Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013, 17: 127-137EXPERT SYSTEM FOR FAILURE ANALYSISONLEADING EDGE FLAP AND SLATPOSITION INDICATING SYSTEM BOEING 737NG Vicky Diaz Nevangga, Romi Wiryadinata Electrical Engineering Department, Sultan Ageng Tirtayasa University - UNTIRTA
[email protected] Abstract Number of aircraft accidents occurred within the last few decades led toaircraft manufacturers continue updating the technology in their products, however air transportation accidents were still happen, with one of the cause were due to failure on the flaps and slats which was parts of the flight controls system. This study aims to determine the factors of failure of Leading Edge Flap and Slat Position Indicating System Boeing 737NG series aircraft and design expert system decision makers for maintenance of the system. The method of analysis in this study conducted in three phases, namely graph analysis, FMEA (Failure Mode Effect Analysis) approach and the analysis through simulation of a forward chaining expert system using MATLAB. Analysis shows that the most cases occured in Leading Edge Flap and Slat Position Indicating System was light illuminate cases and the proximity sensor failure was one cause. Another factor affecting the failure is the aircraft ages, the older the aircraft, the level of aircraft’s reliability and allof the components will decrease. Key Words: accidents, aircraft,flap slat, failures, expert system 1. Introduction Air transport plays an important role in supporting the economic growth of a country. One of important factor that is required to achieve reliable air transportation is good conditions of aircraft, to meet safety and security requirements. Aircraft maintenance is conducted on a regular basis in accordance with the established regulations by the world's civil aviation organization ICAO (International Civil Aviation Organization), the world air transport association IATA (International Air Transport Association), and the Indonesian aviation authorities (Office of Airworthiness Indonesia). The number of aircraft accidents that occurred within the last few decades led to the aircraft manufacturers are constantly updating the technology on the aircraft products, but in fact variety of accidents involving air transportation continues to happen. If analyzed, in general a plane crash can be caused by the following factors namely human error, engineering problem, and weather condition. Of the three factors above, which become the focus of discussion in this paper is the second factor, namely engineering problem and will be devoted to the case of flight controls failure. This research was conducted at PT. GMF which is an SBU (Strategic Business Unit) of PT Garuda Indonesia Group. GMF AeroAsia does care and maintenance of the entire fleet of PT Garuda Indonesia, including Boeing 737 Next Generation Series which is the object of this research. 2. Literature Review 2.1. Flight Control System Flight control system consists of three parts, the main part (Primary / Main Control Surface), which consists of aileron, elevator, and rudder, then the secondary part (Auxiliary Flight Control Surface), or commonly referred to as secondary Flight Control Surface consisting the flaps, slats, and speed brakes, as well as tertiary section (Supplementary Flight Control Surface)15). Figure .1. Flight Controls Design 127 The use of flaps and slats when landing would be useful to reduce speed and maintain a stable plane11). inboard and outboard sensor reading each target position. Speed brakes(spoiler) Speed brake alsocalled drive flaps / spoilers which used to slow down the aircraft during flight and descent. LE (Leading Edge) Flap and Slat Position Indicating System In this system there are 30 pieces of distance sensors (proximity sensors). Figure 2 shown for LE slat 2-4. 2. 4. and when at the fully extend position only outboard sensor that reads the target. and outboard sensors. 2. this indicator has 2 pieces of colors: green and amber. The figure 3 shows all the indicator light (LE flap 1-4 and LE slat1-8) after the test button is pressed. The picture is shown for LE slat 1. Aileron Aileron function is to control the aircraft movement roll to the right or left which is called roll. and each of the three pieces of slat numbers 2 to 7. Figure 2. 5. When at the retracted position. When at the retracted position. Elevator Elevators function is to move the plane ride (climb) and down (descend) which is called pitch up and pitch down. while LE slat 5-7 in contrary position to the figure. 3. 17: 127-137 1. While in the LE slat 2 to 7. Figure3. when extended position only inboard sensor that reads the target. Wing flaps & slats Wing flaps and slats are used to give lift force whose function is to reduce the path length through the runway by the time plane taking off. The distance sensor measures the position of a moving target with the surface. when at extended position the inboard sensor only that reads the target.