What happened
On 11 July 2007, an Enstrom 480B, registration N480KP, was conducting a sales demonstration flight at Shoreham Airport. The flight included a final maneuver designed to simulate an engine failure, involving a nose-low attitude at approximately 30 kt.
As the aircraft approached a grass training area at an altitude of 300 ft, the engine was set to idle. The pilot increased the airspeed to 60 kt. During the final 100 ft of the descent, the rate of descent increased significantly. In an attempt to mitigate this, the pilot performed a gentle flare and increased collective pitch, but the high rate of descent persisted. Just prior to touchdown, the rotor low RPM warning horn activated. The helicopter struck the ground on its left skid, sliding along the surface for approximately 10 ft before pivoting left and dropping onto the right skid. The pilot confirmed that the two passengers were uninjured, notified air traffic control, and shut down the engine.
The investigation
The investigation focused on the circumstances of the descent and the mechanical state of the aircraft. The investigation examined the flight profile, the weather conditions at the time, and the pilot's actions during the simulated engine-off landing. The aircraft sustained damage including creasing to the tail boom, separation of the tail rotor drive and control runs, and damage to the skid assembly. There were no injuries to the crew or passengers.
Findings
- The aircraft was performing a planned simulated engine-off landing maneuver.
- At the time of the accident, the wind at Shoreham was 230° at 15 kt, gusting to 25 kt.
- The pilot experienced an increased rate of descent during the final stages of the maneuver.
- The pilot's assessment suggested the heavy landing was likely caused by windshear.