and erosion potential in a FOD environment • Location – Peebles Test Operation -8EFLIGHTOPS. NOTES 60 .PPT Shown above is CFM56-7 engine. NOTES Shown above is CFM56-5C engine. 61 .PPT This test simulates a worst case downpour. The engine must demonstrate satisfactory operability.Water Ingestion Testing • Objectives – Demonstrate engine operability in a heavy rain environment – Demonstrate starting with water ingestion • Location – Peebles Test Operation -8EFLIGHTOPS. NOTES In another test (not shown here). .PPT One half inch ice cubes are fired through air powered “guns. 62 . 1½ inch hailstones are fired into the engine at high thrust to evaluate hardware impact. for certification • Location – Peebles Test Operation -8EFLIGHTOPS. . Shown above is GE90 engine.Hail Ingestion Testing • Objective – Demonstrate engine operability in a heavy hail environment .” The engine must demonstrate satisfactory operability. PPT • Objectives – Demonstrate effect on engine of fan blade released at takeoff thrust • Success Criteria – No fire – No uncontainment – No exceedance of mount loads – Safe shutdown • Location – Peebles Test Operation NOTES Shown above is CF34 engine. 63 .Fan Blade-Out Testing Blade Release Subsequent Stall -8EFLIGHTOPS. Mojave Airport -8EFLIGHTOPS.PPT NOTES 64 . was used as a flying test bed for the CF6-80C2 PMC and FADEC engines. an A300B2 leased from Airbus Industrie.A300 Test Bed Aircraft (CF6-80C2 Installed) -8EFLIGHTOPS.PPT This aircraft. NOTES 65 . A300 Test Bed Aircraft (CF6-50C2 Installed) Water Ingestion Tests -8EFLIGHTOPS.PPT NOTES 66 . B707 Test Bed Aircraft (CFM56-5B Installed) -8EFLIGHTOPS. NOTES 67 .PPT This aircraft was used as a flying test bed for CFM56-3/-5A/-5B/-5C engines. PPT NOTES 68 .B707 Test Bed Aircraft (CFM56-3 Installed) Water Ingestion Tests -8EFLIGHTOPS. PPT NOTES 69 .B727 Test Bed Aircraft (UDF Engine Installed) -8EFLIGHTOPS. B747 Test Bed Aircraft (GE90 Installed) -8EFLIGHTOPS.PPT This aircraft, a B747-100, has been used as a flying test bed for all GE and CFM56 engines since 1992, including the GE90, CFM56-7 and CF34 engines. GE believes there is no substitute for in-flight testing. This test bed allows GE to subject our new engines to very rigorous in-flight operability testing before delivery of a new engine to the aircraft manufacturer. This helps account for the outstanding operability reputation of GE and CFM56 engines relative to those of other manufacturers. This test bed was most recently used to flight test the world’s highest thrust engine, the GE90-115B (115,000 pounds of thrust). The GP7000-series (Engine Alliance) engine for the A380 will be tested on the same aircraft as will the CF34-10 regional jet engine. NOTES 70 B747 Test Bed Aircraft (CFM56-7 Installed) -8EFLIGHTOPS.PPT NOTES 71 B747 Test Bed Aircraft (CF34-8C Installed) -8EFLIGHTOPS.PPT NOTES 72 Development and Certification Tests • Operability and Hardware Impact • Crosswind • Ice – Induction icing – Ice slab ingestion – Natural icing (in-flight) • Medium bird* – Eight 1-1.5 pound birds (four 2.5 pound birds) – Takeoff power – Maintain thrust lever setting for 5 minutes (demonstrate operability for 20 minutes) – Retain 75% thrust • Large bird* – – – – – – Four pound bird (8.0 pound bird) Takeoff power No fire No uncontainment Mount loads not exceeded Normal shutdown • Water and hail ingestion • Fan blade out • Overlimit *Additional requirements for larger engine effective 9/2000 are shown in parentheses -8EFLIGHTOPS.PPT NOTES 73 Typical Operability Test Maneuvers Performed • Start – – – – Ground Air Manual Auto • Steady state operation – High thrust – Low thrust • Acceleration – Normal – Burst • Deceleration – Normal – Chop • Bodies -8EFLIGHTOPS.PPT NOTES 74 . Conditions Under Which Maneuvers are Performed • Normal • Bird ingestion • Crosswind • Off schedule VSV’s • Tailwind • Off schedule fuel • Icing • Suction feed • Rain • High angle of attack • Hail • Slow speed -8EFLIGHTOPS.PPT NOTES 75 . PPT NOTES 76 .g. to start.Operability Measurements • Time (e. accel. decel) • ITT • Thrust response • Stall free • Flameout free • Crew workload requirement -8EFLIGHTOPS. F* G - G.G.F G.F F - F G.F F - F G.F* - G - - F F - G.F G G G G.F* G - G.G.F G.PPT NOTES 77 .F G - .F - - F G.F* G - G.Condition Maneuver Cross Tail Normal Wind Wind Ground start Air start Accel (Norm) Accel (Burst) Decel (Norm) Decel (Chop) Bodies Steady State (High) Steady State (Low) Icing Rain Hail Off Sched Off Bird VSV/ Sched Suct Strike VBV Fuel Feed Slow High Air Alpha Speed G G G G G - - G G - - - F - - - F* - - F F F - F G.F - F F F - *Not routine test - G = Ground F = Flight -8EFLIGHTOPS.F G - - - - G.F - - - G.F G - G G.F - F - G G.F* G - G.F G - G G.F G - .F* G - G.F G.F G - G G. . Normal Operating Considerations -8E FLIGHTOPS.PPT NOTES 79 . PPT NOTES 80 .Note • If there are inconsistencies between this presentation and the Aircraft Operations Documents the Aircraft Operations Documents take precedence -8EFLIGHTOPS. loose snow and ice prior to engine start 81 .PPT Inlet Area NOTES • Ensure ramp area near inlet is free of FOD.CF34-8E Preflight -8EFLIGHTOPS. CF34-8E Preflight -8EFLIGHTOPS.PPT Inlet NOTES • Remove engine covers and plugs 82 . spinner or in the lower inlet near the fan • Remove snow or ice with warm air instead of deicing fluid • Check for damaged fan blades • Ensure fan is free to rotate prior to engine start 83 .PPT Inlet/Fan NOTES • Check for tools. snow.CF34-8E Preflight -8EFLIGHTOPS. ice or FOD on fan blades. equipment. PPT NOTES 84 .Ice Damage to Fan (CF6) -8EFLIGHTOPS. PPT T2 Sensor NOTES • Check for FOD damage 85 .CF34-8E Preflight -8EFLIGHTOPS. PPT Cowls and Thrust Reverser in Open Position NOTES • Cowls and thrust reverser are hinged to pylon 86 .CF34-8E Preflight 3 Fan cowl latches .unlatched -8EFLIGHTOPS. 87 .PPT Fan Cowl NOTES • Difficult to see if latches are latched at standing height when close to nacelle • Verify that all three latches are latched.unlatched Fan compartment vent 2 of 3 Fan cowl latches .CF34-8E Preflight 3 Fan cowl latches .unlatched -8EFLIGHTOPS. Fan cowl may look secure even though two latches may be unlatched. Loss of Fan Cowl (CF6) -8EFLIGHTOPS.PPT We believe this incident was the result of takeoff with one or more cowl latches open. NOTES 88 . Loss of Fan Cowl (CF6) Holes Through Fuselage Above Window Line -8EFLIGHTOPS.PPT NOTES 89 . unlatched Thrust Reverser latches (2) .CF34-8E Preflight Core cowl latches (3) .PPT View of Nacelle – Aft Looking Forward NOTES 90 .unlatched -8EFLIGHTOPS. latched -8EFLIGHTOPS.PPT Core Cowl – View from 6 o’clock NOTES • Open pressure relief door may indicate a pneumatic duct separation 91 .CF34-8E Preflight Pressure Relief Door Core cowl latches . PPT Drain Mast NOTES • Maintenance should be requested if large puddles appear under the drain mast 92 .CF34-8E Preflight Drain Mast -8EFLIGHTOPS. PPT • At min idle thrust.9 M (2. NOTES 93 . the 65 mph exhaust wake danger area extends aft of the engine approximately 86 feet.1 M (3. Contingency Factor Exhaust Hazard Area Includes Worst Case 20 Knot Headwind with Ground Effects 2.7 M (5.3 ft) Entry Corridor .3 ft/sec) 1.5 ft) 26 M (86 ft) -8EFLIGHTOPS.5 M (8.7 ft) Wide Engine Exhaust Hazard Area Velocity = 65 MPH or greater = 29.7 ft) 1.0 m/sec (95.Physical Hazard Areas Minimum Idle Thrust WARNING: AIRCRAFT MUST BE POINTED INTO WIND FOR ACCESS TO ENGINE COMPONENTS AT GROUND IDLE Inlet Hazard Area Includes Worst Case 20 Knot Headwind Based on 40 ft/sec Critical Velocity with 3 ft. Feet 5 4 Meters Exhaust Velocity Contours Include Worst Case 20 Knot Headwind with Ground Effects 3 2 1 0 16 A B C 14 12 10 8 6 4 D E 2 0 0 4 8 12 20 24 28 32 36 40 Distance from Core Nozzle Exit. Feeet 7 Meters Velocity (ft/sec) MAX = 1583 A 50 B 100 C 200 D 400 E 800 F 1500 A B C 20 16 D E F 12 8 4 0 0 0 4 8 2 12 16 4 20 24 28 32 36 40 Distance from Core Nozzle Exit.PPT NOTES 94 . Feet 6 8 10 12 44 48 14 52 16 56 60 18 Meters -8EFLIGHTOPS.Physical