What happened
A group of five Kawasaki C-1 aircraft departed from Nagoya-Komaki, bound for Iruma Air Force Base. During the mission, the formation encountered extremely hazardous meteorological conditions near Suga Island, characterized by heavy rainfall, fog, and a low cloud ceiling that significantly restricted visibility.
While operating under a special VFR clearance at an altitude of 600 feet, one aircraft impacted a mountain slope measuring 1,018 meters in height. This impact resulted in eight fatalities among the crew members on board.
Simultaneously, a second Kawasaki C-1 crashed under the same weather conditions, leading to the deaths of all six crew members. A third aircraft in the group also experienced an incident when it struck treetops, though the crew managed to perform an emergency landing at the closest available airfield.
Findings
The primary factor contributing to these accidents was the encounter with severe weather and degraded visibility while flying at low altitudes.