Power Plant / APU

Question 1

What is the meaning of the FLAP OPEN indication on the ECAM APU page?

Answer 1

FLAP OPEN:
▪ APU air intake flap is fully open.
▪ Flap is commanded open when APU MASTER SW pb is selected to ON.
▪ APU starter motor is inhibited until flap is fully open.

Question 2

What is the meaning of the LOW OIL LEVEL indication on the ECAM APU page?

Answer 2

LOW OIL LEVEL:
▪ APU’s oil tank quantity is sensed to be low.
▪ Indication would appear immediately when the APU MASTER SW pb is selected to ON and the aircraft is on the ground.

NOTE: With LOW OIL LEVEL indicated, the APU START pb should not be selected to ON. Contact maintenance for assistance.

Question 3

What are the indications when the APU is “On-Speed”?

Answer 3

AVAIL appears on the:
▪ APU START pb
▪ ECAM APU page,

APU AVAIL appears on
▪ ECAM Memo Section

Question 4

What is taking place with the APU MASTER SW pb. Displaying ON ?

Answer 4

▪ APU computer is enabled and performs a self-test.

▪ Air intake flap is commanded open.

Question 5

What is taking place with the APU MASTER SW pb. Displaying Lights out?

Answer 5

Light out
– the APU computer is deactivated, and the APU shuts down.

NOTE: Selecting the APU MASTER SW to OFF (light out) will accomplish a normal shutdown sequence.

Question 6

What is taking place with the APU MASTER SW pb. Displaying FAULT?

Answer 6

FAULT–

an automatic shutdown or failed start has occurred.

Question 7

What are two reasons the aircraft batteries must be on for all APU starts and when the APU generator is the sole source of electrical power?.

Answer 7

1. Turning the batteries ON permits the APU starter motor to connect to the aircraft Battery Buses, which are the only power source available to the starter motor.
2. On the ground, in the event of an APU fire while the APU generator is the sole source of power, the batteries being on ensure a power source for proper APU shutdown and extinguisher discharge

Question 8

What is the function of the APU BLEED pb?

Answer 8

APU BLEED pb:

▪ ON - commands the APU bleed valve open

Question 9

What is the function of the APU GEN pb?

Answer 9

APU GEN pb:
▪ Light out – APU generator will automatically energize once the APU is on speed
▪ OFF - APU generator is de-energized

Question 10

Name two things APU bleed air CAN be used for?

Answer 10

▪ Engine starts.

▪ Air conditioning pack operation.

Question 11

APU bleed air MAY NOT be used for:

Answer 11

▪ Wing anti-icing.

Question 12

Which start malfunction can a FADEC cannot sense and therefore cannot automatically abort?

Answer 12

▪ Tailpipe fire

NOTE: This start malfunction requires the pilot to manually abort the start by placing the respective ENG MASTER switch to OFF.

Question 13

How can Continuous Ignition can be manually activated?

Answer 13

❇️Following an engine start, cycle the ENG MODE selector from NORM back to IGN/START .

Question 14

Recall the E/WD N1 gauge’s indications.  
❇️Green?
❇️Amber tick mark?
❇️Red Arc?
❇️Circle?
❇️Blue Arc?
❇️ Boxed amber REV?
❇️ Boxed green REV?

Answer 14

▪ Green digital numeric N1 speed and analog green line N1 speed.
▪ Amber tick mark – FADEC computed maximum N1 for current ambient conditions.
▪ Red arc – maximum permissible.
▪ Circle – current position of the associated thrust lever.
▪ Blue arc – indicates the difference between actual N1 and the thrust commanded by the autothrust system.
▪ Boxed amber REV – one or more of the reverser blocker doors is not stowed or not locked.
▪ Boxed green REV – all four reverser blocker doors are fully deployed.

Question 15

What is the meaning of the grey background of an N2 display on E/WD?

Answer 15

❇️ An engine start sequence is in progress.

❇️When the start sequence is complete or aborted, the grey background is removed.

Question 16

What is the function of the ENG MASTER 1(2) switches?

Answer 16

▪ ON – initiates the automatic start sequence when ENG MODE selector is set to IGN/START
▪ OFF – shuts down the engine or aborts the start sequence

Question 17

What is the function of the following ENG MODE selector positions? What takes place when each one is selected?

1. ▪ NORM?
2. ▪ IGN/START?
3. ▪ CRANK?

Answer 17

▪ NORM – normal operations following engine start
▪ IGN/START – selected prior to all engine starts:
• Displays the ECAM ENGINE page on the SD
• Activates both FADECs
• Commands both pack valves to close for 30 seconds
• Increases APU speed (If being used)
• Following an engine start, continuous ignition is activated when cycled from the NORM position
▪ CRANK – selected to Dry Crank / Ventilate the engine.
• No fuel or ignition will be supplied
• Displays the ECAM ENGINE page on the SD
• Activates both FADECs

Question 18

What has happened when FAULT is displayed on the ENG panel?

Answer 18

❇️FAULT – illuminates when
• Automatic start has been aborted (FADEC start fault)
• There is a disagreement between the actual position of the HP fuel valve and its commanded position.

Question 19

What occurs when an ENG MAN START pb is selected ON?

Answer 19

▪ The respective engine start valve opens provided: - ENG MODE selector is in IGN/START or CRANK - Bleed air pressure is available
▪ The respective start valve automatically closes at approx. 50% N2 but the ON remains illuminated until reselected.

Question 20

Describe igniter behavior during automatic versus manual starts.

1. Automatic?
2. Manual?

Answer 20

▪ Automatic starts – engine igniters alternate between starts (A or B). ▪ Manual starts – both igniters are automatically activated (AB).

Question 21

Describe the position of the EGT Limit tick mark (amber) on the EGT display during and after engine start.

Answer 21

▪ During engine start, the tick mark moves to the start EGT limit.
▪ When the start is complete, the tick mark returns to the Maximum Continuous Thrust (MCT) EGT limit.