Accident Details
The pilot and co-pilot were conducting a test flight that involved practicing autorotations. On the seventh autorotation, at an altitude of approximately 100 feet above ground level, the engine lost power. The crew continued the autorotation and reported encountering a downdraft. The helicopter landed hard, resulting in substantial damage.
Wind Conditions
The control tower reported winds from a magnetic bearing of 240 degrees at 15 knots with gusts to 30 knots. However, in his written report, the pilot stated that the winds were from a magnetic bearing of 230 degrees, variable to 270 degrees, at 23 knots with gusts to 35 knots.
Manufacturer's Guidance
The manufacturer's flight manual states: "Controllability has been shown to be adequate in 20 mph winds from any direction."
Cause
The reason for the engine's loss of power was not determined.