ATA 49 - APU

What is the primary function of the Auxiliary Power Unit (APU)?

• Electrical power generation

• Engine thrust

• Fuel storage

• Wing anti-ice

Besides electrical power, what else does the APU provide?

• Engine cooling

• Air conditioning in-flight

• Navigation assistance

• Oxygen supply

When does the air intake flap open and close?

• Opens when APU is ON, closes when OFF

• Opens during landing, closes during takeoff

• Opens during takeoff, closes during landing

• Opens when the main engines are running

What is the purpose of the air intake flap?

• Engine cooling

• Reducing noise

• Pneumatic supply

• Preventing fires

Where is the APU installed on the aircraft?

• In the cockpit

• In the wing

• In the fuselage tail cone

• In the landing gear

How is vibration transmission reduced between the APU and the aircraft structure?

• Through tie rods

• Through isolators

• Through exhaust muffler

• Through air intake

How is the APU attached to the structure brackets in the APU compartment ceiling?

• Through tie rods

• Through bolts

• Through welding

• Through adhesive

What is the purpose of the vibration isolators in the APU mounting system?

• To increase vibration

• To reduce noise, prevent transmission of vibrations

• To transfer vibrations to the aircraft structure

• To connect to the APU three point mounting system

What is the primary purpose of the drain system in the APU compartment?

• To collect fluids for reuse

• To prevent fluid accumulation

• To supply water for aircraft cleaning

• To collect APU exhaust gases

How are fluids collected and removed from the APU compartment?

• Through a drain mast

• Through an APU exhaust pipe

• Through an APU cooling system

• Through an APU fuel line