The NP parameter is described as which?

The NP parameter is described as which?

• A. Constant
• B. Variable
• C. Increasing
• D. Decreasing

Answer: (A)

Rotor speed is kept constant by the helicopter’s governor. NP refers to the main rotor speed, and in normal flight the governor adjusts fuel flow to hold NP at a set value. This stable rotor speed ensures predictable blade pitch and lift, making flight control smooth and safe. The throttle or collective changes primarily affect Ng (gas generator speed), not NP, because the system is designed to keep the rotor speed steady while the engine’s gas generator varies to meet power demands. So NP is described as constant because the rotor speed is actively regulated to stay at the commanded setting, rather than continually rising or falling during standard operation.

Rotor speed is kept constant by the helicopter’s governor. NP refers to the main rotor speed, and in normal flight the governor adjusts fuel flow to hold NP at a set value. This stable rotor speed ensures predictable blade pitch and lift, making flight control smooth and safe. The throttle or collective changes primarily affect Ng (gas generator speed), not NP, because the system is designed to keep the rotor speed steady while the engine’s gas generator varies to meet power demands. So NP is described as constant because the rotor speed is actively regulated to stay at the commanded setting, rather than continually rising or falling during standard operation.