What happened
On December 26, 2010, at approximately 11:34 JST, a runway incursion occurred at Fukuoka Airport involving two Boeing 737-40 and 737-400 aircraft. The departing aircraft, an Air Busan Co., Ltd. Boeing 737-400 registered HL7517, was taxiing toward runway 34 for a scheduled flight to Gimhae International Airport. Simultaneously, a JAL Express Co., Ltd. Boeing 737-400 registered JA8998 was on final approach to the same runway, having received landing clearance.
As HL7517 approached the runway via taxiway W8, the flight crew entered the active runway. This movement prompted the air traffic controller to immediately instruct the arriving JA8998 to perform a go-around to avoid a collision. The incident resulted in no injuries and no aircraft damage, though the separation between the two aircraft was significantly reduced during the maneuver.
The investigation
The Japan Transport Safety Board (JTSB) examined air traffic control transcripts, radar tracking data, and flight data recorder records from both aircraft. The investigation also included interviews with the flight crews of both aircraft and the air traffic controllers involved. The investigators focused on the communication between the tower and the departing crew, specifically looking at the clarity of the holding instructions and the accuracy of the pilots' read-backs.
Findings
The primary cause of the incident was the failure of the departing crew of HL7517 to recognize a hold short instruction, leading them to misinterpret their clearance as permission to enter the runway.
Several contributing factors were identified:
- The flight crew of HL7517 misinterpreted the controller's instruction as a clearance to line up and depart, likely influenced by a prior discussion regarding an intersection departure.
- The air traffic controller did not verify the pilot's read-back of the holding instruction, which contained ambiguous phraseology.
- The use of "at" or "via" in the controller's instruction, while intended to indicate a taxi route, contributed to the crew's belief that they had obtained runway entry permission.
- The departing crew believed the controller was attempting to expedite their departure to avoid conflict with the inbound traffic, leading to a rushed interpretation of the instructions.