If there is any conflicting information, your FCOM shall be the overriding reference.
Q1. What are the various sections of an engine?
A1. The following are the various sections of an engine:-
(a) Air Inlet
(c) Combustion Chamber
Q2. What do you mean by N1?
A2. N1 is the low pressure compressor/turbine and fan rotational speed expressed in percentage.
Q3. What do you mean by N2?
A3. N2 is the high pressure compressor and turbine rotational speed expressed in percentage.
Q4. What do you mean by EPR?
A4. EPR is short for Engine Pressure Ratio. The EPR instrument provides a readout of the ratio of the turbine discharge total pressure to the compressor inlet total pressure.
Q5. What do you mean by EGT?
A5. EGT is short for Exhaust Gas Temperature. This is the temperature of the gases escaping at the exhaust of an engine, the temperature atthe outlet from the turbine is usually measured bysuitably positioned thermocouples.
Q6. What is the meaning of hot start?
A6. A Hot Start is one of the starting malfunctions in a Jet Engine. During starting if the temperatures inside the combustion section get hot enough to cause internal damage to the engine, a Hot Start is said to have occurred.
Q7. What is the meaning of hung start?
A7. A Hung Start is one of the starting malfunctions in a Jet Engine. During start, if the EGT becomes higher than what would be expected for the RPM at which the engine has stabilized, which itself is lower than the self-sustaining speed, a Hung Start is said to have occurred.
Q8. What do you mean by no light up of an engine?
A8. Light up in an engine is indicated by the increase in EGT, thus, if there is no rise in EGT, it indicates a no light up.
Q9. What is FADEC? What is its other name?
A9. FADEC is short for Full Authority Digital Engine Control. FADEC, also called the Electronic EngineControl (EEC), is a digital control system that performscomplete engine management.
Q10. How many channels does the FADEC computer have?
Q11. What are the functions of the FADEC?
A11. The following are the functions of FADEC:-
(a) Control of Gas Generator
(b) Protection against engine exceeding limits
(c) Power management
(d) Automatic engine starting sequence
(e) Manual engine starting sequence
(f) Thrust reverser control
(g) Fuel recirculation control
(h) Transmission of engine parameters and engine monitoring information to cockpit indicators
(i) Detection, recording and isolation of failures
(j) FADEC cooling
(k) Protection against fan flutter
Q12. How is the FADEC powered?
A12. The FADEC system is self-powered above 10 % N2.In case of a FADEC self-power loss, the aircraft electrical network automatically supplies the FADEC.
Q13. What happens during Auto-Start on ground?
a) When you select the ENG MODE selector to IGN/START,
b) When you select the ENG MASTER switch to ON.
A13. The following happens during Auto start on ground:
(a) ENG MODE selector to IGN/START :
-START IDENTIFICATION: ECAM displays ENG page
-PACK valve closes
(b) ENG MASTER ON:
-LP fuel valve opens
-START valve opens
-After automatic dry crank sequence
*HP fuel valve opens
-When N2 > 43 %
*START valve closes
*Pack Valve reopens
Q14. What are the conditions when ECAM of ENG “START FAULT” can come for an engine during auto-start?
A14. The following are the conditions:
(a) ENG IGNITION FAULT: the engine does not start within 20 seconds that follow the ignition start
(b) NO N1 Rotation
(d) EGT Over limit
(e) Hung Start
Q15. What happens during AUTO Start on ground, if FADEC detects a hot start, hung start or no light up?
A15. The FADEC will immediately shut off fuel and turn off ignition. After any start attempt that is not successful, a dry crank automatically occurs. At the end of the dry crank sequence, the start valve is closed.
Q16. During engine start, if the amber FAULT light illuminates on the ENG MASTER panel. What could have gone wrong? What does this light indicate?
A16. The amber FAULT light comes on, and a caution appears on ECAM, if there is:
(a) An automatic start abort
(b) A start valve fault
(c) A disagreement between the HP fuel valve position and its commandedposition.