Hazard Areas Takeoff Thrust Height Above Ground Plane. Feet 6 4 2 0 16 8 Meters 10 12 44 48 52 14 56 60 18 16 F 24 6 5 4 3 2 1 0 Distance from Airplane CL. Embraer 170 Cockpit -8EFLIGHTOPS.PPT NOTES 95 . Embraer 170 Cockpit Layout -8EFLIGHTOPS.PPT NOTES 96 . CF34-8E Engine Control Panel -8EFLIGHTOPS.PPT NOTES 97 Embraer 170 Thrust Levers -8EFLIGHTOPS.PPT • Flats (detents) at TO/GA and MAX NOTES • Thrust reverser deployed by lifting the idle stop lever on the thrust lever and moving thrust lever into the reverse position 98 Embraer 170 EICAS Display CF34-8E Starter Operating Limits Starting - Ground Operation Start Number Maximum Time Followed By 1&2 90 seconds 10 second cool-down 3 through 5* 90 seconds 5 minute cool-down Starting – In-flight Operation Start Number Maximum Time Followed By 1&2 120 seconds 10 second cool-down 3 through 5* 120 seconds 5 minute cool-down Motoring – Ground or In-flight Operation Motoring Number Maximum Time Followed By 1&2 90 seconds 5 minute cool-down 3 through 5* 30 seconds 5 minute cool-down -8EFLIGHTOPS.PPT Starter Notes NOTES • * After 5 sequential start attempts/motorings, cycle may be repeated following a 15 minute cooldown • For ground starts only, the maximum accumulative starter run time per start attempt is 90 seconds (motoring plus start time) • For in-flight starts, the maximum accumulative starter run time per start attempt is 120 seconds (motoring plus start time) 100 ignition and fuel flow .Fuel on at 20% N2 .Ignition A (essential bus) – No dispatch message if Ignition A inop.Ignition B – Short term dispatch if Ignition B inop.Starter air valve opens when start switch moved to START - Ignition sequenced on at 7% N2 . Thrust Lever – IDLE position 2.Alternate ignitor selected if no light-off in 15 seconds after fuel on . .PPT Ground Start Notes • FADEC will prevent engine start if thrust lever is not in the idle position • On the ground FADEC will automatically turn off ignition and fuel if a hot start or a hung start is detected • Engine will continue to motor until the pilot manually closes starter air valve by moving STOP/START switch to STOP • If no light off within 30 seconds of fuel on the pilot must abort start manually (STOP/START switch to STOP) • Dry motor the engine for at least 30 seconds after aborting a start to purge the combustor of residual fuel prior to the next start attempt NOTES 101 . .Alternate ignition selected for every other start - Automatic Fuel Control .CF34-8E Ground Starting Start Sequence 1.Either FADEC channel can control each ignition exciter . Ignition switch – AUTO 2.Light-off typically within 5 seconds after fuel on - Starter air valve closes and ignition off at approximately 50% N2 -8EFLIGHTOPS. Start switch – move to START then release to RUN • FADEC controls starter air valve. PPT • Light-off .Typical start time: 40 to 60 seconds . 60% N2.Indicated by ITT and fuel flow reduction .Must be indicated by ground idle .22% N1.May indicate full scale for cold soaked engine • Idle .Typically within 2-4 seconds NOTES • ITT start limit . typical idle speeds 102 .CF34-8E Starting Characteristics Normal Ground Start (All Numerical Values Are “Typical” Not Limits) Idle N2 Idle light-off (2-4 sec) N1 Min N1 Display = 8% 30-50 seconds to idle from light-off Time light-off occurs before N1 = 8% Peak ITT = 550-650°C Light-off ITT FF Time Peak FF = 110-180 pph prior to light-off 500-650 pph after light-off Fuel shutoff open 450-550 pph at idle 460-550°C ITT at idle Time Time -8EFLIGHTOPS.815°C • Oil pressure . PPT NOTES 103 . • Starts with high residual ITT – – Expect delayed light-off if starting with residual ITT > 120°C FADEC will automatically dry motor until ITT is less than 120°C. then turn on ignition and fuel -8EFLIGHTOPS.CF34-8E Ground Start Considerations • START/STOP switch – Switch must be moved from STOP to START in 30 seconds or less or FADEC will prevent engine start – Recycle switch through STOP position for next start attempt • Starter air pressure – 41 – 48 psi air supply pressure required – Slower starts with lower pressure • Fan rotation – – – – – • Ignition selection is automatic – FADEC alternates A and B ignitors on every other start • Cold Soaked Engine – Oil temperature must be at least -40 °C prior to engine start – Oil pressure peaks to full scale may occur due to high oil viscosity – Oil pressure should decrease as the oil temperature increases N1 indication is absolute Tailwind may cause opposite fan rotation Core airflow will gradually override tailwind effect and eventually turn fan in correct direction Minimize tailwind prior to start by repositioning aircraft if practical With strong tailwinds consider manually drymotoring engine (ignition switch OFF) to achieve positive. increasing N1 prior to continuing start (ignition switch AUTO). PPT • FADEC will not allow engine start if thrust lever is not in the idle position • FADEC does NOT provide hot start.2% 15000 Starter Assist Required 10000 5000 0 -5000 0 50 100 150 200 250 300 350 Airspeed (kias) -8EFLIGHTOPS.CF34-8E In-Flight Starting Air Start Envelope Windmill Windmill Only if N2 is greater than 7.2% Starter Assist 25000 Altitude (ft) 20000 Starter Assist or Windmill if N2 is greater than 7. hung start or stall protection in the air NOTES 104 . hung start or stall protection in the air • If N2 has not reached 20% after 15 seconds ignition and fuel will be turned on automatically • If no light-off within 30 seconds of initiating start the pilot must abort start manually (STOP/START switch to STOP) • Dry motor the engine for at least 30 seconds after aborting a start to purge the combustor of residual fuel prior to the next start attempt NOTES 105 . Start switch – move to START then release to RUN • FADEC controls starter air valve. Thrust Lever – IDLE position 2.Starter air valve opens when start switch moved to START - Ignition sequenced on at 7% N2 . ITT must be less than 90°C for all air starts • May have to dry motor engine if ITT > 90 °C (Ignition OFF) 4. Ignition switch – AUTO 3.Fuel on at 20% N2 - Starter air valve closes and ignition off (auto) at approximately 50% N2 -8EFLIGHTOPS.Both ignitors are on for all air starts - Automatic Fuel Control .PPT Assisted Air Start Notes • FADEC will prevent engine start if thrust lever is not in the idle position • FADEC will NOT provide hot start. ignition and fuel flow .CF34-8E In-Flight Starting Starter Assisted Air Start 1. CF34-8E In-Flight Starting Windmill Air Start 1.2% after 15 seconds ignition and fuel will be turned on automatically • Increasing airspeed will increase windmilling engine RPM • Start attempt should be discontinued if no light-off within 30 seconds of fuel flow • Dry motor the engine for at least 30 seconds after aborting a start to purge the combustor of residual fuel prior to the next start attempt NOTES 106 . ITT must be less than 90°C for all air starts 4. Ignition switch – AUTO 3.Fuel on at 7.Both ignitors are on for all air starts - Automatic Fuel Control . ignition and fuel flow - Ignition sequenced on at 7% N2 . Thrust Lever – IDLE position 2. Start switch – move to START then release to RUN • FADEC controls. hung start or stall protection in the air • FADEC will not open starter air valve if outside the assisted air start envelope • If N2 has not reached 7.PPT Windmilling Air Start Notes • FADEC will prevent engine start if thrust lever is not in the idle position • FADEC will NOT provide hot start.2% N2 - Ignition off (switch in AUTO position) at 50% N2 -8EFLIGHTOPS. -8EFLIGHTOPS. The FADEC will not provide automatic hung start protection in the air.PPT NOTES 107 . • Hung Start – A hung start is identified by abnormally slow acceleration after ignition and rpm that stabilizes below idle. the FADEC will automatically turn off fuel and ignition if a hung start is detected. – During ground starts. – A start stall condition is indicated by an abnormally slow core speed acceleration and an abnormal increase in ITT as compared to core speed.CF34-8E Abnormal Starts • Hot Start – The indication of a hot start is an unusually fast ITT increase after ignition. – The FADEC provides automatic hot start protection (fuel and ignition off) on the ground. The FADEC will not provide automatic hot start protection in the air. PPT NOTES 108 . 