NTSB Factual Report

On July 25, 2011, about 1145 Pacific daylight time, a Sikorsky S-55B helicopter, N855TC, sustained substantial damage after impacting terrain near Brewster, Washington. The private pilot and pilot rated passenger were not injured. The helicopter sustained substantial damage to the fuselage, tail boom and main rotor drive system. The helicopter was registered to Golden Wings Aviation and operated under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the flight. The local flight originated from Brewster about 45 minutes prior to the accident.

The private pilot reported that he was conducting a low level flight, for hire, over cherry orchards for the purpose of drying cherry trees. He reported that the orchard was bordered by a series of power lines and that gusty variable winds, with peak gusts to 30 knots, were present at the time of the flight. The pilot reported that during a low hovering pass over the orchard, a gust of wind from the left pushed the helicopter to the right, and towards the power lines. In an attempt to avoid the power lines, the pilot increased collective pitch and the helicopter began to climb. During the climb, the main rotor rpm decayed, and the nose of the helicopter yawed to the right. The pilot lowered the collective and increased the engine power in an effort to regain main rotor rpm; however, the helicopter descended into the orchard.

The pilot reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operations. The pilot further reported that the accident could have been prevented if the flight had been conducted after the wind diminished.

NTSB Probable Cause

The pilot did not maintain main rotor rpm while hovering in gusting wind conditions.