What happens to the rotor if the engine is lost in flight?

Prepare for the TH-73 Systems Test with interactive quizzes. Study essential systems both online and offline. Ace your exam with detailed explanations and study aids.

The rotor continues to spin due to the freewheeling unit, which is a critical feature in helicopter design. When the engine fails during flight, the freewheeling unit allows the rotor system to maintain its rotational motion. This mechanism disengages the rotor from the engine, so while the engine may stop providing power, the inertia of the rotor blades enables them to keep spinning. This is essential for maintaining autorotation, a state that allows the helicopter to descend safely and provides the pilot with control during an emergency landing. The ability of the rotor to continue spinning is crucial for generating lift and ensuring the helicopter can be maneuvered effectively during descent.

The other options do not accurately describe the behavior of the rotor in an engine failure scenario. Immediate stopping or uncontrollable increase in speed does not occur due to the engineering design of the helicopter's rotor system and the function of the freewheeling unit. The rotor will also not enter a controlled descent automatically; that relies on the pilot maintaining control and executing the proper recovery procedures.