163°C for 15 minutes • Oil quantity – “Gulping” -8EFLIGHTOPS.Taxi • Minimize breakaway thrust – Less than 40% N1 if possible • Reduces FOD potential • Reduces blast hazard • Operate (warm up) engines two minutes minimum prior to takeoff • Reverse thrust during taxi only in emergency • Oil pressure – Varies with N2 – Minimum 25 psi – May be full scale for cold soaked engine • Should come off full-scale after required minimum 2 minute warm up time prior to takeoff • Oil temperature – Rise must be noted prior to takeoff – Maximum 155°C continuous. CF34-8E Oil Pressure -8EFLIGHTOPS.PPT • Oil pressure varies with N2 NOTES • Oil pressure less than 25 PSID is permissible for maximum of 10 seconds during “Negative G” operation • Oil pressure below 25 PSID (other than negative-G condition) requires engine shutdown 109 . CF34-8E Oil Quantity • Varies inversely with engine speed • Remains constant during steady-state operation • Oil gulping: after engine start. gearboxes and supply scavenge lines) • Increasing oil quantity or lack of gulping could indicate leak in fuel/oil heat exchanger -8EFLIGHTOPS.PPT NOTES 110 . oil level decreases due to distribution within system (sumps. pressure increase and temperature rise • Perform this procedure – Every 30 minutes – Just prior to or in conjunction with the takeoff procedure. with particular attention to engine parameters prior to final advance to takeoff thrust – Any time fan ice accumulation is suspected by perceived or indicated fan vibration -8EFLIGHTOPS. considering airport surface conditions and congestion) – Allows immediate shedding of fan blade and spinner ice – De-ices stationary vanes with combination of shed ice impact.Taxi (Continued) • Ground operation in icing conditions – Anti-ice on • Anti-ices inlet lip – During extended operation (more than 30 minutes): • Accelerate engines to 54% N1 and hold for 30 seconds (or to an N1 and dwell time as high as practical.PPT NOTES 111 . 112 .PPT • FADEC will automatically reduce fan speed to compensate for ITT increase of ECS/anti-ice bleeds based on Takeoff Data Set inputs to the FMS prior to takeoff. • Manual or automatic selection of cowl or wing anti-ice ON below 1700 feet above airport altitude at high thrust levels may result in ITT rise above limits unless thrust is momentarily reduced prior to selecting cowl or wing anti-ice ON or prior to entering icing conditions with anti-ice in auto mode. rolling takeoff is preferred – – – – Less FOD potential on contaminated runways Inlet vortex likely if takeoff N1 set below 30 KIAS Less potential for engine instability or stall during crosswind/tailwind conditions Observe limitations per aircraft manufacturer’s operations documents • N1 thrust management – FADEC computes command N1 for max or reduced thrust based on FMS inputs – Thrust lever “stand up” at approximately 40% N1 prior to full thrust (minimizes uneven acceleration) – Pilot sets thrust lever to thrust set (TOGA) position for full thrust or reduced thrust – FADEC maintains N1 at command value -8EFLIGHTOPS. NOTES • Manual selection of ECS ON below 500 feet above airport altitude at high thrust levels may result in ITT rise above limits unless thrust is momentarily reduced prior to selecting ECS ON.Takeoff • Reduced thrust takeoff if conditions permit • Bleeds – On/off depending on company policy/performance requirements – Avoid bleed configuration changes at low altitudes after takeoff • From an engine standpoint. PPT • Thrust lever will stay in TOGA position if thrust increased to RSV level by automatic ATTCS activation NOTES • Pilot must manually reduce thrust to maintain ITT within limits 113 .ATTCS (Automatic Takeoff Thrust Control System) • Provides additional thrust on takeoff or go-around • Enabled automatically during engine start • Can be turned off for takeoff by pilot input on Takeoff Data Set page on FMS – For takeoff with ATTCS turned off. thrust increase to RSV thrust is NOT available automatically or manually (even with thrust lever push to MAX) – Re-enabled automatically after takeoff phase completed – Always available for go-around • Windshear (caution or warning) detected – Automatic increase to RSV thrust if ATTCS enabled for takeoff – If ATTCS selected off for takeoff. RSV thrust is still available by manually pushing thrust lever to the MAX position – Automatic increase to RSV thrust is always available for approach/go-around -8EFLIGHTOPS. PPT NOTES * ITT Time limits • 965°C for first 2 min.CF34-8E5 ITT Operating Limits Thrust (lbf) and ITT Limits Thrust Mode T/O-1 T/O-2 GA ATTCS AEO OEI ON T/O-1 13000 (965/949)* T/O-1 RSV 14200 (1006/990) OFF T/O-1 13000 (965/949) T/O-1 13000 (965/949) ON T/O-2 11700 (932/916) T/O-2 RSV 13000 (965/949) OFF T/O-2 11700 (932/916) T/O-2 11700 (932/916) ON GA 13000 (965/949) GA RSV 14200 (1006/990) CON 12800 (960) CON 12800 (960) CON -8EFLIGHTOPS. • 949°C for remainder of 5 min. of the 5 min. 114 . PPT NOTES 115 .Maximum Continuous Thrust • Intended for use during single engine conditions or emergency situations • NOT intended for normal two engine operations -8EFLIGHTOPS. PPT NOTES 116 .Climb • No fixed detent or flat • Based on thrust lever position -8EFLIGHTOPS. PPT NOTES 117 .Cruise • Avoid unnecessary use of ignition – Conserves ignitor plug life • Trend monitoring – Per company policy -8EFLIGHTOPS. Descent • Smooth thrust reduction • Idle most economical • FADEC maintains idle speed to meet bleed demands -8EFLIGHTOPS.PPT NOTES 118 . CF34-8E Idle Modes • Flight Idle – Activated when in-flight and not in the approach idle mode (see below) – Provides minimum engine bleed pressure sufficient for ECS and anti-ice systems – Fan speed varies as a function of ECS bleed.000 feet. radar altitude is less than 1200 feet above landing altitude – engine idle speed will drop slightly from flight idle to approach idle to allow more descent profile flexibility during the final approach phase of flight – wing anti-ice system performance is maintained by the pilot through thrust lever modulation (cyan line on N1 indication showing minimum N1 to meet wing anti-ice requirements) -8EFLIGHTOPS. and anti-ice bleed requirements • Approach Idle – Activated when the aircraft altitude is less than 15.PPT • Idle modes only activated when thrust lever is in the idle detent NOTES 119 . and the flaps are down or the landing gear is down and locked – Used in flight to enable rapid acceleration to go-around thrust • Final Approach Idle – Activated when: wing anti-ice is selected on. PPT NOTES 120 .Icing • Cowl anti-ice system protects inlet cowl lip only • Turn on anti-ice prior to entering icing conditions • If ice is inadvertently allowed to accumulate: – Retard one engine at a time to idle before turning A/I on – Turn A/I on. monitor engine while increasing thrust -8EFLIGHTOPS. then advance to minimum of 70% N1 for 10-30 seconds or until vibration ceases .Return thrust lever to position required for flight conditions – Repeat every 15 minutes as required -8EFLIGHTOPS.Retard thrust lever towards idle.PPT NOTES 121 .Icing (Continued) • While in icing conditions in flight and – N1 is less than 70% or – If fan/spinner ice build-up is suspected (high indicated or perceived vibration): . Landing/Reversing • Fan reversers only • FADEC controls N1 in full reverse – Pilot can move thrust lever(s) to MAX REVERSE detent immediately.PPT NOTES 122 . but thrust will be limited to idle until reverser(s) deployed • Modulate reverse if full thrust not needed – Less thermal stress and mechanical loads – Reduced FOD • Reduce reverse thrust at 80 KIAS • Forward idle by 60 KIAS -8EFLIGHTOPS. 