Oral Board Flashcards
Where are most APUs located in modern jet aircraft?
In the tail cone of the fuselage.
What is the function of an APU?
An APU provides electric power and compressed air when the main engines are not operating.
What are two sources of compressed air from an APU?
From bleed air from the APU turbine compressor, or from a load compressor driven by a free turbine in the engine.
Where in maintenance information based on the ATA-100 system would you find instructions for inspecting and servicing the engine of an airborne APU?
In section 49 20
How is most of the troubleshooting done for a modern APU?
By the fault codes generated by the FADEC
What ensures that an APU will not be shut down while it is hot?
The APU fuel control incorporates an automatic time-delay feature that closes the bleed air valve to remove most of the load and reduce the APU temperature before it is shut down.
What prevents the APU exceeding it’s safe operating limits when the bleed valve is wide open?
The FADEC monitors the load and regulates
the fuel going to the APU to prevent it from exceeding it’s safe limits.
What document would you use to find the safety procedures to follow when replacing an igniter plug in an APU?
The maintenance manual for the APU
What is the extent of the repairs a mechanic with a powerplant rating can make to a propeller?
Only minor repairs or minor al
