FAA Aviation Mechanic Powerplant (AMP)PropellersHard
A turboprop pilot moves the power lever into the Beta range during landing rollout. What does operating in this range allow?
- AThe propeller blade angle is controlled directly by the power lever, including into reverse pitch
- BThe governor takes full control of blade angle independent of the power lever
- CThe engine fuel flow is cut off completely while the propeller freewheels
- DThe propeller automatically feathers to reduce drag during rollout
Show answer & explanationAnswer & explanation
Correct answer: A. The propeller blade angle is controlled directly by the power lever, including into reverse pitch
The Beta range allows the pilot to directly control propeller blade angle through the power lever, independent of the governor's normal constant-speed operation. This range extends from flight idle down through ground idle and into reverse pitch, providing effective braking and ground handling control.
Why the other options are wrong
- B. In Beta range, direct power lever control replaces governor-only control, the opposite of this statement.
- C. Fuel is not cut off in Beta range; the engine continues running to drive reverse thrust.
- D. Feathering is a separate function used for engine shutdown, not ground rollout braking.
Beta Range (Turboprop Propeller)
An operating range in which the power lever directly controls propeller blade angle, from flight idle through reverse pitch, rather than the governor alone.
- Used mainly for ground operations: taxi, landing rollout, reverse thrust
- Bypasses normal governor-only constant-speed control
- Distinct from Alpha range, where governor controls pitch for flight
Memory trick: Beta = Braking on the ground, direct lever control down to reverse