Aircraft Propeller Systems Flashcards
7 cards from real AMT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Aircraft Propeller Systems flashcards as text
When performing a propeller dynamic balance check, vibration sensors are placed:
Answer: On the engine mount or engine case near the propeller
Vibration accelerometers are attached to the engine case or mount near the propeller plane to measure the vibration signature used to calculate imbalance.
Which statement about propeller aerodynamic efficiency is correct?
Answer: Maximum efficiency occurs at a specific advance ratio
Propeller efficiency peaks at a specific advance ratio (J = V/nD) where the angle of attack along the blade produces the best lift-to-drag ratio.
A feathering propeller that fails to feather completely on an engine shutdown test most likely has:
Answer: A clogged feathering pump filter
A clogged feathering pump filter restricts oil flow to the pitch change mechanism, preventing complete blade rotation to the feather position.
The station at which propeller blade angle is typically measured and adjusted is located:
Answer: At 75% of the blade radius from the center
Blade angle is measured and specified at 75% of the propeller radius because this station best represents the average aerodynamic performance of the blade.
Which component in a hydromatic propeller controls the blade angle during normal flight?
Answer: The flyweight governor and distributor valve
The flyweight governor senses overspeed or underspeed and directs the distributor valve to route high-pressure oil to the appropriate side of the pitch change piston.
What does a propeller manufacturer's part number suffix of 'L' indicate?
Answer: The propeller is for left-hand (counter-clockwise) rotation
The suffix 'L' in a propeller part number indicates a left-hand (counterclockwise as viewed from the front) rotating propeller.
Gyroscopic precession of a propeller affects aircraft handling because:
Answer: A force applied to the spinning propeller disc is felt 90° later in the direction of rotation
Gyroscopic precession means any force or pitch/yaw input applied to the spinning propeller disc produces a reaction 90° ahead in the direction of rotation.