000 Knots TAS Training information only 8.000 Net reverse 5.000 1.000 6.000 0 20 30 40 50 60 70 80 90 Percent N1 -8EFLIGHTOPS.000 7.000 0 2.000 150 Reverse thrust 737-300/CFM56-3 SL/STD day Flaps 40 100 50 3.Reverse Thrust Effectiveness vs Airspeed 9.000 thrust (lb/engine) 4.PPT NOTES 123 . N1 and N2 for decrease -8EFLIGHTOPS.Shutdown • Cool-down prior to shutdown to thermally stabilize engine hot section – Two minute cool-down after coming out of reverse (includes normal taxi thrust lever movements) – One minute cool-down if required .minimize N1 during reverse – Five minute cool-down after high power ground operation such as maximum power assurance check – Cool-down not required for emergency shutdown • Monitor fuel flow. ITT.PPT NOTES 124 . Reduced Thrust CF34-8E -8E FLIGHTOPS.PPT NOTES 125 . PPT NOTES 126 .Overview • Definitions and restrictions • Benefits • Severity analysis • Performance aspects • Process map and cause/effect chart • Summary -8EFLIGHTOPS. PPT NOTES 127 . Corresponds to an “alternate” thrust rating – V-speeds used protect minimum control speeds for the derated thrust ... a derated thrust can be selected and thrust further reduced using the assumed temperature method -8EFLIGHTOPS.g. e. not original maximum takeoff thrust – The derated thrust setting becomes an operating limitation for the takeoff • On some installations derated thrust and reduced thrust can be used together. i.Reduced Thrust Versus Derate • Reduced thrust (Flex thrust) takeoff – Takeoff at less than maximum takeoff thrust using the assumed temperature method or a fixed thrust reduction – V-speeds used protect minimum control speeds for full thrust – Reduced thrust setting is not a limitation for the takeoff. full thrust may be selected at any time during the takeoff • Derated takeoff – Takeoff at a thrust level less than maximum takeoff for which separate limitations and performance data exist in the AFM. . .e. within the width being used. An approved maintenance procedure or engine condition monitoring program may be used to extend the time interval between takeoff demonstrations • Reduced thrust takeoffs may not be performed – On contaminated runways • “More than 25 percent of the required field length.PPT NOTES 128 . is covered by standing water or slush more than . not by AC 25-13 -8EFLIGHTOPS.AC 25-13 Restrictions • Reduced thrust setting must be at least 75% of the full thrust rating or alternate thrust rating • A periodic takeoff demonstration must be conducted using full takeoff thrust.125 inch deep or has an accumulation of snow or ice.” – If anti-skid system is inoperative – These restrictions do not apply to “derated” takeoffs – Any other restrictions on reduced thrust or derated thrust are imposed by the aircraft manufacturer or operator. Typical Additional Restrictions on Reduced Thrust Takeoffs • • • • • Possible windshear Other MMEL items inoperative Anti-ice used for takeoff Takeoff with tailwind Performance demo “required” Note: These are typical restrictions that are applied by individual operators. NOTES 129 . the operator should examine the rationale for each of the additional restrictions that might exist and eliminate restrictions where consistent with flight safety. Each additional restriction should be investigated to determine whether or not it is valid. -8EFLIGHTOPS.PPT When assessing a reduced thrust program. Benefits of Reduced Thrust/Derate • Less severe operation due to lower – Rotational speed – Temperature – Internal pressure • Less severe operation tends to lower – ITT deterioration rate • Increased time-on-wing – SFC deterioration rate • Lower fuel burn over the on-wing life of engine – Maintenance costs • Lower shop visit rate and cost per shop visit • Reduced thrust on a given takeoff reduces engine stress level and probability of a failure on that takeoff -8EFLIGHTOPS.PPT NOTES 130 . 8% ITT (oC) 920 805 -115oC PS3 (psia) 353 288 -18. 0.4% -8EFLIGHTOPS.878 6262 -9.25 Mach.0% N2 (rpm) 16.PPT NOTES 131 .670 16030 -3.CF34-8E5A1 Engine Parameters (Full Versus Reduced Thrust) At Sea Level. Flat Rate Temperature of 30oC. Typical New Engine Full rated thrust 25% reduced thrust ∆% (or delta) Thrust (lbs) 11087 8315 -25% N1 (rpm) 6. we do know that for different thrust ratings of the same engine model the ITT deterioration rate tends to be greater on the higher thrust ratings.PPT Although we do not have empirical data to allow us to plot ITT deterioration versus derate. NOTES 132 .Exhaust Gas Temperature (ITT) Deterioration Versus Thrust Rating (Lack of ITT Margin Drives Engines Off Wing and Into the Shop) Cruise ITT Deterioration Increasing ITT Deterioration Rate SL Static Takeoff Thrust Rating Increasing -8EFLIGHTOPS. This concept is shown in the above chart. we do know that for different thrust ratings of the same engine model the SFC deterioration rate tends to be greater on the higher thrust ratings. NOTES 133 . This concept is shown in the above chart.PPT Although we do not have empirical data to allow us to plot SFC deterioration versus derate.Specific Fuel Consumption (SFC) Deterioration Versus Thrust Rating (Rate of SFC Deterioration Impacts Fuel Costs) Cruise Fuel Flow Deterioration Increasing FF Deterioration Rate SL Static Takeoff Thrust Rating Increasing -8EFLIGHTOPS. we do know that for different thrust ratings of the same engine model the cycles to shop visit tend to be lower on the higher thrust ratings. NOTES 134 .Cycles to Shop Visit Versus Thrust Rating Cycles to Shop Visit Increasing Cycles to Shop Visit SL Static Takeoff Thrust Rating Increasing -8EFLIGHTOPS. This concept is shown in the above chart.PPT Although we do not have empirical data to allow us to plot cycles to shop visit versus derate. the data would show a significantly higher chance of engine failure at full thrust than reduced thrust. To make the point that an engine failure is less likely at reduced thrust.Engine Power Loss Versus Thrust Level • No data on reduced thrust versus engine failures • Following data is for flight phase (takeoff. NOTES 135 . Thus.” 1998 -8EFLIGHTOPS.6 Takeoff vs Climb Factor 2 21. one can think of the takeoff phase as a “full thrust” takeoff and the climb phase as “reduced thrust. an uncontained failure is 21.5 22 1.5 times more likely to occur in the takeoff (higher thrust) phase than the climb (lower thrust) phase of flight.PPT Example: For an average high bypass turbofan mission (approximately 2 hours) 43% of the uncontained engine failures occur in the 1% of the time spent in the takeoff phase. This yields an “uncontained factor” of 43÷1 = 43 versus the “uncontained factor” for climb which is 30÷14 ~ 2. climb) versus engine failures – Show significantly higher chance of failure at higher thrust settings associated with takeoff Phase % Time % Exposure IFSDs IFSD Factor % Uncontained Uncontained Failures Factor % Fire Fires Factor % Component Separation % All-engine Power Separation Power Loss Factor Loss Factor Takeoff 1 4 4 43 43 12 12 23 23 8 8 Climb 14 31 2 30 2 42 3 34 2.5 4 9 5 Note: Data for entire high-bypass engine-powered commercial transport fleet Source: “Propulsion Safety Analysis Methodology for Commercial Transport Aircraft.” Thus. PPT NOTES 136 .Severity Analysis • A means of quantifying and predicting mission severity based on how the engine is used • Analysis and limited field data has shown that mission severity is a function of average flight length and the amount of reduced thrust used and is expressed as a “severity factor” -8EFLIGHTOPS. a new severity factor results – Impact on severity is estimated by ratioing the new severity factor to the baseline severity factor * For the purpose of this discussion “derate” is used interchangeably with “reduced thrust” -8EFLIGHTOPS.Severity Analysis (Continued) • Application – Establish baseline severity factor using • Actual flight length • Current effective derate* –The sum of 3 “partial derates” representing takeoff. and cruise – When these values are varied. climb.PPT NOTES 137 . 