Powerplant and Props Flashcards
What accessories are on the accessory gearbox?
Hydraulic Pump, AC Gens, Prop Over-speed Governor and Prop Control Unit
What accessories are on the reduction gearbox?
Fuel pump, oil pump and DC starter/generators
What does the EEC(ECU) provide?
Mainly refines fuel schedule. Other functions are HBOV control, prop under-speed, and up-trim during engine failure.
What do the torque bugs on the Q200 do?
Using the ECU switch, torque limits can be set for phase of flight.
How does the propeller pitch change towards feather?
Via the pitch change mechanism, fine pitch oil is dumped from the mechanism and the blade is pushed to feather by coarse pitch oil.
How does the autofeather system arm?
System arms when the system is:
- Selected on
- Torque is above 38% (approx)
- Power lever angle beyond 60 degrees
How does the autofeather function?
Autofeather system:
Senses torque loss of 10%
Uptrims remaining engine
Starts feathering propeller on failed engine
How does the propeller overspeed function work
On the ground: Reduces P3 to MFC from engine, slowing the engine and blade speed.
In the air: Dumps fine pitch oil, forcing blade to coarse pitch, slowing blade.
Constant illumination of Ground Range lights on the ground?
This is normal when ground beta is selected.
Cycling illumination of Ground Range lights in the air?
Means the Beta Backup is functioning, keeping the blades from feathering. Advance power levers from flight idle position.
The difference between Ground Beta and Flight Beta?
Blades are limited to forward range in flight. Blades may be set to negative or reverse angles in Ground Beta.
How does the beta lockout system function?
If an attempt to move the power levers into ground beta in flight, the beta horn will sound as soon as the triggers are lifted. The Beta Lockout will not allow the blades to enter ground beta during flight.
