APU

Question 1

Frequently, an aircraft’s auxiliary power unit (APU) generator

Answer 1

Is identical to engine driven generators

Question 2

Fuel is normally supplied to an APU from

Answer 2

The airplanes main fuel supply

Question 3

An APU is usually rotated during start by

Answer 3

Electric starter

Question 4

The function of an APU air inlet plenum is to

Answer 4

Stabilize the pressure of the air before it enters the compressor

Question 5

When in operation, the speed of an APU

Answer 5

Remains at or near rated speed regardless of the load condition

Question 6

Generally, when maximum APU shaft output power is being used in conjunction with pneumatic power

Answer 6

Pneumatic loading will be automatically modulated to maintain a safe EGT.

Question 7

When necessary, APU engine cooling before shutdown may be accomplished by

Answer 7

Closing the bleed air valves

Question 8

Usually, most of the load placed on an APU occurs when

Answer 8

Bleed air valves opened

Question 9

Fuel scheduling during APU start and under varying pneumatic bleed and electrical loads is maintained

Answer 9

Automatically by the APU fuel control system

Question 10

On APU’s equipped with a free turbine and load compressor, the primary function of the load
compressor is to

Answer 10

Provide bleed air for aircraft pneumatic systems