0 4. NOTES • T/O is weighted heavier on shorter flights.Severity Analysis (Continued) 1-Hour Flight Length 16 Partial Derate (%) 2-Hour Flight Length Takeoff Takeoff 16 12 3-Hour Flight Length 8 8 4 Cruise 4 0 10 20 30 Operational Derate (%) Takeoff 12 12 Climb 16 Climb Cruise 0 10 20 30 Climb Cruise 8 4 0 Operational Derate (%) 10 20 30 Operational Derate (%) (Effective Derate = Partial Takeoff % + Partial Climb % + Partial Cruise %) 1.6 Severity 1. • The above charts are intended only to help illustrate the concept that effective derate is a composite of takeoff. is takeoff. a given amount of effective derate has more impact on shorter flights. in terms of effective derate contribution. climb and cruise. climb and cruise reduced thrust/derate. This visualization is not used in the pricing of maintenance service contracts. climb and cruise derate are weighted heavier (relative to takeoff) on long flights.PPT • Severity of operation is a function of flight length and “effective derate” which is a composite of takeoff. climb and cruise derate. Further.0 Flight Length . 138 .2 Factor 0. depending on flight length and the impact of flight length on severity factor.8 0 10 % Effective Derate 20 0. The contributions of each phase are additive and the sum of the contributions represents “effective derate.Hours -8EFLIGHTOPS.4 0 2.” The charts above demonstrate this concept as well as the fact that the order of importance. 25 0.662 0.739 0.875 0.674 2.683 0.405 1.820 0.690 0.952 0.00 8.891 0.724 0.044 0.151 1.832 0.864 0.689 0.781 0.817 0.703 0.675 0.974 0.943 0.634 0.651 1.988 0.659 0.983 0.25 1.676 2.880 0.383 1.681 0.743 0.210 1.735 1.671 0.739 0.829 0.078 0.00 4.952 0.067 1.809 0.916 0.698 0.864 0.677 0.789 0.40 1.918 0.015 0.636 0.640 0.690 0.762 0.025 0.670 1.765 0.683 0.793 0.50 4.755 0.185 1.570 1.730 0.621 0.75 2.919 1.469 1.656 0.722 0.0% 5.186 1.709 0.722 0.959 1.387 1.841 0.669 0.800 0.696 0.623 1.755 0.749 3.859 0.712 0.780 0.656 0.888 0.00 2.005 1.928 0.731 0.966 2.792 0.25 3.645 0.611 -8EFLIGHTOPS.0% 20.50 3.669 0.703 0.626 0.698 0.792 0.689 0.777 0.093 1.629 0.50 0.721 0.75 1.185 1.698 0.537 2.786 0.30 0.016 3.765 0.0% 25.795 1.20 2.651 0.643 2.Severity Analysis (Continued) CFM56 Severity Factor Table Flight Length (Hours) Effective Derate 0.729 1.50 5.866 0.733 0.749 0.663 0.813 0.837 0.686 4.791 0.35 0.966 1.795 2.816 0.819 0.855 0.553 1.757 0.502 2.933 0.75 3.874 0.250 1.0% 15.681 0.122 1.715 0.50 1.805 0.0% 10.646 0.000 0.335 1.651 0.775 0.653 3.959 0.750 0.742 0.50 7. It is not intended for use in pricing maintenance contracts.00 9.850 0.168 1.859 0.920 0.00 5.00 12.079 1.00 6.274 1.50 3.50 6.153 2. NOTES 139 .00 10.950 0.712 2.121 0.639 0.150 1.722 0.0% 0.617 0.820 0.900 0.239 1.236 1.678 0.771 0.909 0.PPT This chart is used for illustrating the concept of severity factor.740 0.652 0.771 0.848 0.043 1.00 1.00 3.991 0.297 1.709 0.00 4.575 2.400 1.632 0. 2877 0.3717 0.3017 0.3250 0.3323 0.3683 0.50 9.4500 0.3707 0.3047 0.50 5.3057 0.2967 0.3490 0.4033 0.3300 0.50 0.3050 0.75 1.3647 0.0433 0.2723 0.3580 0.25 0.3473 0.00 20.00 3.0773 0.3540 0.00 1.PPT NOTES 140 .2923 0.2907 0.2200 0.50 8.3507 0.3730 -8EFLIGHTOPS.3010 0.3597 0.3030 0.3720 0.2100 0.50 10.00 11.7100 0.3210 0.3023 0.2470 0.50 6.3723 0.00 13.3063 0.4807 0.2800 0.2993 0.3767 0.3380 0.3883 0.00 4.3303 0.00 5.3033 0.3727 0.3280 0.8667 0.3003 0.3403 0.3667 0.50 7.1110 0.5200 0.1790 0.00 19.3630 0.5717 0.3220 0.00 16.3043 0.00 12.3040 0.3570 0.2600 0.3533 0.2980 0.3027 0.3713 0.2400 0.00 P T/O P CL P CR 0.0900 0.00 14.3053 0.50 4.2930 0.3037 0.3090 0.3213 0.3413 0.50 2.3693 0.Severity Analysis (Continued) CFM56 Partial Derates Flight Time Hours 0.00 18.2843 0.3623 0.3233 0.00 8.1410 0.00 7.3440 0.1500 0.3697 0.3357 0.4233 0.00 17.3240 0.6400 0.2700 0.1883 0.00 6.3350 0.00 2.3227 0.00 15.7817 0.00 9.3450 0.3263 0.3060 0.3207 0.2950 0.50 3. partial derate Climb derate 10%.4% reduction in severity -8EFLIGHTOPS.3% 11. 1 (CFM56) .PPT NOTES 141 . partial derate Cruise derate 15%.956 • Approximately 4. .1% – Variant • • • • • • 2.3% 13.2% 2.0-hour flight leg Takeoff derate 15% .0-hour flight leg Takeoff derate 10%.861 ÷ 0.861 7. partial derate Effective derate Severity factor: 0. .6% 3.8% 2.901 = 0. partial derate Effective derate Severity factor: 0.901 5. partial derate Climb derate 10%.6% 3.7% – Severity ratio (variant/baseline) = 0. varying takeoff derate (increase from 10% to 15%) – Baseline • • • • • • 2.Severity Analysis (Continued) • Example No. partial derate Cruise derate 15%. 3% 8. partial derate Effective derate Severity factor: 0.Severity Analysis (Continued) • Example No. partial derate Effective derate Severity factor: 0.950 5. partial derate Climb derate 5% .2% 0.0-hour flight leg Takeoff derate 10%.3% 9.922 ÷ 0.3% 3.PPT NOTES 142 .0-hour flight leg Takeoff derate 10%.0% 3. . . varying climb derate (increase from 0% to 5%) – Baseline • • • • • • 2.8% – Severity ratio (variant/baseline) = 0. partial derate Climb derate 0%.9% reduction in severity -8EFLIGHTOPS. 2 (CFM56) . partial derate Cruise derate 15%.971 • Approximately 2.950 = 0.2% 1.922 5.5% – Variant • • • • • • 2. partial derate Cruise derate 15%. NOTES 143 .PPT This chart represents the relative impact of reduced thrust increments on severity. but that the slope is still substantially positive even at the higher increments of reduced thrust.Severity Analysis (Continued) 2-Hour Flight Leg Climb Derate = 10% Cruise Derate = 10% Estimated Severity Reduction Due to the Use of Reduced Takeoff Thrust Estimated Severity Reduction % 0 5 10 15 20 25 Average Takeoff Reduced Thrust . This shows that the first increment of thrust reduction is the most important but that thrust reduction even at the higher increments is important.% -8EFLIGHTOPS. Note that the slope of the curve is greater in the 0 to 5% increment than in the 20 to 25% increment. PPT This chart shows that the impact of climb thust reduction on severity. 144 . is not as great as for takeoff thrust reduction. while still positive. NOTES Although climb thrust reduction may reduce engine severity.Severity Analysis (Continued) 2-Hour Flight Leg Takeoff Derate = 10% Cruise Derate = 10% Estimated Severity Reduction Due to the Use of Reduced Climb Thrust Estimated Severity Reduction % Takeoff Climb 0 5 10 15 20 25 Average Climb Derate Thrust .% -8EFLIGHTOPS. its use may actually increase fuel burn on a given flight because of the lesser time spent in the highly fuel efficient cruise phase of flight. Performance Aspects • Logic for calculating reduced takeoff N1 with the assumed temperature method: Note: this logic is incorporated in your FCOM/Operations Manual procedures – not a manual crew calculation – 1. Convert this corrected N1 back to the gage N1 using the actual temperature • This gage N1 value will yield a corrected N1 (and thrust) equivalent to that achieved in Step 3 -8EFLIGHTOPS. Find allowable assumed temperature using takeoff analysis chart – 2.PPT NOTES 145 . Convert the gage N1 (maximum) for the assumed temperature to a value of corrected N1 using the assumed temperature • This represents the thrust required if actual temperature was equal to assumed temperature value – 4. Find gage N1 (maximum) corresponding to assumed temperature – 3. Find max N1 N1K at TF decorrected to N1 at ambient TA for TF ∆N1 3.Performance Aspects (Continued) 1.PPT This is a graphic representation of the logic on previous chart NOTES 146 . 