APU Flashcards
What is the max airspeed to start the APU?
285KIAS
Can the APU be used to heat the aircraft during anti ice application?
No
What is the max altitude at which the APU provides bleed air ?
20000ft
What is the max certified operating altitude for the APU?
37000 ft
What is the primary purpose of the APU
load control valve ?
To prevent Overtemperature condition
What is the limitation for extraction of bleed air from the APU for engine start and environmental air?
20000 ft
What is the max altitude for APU generator use?
30000ft
What is the max altitude for APU start ?
30000 ft
14000 on ground
What is the max speed for starting the APU?
285 KIAS
In addition to operating the gear mounted generator, what is the other purpose for the APU?
Airconditioning / pressurization and engine start
When does the APU surge valve extract air from the APU?
When the load control valve is not open, and air must be removed from the compressor to prevent compressor stall
Where does the APU obtain fuel for operation ?
From the right wing collector tank.
On the ground how is the APU remotely shut down?
Remote cutoff switch located behind the external power access door
Can the APU be used during de/anti icing procedures ?
No
What is the limitation for left engine starting on the ground using bleed air ?
9000 ft
During APU start, the crew must abort the start if the APU RPM is less than 30% after how long?
30 sec
What are the cooling time limitations for APU starts on the ground?
One minute between the first 2 start attempts and 20 minutes after the 3rd
Is another start attempt permitted after an unsuccessful APU start attempt in the air ?
No
Do not attempt another start until after landing
What are the memory items for an APU fire on the ground?
None.
Automatic fire suppression and shutoff
The APU operates the gearbox mounted generator , supplies bleed air for air conditioning and pressurization , and _____
Main engine starting
Following an unsuccessful start or a hung start of an APU in flight, can a second start attempt be made after observing a one minute cooking period?
No
The ______ panel allows the selection of the APU as the bleed air source.
AIR COND/ BLEED PANEL
Where is the APU cutoff switch located ?
Right side , aft of wing behind electrical connection access door
Which fuel pump delivers fuel under pressure to the APU fuel control unit?
Right DC Fuel pump
The APU bleed valve controls airflow to the aircraft bleed air system and protects the APU from _______
Over temperature condition
Is it possible that the surge valve may cause a noticeable hissing type sound in the APU area ?
Yes
Which synoptic pages monitor the APU system and services ?
Fuel
Electrical
ECS