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. 128 . At LE slat 1 and 8 there are 2 pieces proximity sensor that is in board and outboard sensor. The proximity sensor sends data to the FSEU. Working Principle of Proximity Sensor schematic on the LE Slat Schematic working principle of proximity sensor on the LE slat (Figure 2) can be described as follows. LE Devices Annunciator Panel Leading edge devices annunciator panel is an indicator components of LE flaps and slats which is found on the overhead panel in the cockpit. which is a normal procedure in checking the condition of the indicator lights15). while on LE slat 8 contrary to the position in the figure. each of the two pieces on each LE flap and slat numbers 1 and 8. there are 3 types of proximity sensornamely inboard sensor. retract sensor. speed brakes provide lateral control. while in spoilers system as speed brakes. In deal with the aileron. and when at the fully extended position the outboard sensor only that read the target. the retract sensor only that reads the target position. which also known as yaw.2. Rudder Rudder function is to provide the plane maneuver to the right or left of that . then FSEU use this data to control the LE devices annunciator panel in the cockpit. namely: The cause of a potential failure of the system. explanation facilities. and inference engine. 2. product design and process during its life cycle. evaluation and implementation of the final stage. workplace. recommended actions.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. journals. Expert System Expert System is a branch of AI (Artificial Intelligence) or computer-based artificial intelligence that uses knowledge. namely the collection of data by making observations to the PT GMF to know about how the leading edge slat and flap position indicating system in Boeing 737 Next Generation series works with a wide variety of cases. namely 13): 1. 129 . Research Methode Design and analysis methods in this study requires the completion of steps using scientific methods. product design and process. Research design. Literature study. To build such a system like it. Development environment. expert. the following basic components should be included: 1. AMM (Aircraft Maintenance Manual) and CMM (Component Maintenance Manual). To build a system that functioned to mimic a human expert should be able to do things that can be done by experts. selection tools. Inference engine Figure4. as well as to obtain data required parameters used in this study. and other materials related to the system flaps and slats on aircraft flying through books.4. FMEA is an engineering evaluation of system reliability to determine the effect of the failure of the system. verification and validation. implementation. the part used by non-expert users to gain knowledge. knowledge engineer. FMEA Failure Mode and Effect Analysis (FMEA) is a systematic approach that applies a method creating tables to help the thought process used by engineers to identify potential failure modes and their effects. the development of software systems in accordance with step by step on Expert System as follows: problem identification. Components included in this section are user. knowledge improvement. 2. analysis and knowledge acquisition. The effect of these failures. 2. Field studies. 3. and inference engine.3. 17: 127-137 2. Knowledge base 3. learn and understand the basic theory of the Expert System. the part which is used to insert expert’s knowledge into an expert system environment. FMEA (Failure Modes and Effects Analysis) is defined as a technique that identifies three things. In general. knowledge representation. The critical level failure effects on the function of the system. Components included in this section are knowledge base. User interface 2. 3. and reasoning techniques to solve a problem that usually can only be solved by an expert in that field6). Failure characterized by a given impact on the success of a mission of a system. Expert System Structure Expert System has two main parts. The methods used in this study are: 1. interface. facts. research. Consultation environment. visualization. Research Design In the rule-based expert system. Therefore. After processing and data selection. MATLAB is widely used in the areas of research that require complex numerical computation. 17: 127-137 4. 3. Analysis of the results of testing and making conclusions. domain knowledge represented in a collection of IF-THEN-shaped.80GHz (4 CPUs) Memory : 4096 MB RAM System type : 64-bit Operating System Op. MATLAB has the capability of integrating computation. Model : K46CM Rating : 4. Hardware The hardware used in this study is a laptop with the following system specifications: Manufacturer : ASUSTek COMPUTER INC. table design and decision-making tree corresponding forward chaining method.9 (Windows Experience Index) Processor : Intel (R) Core(TM) i3-3217U CPU @ 1.1. 