NTSB Factual Report

On October 29, 2002, about 0930 Hawaiian standard time, a Hughes 369D, N220AL, rolled over and slid about 150 feet down a mountainside during an attempted takeoff from a ridge about 4 miles southwest of Kaaawa, Oahu, Hawaii. The accident occurred during an on-demand air taxi flight performed by Cherry Helicopters, Inc., based in Kahuku, Oahu, Hawaii, under the provisions of 14 CFR Part 135. The helicopter was destroyed. The airline transport certificated pilot and one of the two passengers sustained serious injuries; the second passenger received minor injuries. Visual meteorological conditions prevailed, and a company flight plan had been filed. The flight originated from Kahuku, about 0900.

According to the pilot, he picked up three passengers and transported them to a landing zone at a remote site on top of a ridge. Upon arrival, the pilot performed a reconnaissance of the area and landed on a part of the ridge that sloped to the right. The pilot reported that the wind was strong and gusty, but was most directly on the nose of the helicopter. The pilot said he maintained full flight rotor rpm and completely lowered the collective pitch, then the helicopter settled right skid downslope. He noted that the ground was soft. One of the passengers, who was seated directly behind the pilot, disembarked, which left two passengers on the right side of the helicopter. Then the pilot applied collective pitch, and the helicopter began to roll right. The pilot decreased the collective but this had no effect. The helicopter tipped over and slid down the steep incline.

A Federal Aviation Administration (FAA) aviation safety inspector reported to the National Transportation Safety Board investigator that the landing zone (pinnacle) was approximately 18 feet wide. The pilot had, according to a passenger, landed on the extreme edge of the pinnacle, on the sloping ground. The FAA inspector further indicated the pilot stated that upon initially landing the helicopter tilted to the right. During the pilot's subsequent attempted takeoff, as the pilot raised the collective he had full left cyclic displacement, but to no avail.

The FAA also reported to the Safety Board investigator that when the occupants were rescued, the pilot of a rescue helicopter noted the local wind condition at the ridgeline. The rescue pilot reported that the wind speed was about 25 knots, and it was gusting to 30 knots.

NTSB Probable Cause

Dynamic rollover during an attempted takeoff, due to the combined effects of the soft sloping terrain and the pilot's failure to redistribute the passengers to a more favorable lateral CG condition.