WPR13LA023

The pilot’s failure to maintain precise altitude control, which resulted in the helicopter entering a settling with power condition while hovering out of ground effect.

The pilot said that he was using a long line to lift harvested evergreen tree boughs from his property on the side of a mountain. The helicopter was hovering out of ground effect, and he was looking outside at ground personnel when the flight controls began to feel "mushy." The pilot stated that the helicopter began "settling with power" and descending. He attempted to turn and fly more directly into the wind but then he heard the low rotor rpm horn. He entered an autorotation to an open area, but, on touchdown, the steep sloping terrain caused the helicopter to slide into trees and come to rest on its right side. The helicopter was hovering out of ground effect, which created a situation conducive to entering a settling with power (vortex ring state) condition, and the pilot needed to maintain precise altitude control to prevent the condition from developing. The pilot reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

On October 26, 2012, about 1130 Pacific daylight time, a Robinson Helicopter Company R-44 II, N7530F, sustained substantial damage when it impacted trees following a loss of control while hovering out of ground effect trees near Toutle, Washington. The private pilot, the sole occupant, was not injured. The pilot was operating the helicopter under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the personal local flight, which had originated from a remote operating site about 30 minutes before the accident. A flight plan had not been filed. The pilot said the he was using a long line to lift evergreen tree boughs from the side of a mountain to sell as Christmas decorations. He was harvesting these boughs from his own property. The pilot said he was looking outside at his ground personnel when the flight controls began to feel mushy. He knew the helicopter was "settling with power" and "sinking." He attempted to turn towards clean air and fly more directly into the wind. He heard the low rotor horn. He entered an autorotation to an open area but, on touchdown, the steep sloping terrain caused the helicopter to slide into trees and subsequently come to rest on its right side. The helicopter's tail boom and landing skids were bent and/or broken from the helicopter. According to the FAA's Helicopter Flying Handbook, situations that are conducive to a settling with power (vortex ring state) condition include any hover above ground effect altitude and attempting to hover out of ground effect without maintaining precise altitude control. The pilot reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation.