M. Propellers exam
Why do some aircraft engines have a critical range of operation?
(AM.III.M.K1)
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 is practical
Does centrifugal twisting moment on a propeller blade tend to move
the blades toward high pitch or toward low pitch? (AM.III.M.K1)
Toward low pitch
Do the counter weights on a propeller tend to move the blades
toward high pitch or toward low pitch? (AM.III.M.K1)
Toward High pitch
What is the function of the accumulator used with some McCauley
feathering propellers? (AM.III.M.K1)
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 alpha range of operation of a turboprop
propeller? (AM.III.M.K1)
This is the in-flight mode of operation from takeoff to landing.
Should an adjustable pitch propeller be in high pitch or low pitch for
takeoff? (AM.III.M.K1)
