FADEC

1. FADEC

2. What is FADEC? Digital Electronic Controls Design Requirements : Modern Engine Control System Why is FADEC Preferred? A Backgrounder Location of FADEC Electronic Aspects of FADEC How does FADEC work? FADEC : Functions FADEC : Essential Features FADEC : Infrastructure (Simplified) Schematic Diagram Advantages & Limitations FADEC

3. WHAT IS FADEC? • FADEC:(Full Authority Digital Engine Control System) • adigital electronic control system • able to autonomously control the engine • - throughout its whole operating range • - in both normal and fault conditions

4. WHAT IS FADEC? FADEC:(Full Authority Digital Engine Control System) - has a self-monitoring, self-operating, redundant & fail-safe setup - comprises of a digital computer and the other accessories (that control all the aspects of aircraft engine performance)

5. WHAT IS FADEC? • FADEC:(Full Authority Digital Engine Control System) • key system of gas turbine engines • provides optimum engine efficiency for a given flight condition • also controls engine starting and restarting.

6. WHAT IS FADEC? • FADEC:(Full Authority Digital Engine Control System) • -lowers the work-load of pilots, • - reduces the occurrence of pilot errors, • provides for efficient engine operation.

7. WHAT IS FADEC? FADEC:(Full Authority Digital Engine Control System) allows the manufacturer to -program engine limitations and -receive engine health and maintenance reports.

8. WHAT IS FADEC? - no form of manual override available - places full authority to the control of operating parameters of the engine in the hands of the computer. - if a total FADEC failure occurs, the engine fails.

9. WHAT IS FADEC? Note:If the engine is controlled digitally and electronically but allows for manual override, it is considered solely an Electronic Engine Control(EEC)or Electronic Control Unit(ECU). An EEC, though a component of a FADEC, is not by itself FADEC. When standing alone, the EEC makes all of the decisions until the pilot wishes to intervene.

10. DIGITAL ELECTRONIC CONTROL The benefits of digital electronic control of mechanical systems are evident in greater precision and an ability to measure or predict performance degradation and incipient failure. Typical examples of this are digital implementations of flight control or fly-by-wire (FBW) and digital engine control, or Full-Authority Digital Engine Control (FADEC).

11. DIGITAL ELECTRONIC CONTROL Integrated Flight and Propulsion Control (IFPC) allows closer integration of the aircraft flight control and engine control systems. Flight control systems are virtually all fly-by-wire (FBW) in the modern fighter aircraft of today; the benefits being weight reduction and improved handling characteristics.

12. Speed / Accuracy / Ease of Control (Least Aircrew Workloads) Wide Operational Range Reliability & Operational Safety Low Operating & Maintenance Costs Should Not Add Weight Fuel Efficiency Dependable Starts DESIGN REQUIREMENTS OF MODERN ENGINE CONTROL SYSTEM

13. WHY IS FADEC PREFERRED? New engines are adopting FADEC for -the benefits offered by digital control, -improved reliability and performance, -weight-reduction and -other improvements in system integration and data flow.

14. The FADEC systems were first used in the automotive Industry where it is well proven. Now-a-days airlines and the militaries all over the world incorporate it on turbine powered aircraft. FADECs are made for piston engine and jet engines both but they differ in the way of controlling the engine . A BACKGROUNDER

15. Advanced, intelligent & robust propulsion controls are critical for improving the safety and maintainability of future propulsion systems. Propulsion system reliability is considered to be critical for aircraft survival. Hence, FADEC systems came into being. A BACKGROUNDER

16. FADEC is now common on many engines. Semiconductor and equipment cooling technology has advanced so that control units can now be mounted on the engine and still provide highly reliable operation for long periods. A BACKGROUNDER

17. Developing and implementing modern intelligent engine systems requires the introduction of numerous sensors, actuators and processors to provide the advanced functionality. A BACKGROUNDER

18. The application of artificial intelligence and knowledge-based system for both software and hardware provides the foundation for building the intelligent control system of the future. A BACKGROUNDER

