SH Chapter 7 - Engines And APU Flashcards
1) What are the primary differences between an automatic and a manual start?
Automatic is under full authority of FADEC. Manual used if auto start is unsuccessful due to engine stall, EGT over limit, or low air pressure
2) When would you use a manual start?
When an auto start unsuccessful due to engine stall, EGT over limit and low start air pressure
Also when we have a marginal pneumatic source, such as high alt or hot conditions causing reduced EGT margins on APU.
Also with intermittent ECAM ENG 1(2), IGN A(B) fault alert during first start of the day.
3) What controls the engines in all operating regimes?
FADEC
4) What functions does the FADEC control?
All engine parameters and starts
5) Describe the redundancy of the FADEC
Two channels. One active and one standby.
6) What is the power source for the FADEC?
Engine Control Unit (ECU) magnetic alternator. If this fails, auto switches to a/c electrical power
7) If the FADEC detects a fault during automatic start, is any crew intervention required?
None
8) When does the Idle Control function of the FADEC system regulate idle speed?
Modulated Idle
- Bleed system demands and ambient conditions (in flight when flaps retracted and ground, except reverse)
Approach Idle
- When flaps extended, regulated according to altitude to allow faster acceleration from idle to go around
Reverse Idle
- Slightly higher than forward idle thrust
9) When will the FADEC abort a start?
Hot start Hung start Stall No light up Low start air pressure Starter time exceeded Thrust levers not at idle
10) How is the IDG cooled?
Fuel/oil heat exchanger
11) How many igniters fire on an in-flight start attempt?
Both
12) How many igniters fire during a manual start?
Both
13) When does continuous ignition automatically operate?
When commanded by FADEC, when:
- Engine flameout detected
- Possible EIU failure
- Ignition delay during start
14) What is the active range of the A/THR?
Just above idle to CL detent or MCT detent with OEI
15) What determines the maximum thrust the A/THR system will be able to command?
FMGC computes the thrust limited to the value corresponding to the lever position, except in Alpha Floor.