What happened
During an initial attempt to fly through Lake Clark Pass, the pilot mistakenly turned into the wrong valley. As flight visibility continued to decline, the pilot initiated a 180-degree turn to exit the valley, but encountered whiteout conditions during the maneuver.
Upon observing mountains on both sides of the aircraft, the pilot realized the exit from the valley had been missed. Due to a lack of depth perception to estimate altitude above the ground, the pilot applied full engine power and maintained the best climb attitude. Shortly thereafter, the aircraft collided with a glacier and subsequently nosed over.
Prior to the flight, the preflight weather briefing had indicated that Lake Clark Pass was forecast for marginal VFR to IFR conditions.