ATA 49 APU Flashcards
Describe the APU engine configuration.
Single Spool Engine
Single Stage Load Compressor
Single Centrifugal Compressor
Two Stage Turbine
Describe the APU engine mount configuration.
Three Cone Bolt Type Mounts.
During start when does the APU starter/generator cutout?
70%
The APU fuel system provides pressurized fuel to the fuel nozzles and ________
Servo fuel for the Inlet Guide Vane actuator and Surge Control Valve
When does the APU ignition start and stop?
The ECU energizes the ignition system at 0% speed and de-energizes it at 60% speed.
The APU bleed valve is __________ controlled and ______________ operated?
Solenoid, load compressor air
List the three components that control pneumatic airflow out of the APU.
Main engine start
Air Conditioning
Pressurization
Where is the APU bleed valve located?
Forward right side of the APU. Access is through the APU cowl door.
Where is APU EGT displayed?
MDS
Maint display pages
List three of the many protective shutdowns that also cause the APU FAULT light
to illuminate.
APU Fire
APU inlet overheat
No APU rotation
One of the EGT thermocouples has failed, will the APU shutdown?
Nope
What is the purpose of the Data Memory Module?
Keeps specific APU data in non-volatile memory
Describe the APU exhaust duct installation.
V-Band clamp holds exhaust to the APU duct muffler assembly.
The APU FCU is mounted to the ________________________________.
Mounts to the front of the lube module with a V-band clamp
The Lube Module has two filters, what are they for?
Generator Filter Element-Filtering oil from the APU generator
Oil Filter Element-Filters pressurized oil after its gone through the oil cooler
How many pumps are inside the lube module?
7
How is the cooling airflow provided for the APU oil cooler?
APU exhaust causes a suction of air through the eductor inlet duct which causes compartment and outside air to flow through the oil cooler and cool APU oil.
How can you check APU oil level?
MDS or the oil level sight gauge on the AGB
What’s the maximum altitude you can turn the APU on?
41,000 feet
All the components in the APU engine that turn are on a _________________shaft.
Common
How much psi does the actuator supply for the Inlet Guide Vane Actuator and Surge Control Valve?
250psi
The start power unit changes 115VAC or 28VDC electrical power to __________
270VDC power
What’s the APU starter converter cranking voltage?
115V AC
Where is the ECU located?
E-6 Rack
What must be removed before the oil lube module can be removed?
FCU
If battery switch is selected OFF the APU will?
Shut Down
