Challenger 604 Apu

Front 1

Air enters the APU through

Back 1

Inlet on the upper fuselage

Front 2

Ventilation of the APU enclosure is accomplished by

Back 2

Air entering through a flapper door. The air is drawn by the venturi action created by the APU exhaust passing through the muffler/injector

Front 3

APU oil level is checked

Back 3

By opening the oil service door which gives access to two dipsticks

Front 4

The APU load control valve closes automatically if

Back 4

The left 10th stage bleed air swithchlight is pushed in

The ISOL and the right SOV switchlights are pused in together

Front 5

The APU automatically shuts down for he following faults

Back 5

Low or high oil temp, overspeed, EGT overtemp, fire, ECU failure, or sensor overcurrent

Front 6

The ECU for the APU recieves electrical power from the

Back 6

Battery bus when the PWR FUEL switchlight is pused in

Front 7

The cause for automatic APU is indicated by

Back 7

A magnetic indicator on the APU FAULT panel

Front 8

To prevent APU compressor stalls, the APU surge valve

Back 8

Operates inversely to load control valve movement

Front 9

During APU starting, the EGT scale on ED2 resets to normal limits

Back 9

At starter dropout (60% rpm)

Front 10

APU fuel pump Is controlled by

Back 10

the PWR FUEL switchlight

Front 11

All white captions illuminated in the 10th STAGE switch group indicates

Back 11

The APU is providing air to the packs

Front 12

Minimum APU air pressure required for starting the engines is

Back 12

40 psi

Front 13

Fuel is supplied to the APU from

Back 13

The right main tank or the left engine feed line

Front 14

The green APU SOV CLSD advisory indicates

Back 14

The APU FIRE PUSH swithchlight has been pushed (both fuel valves closed properly)

Front 15

APU oil level checks should be conducted

Back 15

30 minutes after shutdown

Front 16

The APU starter is supplied power from

Back 16

APU battery direct bus

Front 17

The APU generator may be used

Back 17

Up to 20000ft with one gen inop