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Gulfstream V Systems Review

 

APU

The APU is guaranteed to start below ___________feet.

39,000

At high altitudes ___________ bleed air is introduced into the apu air inlet to assist apu starting (bleed air augmentation valve open above 35,000 feet).

Main engine

The ________ provides automatic shutdown and start inhibit functions.

Electronic control unit (ECU)

The APU inlet door opens when the the ______________ switch is turned on.

APU master switch

The ____________ valve is installed to control APU surge potential when operating under electrical loads. The ECU logic commands the surge control valve open when sensed altitude reaches approx. 16,500 feet.

Surge control valve

You are flying at FL390 and wish to start the APU. You turn the master switch on, get the ready light, and depress the start switch. The APU does not start (no rpm). As you are discussing this with the boss, the APU starts. Is anything wrong?

No. The bleed air augmentation valve will open for 15 seconds when above 35,000 feet prior to starter engagement

Where does the APU get its fuel?

Left main boost pump

You are having a very long ground delay, engines off and apu running. You notice the left main fuel is getting out of balance due to the lengthy APU burn. Can you feed fuel to the APU with the R MN boost pump and the xflow switch?

Yes

Will the ECU automatically shut down the APU for a fire condition? 

Yes

Can you use bleed air to start the engines in flight?

Yes

Can you use the APU bleed air to pressurize the aircraft in flight?

No

If the APU load control valve is left on during takeoff, will it automatically close once airborne?

Yes, when WOW shifts to airborne

True or false: In order to use apu bleed air for airstarts, both packs, wing A/I, and bleed air switches must be turned off.

True

APU shutdown: If the APU was loaded at the time of shutdown the loads are shed within 2 seconds. On the ground and up to 20,000 feet, the ECU decreases APU RPM on a linear scale for ______ seconds to 70% RPM Then shuts down the APU.

60 seconds

APU shutdown: On the ground and up to 20,000 feet, the ECU decreases APU RPM on a linear scale for 60 seconds to 70% RPM then shuts down the APU. can you restart the APU during this 60 sec period? 

Yes

APU Shutdown: When the APU speed decreases to 63% the ECU commands the door to 10% open. When the door stops at 10%, the ECU examines the speed, waits until the speed reaches 40% RPM and then commands the door to _________.

Close

How can you reboot the ECU to begin another APU cycle?

Turn the master off then on

Starting the APU in flight will put the ECU into the ___________ mode.

Essential mode

Starting the APU in flight will put the ECU into the essential mode. Once you land, what mode will the APU be in? 

Will remain in essential mode

The two operational modes of the APU are the essential (flight) and non-essential (ground). The essential mode means some protective shutdowns are __________ to allow continued operation.

Disabled

You are on the ground and press the apu stop button. You decided this is a mistake and wish to abort the shutdown. CAn you do so by pressing the start switch?

Yes provided the RPM is greater than 70%, the ECU will command 100% RPM

During the shutdown check, you are waiting for the APU to reach 5% so you can turn the master switch off. Being impatient and real hungry you tell the FO to continue the checklist. He does and turns off the batteries. What is APU door position? 

Will be in position at time of electrical power loss (batteries off)