19. With time, control systems became more sophisticated with the introduction of additional engine condition sensors and multiple servo-loops. A BACKGROUNDER

20. The task of handling engines was eased by the introduction of electronic control in the form of magnetic amplifiers in early civil and military aircraft. A BACKGROUNDER

21. The magnetic amplifiers allowed engines to be stabilized at any speed in the throttle range by introducing a servo-loop with engine exhaust gas temperature as a measure of engine speed and an analogue fuel valve to control fuel flow. A BACKGROUNDER

22. Transistors, integrated circuits and high temperature semi-conductors have all played a part in the evolution of control systems from range temperature control through to full digital engine control systems. A BACKGROUNDER

23. This allowed the pilot to accelerate and decelerate the engine while the control system limited fuel flows to prevent over- speeds or excessive temperatures. A BACKGROUNDER

24. With modern FADEC systems there are no mechanical control rods or mechanical reversions, and the pilot can perform carefree handling of the engine throughout the flight envelope. A BACKGROUNDER

25. On modern aircraft the engine is supervised by a computer to allow the pilot to operate at maximum performance in a combat aircraft or at optimum fuel economy in a passenger carrying aircraft. A BACKGROUNDER

26. Today, each FADEC is unique and therefore is expensive to develop, produce, maintain, and upgrade for its particular application. A BACKGROUNDER

27. In the future, it is desired to establish a universal or common standard for engine controls and accessories. This will significantly reduce the high development and support costs across platforms. A BACKGROUNDER

28. LOCATION OF FADEC FADEC is normally located on the engine fan casing. Therefore, FADEC cooling is difficult.

29. LOCATION OF FADEC However, there are many features of engine control which are distributed around the engine – such as reverse thrust, presently pneumatically actuated – which would need to be actuated by alternative means in a more-electric engine. This leads to the possibility of using distributed engine control.

30. ELECTRONIC ASPECTS OF FADEC Modern ECUs use a microprocessor which can process the inputs from the engine sensors in real time. An electronic control unit contains the hardware and software (firmware).

31. ELECTRONIC ASPECTS: FADEC The hardware consists of electronic components on a printed circuit board (PCB), ceramic substrate or a thin laminate substrate. The main component on this circuit board is a microcontroller chip (CPU).

32. ELECTRONIC ASPECTS : FADEC The software is stored in the microcontroller or other chips on the PCB, typically in EPROMs or flash memory so the CPU can be re-programmed by uploading updated code or replacing chips. This is also referred to as an Electronic Engine Management System (EMS).

33. HOW DOES FADEC WORK? FADEC works by receiving multiple input variables of the current flight condition including air density, throttle lever position, engine temperatures, engine pressures, and many others.

34. HOW DOES FADEC WORK? Each FADEC is essentially a centralized system, with a redundant, central computer and centrally located analog signal interfacing circuitry for interfacing with sensors and actuators located throughout the propulsion system.

35. Engine operating parameters such as fuel flow, stator vane position, bleed valve position and others are computed from this data and applied as appropriate. HOW DOES FADEC WORK?

36. For example, to avoid exceeding a certain engine temperature, the FADEC can be programmed to automatically take the necessary measures without pilot intervention. The inputs are received by the EEC and analyzed up to 70 times per second. HOW DOES FADEC WORK?

37. HOW DOES FADEC WORK? FADEC computes the appropriate thrust settings and applies them. During flight, small changes in operation are constantly being made to maintain efficiency. Maximum thrust is available for emergency situations if the throttle is advanced to full, but remember, limitations can’t be exceeded.

38. HOW DOES FADEC WORK? Another new feature of the FADEC system is the ability to record the last 900 hours of flight. With readings taken every second, this stored information can be used to diagnose problem areas as well as review recent flight history.

