AUXILIARY POWER UNIT SYSTEM Flashcards
The APU system provides:
pneumatic power for starting the engines
operating the Environmental Control System (ECS)
APU design and components
Gas turbine engine
power section
reduction gearbox
appropriate controls/ accessories
APU lubrication system
self-contained oil system
APU Fuel Consumption
150lbs per hour
Acceptable in-flight use of APU includes:
emergency procedures
single engine training
practice autorotations
powering the ECS during extreme temperature operations
Prime boost pump altitude restriction
8000ft PA
The minimum accumulator pressure required for starting
the APU is approximately
2,650 psi
APU FAIL indicates the APU has failed due to one/ some of the following:
high Ng
low Ng
high TGT
low TGT
low oil pressure
start sequence failure
TEMP HI indicates the APU has
reached the maximum oil temperature for continuous operation
Digital Electronic Sequence Unit (DESU)
control and monitor APU
APU draws fuel from which tank?
left
If the backup pump is cycled ON then to the OFF or AUTO position,
it will remain on for one cycle of…
90 seconds (180 seconds with winterization kit installed)
