The lift capability of the rotor system is limited by the actual collective stop and NR will not increase above ______ RPM in the Training Mode until the collective is reduced to a power level below the good engine topping.

• A. 400 RPM
• B. 360 RPM
• C. 320 RPM
• D. 280 RPM

Answer: (C)

In Training Mode, rotor speed is capped by a fixed NR limit when the collective is at its actual stop and the engine is at topping. That means even if you push the collective further or try to drive more lift, NR won’t climb past this ceiling while the power condition stays at or above topping. The reason for this is to protect the rotor system and engine from overspeeding or loading too much while there’s no opportunity to reduce power.

To allow NR to rise beyond that cap, you must back off the collective enough to reduce engine power below the topping threshold. Once power falls below topping, the governor can allow NR to increase toward the next limit, enabling higher rotor speed and lift as appropriate.

So the correct option describes this NR cap in Training Mode and the requirement to reduce power below topping to permit NR to increase.