Accident Details
A Hiller helicopter landed on a mountainside helipad where two passengers were waiting. The pilot of a nearby Sikorsky S-61 helicopter cautioned the Hiller pilot about clouds moving up the valley, also noting that it was quite windy and turbulent. The Hiller pilot replied that he was aware of the approaching clouds and acknowledged that conditions were bad.
Shortly thereafter, the Sikorsky pilot heard the Hiller pilot say, "I lost it."
Wreckage Examination
The main rotor blades and one paddle were found in close proximity to the helicopter; the other paddle was located 300 feet away. Examination of the main rotor head disclosed damage between the hub static stops and the main rotor mast. Metallurgical examination of the fractured surfaces indicated all the breaks were the result of overload forces.
The helicopter had landed on the pad and was awaiting the passengers when the loss of control occurred. No further information regarding the circumstances leading to the overloads is provided in the source material.