Accident Description
The aircraft was on the second leg of a flight from Clark Air Force Base in Manila to Tachikawa Air Force Base in Tokyo, with an intermediate stop at Kadena Air Force Base in Okinawa. While approaching Tachikawa Air Force Base at night, the crew encountered poor weather conditions, including low clouds and rain.
As the aircraft descended to an altitude of 5,000 feet, it struck the slope of Mount Hirugatake, a 1,279-meter peak located 34 kilometers southwest of Tachikawa Air Force Base. The four-engine aircraft was destroyed by the impact forces. The accident claimed the lives of all 35 occupants.
Investigation and Findings
The official investigation into the crash examined the circumstances leading to the collision. According to the probable cause statement, the crew reported their position over the O-Shama radio range station at an altitude of 5,000 feet. However, due to a navigation error, the aircraft was actually 40 kilometers farther south than the reported position. This discrepancy placed the aircraft on a collision course with Mount Hirugatake.
Conclusion
The investigation concluded that the probable cause of the accident was the crew's navigation error, which resulted in the aircraft being significantly off course during the approach to Tachikawa Air Force Base.