EICAS, Power, plant APU, Air Conditioning & Pressurization Flashcards
(108 cards)
APU;
What is indicated by the illumination of the PUMP FAIL light?
APU fuel pump failed to energize
APU;
What happens when you push the PWR FUEL swichlight
When pressed in: APU fuel pump is energized ECU powers up APU IN BITE status message appears on ED2 APU and RPM gages appear on ED2 The door open on the ground APU shut off valve opens
APU;
What is indicated by the illumination of the SOV FAIL light?
APU fuel shut off valve is not in the commanded position
APU;
What happens when the START/STOP switchlight is pressed in?
In flight the APU door will modulate open as needed
The starter motor is energized
White start light illuminates
At 40-60% RPM the START light extinguishes
At 99% RPM plus 2 seconds the green AVAIL light illuminates
APU;
When the START/STOP switchlight is pressed out what happens
Fuel shut off valve closes
APU shuts down
The green AVAIL light extinguishes
The inlet door closes
What is the primary function of the APU
To provide electrical power
How many VAC does the APU generate
115 VAC
Where is the APU fuel pump and how many volts DC is it
In the left collector tank
28 VDC
What would cause the APU to shut down in flight or on the ground
Overspeed >106%RPM Loss of OVERSPEED protection Loss of speed sensor signals No APU rotation No APU light off Slow start No acceleration Speed fallback APU fire/emergency Loss of air inlet APU door failure Uncommanded door closure ECU internal failure Loss of DC power
Will the APU shut down on the ground due to high oil temp or low oil pressure
Yes
Will the APU shut down in flight due to high oil temp or low oil pressure
No
If the APU shuts down due to fire on the ground will the bottles fire
Yes
At what altitude will the surge control valve open
17000
The APU will not start if the RPM is rotating above what speed on the ground and in flight
5% on ground
12% in flight
If the APU door is open or the door position is unknown with the APU shut down what is the limitations
Flight restricted to 220 KIAS
Why is the APU door restricted to 220 KIAS while shut down
To prevent APU from windmilling without proper lubrication
To insure RPM stays below 12% in the event the APU becomes necessary to start in flight
Is there a way around the 220 KIAS restriction with the APU door open
Yes, normal speed may be used if APU is running
If the APU fuel pump fails will the APU continue running
Yes, but cannot be restarted without the pump
What is the purpose of the load control valve (LCV)
The LCV varies pneumatic load to ensure electrical power and 45psi in the manifold
Can APU bleed air be used for anti-ice
No
What is the minimum battery voltage for the APU
22 volts
What powers the APU door, and what powers the ECU
APU battery provides power to the door and is secondary for the ECU. the main battery is the primary power source for the ECU
If the APU is left unattended can the ground crew shut it down
Yes, APU shut off switch on the forward nose or in the APU compartment
What do the following EICAS display color codes mean:
Red, amber, green and white
Warning, caution, advisory, status