What happened
A special military flight was operating between Fort Ord Air Force Base in Monterey and McChord Air Force Base when the accident occurred. The aircraft was transporting 19 passengers along with two pilots. During the mission, the crew opted to cancel their existing instrument flight rules (IFR) flight plan, choosing instead to proceed under visual flight rules (VFR).
While flying at an altitude of approximately 2,600 feet, the aircraft encountered heavy fog. While navigating these low-visibility conditions, the plane struck a mountain slope. The impact and subsequent fire resulted in the total destruction of the aircraft. There were 21 fatalities among the occupants.
Findings
Investigation into the crash revealed that the flight was proceeding under VFR at the time of the collision. Although all ground-based radio equipment was operating correctly, the aircraft struck a fog-covered hillside during daylight hours. The investigation concluded that the primary factor in the accident was the pilot's decision to maintain visual flight rules while flying through instrument meteorological conditions.