In a propeller-driven system, Alpha and Beta ranges are used to monitor which of the following?

In a propeller-driven system, Alpha and Beta ranges are used to monitor which of the following?

• A. Inlet guide vanes
• B. Reversible-pitch turboprop propellers
• C. Exhaust system
• D. Fuel pump

Answer: (B)

Alpha and Beta ranges refer to the blade pitch control states of a reversible-pitch turboprop propeller. The Alpha range is the forward-thrust position, with blades set to a positive pitch for normal flight. The Beta range is the reverse-thrust position, where blades take on a low or negative pitch to produce braking thrust. The control system switches between these ranges to allow safe transitions and braking after landing, as well as proper load management during thrust reversal. Inlet guide vanes, the exhaust system, and the fuel pump aren’t related to the propeller pitch states, so they don’t use Alpha/Beta ranges.

Alpha and Beta ranges refer to the blade pitch control states of a reversible-pitch turboprop propeller. The Alpha range is the forward-thrust position, with blades set to a positive pitch for normal flight. The Beta range is the reverse-thrust position, where blades take on a low or negative pitch to produce braking thrust. The control system switches between these ranges to allow safe transitions and braking after landing, as well as proper load management during thrust reversal. Inlet guide vanes, the exhaust system, and the fuel pump aren’t related to the propeller pitch states, so they don’t use Alpha/Beta ranges.