39. FADEC : FUNCTIONS FADEC

40. Control & Monitoring of Engine Operations Dual Channels & Redundancy Engine Life Monitoring Record of Engine Performance Parameters Automated Troubleshooting Memory Read or Recall of Engine Data Control of Common Engine Problems Display of Warnings Adaptation Isochronous Idle Speed FADEC : ESSENTIAL FEATURES

41. CONTROL OPERATIONS IN GAS TURBINE ENGINES FADEC :INFRASTRUCTURE

42. CONTROL OPERATIONS IN GAS TURBINE ENGINES - Air Control (Compressor Entry) - Fuel Control (Main / AB / Starting System) - Starting & Ignition Control - Lubrication Control - Surge Control (Through Bleed Valve) - Thrust Control (Through Exhaust Nozzle) - Vibration Control (Through Air / Fuel Control) FADEC: INFRASTRUCTURE

43. SAMPLE CHAIN OF CONTROL (MECH.) OPERATION FADEC: INFRASTRUCTURE GEAR DRIVEN MECHANICAL PUMP WORKING FLUID FROM ENGINE / AIRCRAFT ACTUATED ASSEMBLY MECHANICAL ACTUATORS ELECTRO-HYDRO-MECHNICAL CONTROL UNIT SERVO ACTUATING MOTORS POSITION SENSORS SOLENOID VALVES POSITION SENSOR-1 POSITION SENSOR-2 FADEC COMPUTER AIRCRAFT COMPUTER COCKPIT

44. SAMPLE CHAIN OF CONTROL (ELECT.) OPERATION FADEC : INFRASTRUCTURE ELECTRO-HYDRO-MECHNICAL CONTROL UNIT MECHANICAL ACTUATORS FADEC COMPUTER POSITION SENSOR-1 POSITION SENSOR-2 SERVO ACTUATING MOTORS POSITION SENSORS SOLENOID VALVES PILOT’s THROTTLE IN COCKPIT VARIOUS INPUTS FROM AIRCRAFT POWER SUPPLY DISPLAY PANEL IN COCKPIT VARIOUS INPUTS FROM / COMMANDS TO ENGINE

45. HARDWARE: - Dual Power Supply - FADEC Computer (With Logic Circuit PCBs & Programmed / Programmable Memory) A Set of Servo Actuating Motors / Solenoid Valves / Position Sensors (for every System Control Unit) Dual Position Sensors for Actuators (of every System) A Set of Electrical Harnesses (for every System) Display Panel with Indicators / Warning Lights (in Cockpit) Multiple Engine RPM, Pressure Sensors & Thermocouples Pilot’s Throttle FADEC: INFRASTRUCTURE

46. SOFTWARE: -EPR Schedules (For Thrust, over Entire Range of Engine Operation Without FADEC Computer Failure) - N Schedules (For Thrust as per Pilot’s Throttle, Engine Operation in case of Limited FADEC Computer Functionality) Note:In case of certain degree of FADEC failure, there is an automatic mode switch-over from EPR to N rating. However, if the failure disappears, the pilot can reset the mode to switch-back to EPR mode. FADEC : INFRASTRUCTURE

47. INPUTS: From Aircraft. Ambient Temperature Altitude Mach Number Angle of Attack Impact Pressure Landing Gear Position Missile / Rocket Firing Signals etc. FADEC: INFRASTRUCTURE

48. INPUTS: From Engine. Throttle Lever Position RPM Turbine Outlet / Exhaust Gas Temperature Exhaust Nozzle Area Fan Duct Flaps Position Bearing Temperatures Engine Vibration Engine Pressures FADEC: INFRASTRUCTURE

49. SIMPLIFIED FADEC ARCHITECTURE FADEC: INFRASTRUCTURE FADEC LANE-A FADEC LANE-A MONITOR FADEC LANE-A CONTROL ENGINE THRUST DEMAND ENGINE FUEL DEMAND FADEC LANE-B FADEC LANE-B MONITOR FADEC LANE-B CONTROL

50. SIMPLIFIED FADEC ARCHITECHTURE This simplified architecture is typical of many dual-channel FADECs. There are two independent lanes: Lane A and Lane B. FADEC: INFRASTRUCTURE