Primary finding
Probable cause
The pilots failure to maintain terrain clearance during the downslope, downwind, high altitude, takeoff. Factors were the snow and lighting conditions, and the tailwind takeoff.
Investigator assessment
Analysis narrative
The pilot made a steep downslope, downwind, departure from a 1,000-foot-long packed snow strip at 9,500 feet msl. The departure path was down a steep canyon. The lighting was flat, with no contrast available to see the snow covered terrain. The airplane impacted rising terrain shortly after takeoff.
Source record
Factual narrative
On July 23, 1997, at 1400 Alaska daylight time, a Cessna 185 ski equipped airplane, N9855X, sustained substantial damage when it impacted terrain during takeoff from the 9,500 foot msl level of the Kahiltna Glacier, Alaska, at position 63-03.4 north latitude, 151-11.0 west longitude. The commercial certificated pilot and three passengers were uninjured. The airplane was operated by Hudson Air Service, Inc., of Talkeetna, Alaska. The flight was conducted under 14 CFR Part 135 in visual meteorological conditions, as an on demand air taxi. A company VFR flight plan was filed. The pilot stated that he departed downhill from the 1,000 foot long by 50 foot wide snow strip, with a 10-15 knot down-glacier wind. The pilot said that just after becoming airborne, the airplane contacted rising terrain on the canyon side, and came to rest at 8,400 feet msl. He described the lighting conditions as "flat," and as he was unable to distinguish the ground's snowy surface, he was using the surrounding ridges for visual reference. -