1950s Marine Transport Squadron 152 Aircraft Collision with Mt Sunol Ridge (39116)

Incident Overview and Flight Details The aircraft departed El Toro Airbase at 1030LT, operating on behalf of Marine Transport Squadron 152, with Alameda NAS as its destination. The flight carried United States Marines from Camp Pendleton who were en route to Hickam Field, along with five crew members. ## Approach and Collision While approaching the destination, the captain was instructed to follow a 30-minute holding circuit. At 1342LT, the pilot began the approach while descending at an altitude of 3,500 feet in marginal weather conditions. The aircraft struck the slope of Mt Sunol Ridge, located about 21 miles southeast of Alameda Airbase, approximately 200 feet below the summit. The aircraft was destroyed upon impact, and all 40 occupants were killed. ## Crew The five crew members were: - Maj Alexander Watson, pilot - 1st Lt Thomas E. Straughan, copilot - M/Sgt Donald J. Down, navigator - S/Sgt Terrell M. Young, flight engineer - S/Sgt Harry E. Knight, radio operator ## Probable Cause The official findings determined that the collision resulted from several errors and omissions by the flying crew, who neglected approach procedures and misinterpreted signals from local beacons. These errors led to a premature descent and caused the aircraft to drift off course by six miles to the northeast at the time of the accident. Low visibility due to clouds was considered a contributing factor.