Block 2

Question 1

APU

Answer 1

Installed in non-pressurized compartment.
Fully automatic gas turbine (electrical + bleed air)

Self contained power source with exception of DC electrical power from AC batt and fuel to maintain operations.

Question 2

APU - autoshutdown

Answer 2

Input signals from sensor to the ECU are out of range (abnormal condition)
ECU bit test circuit detects a fault condition

Question 3

APU - Emergency shutdown

Answer 3

APU fire push button is pushed (overhead panel)
APU fire switch pushed (DC external power panel)

they activate;
APU shutdown
APU shutoff valve (fuel
APU fire extinguishing system

Question 4

APU Parts

Answer 4

Inlet, Intake, Exhaust

Exhaust pipe directed up to allow for movement during APU operations

Question 5

Do-328 type of aircraft

Answer 5

Transport A/C

Question 6

APU - Operation

Answer 6

is fully automatic from start to finish
Operational control is provided by the APU panel located on overhead panel
The APU panel has the following switch and switch/lights:

APU stop button
APU master button/light
APU start button/light

Question 7

APU Master Switch

Answer 7

“ON” comes on and the following occurs:
APU fuel shutoff valve moves to the open position. apu “FUEL SOV CLOSED” MESSAGE ON THE EICAS APU goes out of view. APU fuel shut off valve is shown on the fuel page in the open position. Electrical power (+28VDC) is supplied to the start sw/light and to the APU electronic control unit (ECU)

Question 8

APU Stop Button

Answer 8

A false overspeed signal is sent to the ECU speed sensing circuit to cause the ENG to shutdown.
Automatically test the overspeed shutdown circuit.

Question 9

APU Start Switch

Answer 9

Suck, Squeeze, Bang, Blow

When APU is able to accept electrical power or bleed air loads, also “Ready to Load” msg will also be displaced on the APU system page and will remain on until shutdown.

Start: Indicates good engine start of APU

Question 10

Engine Fuel and Control

Answer 10

APU fuel is taken from the right wing tank group
Taps into the main engine Xfeed line and fuel is supplied to the APU shutoff valve located on the rear wall of the left inner tank.
Must monitor APU system page during APU operation.

15ft of external power door, qualified aircrew/mx