Powerplant & APU Flashcards
What is APR and what does it do?
Automatic Performance Reserve
If an engine fails during TO, the system will increase thrust 2% on the operating engine.
Above 79% N1, how is the engine speed controlled?
By thrust levers
Approximately what percentage of total thrust is produced by the air that passes through the N1 fan?
85%
Which ignition system must be used when starting with DC power? Why?
B - Because A is on the AC system and B is on the DC system.
How is oil cooled?
By the fuel/oil heat exchanger
What components are located on the accessory gear box of the engine?
- Engine lubrication pumps
- Integral drive AC generator (IDG)
- Air turbine starter
- Engine fuel control unit & pump
- Hydraulic pump
- Alternator that powers N1 control Amp.
What is the purpose of Variable Geometry (VG) vanes on the APU and engine compressor sections?
Improves efficiency of the compressor by changing the airflow angle of attack (AOA) at the compressor blades and protects compressor from stall & surge damage.
How is revers thrust actuated when the pilot lifts the thrust levers?
Air is ducted forward through cascade vanes by 14th stage bleed air that moves the engine cowl aft activating the reverse flow.
- How many fire detection loops are located around the engine?
- How many fire detection loops are located in the engine pylon?
- 2
2. 2
Are any fire extinguishers available to fight a fire in the jet pipe or engine pylon?
NO
Name five things that happen when an engine fire push switchlight is pressed?
- LH & RH squibs are armed.
- Fuel feed shutoff valve closes.
- Bleed air shutoff valve closes.
- Hydraulic shutoff valve closes.
- Engine driven generator is tripped.
What is the EGT limit for starting the APU?
743 degrees C
What is the maximum allowable altitude for bleed air extraction from the APU?
15,000’
Under which in-flight condition is APU bleed air extraction permitted for engine starting?
13,000’
What is the maximum allowable altitude for starting the APU?
30,000’
