The 166-page document charts the hours and final chaotic minutes before the fatal collision between a Japan Airlines Co. jet and a coast guard plane at the Tokyo airport in the early evening of Jan. 2, 2024.
The crash killed five of the six people aboard the smaller plane, which had entered the runway into the path of the arriving JAL flight. All 379 passengers and crew aboard the JAL Airbus SE A350 miraculously survived the fireball that engulfed the plane.
Investigators have previously pointed to inconsistencies between the instructions by air traffic controllers to the coast guard pilots, and the subsequent actions by the cockpit crew, as the reason for the crash. The report also details the strains of controlling traffic at one of the world’s busiest commercial airports, as well as inadequacies with systems designed to prevent the exact kind of crash that occurred.
Here’s a closer look at what investigators have found so far:
Alert Confusion
The safety system that alerts air traffic controllers to potential runway collisions didn’t have an audio alarm installed, though a visual alert was functioning across multiple screens in the tower.
At Haneda, the alert is triggered when a departing aircraft is in the path of a jet due to land in 48 seconds or more. But investigators say that it could be triggered when there’s no actual overlap, or in a situation that doesn’t pose a safety hazard. Air traffic controllers said they found the system unreliable and, additionally, there were no formal procedures for what to do once an alert was triggered, the report found.
The report said the safety system was operating normally on the day of the crash and was triggered at 5:46 p.m. local time — less than two minutes before the collision — due to the runway incursion by the coast guard plane. Staff in the control tower were visually checking the movement of aircraft and none recalled seeing the alert on their monitors.
Congestion
The evening hours are some of the busiest at Haneda Airport and air traffic controllers were juggling congestion. The worker overseeing runway 34, where the crash occurred, was supervising five aircraft — three departing and two landing — as well as visually monitoring two other jets on a different runway.
The airport is staffed by air traffic controllers from the Tokyo Aerodrome Control Center and the Tokyo Terminal Air Traffic Control Center, who take turns performing control duties. At the time of the accident, there were 12 air traffic controllers on duty at the Tokyo Aerodrome Control Center.
Investigators are looking into the workload of the controller supervising the movements of the planes involved in the collision. In the wake of the incident, the union for transport workers in Japan said it will push for more staff to assist air traffic controllers at the country’s main airports to strengthen safety measures.
Regardless, the heavy congestion at such a busy time of day created a sense of urgency to get aircraft moving. The controller overseeing runway 34 had already rejected multiple requests to speed up landings, citing the many jets waiting to take-off in a short period of time.
The coast guard pilots were particularly harried. They were set to provide supplies to victims of a deadly earthquake that struck northwestern Japan on Jan. 1, 2024, but had faced mechanical issues that delayed their departure.
Confusion about whether they had been given priority to take off led to the coast guard plane being in the path of the arriving JAL jet, the report said.
Power Problems
The coast guard mission had its flight pushed back by about 40 minutes due to a problem with the De Havilland Canada Dash 8’s auxiliary power unit.
That left the crew scrambling to troubleshoot — potentially replacing the part or seeking assistance from airports along its multi-stop route. The day had started with a plan to use an entirely different jet for the operation. The decision to use the De Havilland, which was capable of carrying more cargo, then presented an issue of being short-staffed for that type of jet.
The mechanical problem was still being discussed as the coast guard plane taxied toward the runway, according to the cockpit voice recorder, which cut out at 5:47 p.m. — when the JAL jet struck the smaller plane.
Investigators are continuing their probe and haven’t given details on when a final report will be published.
Photograph: The wreckage of a Japan Airlines passenger jet that collided with a Japan Coast Guard plane at Haneda Airport, on Jan. 5, 2024. Photo credit: Akio Kon/Bloomberg
Related:
Copyright 2025 Bloomberg.
The most important insurance news,in your inbox every business day.
Get the insurance industry’s trusted newsletter