Q17. What is the meaning of “AUTO CRANK IN PROGRESS” message appearing on E/WD during auto start?
A17. After any start attempt that is not successful, a dry crank automatically occurs. This auto dry crank sequence is initiated by the FADEC and is what the E/WD message means.
Q18. What happens after Dry Crank sequence during Auto start?
A18. At the end of the dry crank sequence, the start valve is closed.
Q19. Will FADEC always perform second start if first attempt is aborted by it?
Q20. During Auto-Start usually one igniter is on. Do you remember any situation during auto start when both igniters come on? What is that?
A20. If the automatic start fails, the FADEC energizes both igniters at the same time during thesecond attempt at an engine start.
Q21. What happens when N2 > 43% during AUTO start of the engine?
A21. The following happens:
àWhen N2 > 43 %
*START valve closes
*Pack Valve reopens
Q22. What happens when N2 >50% during AUTO Start?
A22. Above 50% N2, the FADEC would not run an abort sequence if a start aborts on the ground.
Q23. What is the role of FADEC during auto-start of an engine?
A23. This sequence is under the full authority of the FADEC, which controls:
‐ The start valve
‐ The igniters
‐ The fuel HP valves
‐ detects a hot start, a hung start, a stall, or no light up
‐ announces FAULT and identifies the fault in an ECAM message
‐ Runs an abort sequence if a start aborts on the ground when N2 < 50 %
• closes the HP valve
• closes the start valve
• turns off ignition
• cranks the engine crank after the start abort in order to clear out fuel vapors
‐ ensures an automatic dry crank sequence of 30 s at maximum motoring speed.
Q24. When can you say that engine start sequence is over?
A24. When the following parameters are reached:
– N1 about 21.4 %
– N2 about 57.8 %
– EPR about 1.01
– EGT about 414 deg Celsius
– FF about 350 kg/h
è AVAIL indication is displayed
è Grey background on N2 indication disappears.
The engine start sequence is supposed to be over.
Q25. What does the FADEC control during Manual engine start?
A25. The FADEC has limited authority over manual starting controlling:
‐ The opening of the start valve when the ENG MODE selector is set to IGN/START and the MAN
START pushbutton switch is pressed.
‐ The position of the HP fuel valve and the operation of both igniters, when the master switch is turned ON
‐ The closing of the start valve at approximately 43 % N2, and, on the ground, the cutting off ofIgnition.
The FADEC makes a passive survey of the engine during the starting sequence (up to 50 % N2).
Q26. During a manual start, how is the start valve opened?
A26. During a manual start, the start valve is opened by switching on the ENG MAN START P/b to on.
Q27. What takes place when you push the MAN START button during manual start of engine?
A27. The Start Valve opens.
Q28. What happens when you select Master Switch to ON, in Manual Start?
A28. The following happens:
– Both igniters come on.
– LP and HP fuel valves come on.
– When N2 > 43%, start valve closes and if on ground, ignition stops.
Q29. Does the FADEC provide EGT limit protection constantly?
Q30. How do you carry out dry cranking cycle, if required manually?
A30. The flight crew can manually select cranking by setting the ENG MODE selector to CRANK and theMAN START pushbutton switch to ON (MASTER switch OFF).
Q31. During a manual start, are the automatic start interruption and auto-crank functions available?
Q32. During a manual start of the #1 engine, does the ENG MAN START pushbutton have to be depressed to close the start valve?
Q33. Due to a tailwind of greater than 10 knots the crew should select the Manual Engine Start procedure. Give examples of other conditions that may require a Manual Engine Start.
A33. Manual starting is recommended in the following cases:
->After aborting a start, because of:
-Engine stall, Engine EGT over limit, LO START AIR PRESS, or No N1 rotation, or Hung start.
->When expecting a start abort, because of:
-Degraded bleed performance due to hot conditions or at a high altitude airfield.
-An engine with a reduced EGT margin, in hot conditions or at a high altitude airfield
-Marginal performance of the external pneumatic power group.
Q34. During an engine start sequence, the gray background on N2 disappears at about 57%. What does this indicate?
A34. This indicates that the start sequence has been completed.
Q35. FADEC takes care of start abort or recycle of engine starting but only on ground and that too in Auto-Start.
True / False?
Q36. What is the Manual Engine Start procedure?
A36. Manual Engine start sequence:
- ENG Mode selector to IGN/START
- ENG MAN START p/b ON
- At Max Motoring (min. 20% N2) select ENG Master switch ON
Fuel and ignition will begin when ENG Master selected ON
At 50% start valve closes, ignition off
- At idle, about 58%, ENG MAN START p/b OFF
- ENG mode selector to NORM
Q37. What is the limitation of engaging start valve/motor vis-à-vis N2?
A37. Starter limit:
o Three consecutive cycles: 2 cycles of 2 min each, followed by a third cycle of 1 min.
o Time between start attempts is 15 sec,
o Cooling period after three attempts or 4 minutes of continuous cranking: 30 min
No starter engagement with N2 > 10% on ground and 18% in flight.
NOTE! Reader’s comment:
“A37) Limitation given in A37 are for CFM.
3 consecutive cycles : 2 cycles of 2 min each, followed by a 3rd cycle of 1 min .
Pause between start attempts : 15 s.
Cooling period, following 3 start attempts or 4 min of continuous cranking : 30 min.
No running engagement of the starter, when N2 is above 10 % on ground, and 18 % in flight.”
Q38. What is an indication that the start sequence is complete?
A38. The following are the indications:
– N1 about 21.4 %
– N2 about 57.8 %
– EPR about 1.01
– EGT about 414 deg Celsius
– FF about 350 kg/h
à AVAIL indication is displayed
à Grey background on N2 indication disappears.
Q39. If a thrust lever is set between two detents, what is the rating limit?
A39. When a thrust lever is set between two positions, the FADEC selects the rating limit corresponding to the highest mode.
Q40. When is Continuous ignition provided automatically?
A40. Continuous ignition is provided automatically when:
à EAI selected on
à TOGA/FLEX Thrust selected
à EIU data failed
à Approach idle selected
à In-Flight unscheduled sub-idle or surge
à Master lever cycled from ON to OFF then back to ON.
Q41. On ground, after engine start, how would the PF select continuous ignition on the engine?
A41. On the ground after the engine is started, because ignition cuts off automatically, the flight crewmust switch the ENG MODE selector to NORM then back to IGN/START to turn on continuousignition.
Q42. What is keep-out zone?
A42. The range of N1 60-74 % is the Keep-out zone. When on ground at low speed (less than or equal to M 0.1), the Electronic Engine Computer(EEC) protects against fan flutter. In so doing, the EEC prevents the engine from being stabilized in this zone.
Q43. What is RATED N1 Mode?
A43. If no EPR is available (either sensed or computed) the affected FADEC will automatically revert toN1mode.An automatic reversion to rated N1 mode occurs in the event of loss of sensed EPR. This occurswhen P2 (engine inlet total pressure) and/or P5 (LP turbine exit total pressure) engine parameters are not available.
Q44. What are the indications if an engine goes to Rated N1 Mode?
A44. In the Rated N1 Mode, EPR indications are lost. N1 Mode indication is displayed in Blue on E/WD. The N1 rating limit, corresponding to the thrust lever position, and the N1 thrust limit modearedisplayed in blue.
Q45. What is UN-RATED N1 Mode?
A45. . If no EPR is available (either sensed or computed) the affected FADEC will automatically revert to N1 mode.An automatic reversion to unrated N1 mode occurs in the event of loss of computed EPR due tothe loss of T2 (engine inlet total air temperature) or ambient pressure (ambient pressure enginesensor) engine parameters.
Q46. What are the indications if an engine goes to Un-Rated N1 Mode?
A46. In the Un-Rated N1 Mode, the N1 rating limit, N1 TLA and maximum N1 indications on ECAM E/WD are lost.
Q47. How is Unrated N1 mode identified to the crew on ECAM?
