Inspect, Check, Service, and Repair Fixed-Pitch, Constant-Speed and Feathering Propellers, and Propeller Governing Systems. Flashcards
Who, or what facility, is authorized to perform major repairs to a propeller?
An FAA-approved propeller repair station that is authorized for the specific peopeller.
What checks and maintenance is a mechanic with a powerplant rating allowed to make on a propeller?
- Check the track of the propeller blades
- Remove the small nicks and scratches from the blades
- Check the dynamic balance of a propeller
- Lubricate the propeller
What adjustment can a mechanic with a powerplant rating make to a propeller governor?
Adjust the max RPM stop.
Why do some aircraft engines have a critical range of operation?
The engine and propeller combination have a resonant frequency problem in which excessive vibration can occur in a certain range of RPM. The tachometer for an aircraft with this limitation is marked with a red arc. When it is necessary to pass through this range it must be done as quickly as practical.
What is the difference between a controllable propeller and a constant-speed propeller?
Basically, it is the control system. A controllable-pitch propeller uses a manually operated oil valve to control the pitch, and a constant-speed propeller uses a governor to control the valve.
Does centrifugal twisting moment on a propeller blade tend to move the blades toward high pitch or toward low pitch?
Toward low pitch.
Do the counterweights on a propeller tend to move the blades toward high pitch or toward low pitch?
Toward high pitch.
What is adjusted inside the governor for a constant-speed propeller to change the speed at which the propeller is operating?
The compression of the speeder spring.
What is the function of the accumulator used with some McCauley feathering propellers?
The accumulator stores oil under pressure when the engine is operating normally. This oil is used to help the propeller blades move toward low pitch when the propeller is being unfeathered.
What is meant by the beta range of operation of a turboprop propeller?
This is the mode of ground operation, and it includes starting, taxing, and ground reverse operation.
What is meant by the alpha range of operation of a turboprop propeller?
This is the in-flight mode of operation from takeoff to landing.
What is done to cause a McCauley propeller to feather?
Oil is allowed to drain out of the propeller.
What keeps a McCauley feathering propeller from feathering when the engine is shutdown on the ground?
A spring-loaded latch mechanism prevents the blades moving into the feather position when the engine is shut down on the ground. In the air, aerodynamic forces keep the propeller rotating fast enough that centrifugal force holds the blades unlatched so they can move to the feather position when oil pressure is taken out of the propeller.
Should an adjustable-pitch propeller be in high pitch or in low pitch for takeoff?
In low pitch.
What is done to cause a Hydromatic propeller to feather?
High-pressure engine oil is directed into the propeller through the governor.
