Aural Warnings: NR less than or equal to _______ RPM.

Aural Warnings: NR less than or equal to _______ RPM.

• A. 360 RPM
• B. 345 RPM
• C. 320 RPM
• D. 355 RPM

Answer: (B)

Low rotor speed alerts are meant to warn the crew before NR reaches a dangerous level, so there’s time to take corrective action and recover rotor speed. In the MH-65E, the aural warning is set to trigger at 345 RPM. This sits below normal operating rotor speeds but well above the point where rotor authority could be lost, giving a practical warning window to adjust power and rotor loading. Setting the threshold higher would cause nuisance warnings during normal dips, while setting it lower would leave less time to react. Hence 345 RPM is the appropriate threshold for this helicopter.

Low rotor speed alerts are meant to warn the crew before NR reaches a dangerous level, so there’s time to take corrective action and recover rotor speed. In the MH-65E, the aural warning is set to trigger at 345 RPM. This sits below normal operating rotor speeds but well above the point where rotor authority could be lost, giving a practical warning window to adjust power and rotor loading. Setting the threshold higher would cause nuisance warnings during normal dips, while setting it lower would leave less time to react. Hence 345 RPM is the appropriate threshold for this helicopter.