What is meant by the beta range of operation of a turboprop propeller?

What is meant by the beta range of operation of a turboprop propeller?

• A. This is the mode of ground operation, including starting, taxiing, and ground reverse operation.
• B. It is the high-altitude cruise range.
• C. It is the reverse of normal full-power operation.
• D. It is the rate at which propeller blades are feathered.

Answer: (A)

Beta range is the ground operation mode for a turboprop propeller. In this range the propeller blades are set to a low pitch to create significant drag or even negative thrust, which helps control the aircraft on the ground—starting the engine, taxiing, and providing ground reverse as needed. It’s a special mode used for ground handling, not for flight. In flight, the propeller operates in the normal in-flight pitch settings to produce forward thrust, and blade feathering or other functions are handled separately.

Beta range is the ground operation mode for a turboprop propeller. In this range the propeller blades are set to a low pitch to create significant drag or even negative thrust, which helps control the aircraft on the ground—starting the engine, taxiing, and providing ground reverse as needed. It’s a special mode used for ground handling, not for flight. In flight, the propeller operates in the normal in-flight pitch settings to produce forward thrust, and blade feathering or other functions are handled separately.