Narrative
The pilot was making his first attempt to fly through Lake Clark Pass. During the flight, he mistakenly turned up the wrong valley. The flight visibility, which was already poor, continued to deteriorate. In response, the pilot began a 180-degree turn to exit the valley. During the turn, he entered whiteout conditions. When he saw mountains on both sides, he realized he had missed the turn out of the valley. With no depth perception to estimate his altitude above the ground, the pilot applied full engine power and maintained the best climb attitude. Very soon afterward, the airplane collided with a glacier and nosed over on it.
Preflight Weather Briefing
During the preflight weather briefing, the pilot was told that Lake Clark Pass was forecast to be marginal VFR to IFR.
Probable Cause
The investigation did not assign a probable cause.