7. Testing expert system according to the reference of the expert. MATLAB is a programming language with high ability in the field of computing.1. Expert System General Design Flowchart 130 . Comparing interference engine each rule stored in the knowledge base with the facts contained in the database. Software This study used MATLAB software. namely the development of software systems in accordance with step by step on Expert System as follows: database design. and analysis of second phasewith FMEA method approach. 3. analysis of first phase by using a graphic display.2. Figure5.3. then design interface (GUI). 5. and programming. while the data represented in a collection of facts about the incident at this time. System : Windows 7 Ultimate (6. Design of an expert system which is the third stage of the analysis. Build 7600) Product ID : 00426-OEM-8992662-00400 While display device specification as follows: Name : Intel(R) HD Graphics 4000 Manufacturer : Intel Corporation Chip Type : Intel(R) HD Graphics Family DAC Type : Internal Total Memory : 1696 MB Monitor : Generic PnP Monitor 3. whether it is as expected or not.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. 6. Table 2. 9. 11. 17. 25. 23. while the action is the proceeding taken by the engineers in solving problems. 19. Table1. Table Contents Design While designing the contents of the table. 7. 8. 21. 6. 22. 2. this study used some codesfor represent the problem. there is another code which also used to represent the action. 8. 17: 127-137 The block diagram for the Expert System in this study are as follows. 1. 13 14. 27. Figure6. the following tables informed some phase or condition contained on the problem with the code.Action Code(Phase) No. 2. 29. 28. 10. 16. 7. 1.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. 4. 5. 26. Condition/phase Taxi Take off Climb Cruise Descend Approach Landing No remarks Code TAXI (A) T/O (B) CLB (C) CRZ (D) DES (E) APP (F) LDG (G) NO RMK (H) After knowing the code of the problem. Action Adjustment Alternate and Asymmetry Check Circuit Breaker Clean Clear Computer Connection Electrical Flight Data Acquisition Unit Flap Slat Electronic Unit Flaps / Slats Hydraulic Indicator Leading Edge Left Hand Mechanical Message Operational Check Performance Position Proximity Recycle Replace Reposition Retract Trailing Edge Transmitter 131 Code adj alt n assy chk CB cln clr comp conn elect FDAU FSEU F/S hyd ind LE LH mech msg OPC perform post prox rcl rpl repost ret TE tx . 12. 30.Problem Code(Phase) No. 15. 4. 18. 6. 3. Expert System Block Diagram 3. 24. 3. 20. 5.4. 7. 17: 127-137 Table 3. 2. Position Flap 1 (F1) Flap 2 (F2) Flap 3 (F3) Flap 4 (F4) Retract A1 A2 A3 A4 Extend B1 B2 B3 B4 Table 3 is a problem code for theflap position with 2 classifications that are in retracted flaps (docked) or extended (widen) flap1 to 4. This study used 4 pieces of the task FIM 27-88 803 numbers up to 806.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013.Action Code (FIM Task) No. Position Slat 1 (SL1) Slat 2 (SL2) Slat 3 (SL3) Slat 4 (SL4) Slat 5 (SL5) Slat 6 (SL6) Slat 7 (SL7) Slat 8 (SL8) Inboard C1 C2 C3 C4 C5 C6 C7 C8 Outboard D1 D2 D3 D4 D5 D6 D7 D8 Table 4 is a code table to position the slat problem with the classification of 2 position i.e. 3. Table5. 1. 1. 3. 8. 2.5. 4. Inference Mechanism Inference is the process to generate information from known or assumed facts. 4. 6. Action FIM 27-88 TASK 803 FIM 27-88 TASK 804 FIM 27-88 TASK 805 FIM 27-88 TASK 806 Code P Q R S Table 5 is the encoding of action that leads into the FIM task engineer / mechanic while doing aircraft maintenance process. 3. 3. Inference is a logical conclusion (logical conclusion) or implications based on the information available. 5.Problem Code (Flap Position) No. 1. START Problem Name For I = 1 Input Value Problem do If problem1 = true And problem 2 = true Then Search for Solution If Solution found Then Displaying Solution I FINISH Figure7.Problem Code (Slat Position) No. 4. Table4. Forward Chaining Process Flowchart 132 . inboard slat and outboard slat in location from slat 1 through slat 8. 2. Figure 9. 18. and so on) is the representation of the problem that is in accordance with Table 1. 6. In this expert system design using advanced tracking reasoning (forward chaining) which start from a set of facts about a problem that is given by the user as an input system. 17. B. 2. 25. C. 3. Figure can be seen in Figure 10 below. 43. 1. 46 IF (B AND D AND F AND G AND H) THEN 7 IF (B AND D AND H) THEN 37 IF (D AND G AND H) THEN 22 IF (D AND H) THEN 15 IF (E AND F) THEN 6 Rules can be explained briefly that the code letter (A. 32. 8. 36. Combined Decision Tree II Figure 9 is a decision tree based on the location of the position parameters of the likelihood of error. 3. 28. Rules No. 7. 27. 24 IF D THEN 1. 17: 127-137 3. 5. 45. 2. GUI Design Modeling expert system that is designed to use graphical user interface configuration (graphic user interface) or commonly called a GUI in MATLAB programming. 