SIFT Army Aviation Information Practice Test 2025 – All-in-One Study Guide for Exam Success!

When a helicopter engine fails, the freewheeling unit plays a crucial role in maintaining control of the aircraft. In the event of an engine failure, this unit automatically disconnects the engine from the main rotor, allowing the rotor blades to continue spinning. This is important because it provides the pilot with a means to control the helicopter's descent and maneuverability during an emergency situation. The rotor system can maintain sufficient lift even after engine failure, allowing for a controlled autorotation landing. This mechanism is essential for safe operation and increases the pilot's chances of successfully landing the helicopter even in the loss of engine power.

Understanding the function of the freewheeling unit is vital for pilots as it directly influences their ability to manage various emergency scenarios effectively. The other mechanisms mentioned do not serve the same purpose or directly contribute to overcoming the challenges posed by an engine failure in a helicopter.