Schweizer 269C-1 N1835E accident near Lewiston, Maine

Probable cause

The loss of tail rotor effectiveness (LTE) resulting from hovering the helicopter in a tailwind.

NTSB analysis

The pilot of a helicopter was conducting a non-revenue sightseeing flight for one passenger. After lifting off, the pilot stated that he was hovering eastbound with the winds out of the west. A METAR taken on the airport approximately 5 minutes before the accident indicated the wind was from 340 degrees at 11 knots with gusts to 16 knots. The pilot further stated that the helicopter’s nose made a sudden yaw to the right, which could not be corrected with reduction of throttle and full left pedal application. The helicopter touched down after a 270 degree turn, came to rest upright, with substantial damage to the main rotor blades, skids and tailboom. According to a Federal Aviation Administration Advisory Circular (AC) 90-95 titled "Unanticipated Right Yaw in Helicopters", operation of a helicopter with a tailwind as reported by the pilot or with a left quartering tailwind as determined by the METAR and the pilot's statement can result in unanticipated right yaw or loss of tail rotor effectiveness (LTE).

Text from the NTSB. Open the NTSB docket for ERA10CA010 for the full record.