What happened
On the afternoon of the accident, a Convair 880, registration JA8030, commenced its takeoff roll on runway 33R at Tokyo International Airport under visual flight rules. The flight was being conducted on behalf of Japan Air Lines for the purpose of a practical examination regarding a type rating change. The aircraft was occupied by five individuals, including the pilot, a flight engineer, and several examiners.
As the aircraft reached rotation speed and assumed a nose-up attitude, it experienced a significant left yaw and entered a right side-slip. At roughly 1,500 meters from the runway threshold, the right main landing gear began to lift. As the side-slip intensified, the underside of the number one engine made contact with the runway surface at approximately 1,600 meters. The aircraft subsequently drifted off the runway at the 1,700-meter mark.
The aircraft traveled across the grass and intersected taxiway C-4. During this excursion, the aircraft's heading shifted significantly before a sudden nose-down attitude occurred, triggering a fire near the number three engine. As the vessel continued its movement, the left main landing gear, nose gear, and engines 3, 2, 1, and 4 separated from the airframe in succession. The wreckage came to rest approximately 2,100 meters from the threshold. An intense fire consumed most of the aircraft, leaving only parts of the empennage, aft fuselage, and wing sections intact. All five people on board were killed.
Findings
Investigators were unable to identify a specific cause for the initial uncontrollable left yaw, as no conclusive evidence was found within the wreckage or the crew's professional backgrounds. It was noted that the pilot was operating from the left-hand seat and was likely using left rudder and right wing down positioning to manage a crosswind from the right.
Evidence suggested the number one engine may have been at idle around the time of rotation. While the use of left rudder was observed, the timing and reason for this input remained unclear. The investigation concluded that the aircraft entered a state of right side-slip that became unrecoverable, as an abrupt increase in the side-slip angle created a rolling moment to the left that the crew could not counteract.