2. N1 max at TF corrected N1K to N1K at TF ∆N1K N1 TISA TA TFRT TF OAT N1 = Physical (gage) N1 N1K = N1 corrected for temperature -8EFLIGHTOPS. Obtain max assumed temp (TF) from airport analysis N1 with no thrust reduction 4. takeoff weight will be 52.16) = 88.9 X (20 + 273.9% 93.PPT NOTES 147 . Temperature is 20oC.7% 87.16 -8EFLIGHTOPS. wind is calm.9% corrected N1 at 20oC is 88.16) = 87. CFM56-3B-2 (22k rating) engines.16 • The gage N1 for 87.8 ÷ (55 + 273.8% • The corresponding corrected N1 is 87.Performance Aspects (Continued) • Calculating reduced thrust N1 using the assumed temperature method – Example 1 737-400.9 288.300 kg • From the takeoff analysis the assumed temperature will be 55oC • From the takeoff N1 chart the gage N1 at 55o is 93.7 288. the performance margin is greater than for a full thrust takeoff at an ambient temperature equal to the assumed temperature -8EFLIGHTOPS. – Reduced thrust takeoffs meet or exceed all the performance requirements of the FAA and other regulatory agencies – For a reduced thrust takeoff at a given assumed temperature. however.PPT NOTES 148 .Performance Aspects (Continued) • For a given takeoff. there is obviously more performance margin at full thrust than at reduced thrust. V-speeds are based on assumed temperature while aircraft is operating under ambient temperature conditions – Thus.Performance Aspects (Continued) • For reduced thrust case. TAS at a given V-speed is less • Significant improvement in field length performance • No significant impact on climb-out performance -8EFLIGHTOPS.PPT NOTES 149 . 210 F. 16°C.07% 3.500 6.A.500 6.036 16.022 Accelerate-stop distance (engine out) (ft) 6.PPT NOTES 150 . The actual take-off weight permits an assumed temperature of 40°C Temperature (oC): 40 16 assuming 40 %N1 95 91.022 Accelerate-go distance (all engine) (ft) 5. field length .990 Second segment gradient 3.19% 475 474 Second segment rate of climb – ft per minute -8EFLIGHTOPS.5 V1 (KIAS/TAS) 137/143 137/137 VR (KIAS/TAS) 139/145 139/139 V2 (KIAS/TAS) 146/153 146/146 Thrust at V1 (lb per engine) 16.400 4.Performance Aspects (Continued) • For Example: a B737-300 (CFM56-3B2) at sea level.R.ft 6.006 Accelerate-go distance (engine out) (ft) 6.500 6. NOTES 151 . Note that there are many hard decision rules and discretionary decisions on the part of the pilot that may result in full thrust takeoffs or takeoffs at less than maximum allowable reduced thrust.Tools to Analyze Reduced Thrust Programs Process Map (Typical) Does one or more of the following conditions exist: Preflight planning • • • • Calculate allowable reduced thrust using: Perfom demo required Brake deactivated Anti-skid inop Other MMEL items No •Load sheet •Runway data •Winds •Outside air temperature Full Thrust Takeoff Performed Yes • • • • • • No Yes Yes Does one or more of the following conditions exist: Is reduced thrust precluded by performance requirements? Contaminated runway Noise abatement required De-icing performed Wind shear forecast Anti-ice for T/O Tailwind for T/O No Deviation due to pilot discretion? No Yes Pilot’s choice Takeoff performed at reduced thrust but not max allowable Takeoff performed at max allowable reduced thrust At time of takeoff -8EFLIGHTOPS.PPT This is a process map for a typical operator with the typical company restrictions on reduced thrust discussed earlier in this presentation. – Every tenth takeoff – Every Friday – Never make dedicated full thrust T/O for performance verification • Take credit for ECM and full thrust T/O’s performed for operational reasons • Less reduced thrust benefits acrue when unnecessary full thrust takeoffs are performed • Full thrust takeoffs meaningful only when takeoff is performed at the flat rate temperature. otherwise the takeoff data must be extrapolated to flat rate temperature – Reduced thrust takeoffs can be extrapolated as well – Cruise ECM data can also be used to predict ITT margin • Negotiate with regulatory agency to extend interval between dedicated performance verification takeoffs – Take credit for ECM programs (T/O or Cruise) – Take credit for full thrust takeoffs performed for operational requirements – Extrapolate data obtained during reduced thrust as well as full thrust takeoffs -8EFLIGHTOPS.PPT NOTES 152 .g.Periodic Takeoff Demonstrations • Operator methods vary e. PPT NOTES 153 .Summary • Reduced thrust benefits – – – – – Longer on-wing time between engine refurbishment Fewer operational events due to high ITT Lower fuel burn over on-wing life of engine Lower probability of engine failure on a given takeoff Lower maintenance costs • Severity analysis helps estimate reduced thrust impact on engine severity factor – Reduced thrust has significant impact on severity – Takeoff thrust reduction has greater impact than climb thrust reduction – 1st increment of thrust reduction has greatest impact -8EFLIGHTOPS. Summary (Continued) • Reduced thrust takeoffs meet or exceed FAR or other regulatory requirements – Significant margin due to operation at actual ambient temperature while V-speeds are based on assumed temperature • May be useful to look at steps in reduced thrust process where use of reduced thrust might be compromised -8EFLIGHTOPS.PPT NOTES 154 . Erosive FOD and Volcanic Ash -8E FLIGHTOPS.PPT NOTES 155 . Erosive FOD • What is it? – Dust – Sand – Volcanic ash – Debris from deteriorated runways/ramps/taxiways -8EFLIGHTOPS.PPT NOTES 156 . Effect on Engines • Erodes airfoils resulting in: – Reduced parts life – Reduced ITT margin – Increased fuel consumption – Reduced airfoil strength (extreme case) – Reduced stall margin (extreme case) • Blocks cooling flow passages – Higher temperatures for hot section parts • May be incurred in single occurrence or cumulatively from frequent exposures -8EFLIGHTOPS.PPT NOTES 157 . volcanic ash) • High FOD potential areas: – Desert and coastal airports – Airports with: • Construction activity • Deteriorated runways/ramps/taxiways • Narrow runways/taxiways • Ramps/taxiways sanded for winter operations • Plowed snow/sand beside runways/taxiways -8EFLIGHTOPS. ramps • Airborne particles (dust. sand.PPT NOTES 158 . taxiways.Sources • Contaminated runways. Engine Vortices • Common cause of ingestion on ground • Strength increases at high thrust. low airspeed • Somewhat destroyed by: – Airspeed – Headwind – General rules: • 10 knots airspeed/headwind will destroy vortices formed up to 40% N1 • 30 knots airspeed will destroy vortices formed at typical takeoff thrust settings -8EFLIGHTOPS.PPT NOTES 159 . Engine Vortex (CF6 Engine) -8EFLIGHTOPS.PPT NOTES 160 . test 2 20 0 10 20 30 40 Air speed relative to inlet. test 1 455-115/4 in Cell 2 1/6 model. % Vortex 70 No vortex 50 40 30 Legend 1/16 model. knots -8EFLIGHTOPS.PPT NOTES 161 .Airspeed Effect on Vortex Formation (Data from scale model and actual engine ground tests) 111 102 N1. PPT NOTES 162 .High Exposure Operations • Thrust advance for breakaway from stop • 180 degree turn on runway or taxiway – Overhang of unprepared surface – Thrust assist in turn from outboard engine • Thrust advance for takeoff • Reverse thrust at low airspeed • Power assurance runs -8EFLIGHTOPS. if possible • Minimize taxi thrust – Avoid allowing aircraft to come to complete stop • Reverse during taxi only for emergency stopping • Avoid taxiing closely behind other aircraft where FOD may be blown -8EFLIGHTOPS. leave engines at idle • Minimize breakaway thrust – Less than 40% N1.PPT NOTES 163 .Recommendations/Considerations • Avoid engine overhang of unprepared surface – If unavoidable. Recommendations/Considerations (Continued) • Minimize thrust for crossbleed starts – Just high enough for adequate manifold pressure – Consider location for minimum FOD prior to crossbleed start • Minimize thrust assist from outboard engine in 180 degree turn. particularly if outboard engine overhangs unprepared surface • Rolling takeoffs. if possible (follow aircraft manufacturer procedures) – 30 kias destroys vortices formed at typical takeoff thrust settings -8EFLIGHTOPS.PPT NOTES 164 . if practical • Most installations are certified for full thrust use to 60 kias (without engine instability) but re-ingestion of exhaust gases/debris may occur at full reverse thrust below 80 kias – Select forward thrust at taxi speed and before clearing runway -8EFLIGHTOPS. if necessary – Start reducing reverse thrust per aircraft operations manual • For FOD conditions. at 80 kias.PPT NOTES 165 .Recommendations/Considerations (Continued) • Reverse thrust – Minimize reverse thrust use on contaminated runways – Reverse thrust is more effective at high speed • Use high reverse thrust early. PPT NOTES 166 .000 engine) “Training information only” Reverse thrust 737-300/CFM56-3 SL/Std day Flaps 40 150 100 50 0 2.Effect of N1 and Airspeed on Net Reverse Thrust Knots TAS 8.000 (lb per engine) 200 “Training information only” Reverse thrust 747-400/CF6-80C2 SL/Std day Flaps 30 150 100 60 30 0 4.000 Net 12.000 reverse thrust 8.000 0 30 40 50 60 70 80 90 100 Percent N1 Percent N1 -8EFLIGHTOPS.000 Net 6.000 reverse thrust (lb per 4.000 0 20 30 40 50 60 70 80 90 Knots TAS 16. PPT In 1982.500 ft. torching from the tailpipe.000 ft and 30. It has been shown that the weather radar cannot be relied on to detect volcanic ash. Successful airstarts were accomplished by 12.000 ft resulting in immediate flameout of all four engines. Elmo’s fire/static discharges Orange glow in engine inlets Multiple engine malfunctions/flameouts Note: Ash may be difficult to detect at night and weather radar is not an effective means of detection -8EFLIGHTOPS. engines surges/stalls. aircraft surfaces were eroded. In one of these incidents. power loss and flameout. Elmo’s fire and an orange glow in the engine inlet. high ITT Severe engine damage. windshield visibility was restricted and airspeed readings were unreliable due to blocked pilot systems.000 ft. power loss Encountered at all altitudes • Recognition – – – – – Smoke/dust in cockpit Odor similar to electrical smoke St. NOTES The volcanic dust affected the engine by causing rapid erosion of the compressor and build up of fused volcanic ash on the HPT nozzles and blades. In 1989. the ash is difficult to detect at night or in clouds but other indications may be present such as St. Also.Volcanic Ash • Problem – – – – – Ash builds up on HPT nozzles and blades Nozzle area reduced. 167 . The result is increased ITT. serious engine damage occurred. cooling holes blocked Engine surges/stalls. two 747 aircraft experienced multiple engine flameouts/shutdowns as a result of flying through volcanic dust at 37. all four engines lost thrust within 50 seconds. In all cases. a 747/400 entered a cloud of volcanic ash at 25. 000 feet • Dust/smoke in cockpit immediately after cloud entry • Maximum climb thrust selected to climb out of ash -8EFLIGHTOPS. B747-400 descended in Mt.PPT NOTES 168 . Redoubt ash cloud • Ash cloud had visual characteristics of normal overcast • Cloud entry at 26.CF6-80C2B1F Encounter • December 1989. 300 feet • Subsequent operation normal.200 feet.CF6-80C2B1F Encounter (Continued) • After approximately one minute at high power. all four engines lost thrust (spooled down to below idle) • After five or six start attempts. engine No. 2 restarted at 17. engine No.PPT NOTES 169 . but higher ITT levels -8EFLIGHTOPS. 4 restarted at 13. 1 and No. 3 and No. PPT NOTES 170 .Fan and Spinner • Spinner erosion was evident • Fan blades were dusted with ash • Fan blade outer panel leading edges were slightly roughened • Light polishing was required to restore original finish -8EFLIGHTOPS. PPT NOTES 171 .-8EFLIGHTOPS. Stage 10 • Leading edge erosion near the blade tip – Resulted in concave leading edge profile • Blades were razor sharp on the corners and tips -8EFLIGHTOPS.PPT NOTES 172 .High Pressure Compressor Blades. -8EFLIGHTOPS.PPT NOTES 173 . PPT NOTES 174 .3 inch • Ash buildup caused reduction in nozzle flow area – Increased compressor operating line – Reduced stall margin – Lowered HPT efficiency -8EFLIGHTOPS.Stage 1 High Pressure Nozzle Guide Vanes • Surface deposits were recrystallized ash • High temperature operation formed harder ceramic layer – Total ash thickness was approximately 0. -8EFLIGHTOPS.PPT NOTES 175 . Stage 1 HPT Blade • All blades were eroded down to the tip cavity • Cooling holes appeared to be open • No indication of overtemperature • Most blades not reusable due to excessive tip wear -8EFLIGHTOPS.PPT NOTES 176 . -8EFLIGHTOPS.PPT NOTES 177 . Volcanic Ash • Recommendations – – – – – – – AVOID FLIGHT NEAR VOLCANIC ACTIVITY Fly on upwind side of dust If in dust. NOTES 178 . restart using published procedures – Resume normal operations upon exiting dust -8EFLIGHTOPS. the lower ITT will reduce the debris build up in the HPT. if volcanic ash is encountered. At high altitude engines are slow to accelerate to idle which may be interpreted as a failure to start. the best policy is to avoid ash clouds. However. Other procedures can be accomplished to reduce engine damage and possible loss of power. Turning on all bleed systems increases the stall margin. exit immediately Turn on continuous ignition Turn off auto-throttle Reduce thrust to idle or low as practical Turn on all available airbleed systems • Wing and nacelle anti-ice • A/C packs on high – If engine is shutdown/flameout. immediate action should be taken to leave the cloud by the shortest distance/time. Successful starts may not be possible until clear of the ash cloud and within the airstart envelope. Turning off the auto-throttle prevents thrust levers from increasing thrust to recapture airspeed that is indicating low due to pitot system blockage with ash. attempt restart(s) using flight manual procedures.PPT Since severe consequences can result by flying through volcanic ash. By reducing power when encountering ash. If the engine is shutdown due to overtemperature/stalls or flameouts. ” By turning bleed on. The locus of points of pressure ratio versus compressor airflow (airflow is higher at higher power settings) represents the “compressor operating line. reducing what we call “stall margin. NOTES When the engine encounters volcanic ash.” There is also a locus of points (above the operating line) of pressure ratio versus compressor airflow at which the compressor will stall. we lower the pressure ratio required for a given airflow. the operating line of the engine goes up toward the stall line. the flow will be disrupted through the compressor.5 Stall line Stall Margin (volcanic ash) Stall Margin (Normal) Operating Line (Volcanic Ash) Operating Line (Normal) Compressor Air Flow P3 = compressor discharge pressure P2.Compressor Stall Margin P3/P2. 179 . This build up of ceramic material causes a higher pressure ratio to drive the same amount of air through the engine. the ash melts in the combustor of the engine and then deposits itself as a ceramic material on the stators (nozzles) leading into the high pressure turbine. that is. lowering the operating line and restoring some of the stall margin that is lost because of the volcanic ash encounter.PPT The engine high pressure compressor operates at a given pressure ratio (compressor inlet pressure/compressor discharge pressure) to push a given amount of air through the compressor.5 = compressor inlet pressure Volcanic ash build up on HPT nozzle raises operating line Bleeding engine lowers operating line -8EFLIGHTOPS. thus. . PPT NOTES 181 .Inclement Weather Operation -8EFLIGHTOPS. PPT NOTES 182 .Inclement Weather Operation • Rain and Hail • Icing Conditions -8EFLIGHTOPS. PPT NOTES 183 .Rain and Hail • FAR 33 Requirements – Water ingestion 4% by weight of engine airflow-idle to takeoff thrust • Confirm operability (acceleration and stall/flameout resistance) in heavy rain – Hail Testing • Confirm mechanical integrity after FOD – Volleys of large hailstones fired at takeoff thrust • Confirm operability in heavy hailstorm conditions (smaller hailstones but heavier concentration) -8EFLIGHTOPS. NOTES 184 .HWC) • Rain: 20 g/m3 (LWC) at 20.LWC.PPT Hail is a more severe engine operating environment than is rain.000 feet -8EFLIGHTOPS.Rain and Hail (Continued) • Weather threat – Worst case precipitation occurs in convective storms – Threat (Liquid Water Content . or Hail Water Content .000 feet • Hail: 10 g/m3 (HWC) at 15. the hail threat occurs at a lower water content than rain. thus. PPT NOTES 185 .Rain and Hail (Continued) • Effect on engine operation – Reduces engine tolerance to: • Engine rollback • Surge/stall • Flameout • Effect varies with: – Engine speed – Aircraft speed – Engine configuration/geometry – Type of precipitation -8EFLIGHTOPS. PPT In rain and hail conditions. the engine requires a higher WF/PS3 ratio to maintain a given N2. At this point N2 will roll back on the accel schedule. which may lead to a flameout.Rain and Hail (Continued) Migration of Operating Line Accel schedule Rollback Fuel flow (WF) Burner pressure (PS3) Operating line in water Operating line dry Decel schedule Core speed (N2) -8EFLIGHTOPS. NOTES 186 . The WF/PS3 ratio to run at a given N2 eventually is constrained by the maximum accel schedule. Thus. NOTES Practically speaking. In general. creating a more severe operating environment for the engine. At lower aircraft speeds this air spillage is not as great. 