What happened
On June 15, 2019, a serious incident occurred at Tokyo International Airport involving two aircraft. A Boeing 787-9, registered JA885A, operated by All Nippon Airways Co. Ltd., was taxiing toward the international terminal after landing on Runway 3 and was cleared to cross Runway 34L. Simultaneously, a Boeing 737-800, registered JA73AB, operated by Skymark Airlines Inc., was on final approach to the same runway after having already received landing clearance.
At approximately 18:04, the aircraft were in close proximity; the Boeing 737-800 was roughly 5,700 meters from the runway threshold, while the distance between the two aircraft was approximately 8,400 meters. The conflict was resolved when the air traffic controller issued a landing clearance to the Boeing 737-800 for confirmation, effectively halting the crossing of the JA885A.
The investigation
The JTSB investigation focused on the actions of the air traffic controllers at the Tower West Position. The team consisted of a trainee receiving on-the-job training (OJT) and a supervisor. The investigation examined radar records, flight data, and communications to determine why the clearance to cross the runway was issued to the JA8HD5A while the JA73AB was cleared to land.
Investigators looked into the workload of the controllers, noting that the supervisor was simultaneously coordinating the movement of a towed aircraft. The investigation also reviewed the use of electronic flight strips and the effectiveness of the supervisor's ability to monitor the trainee's actions from a rear position in the tower.