technical interview questions

Question 1

Explain sources of the ELEC generation and their priorities.

Answer 1

G - Generators
E - External Power
A - APU
R - Ram Air Turbine
B - Batteries

Question 2

In flight in normal ops, which generator has the higher load? why?

Answer 2

Generator 1.

• Supplies AC BUS 1 + DC BUS 1
• Galley and Cabin

Question 3

What does the EMER GEN power?

Answer 3

AC ESS and DC ESS (via essential TR)

Question 4

How long does it take the emergency generator take to come online?

What is powering the a/c in the meanwhile?

What is then powered in the flight deck?

Answer 4

• eight seconds
• Batteries
• PFD 1, ND 1, Upper DU, FMGC 1
  (Pitch) (Power)

Question 5

What is the purpose of GEN 1 Line?

Answer 5

Generator keeps running, but disconnects AC BUS 1.

It runs one fuel pump in each fuel tank.
Generator 2 takes the load of AC BUS 1 via the bus tie break

Question 6

Under what circumstances will the RAT extend automatically?

Answer 6

Loss of AC BUS 1 +2

Question 7

What is the difference between switching the Generator and IDG off?

Answer 7

IDG’s can only be restored on the ground (guarded switch). Generators can be restored at any time.

IDG - Mechanical linkage between engine and generator.

Question 8

What is the purpose of selecting the APU Master switch ON in the Removal of smoke checklist?

Answer 8

It connects the third motor of the outflow valve to the battery bus bar in order to control it.

Question 9

Under what circumstances will the RAT extend automatically?

Answer 9

Loss of AC BUS 1 + 2

Question 10

At what altitude can the APU be started in the Emergency Elec config? why?

Answer 10

25.000ft.

APU Battery Restart Limit in EMER ELEC.

Question 11

Under normal ops, what altitude can the APU support electrical load and bleed demand?

Answer 11

Electrical demand = up to Max cruise

Electrical + Bleed Air = 22.500ft.

Question 12

Name the sources of power for each of the hydraulic systems

Answer 12

Green = ENG 1 Pump

Blue = ELEC Pump + RAT

Yellow = ENG 2 Pump + Elec Pump + Hand pump

Question 13

what services does the

• green
• yellow
• blue

system power?

Answer 13

Priority valves:

Green = L/G + Slats/Flaps

Blue = EMER GEN + Flaps

Yellow = Flaps

Question 14

How are the hydraulic reservoirs pressurized? Why?

Answer 14

Automatically pressured from
ENG 1 HP bleed air.

If the pressure becomes too low, it takes bleed air pressure from the crossbleed duct.

Question 15

What is the purpose of the hydraulic priority valves?

Answer 15

Cut off hydraulic users to ensure functionality of the most important Flight control surfaces.

Question 16

What is the purpose of the hydraulic accumulators?

Answer 16

It provides constant pressure by covering transient demands during normal operation.

Question 17

Explain the purpose of the PTU.

Answer 17

Power transfer unit.

Transfers power between Green and Yellow system if the differential pressure becomes greater than 500psi

Question 18

What is the normal system pressure of the three hydraulic systems?

Answer 18

3000psi.

Question 19

What pressure would expect when the RAT is powering the blue system?

Answer 19

2500psi.

Question 20

Explain the function of ground speed mini.

Answer 20

App = VLS + 1/3 HW component

Question 21

How many motors drive the outflow valve? why?

Answer 21

Three. Two from the CPC and one from the APU

Question 22

SMOKE REMOVAL C/L

In the emergency electrical configuration, what is the purpose of turning the generators back at three minutes or 2000ft AGL?

Answer 22

Restore generators to recover normal breaking and breaking performance.

If the generators are off for more than two minutes, then ADR 2+3 will not be recovered during flight (Direct law when gear down).