But in November 2003, the NTSB blamed the two pilots of Wellstone's plane, Richard Conry and Michael Guess, for the crash. The pilots flew too high and too fast when they began a left turn toward the runway, then let it slow to dangerous levels, the NTSB said...Controlled flight into terrain/pilot error is the single most common cause of private plane crashes. But because Wellstone was on board, this explanation is impossible. Suuuuure.