ERA10CA010

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

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).

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 can result in unanticipated right yaw or loss of tail rotor effectiveness (LTE).