30 IF F THEN 33.10. which is between 1 to flap flap and slat 4 slat 1 to 8. Combined Decision Tree I In this study made a joint decision tree obtained from several decision tree. 9. 35. 8 . 31. GUI design is designed with the format. 21. 9. Knowledge Basis Representation Table6. 3. 20. 42. 5. 16. 133 . While the code numbers (1. 34 IF C THEN 23. 19. For the inference process can be seen in Figure 7 which is a picture of the system solutions expert search using flowchart or flow charts. 10 11.6. 38. 11.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. 29. 26. This decision tree is based coding has been waged and refer to Table 1 is a table problem code (phase) and Table 2 is table action code number (phase). 40. 13. and so on) is a representation of the action in accordance with Table 2. 44 IF H THEN 12. RULES IF A THEN 4. 3. Decision Tree Figure 8.8.7. then tracking is performed calculations to final destination a possible diagnosis and the value of the damage caused to his beliefs. 4. 14. 39 IF G THEN 2. 41. Fig 8 explains the composite image of six decision tree for the input and output parameters phase. 3. flaps stuck. 134 . 17: 127-137 Figure10. Classification of cases that do only take 3 pieces of the most common cases. Then take one piece case that is most common in both types of aircraft.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. starting from the case and case classification B737NG causing operational delays (delay) with the data span January 2010 . 40 30 Flaps assymetry 20 Flaps stuck 10 0 GE* GF* GM* Light illuminate Figure11. B737NG aircraft. the light illuminate the error displayed chart based on the time span of each month in 2010. the asymmetry flaps. and 2012. 2011. Result 4. and illuminate light error. Results Analysis Phase I Here are 5 pieces of graph analysis of data obtained from the PT GMF.1. 8 6 Flaps assymetry 4 Flaps stuck 2 0 GE* GF* GM* Light illuminate Figure12. B737NG Case Classification – Delay Caused Figure 12 graphs show results similar to the previous chart. Matlab GUI figure 4. registered PK-GE* and the case of light illuminate the error is still at the highest chart position.May 2012. B737NG Case Classification Figure 11 drawing graphs shows that the B737NG aircraft with registration number PK-GE* is the most experienced flight cases and cases in each registration is light illuminate error. it is known that the metal material of the proximity sensor-based aluminum has poor reliability. in contrast to the following year (2011) in Figure 14. 17: 127-137 10 GE* 5 GF* Nov Sep Jul May Mar Jan 0 GM* Figure13. Light Illuminate Error Cases in B737NG – 2010 From Figure 13 looks aircraft. 4. when a review of the field to the PT. Results Analysis Phase II From the results of table creation FMEA (Failure Mode Effect Analysis) can be determined one cause of failure in the Leading Edge Flap and Slat Position Indicating System caused by the failure of the proximity sensor. Results Analysis Phase III After the analysis of conventional data processing stage 1 with the output of graphics display and analysis using FMEA table stage 2. 4 3 GE* 2 GF* 1 GM* 0 Jan MarMay Jul Sep Nov Figure14. the proximity sensor is replaced with a titaniumbased metal that has a better reliability in accordance with the maintenance standards. causing many problems. 135 .2. stage 3 analysis by simulation with an expert system using MATLAB programming language. GMF and this thesis report is being structured. Light Illuminate Error Cases in B737NG – 2011 Graph in Figure 15 shows the number of cases that occurred in 2012 until May. which means the fluctuating graph has many cases of light illuminate error. 4 GE* 2 GF* GM* 0 Jan Feb Mar Apr May Figure15. registered PK-GM* and PK-GF* yet many are having problems in its first year in operation (2010).3. After unpacking the causes of failure (failure mode). Therefore. Light Illuminate Error Cases in B737NG – 2012 4.Here are the results and display the GUI (Graphic User Interface) of the expert system program has been created.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. Figure 17. and the parameters included in this phase is TAXI. and SL1SL8 Inboard. SL1-SL8 OUTBOARD. Matlab GUI Expert System Default Shown in figure 16 is a MATLAB GUI after the program is executed. 3. F1-F4 EXTEND. RCL FSEU. The procedure is also 136 . LANDING and NO REMARKS. Example Display Result 1 In Figure 17 is an example of the display when the parameters entered F1 retract position. 2. When the program is executed (Run). 