As the helicopter was brought to a 20 foot hover, it began to swing to the right. The pilot applied left pedal but the rate of turn continued to increase rapidly until the helicopter impacted the ground. The right skid broke off and the aircraft came to rest on its right hand side. Examination of the tail rotor pitch control system revealed that the bolt which connects the tail rotor pitch control arm to the control rod, below the tail rotor gearbox, was missing. The bolt was never found and the reason for its absence could not be determined. It was evident that the loss of the bolt resulted in the loss of tail rotor control.
