NTSB Factual Report

HISTORY OF FLIGHT

On September 08, 2007, about 1505 Pacific daylight time, a Hughes 369D, N31HM, was hovering on a hillside of the Yakima river canyon in Ellensburg, Washington, when the passenger egressed the helicopter and contacted the main rotor disc. Northwest Helicopters, Inc., was operating the helicopter under the provisions of 14 Code of Federal Regulations Part 91, as a sheep relocating mission for the Washington Department of Fish and Wildlife (WDFW). The commercial pilot and one passenger were not injured; the second passenger was killed. The helicopter was not damaged. The local flight originally departed from Puyallup, Washington, about 0630. Visual meteorological conditions prevailed and a flight plan had not been filed.

During a telephone interview with a National Transportation Safety Board investigator, the pilot stated that prior to the accident he and the second passenger, a WDFW biologist, had flown on numerous missions over the course of more than 20 years. The day of the accident, the flight departed early in the morning for the purpose of relocating bighorn sheep. The doors on the left side of the helicopter were removed, enabling the passengers to egress from that side and walk around the nose to the right side, if the situation necessitated such positioning. The front left-seated pilot was maneuvering the helicopter in the Yakima area, and both the gunner (aft left seat) and mugger (aft right seat) where to capture sheep. Thereafter the pilot would then land to refuel, shutting down the helicopter at each fueling.

The pilot further stated that after having captured about 16 sheep, he had refueled and departed to the Yakima river canyon. The crew gunned two sheep in one net, and the pilot maneuvered the helicopter onto the hillside (about a 30-percent grade). He continued toe-ing the helicopter into the hillside with the front skids in contact with terrain and the netted sheep off the right side of the helicopter. The second passenger (gunner) egressed the left side, and the pilot watched the right-seated passenger (mugger) as he too prepared to egress. The pilot then heard a loud noise and shut down the helicopter. The second passenger had walked into the rotating main rotor disc.

In a later conversation, the pilot added that earlier on the day of the accident, the crew had also captured two sheep in one net, where one of the sheep had escaped before the second passenger could tend to the net. The pilot opined that the second passenger may have been feeling added pressure on the accident touchdown from both having a goal of capturing 20 sheep and having 2 sheep in one net. He noted that the position of the mugger can be fatiguing with the physical requirements of climbing steep terrain and managing the wild animals.

ADDITIONAL INFORMATION

Northwest Helicopters provided an electronic copy of the company policy manual titled, "Aerial Capture, Eradication, Tagging of Animals (ACETA) Plan" that is given to their employees.

Contained within the "Gunner Training" section, the manual states in pertinent part that "the gunner must be familiar with helicopter operations." The manual later details the sequence for conducting a net gun shooting operation. It states that following the netting of animal, the pilot is to safely land "as quickly as possible to drop off the gunner to attend the animal" and "if a mugger is also on board they will also depart at this time." It continues to say, "the pilot will depart to pick up the other processing crew if necessary or land nearby and shutdown to minimize noise trauma to the animal."

The manual did not contain information on whether a pre mission brief was to be conducted on how to egress the helicopter, or any information provided about how the gunner was to egress.

The pilot was the company trainer.

NTSB Probable Cause

The passenger's inadequate visual lookout and failure to maintain clearance from the rotating main rotor disc while the helicopter was hovering. An uphill terrain condition was a factor