A47. In the Un-Rated N1 Mode, the N1 rating limit, N1 TLA and maximum N1 indications on ECAM E/WD are lost
Q48. What is LVR ASYM?
A48. When one thrust lever is in the CL detent and the other one out of detent, the “LVR ASYM”amber message comes up on the FMA until both levers are set in the CL detent (only with both engines operative).
Q49. What is LVR CLB? LVR MCT?
A49. LVR CLB: Flashes white (3rd line on the FMA) if the thrust levers are not in CL position while the aircraft is above the altitude of thrust reduction with both engines running.
LVR MCT: Flashes white (3rd line on the FMA) if the thrust levers are not in MCT position after an engine failure (with speed above green dot).
Q50. What do you mean by Modulated Idle?
A50. Modulated idle
‐ Is regulated according to:
• Bleed system demand
• Ambient conditions
‐ Is selected:
• In flight, when the flaps are retracted (FLAPS lever at zero position)
• On ground, provided reverse is not selected.
Q51. What do you mean by Approach Idle?
A51. Approach idle
‐ Is regulated according to aircraft altitude, regardless of bleed system demand.
‐ Is selected in flight, when the flaps are extended (FLAPS lever not at zero position)
‐ Allows the engine to accelerate rapidly from idle to go-around thrust.
Q52. How the thrust is controlled
a) When A/THR active?
b) When A/THR is just armed and not active?
A52. Thrust control:
(a) When A/THR active: In the auto thrust mode (A/THR function active), the FMGC computes the thrust, which is limited tothe value corresponding to the thrust lever position (unless the alpha-floor mode is activated).
(a) When A/THR is just armed and not active: In these conditions, each engine is controlled by the position of its thrust lever. The pilot controls thrust by moving the thrust lever between IDLE and TOGA positions. Each positionof the thrust lever within these limits corresponds to an EPR.
Q53. Is there a mechanical connection between the thrust levers and the engines?
Q54. Which igniters are working when performing a manual start of an engine?
Q55. Before starting the engine, THRUST LEVERs have to be at IDLE.
If THR LEVERS are not at idle, what will happen?
A55. Engines will start, regardless of the thrust lever position; thrust will rapidly increase to the corresponding thrust lever position, causing a hazardous situation, if thrust levers are not at IDLE. Moreover, an ENG START FAULT ECAM warning will be triggered.
Q56. If no FLEX TEMP is set, then only TO/GA power can be selected?
Q57. If the thrust levers are set in the idle detent, is Alpha floor protection still available?
Q58. When will N1 indication pulse red?
A58. It pulses red, when N1 is above 100 %.
Q59. You are just about to take off. You have not inserted a FLEX temperature. Can you still takeoff? How?
A59. Yes, by selecting TO/GA power.
Q60. What happens if you hold the instinctive disconnect push buttons for more than fifteen seconds on THR LEVERS?
A60. If the flight crew pushes and holds one instinctive disconnect p/b for more than15 s, the A/THR system is disconnected for the remainder of the flight. All A/THRfunctions including ALPHA FLOOR are lost, and they can be recovered only at thenext FMGC power-up (on ground).
Q61. What is the minimum oil quantity for dispatch?
A61. 11 qt + estimated consumption (average estimated consumption approx. 0.3 qt/h).
Q62. What is the oil pressure limitation on an engine?
A62. The minimum oil pressure limit is 60 psi. The digital oil pressure indication pulses, if the oil pressure exceeds 390 PSI (increasing), or 386 PSI(decreasing).
Q63. What are the oil temp limitations?
A63. Oil temp. Limitations:
(a) Min. prior to exceeding idle : -10 degree Celsius
(b) Min. prior to T/O : 50 degree Celsius
(c) Max continuous temp : 155 degree Celsius
(d) Max transient temp : 165 degree Celsius
(e) Min starting temp : -40 degree Celsius
Q64. What are the EGT limitations of an engine?
A64. EGT Limitations:
è TOGA : 635 degree Celsius
è MCT : 610 degree Celsius
è Starting : 635 degree Celsius
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