APU Flashcards
APU stands for…
Auxiliary Power Unit
APU burns how much fuel?
170 lbs/hr
ESU stands for…
Electronic Sequencing Unit
Where is the ESU located?
Transition Section
The APU provides what?
1.) Pneumatic power for starting engines and ECS
2.) Electrical power for ground operations and in-flight emergencies
The APU is has a ____ starter.
Hydraulic
The APU starts using only ____ power.
Battery
With only the APU operating, the ____ fire extinguisher switch position must be used.
Reserve
What component shuts down the APU automatically in the event of a malfunction during a start?
The ESU
“APU GEN” cautions means what?
1.) Failure of APU AC Gen
2.) APU AC Gen was turned off while APU is running
3.) APU Switch ON, APU started but not reached operating limits
What charges the APU accumulator?
Backup pump (HYD 3)
When you cycle the back up hydraulic pump switch, how long does the backup pump run?
90 seconds
“APU ACCUM LOW” illuminates when APU accumulator reaches ___ psi.
2650 psi
APU accumulator pressure should be ___ - ___ psi.
2700-3000 psi
What are the two ways to charge APU accumulator?
1.) Cycling the backup pump
2.) Manual hand pump in cabin overhead
