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
What is the primary purpose of a propeller governor in a constant-speed propeller system?
Answer: Maintain a selected RPM by varying blade pitch
The governor senses propeller RPM and adjusts oil pressure to the pitch change mechanism to vary blade angle, maintaining the pilot-selected RPM.
When inspecting a wood propeller, small cracks running parallel to the grain are typically treated by:
Answer: Rejecting the propeller from service
Cracks parallel to the grain in a wood propeller are cause for rejection because they can rapidly propagate and lead to structural failure.
A turboprop engine's propeller is in the FEATHER position when blade angle is approximately:
Answer: 80° to 90° (parallel to airflow)
Feather positions blades nearly parallel to the airflow (≈85–90°) to minimize drag in the event of an engine failure.
Which condition is indicated when a constant-speed propeller surges (hunts) repeatedly between high and low RPM?
Answer: Air or contaminants in the propeller governor oil system
Air or contamination in the governor oil system causes erratic oil pressure delivery, producing the characteristic hunting or surging of RPM.
On a single-engine aircraft with a right-hand rotating propeller, P-factor is most pronounced during:
Answer: Low airspeed, high angle of attack flight
P-factor is greatest at low airspeed and high angle of attack because the descending blade has a much higher angle of attack than the ascending blade.
The blade angle of a propeller is measured from the plane of rotation to the:
Answer: Chord line of the blade
Blade angle is defined as the angle between the propeller plane of rotation and the chord line of the blade at a specified station.
What is the purpose of the centrifugal twisting moment acting on propeller blades?
Answer: It tends to move blades toward low pitch (flat pitch)
The centrifugal twisting moment tends to rotate blades toward flat (low) pitch because centrifugal force acts on the blade's center of mass, which is ahead of the pitch change axis.