Incident Overview
A helicopter conducting a practice autorotation as part of a recurrent flight check experienced a hard landing and subsequent rollover. The flight instructor was administering the required checks under 14 CFR Part 135 to the flying pilot. The event occurred during a simulated engine failure initiated by the instructor.
Sequence of Events
The helicopter entered a landing pattern parallel to runway 22R. At 500 feet above ground level and 80 knots indicated airspeed, the flight instructor simulated an engine failure. The pilot responded correctly, entering an autorotation at 60 knots IAS and 398 rotor rpm. At 60 feet agl, the pilot began the flare, which was more aggressive than necessary. The flight instructor advised the pilot to lower the nose, which the pilot did.
At 30 feet agl, the pilot began increasing collective pitch, causing rotor rpm to drop to 380. The flight instructor then announced, "I am on the controls with you," and subsequently, "I have the controls." The instructor leveled the helicopter and reduced collective. At about 5 feet agl, the instructor applied collective again. As rotor rpm decreased, tail rotor effectiveness was lost, resulting in a left yaw despite full right anti-torque pedal input.
The helicopter touched down with the nose approximately 15 degrees left of the direction of travel. The right skid made contact first, and the helicopter drifted right. Despite corrective control inputs from the instructor, the helicopter rolled to the right. The front of the right skid dug into soft turf, causing the helicopter to pivot forward, and the main rotor blades struck the ground.
Investigation Findings
No mechanical malfunctions were reported during the investigation. The incident was attributed to the sequence of pilot and instructor inputs during the autorotation maneuver.