What happened
A scheduled flight from Sapporo-Chitose Airport to Tokyo-Haneda, operated by All Nippon Airways, was cruising at 28,000 feet when it encountered a military aircraft. The second aircraft involved was a Japan Air-Self Defence Force North American F-86F Sabre, registration 92-7932, which was conducting a training mission with a crew of two.
The two planes collided in mid-air, causing both to lose control and descend into mountainous terrain south of Shizukuishi. While the two military pilots successfully ejected from their aircraft without injury, the impact resulted in 162 fatalities on the Boeing 727, as all passengers and crew members perished.
Findings
The investigation concluded that the primary cause was the failure of a trainee pilot to detect and avoid other aircraft during his training flight. The trainee, who had only 25 total flying hours, did not execute a corrective maneuver in a timely manner after receiving instructions from his instructor. This delay led to the right wing of the F-86F Sabre striking the horizontal stabilizer of the Boeing 727.
Several contributing factors were identified during the inquiry:
- The instructor pilot inadvertently allowed the training flight to exit designated training airspace and enter the J11L jet route without noticing.
- Although the crew of the airliner likely observed the military aircraft at least seven seconds prior to the impact, they did not initiate avoidance maneuvers until moments before the collision, likely because the threat was not anticipated.
- The instructor pilot failed to see the airliner himself and could not provide sufficient warning to the trainee.
- The trainee pilot only visually identified the airliner approximately two seconds before the strike. His focus on maintaining position with the instructor aircraft, combined with a lack of experience in emergency avoidance maneuvers, prevented a successful evasive action.