Normally the NR switch should not be in the HI position above which airspeed?

Normally the NR switch should not be in the HI position above which airspeed?

• A. VX
• B. VA
• C. VR
• D. VY

Answer: (D)

NR sets the rotor speed reference, and the HI position gives the rotor more RPM for certain slow-speed, high-load situations. However, when you fly at forward speeds above the speed that yields maximum climb (best rate of climb), you don’t need that extra rotor energy. Keeping NR in HI at higher forward airspeeds just adds rotor drag and blade loading, which reduces efficiency and can lead to an unwanted rotor overspeed in gusty conditions. So, for efficient forward flight beyond the best rate of climb speed, use the normal range and avoid HI.

NR sets the rotor speed reference, and the HI position gives the rotor more RPM for certain slow-speed, high-load situations. However, when you fly at forward speeds above the speed that yields maximum climb (best rate of climb), you don’t need that extra rotor energy. Keeping NR in HI at higher forward airspeeds just adds rotor drag and blade loading, which reduces efficiency and can lead to an unwanted rotor overspeed in gusty conditions. So, for efficient forward flight beyond the best rate of climb speed, use the normal range and avoid HI.