Praetor APU Flashcards
What services does the APU provide and what are they used for?
-An electrical generator supplies 28VDC to the electrical system. The pneumatic power is used for engine starting and to supply bleed air to the air-conditioning pack of the environmental control system (ECS).
How is the APU controlled and monitored?
Through a dedicated Full Authority Digital Electronic Control Unit (FADEC).
What does pressing the APU ON/OFF button do?
It starts the ECU power-up sequence and initiates the APU built-in test (BIT)
When does the START button on the APU Control Panel flash green?
During the ECU bit test
What does the START button on the APU control panel illuminating steady green indicate?
The APU is ready to start
If the START button on the APU control panel illuminates amber what does that indicate?
The APU start is inhibited
What are the APU starter limitations?
Up to three consecutive unsuccessful start attempts are allowed with 30 second intervals between attempts
What MFD page can APU information be seen on?
The STATUS synoptic page
Which tank normally supplies fuel to the APU?
The right tank
Is it possible to feed the APU from the left-wing tank? If so, how?
Yes, via the cross-feed system
Can the APU supply bleed air on the ground or in flight?
Yes
If the APU is the only source of electrical power on the ground, what buses can the APU power?
All of the airplane electrical loads and can charge both batteries
If the APU is the only source of electrical power in flight, what buses can the APU power?
All electrical loads (except for the SHED BUSES) and also charging both batteries
What is the APU operating envelope for starting, operation, and to supply electrical power?
Up to 31,000 feet
Up to what altitude is the APU able to supply bleed air for engine starting?
Up to 23,000 feet
