Accident Overview
A U.S. Air Force-sponsored mountain flying training clinic included a planned flight route with a contour search pattern through drainages along the Minam River valley. The accident occurred in a canyon within this route.
Flight Details
A trainee who flew the accident route on a previous flight with the same mentor reported refusing to enter most drainages, citing insufficient climb capability and space to turn. The segment where the accident occurred was flown at 90 knots with 10 degrees of flaps.
Wreckage Discovery
After the accident flight failed to return on schedule and contact was lost, a search commenced. The wreckage was located approximately two days later. Both occupants were found with fatal injuries at the accident site.
Accident Site
The crash site was at an elevation of 5,400 feet on sloping terrain, about half a mile beyond the planned turn point (further into the canyon). The planned route required a 135-degree turn at that location to exit and return to base.
Aircraft Damage
Investigators observed damage and impact signatures consistent with an uncontrolled, relatively low-speed impact. The aircraft's flaps were found extended to 10 to 15 degrees. No evidence of pre-impact mechanical problems was discovered.
Environmental Conditions
A METAR observation taken near the estimated accident time at La Grande, Oregon (approximately 19 nautical miles from the site and 2,700 feet lower) indicated a computed density altitude of about 5,000 feet.