Primary finding
Probable cause
The inadvertent activation of the helicopter manufacturer's improperly located, unguarded fuel shutoff switch.
Investigator assessment
Analysis narrative
During a flight test of the experimental helicopter, the pilot inadvertently shut off the fuel supply to the engine while flaring to land, approximately 15 feet above the ground. The helicopter impacted the ground tail first, the landing gear cross tubes collapsed and broke at the fuselage attach points, and the main rotor struck the tail boom. Examination of the helicopter revealed that the fuel shut off switch was unguarded and mounted on the cyclic.
Source record
Factual narrative
During a flight test of the experimental helicopter, the pilot inadvertently shut off the fuel supply to the engine while flaring to land, approximately 15 feet above the ground. The helicopter impacted the ground tail first, the landing gear cross tubes collapsed and broke at the fuselage attach points, and the main rotor struck the tail boom. Examination of the helicopter revealed that the fuel shut off switch was unguarded and mounted on the cyclic.