SH Chapter 7 - Engines And APU

Question 1

1) What are the primary differences between an automatic and a manual start?

Answer 1

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

Question 2

2) When would you use a manual start?

Answer 2

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.

Question 3

3) What controls the engines in all operating regimes?

Answer 3

FADEC

Question 4

4) What functions does the FADEC control?

Answer 4

All engine parameters and starts

Question 5

5) Describe the redundancy of the FADEC

Answer 5

Two channels. One active and one standby.

Question 6

6) What is the power source for the FADEC?

Answer 6

Engine Control Unit (ECU) magnetic alternator. If this fails, auto switches to a/c electrical power

Question 7

7) If the FADEC detects a fault during automatic start, is any crew intervention required?

Answer 7

None

Question 8

8) When does the Idle Control function of the FADEC system regulate idle speed?

Answer 8

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

Question 9

9) When will the FADEC abort a start?

Answer 9

Hot start
Hung start
Stall
No light up
Low start air pressure
Starter time exceeded 
Thrust levers not at idle

Question 10

10) How is the IDG cooled?

Answer 10

Fuel/oil heat exchanger

Question 11

11) How many igniters fire on an in-flight start attempt?

Answer 11

Both

Question 12

12) How many igniters fire during a manual start?

Answer 12

Both

Question 13

13) When does continuous ignition automatically operate?

Answer 13

When commanded by FADEC, when:

• Engine flameout detected
• Possible EIU failure
• Ignition delay during start

Question 14

14) What is the active range of the A/THR?

Answer 14

Just above idle to CL detent or MCT detent with OEI

Question 15

15) What determines the maximum thrust the A/THR system will be able to command?

Answer 15

FMGC computes the thrust limited to the value corresponding to the lever position, except in Alpha Floor.

Question 16

16) What are 3 ways to disconnect the A/THR?

Answer 16

Instinctive button
Thrust levers to idle
A/THR pb on FCU

Question 17

17) What controls the engine LP fuel valves?

Answer 17

Moving ENG 1(2) master to off or pushing ENG FIRE pb

Question 18

18) What does a fault light on the ENG panel indicate?

Answer 18

Position of HP fuel shutoff valve is abnormal
Auto start sequence aborts
Malfunction in thrust control

Question 19

19) What does the green AVAIL light on the APU START pb indicate?

Answer 19

N is above 99.5% or two seconds after N reaches 95%

Question 20

20) How long should you wait to push the APU START pb after engaging the APU MASTER switch?

Answer 20

3 seconds

Question 21

21) What does an amber FAULT light in the APU MASTER SW pb indicate?

Answer 21

Auto shutdown occurs (ie over speed, no acceleration, etc)

Question 22

22) When does the APU fuel pump run?

Answer 22

Automatically if pressure from the left tank pumps not available (batteries only or pumps off)