A deadly two-plane collision in Tokyo on Jan. 2 happened because a pilot mistakenly believed he had been given permission to enter the runway for takeoff, the Japanese government’s crash investigation found.
A 166-page report by the Japan Transport Safety Board released Wednesday confirmed what had been seen as the most likely explanation of the collision, in which a Japan Airlines passenger jet landing at Haneda Airport plowed into a Japan Coast Guard plane waiting on the runway.
Five of the six crew members of the Coast Guard plane were killed, while all 379 passengers and crew aboard the Japan Airlines Airbus A350 escaped safely down evacuation chutes minutes before the jet was engulfed in flames.
Two minutes before the collision took place at 5:47 p.m., the control tower told the Coast Guard plane, “No. 1, taxi to holding point C5,” meaning it was first in line to take off and was supposed to wait at the holding point for further instructions. The Coast Guard pilot—who survived the accident—said he believed the message signified permission to enter the runway, according to the report.
The pilot’s post-accident recollection was affirmed by his actions in those final two minutes, when he ordered his co-pilot to go through a checklist that normally begins when a plane has received final takeoff permission. The report said the pilot also told investigators he believed he heard the control tower say “cleared for takeoff” about a minute before the collision.
The report cited haste as one possible reason for the pilot’s misunderstanding. The Coast Guard plane was delivering rescue supplies to a region of Japan hit by an earthquake the day before. The “No. 1” meant that the plane had been given priority ahead of another plane that normally would have gone ahead, suggesting to the pilot that controllers shared his desire to move quickly, the report said.
Also, the pilot was worried that his colleagues would be late getting home after dropping off the supplies and returning to Tokyo, it said.
The report confirmed earlier suspicions that the air-traffic controllers didn’t notice a warning light indicating a potential runway collision, so they let the Coast Guard plane sit on the runway for about 40 seconds as the Japan Airlines jet descended.
