Casualties unknown

2007-09-08: Hughes 369D (N31HM) — Ellensburg, WA

Ellensburg, WA, US

On September 8, 2007, a Hughes 369D (registration N31HM) was involved in an aviation accident near Ellensburg, WA. Investigators recorded the probable cause as: 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. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During a bighorn sheep capture mission, a gunner exited a helicopter and walked into the rotating main rotor, resulting in his death. The pilot had maneuvered the helicopter onto a hillside with skids contacting terrain.

Accident Details

On the day of the accident, a helicopter crew was conducting a bighorn sheep relocation mission. The front left-seated pilot maneuvered the aircraft, allowing the gunner (aft left seat) and mugger (aft right seat) to capture sheep. After capturing 16 sheep, the mission continued toward a goal of 20 sheep for the day.

The crew gunned two sheep in one net. The pilot then maneuvered the helicopter onto a hillside with approximately a 30-percent grade. He continued toe-ing the helicopter into the hillside with the front skids contacting terrain, while the netted sheep were positioned off the right side of the helicopter.

The gunner egressed the left side of the helicopter and walked into the rotating main rotor disc, killing himself.

Mission Background

Prior to the accident, the pilot and the second passenger (a biologist) had flown on numerous missions over more than 20 years. The flight departed early in the morning for the purpose of relocating bighorn sheep.

The pilot opined that the gunner may have been feeling added pressure and fatigue during the capture.

Post-Accident Findings

A review of the operator's employee manual disclosed that operations on the accident flight were in compliance with the manual. However, the manual did not address passenger briefing of egress instructions on a regular basis.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20070919X01416. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.