Incident Overview
A helicopter engaged in cross-country training experienced a simulated engine failure that led to an uncontrolled descent and impact with terrain. The flight instructor (CFI) had closed the throttle at approximately 900 feet above ground level (AGL) to simulate an engine failure. The subsequent autorotation did not maintain engine rpm at 2,500 as recommended by the pilot’s operating handbook (POH).
Sequence of Events
During the autorotation, the student pilot allowed the rotor rpm to deteriorate while attempting a power-on recovery at about 700 feet AGL. The student later reported that he did not realize the engine had stopped running. The CFI took control of the helicopter at approximately 700 feet AGL and attempted to restart the engine. The student stated that the rotor rpm remained low throughout the descent. Subsequently, the helicopter impacted the ground in a large field. The student noted that the helicopter felt as if it just dropped the last few feet of the autorotation.
Post-Accident Findings
No reason was verified for the loss of engine power. The POH specified that rpm should have been maintained during practice autorotations and that engine restarts should not be attempted below 2,000 feet AGL.