2. This means the option maintenance action to be taken is to clean the surface of the sensor and check the LE flap. Whereas the phase parameters TAXI. as well as by cleaning switch on slat # 6. operational check. Position parameters retract the F1-F4. then the action will be seen advice column 1. CLN slat # 6 switches and 27-88 TASK 806 FIM Task column. Figure 18. Block problem has 2 input parameters namely position and phase. CLN sensor and Chk LE flap surface. In the FIM Task column visible suggestion to refer to the FIM 27-88 TASK 805. This indicates an optional action that is checked flaps performance. RPL prox sensor OPC flap LE. or replace proximity sensor flap Leading Edge. Example Display Result 2 Figure 18 is an example of the display when the position parameters and parameter F2 EXTEND CLIMB execution phase. CRUISE. TAKE OFF. Descend. CLIMB.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. 17: 127-137 Figure 16. with 3 separate blocks of the problem as an input parameter and action as well as the FIM Task as outputs and outcomes. which results in the form of information on the action column 1. APPROACH. recycle FSEU. Chk flaps perform. this is provided by data in the field that shows the registered PK-GE* of B737NG aircraft.(2008). the scope of the object only focuses on the system that is the ATA 27-88 discusses the Leading Edge Flap and Slat Position Indicating System. (2010). Nugraha. et. M. it can be concluded as follows: 1. Vol. Suggestion Suggestions relating to the study.al. S.. P. R. A. A. (2011). & Septi A. ICT Research Center UNAS. & Gary D. (2005). Leading Edge Flap and Slat Indication system must be supported with good care and maintenance and routine so that system reliability can be maintained. Yogyakarta: Penerbit Andi. Failure cases occured in the Leading Edge Flap and Slat Position Indicating System of Boeing 737NG aircraft. 137 . GMF. & Sri W. Broto. Hartati. there is a Leading Edge Flap and Slat Position Indicating System failure caused by improper use of material (stainless steel) for proximity sensor. (2011). the relatively older age compared to the registered PK-GM* and PK-GF*. Sistem Pakar untuk Mendeteksi Kerusakan Kulkas LG Tipe GR-S512 Menggunakan Aplikasi Mobile. et. 4. (2013). TELKOM (Studi Kasus). (2005). 17: 127-137 done according to what is contained in the FIM 27-88 TASK 806. from the most frequent. Boston: Thomson Course Technology. 1. (2011). After analyzing the test results. and flaps asymmetry. Jurnal SNATIKA. (2001). For further research is expected to expand the scope of the object. Sistem Pakar Teori dan Aplikasi. Yogyakarta: Penerbit Andi. Sistem Pakar: Mengidentifikasi Kerusakan Gangguan Sambungan Telepon PT. Konsep Dasar Sistem Pakar. T. Jurnal Informatika. Another factor affecting the failure is the aircraft fleet age. (2006). Sutojo. 3 No. Expert Systems Principles and Programming. C. Kusumadewi. 3. Expert system designed in this work is still modest. have more frequent system failures. 5. J. Kusrini. Sistem Pakar & Pengembangannya. stuck flaps. Schoensleben. Rony.. Vol. Skripsi Jurusan Teknik Elektro Universitas Sultan Ageng Tirtayasa Cilegon. Rangkuti. H. In the research that has been done.which has a better reliability level in accordance with the maintenance standards. namely: 1. ___.Proceedings International Seminar of Aerospace Science and Technology 17th SIPTEKGAN -2013. S. Integrated Trailing Edge Flap Track Mechanism for Commercial Aircraft. it is shown that referral from FIM (Fault Isolation Manual) expert system is in 100% agreement with the referral from existing experts. respectively. 737-600/700/800/900 Aircraft Maintenance Manual. Wulandari. (2005). 4. Conclusion Based on the research that has been conducted in accordance with the formulation of the problem and existing research purposes. & Sari I. Edisi 01 Tahun 2011. M. The older age of the fleet. Artificial Intelligence (Teknik dan Aplikasinya). Pengembangan Media Pembelajaran Sistem Pelacakan pada Mata Kuliah Kecerdasan Buatan Berbasis Multimedia. Flight Controls. when further developed will be great potential in improving the performance of human resources in the company. Deteksi Kerusakan Notebook dengan Menggunakan Metode Sistem Pakar. References 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) Arhami. S. D. Yogyakarta: Penerbit Andi. Jurnal Artificial. Sistem Pakar Diagnosa Operasi Kraniotomi Berbasis Web dengan Metode Forward Chaining Menggunakan Data CT-Scan. Giarratano. United States of America: Boeing Corp. (2003). Ferdian. Makalah Penelitian Jurusan Ilmu Komputer FMIPA Universitas Pakuan Bogor.al. Chapter 27. S. E. The expert system is a decision maker tool that was first created in PT. Kecerdasan Buatan. S.Swiss Federal Institute of Technology Zurich. A. 2. Based on the analysis of FMEA. Perancangan dan Implementasi Sistem Pakar untuk Analisa Penyakit Dalam. A. (2009). 5 No. Skripsi Jurusan Teknik Elektro Fakultas Teknik Universitas Diponegoro Semarang. are light illuminate case. Yogyakarta: Graha Ilmu. 2 Juli 2011. Action is taken to replace the component with a titanium proximity sensor. the level of reliability of the aircraft and all the components in it will decrease..Yogyakarta: Penerbit Graha Ilmu. but can be developed further with more complex algorithm in the next research. 2. 3. (2008).