187 .Rain and Hail (Continued) Scoop Factor Effect • Inlet air spillage at low engine RPM/high aircraft speed increases engine face water/air ratio • High engine RPM/low aircraft speed decreases engine face water/air ratio by reducing air spillage -8EFLIGHTOPS. the water/air ratio increases. the crew cannot vary airspeed much due to the requirement to maintain turbulence penetration airspeed in a thunderstorm. it is more practical to increase engine speed. This same spillage of water does not occur. At higher aircraft speeds and lower engine speeds.PPT An air/water column enters the engine at the inlet. some of the air “spills” over at the inlet. PPT The “coniptical” spinner is a compromise between the conical and elliptical and is used on the newer engine models.Rain and Hail (Continued) Configuration effects • Coniptical spinner . NOTES 188 . CFM56-7 and CF34-8E -8EFLIGHTOPS.used on new GE/CFMI engines Coniptical Conical Elliptical Note: This spinner design is on the GE90. PPT NOTES 189 .Rain and Hail (Continued) • GE/CFM analysis and testing – Driven by CFM56-3 flameouts in late 1980’s – Extensive analysis – Ground test • Water and hail (necessitated developing new test rig) • CFM56-3 (various configurations) • CF6-50 (as baseline…this engine was the standard) – Flight test • Water only…USAF KC135 tanker with water flow capability • B707 test bed with CFM56-3 engine installed • A300B with CF6-50 engines installed – Correlated flight tests with ground tests -8EFLIGHTOPS. Airbus. Although extremely unlikely. In any case. avoidance of thunderstorms and hail by overflight or circumnavigation is always a prudent course. 190 . with all CFM56 FADEC (auto-relight) engines on their airplanes does not have a procedure.PPT These are generic recommendations made by an industry committee formed to address the issue of power loss in rain and hail conditions. For commonality with the NG airplane they have the same procedure even though the CFM56-7 installation has the auto-relight feature.Rain and Hail (Continued) • Operational recommendations – Avoidance – If encountered: • • • • • • Ignition-on Engine anti ice-as required by FCOM/OM Auto-thrust-off Increase engine speed. Boeing has the discussion on the following chart for the B737 classic. NOTES For example. These recommendations have been incorporated to various degrees by the aircraft manufacturers. depending on applicability and manufacturer philosophy. there is always a possibility that the airplane could encounter conditions more sever than those to which the engine/airplane is certified. if practical Avoid rapid thrust lever movements APU-start (if available) – If power loss is experienced • Use appropriate published aircraft manual procedures – Note: Restart may not be possible until exiting rain/hail conditions -8EFLIGHTOPS. which is nonFADEC and does not have auto-relight capability. Icing Areas of Engine Icing HPC first Stages Inlet Spinner Fan blades Fan OGV’s -8EFLIGHTOPS.PPT NOTES 191 . Icing Areas of Engine Icing (Continued) • Spinner shape – Conical: Provides best ice accretion characteristics (minimizes) – Elliptical: Provides best hail ingestion capability – Coniptical: A compromise between ice accretion characteristics and hail ingestion capability Conical Elliptical Coniptical • Fan icing appears on leading edge and pressure face of the fan blades and decreases from the root to the tip (centrifugal effect) -8EFLIGHTOPS.PPT NOTES 192 . PPT NOTES 193 . CFM56-5A -8EFLIGHTOPS.Spinner Ice Build Up. PPT NOTES 194 .Spinner Ice Build Up. CFM56-3 -8EFLIGHTOPS. Fan Blade and OGV Ice Build Up.PPT NOTES 195 . CFM56-3 -8EFLIGHTOPS. etc. power loss.Icing (Continued) • Effects on engine – Operability • Ice ingestion into HPC may cause compressor stall.PPT NOTES 196 . – Engine hardware • Ice slab ingestion may cause damage to fan or compressor – External source – Late application of engine anti-ice • Ice shed from fan or spinner may cause acoustic panel or fan blade tip damage • Asymmetric ice accretion on the fan and spinner may cause high vibration -8EFLIGHTOPS. Icing (Continued) • Recommendations – – – – Anti-ice system protects inlet cowl lip only Use engine anti-ice during all defined icing conditions Turn on anti-ice prior to entering icing conditions Perform ice shed procedure as prescribed in aircraft operations documents – If ice is inadvertently allowed to accumulate on the inlet • Retard one engine at a time to idle before turning A/I on • Turn A/I on. monitor engine while increasing thrust -8EFLIGHTOPS.PPT NOTES 197 . Icing (Continued) Removal of Ice/Snow Prior to Engine Start .PPT NOTES 198 . use fan/spinner ice shedding procedures prior to takeoff • May result in economic damage to engine -8EFLIGHTOPS.Recommendations De-ice inlet. spinner and fan prior to engine start – Use hot air if practical • Ensure any melted ice/snow does not refreeze near fan blades (check for fan rotation prior to engine start) – De-icing/anti-icing fluid may be used if hot air de-icing is not practical • Engine must be off • Avoid spraying de-icing/anti-icing fluid into engine compressor – Do not spray de-icing/anti-icing fluid into a running engine • May cause “hot corrosion” of turbine components • May result in increased maintenance costs – If fan/spinner cannot be deiced prior to starting. with particular attention to engine parameters prior to final advance to takeoff thrust -8EFLIGHTOPS. pressure increase and adiabatic temperature rise (typical rise across fan is about 20°F) – Perform this procedure • Every 30 minutes • Just prior to or in conjunction with the takeoff procedure. increase to approximately 54 percent N1 and hold at that thrust level for 30 seconds or until fan vibration level returns to normal • Allows immediate shedding of fan blade root and spinner ice • De-ices stationary vanes with combination of shed ice impact.PPT NOTES 199 .Icing (Continued) Ice Shedding (Ground) • Ground operation in icing conditions – During ground operations of more than 30 minutes in icing conditions or if excessive fan vibration due to fan ice accumulation is present. reduce towards idle then advance to a minimum of 70% N1 for 10 to 30 seconds. then return thrust lever to position required for flight conditions – Repeat every 15 minutes or as often as required -8EFLIGHTOPS.Icing (Continued) Ice Shedding (Flight) • While in moderate or severe icing conditions and – If fan ice build up is suspected (high indicated or perceived vibration): • One engine at a time.PPT NOTES 200 . PPT NOTES 201 .Typical CF6 Icing Event • Low power descent caused ice build-up • When power applied at level off. ice started shedding and vibs increased dramatically at about 70% • Vibs reduced with further acceleration and subsequent deceleration -8EFLIGHTOPS. Typical CF6 Icing Event (Continued) Ice shed point 100 90 9 80 8 70 7 60 %N1 10 6 N1 50 5 40 4 30 3 20 2 10 0 1 Fan vibes 0 20 40 Fan vibes (units) 60 80 100 120 140 160 180 0 Time (seconds) -8EFLIGHTOPS.PPT Indications on other engine models would be similar. NOTES 202 .