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Ground-adjustable propeller blade angle

Aviation Mechanic Powerplant (AMP) practice question 2 of 10 on Propellers. ACS element AM.III.M.K2 · difficulty: recall. Want to answer it in a timed quiz? Use the Aviation Mechanic Powerplant (AMP) practice mode.

Question bank updated 2026-09-22

QUESTIONOn a ground-adjustable propeller, when may the blade angle be changed?

  1. AOnly in flight, through the governor
  2. BAt any time, by moving the pilot's propeller control
  3. COnly when the propeller is not turning
Show the answer and explanation

Correct answer: C. Only when the propeller is not turning

  • A — incorrect A governor changing pitch in flight describes a constant-speed propeller, not a ground-adjustable one, which has no governor.
  • B — incorrect A flight deck control that changes blade angle while the propeller rotates describes the controllable-pitch propeller; once the ground-adjustable propeller's clamps are tightened, the pitch cannot be changed in flight.
  • C — correct The ground-adjustable propeller operates as a fixed-pitch propeller in flight; its pitch can be changed only when the propeller is not turning, by loosening the clamping mechanism that holds the blades.

BACKGROUND

Propeller complexity increases from fixed-pitch and ground-adjustable types up through controllable-pitch and constant-speed systems. A fixed-pitch propeller has the blade angle built in at manufacture and cannot be changed at all. The ground-adjustable propeller behaves like a fixed-pitch propeller in flight, but its blades can be repositioned on the ground by loosening a clamping mechanism. Once the clamps are retightened, the blade angle is set and cannot be altered to meet varying flight requirements; this type is not often used on present-day aircraft.

STUDY TIP

Sort the propeller types by when the blade angle can move: never (fixed-pitch), only stopped (ground-adjustable), in flight by the pilot (controllable-pitch), and automatically by a governor (constant-speed).

KEY POINTS

  • A ground-adjustable propeller's pitch is changed only while the propeller is stopped.
  • The change is made by loosening and retightening the blade clamping mechanism.
  • In flight it behaves exactly like a fixed-pitch propeller.

SOURCES

  • sources/amp-powerplant/ch07.txt "Ground-Adjustable Propeller"
  • FAA-H-8083-32 ch07, Types of Propellers
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MORE ON PROPELLERS

SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-32B Aviation Maintenance Technician Handbook – Powerplant, and 14 CFR part 43. Regulations and handbooks are revised; confirm details against the current edition.