Accident Details
The accident occurred during a maintenance test flight. The helicopter had undergone an annual inspection and was preflighted and flown by a pilot for a prior maintenance test flight. That pilot did not check the right fuel tank level during the preflight. The following day, two pilots departed on another maintenance test flight. They did not visually check the fuel level in either fuel tank, relying instead on fuel consumption calculations based on previous flight time and fuel gauge indications.
Loss of Engine Power
After approximately 42 minutes of flight time, the helicopter experienced a total loss of engine power. The right seat pilot performed an autorotation and had to maneuver to change the touchdown point to avoid power lines. The helicopter then experienced a hard landing.
Post-Accident Examination
Examination of the wreckage revealed that a connector from the right fuel tank sending unit was disconnected. The left fuel tank contained about one cup of fuel, and the right fuel tank had no fuel. The helicopter sustained substantial damage, including damage to the tail boom. The left seat pilot received minor injuries, and the right seat pilot received serious injuries.