At about 1959 Pacific time, the airplane collided with terrain and was destroyed. The commercial pilot and nine passengers sustained fatal injuries. Visual conditions prevailed at the nearest official reporting station; a ground observer noted instrument conditions prevailed at the accident site.
A preliminary review of recorded radar data indicated the target made a series of left and right turns after passing Yakima at a mode C altitude of 12,400 feet. The target was at a mode C altitude of 14,400 feet when it made a tight 360-degree turn, and lost 1400 feet in 12 seconds. The target stayed at a mode C altitude of 13,000 feet for three radar hits. The last target was in the vicinity of the accident site at a mode C altitude of 8900 feet. The accident site was about 4300 feet.
The structure of the airframe compressed into the principle impact crater so that the leading edges of the horizontal stabilizers were inches above ground level. The propeller and nose of the engine were about five feet below ground level. The cabin seats and ELT were fragmented.
