What happened
On the evening of August 5, 2013, a Korean Air Boeing 737-90 and registered HL7599 experienced a runway overrun at Niigata Airport. The aircraft, operating flight KAL 763 from Incheon, landed on runway 10 at 19:42 JST. During the landing roll, the aircraft was unable to decelerate sufficiently to remain within the runway boundaries, eventually coming to a halt with its nose gear protruding into the grass area at the eastern end of the runway. There were 115 persons on board, including 106 passengers and 9 crewmembers; fortunately, there were no injuries.
The investigation
The Japan Transport Safety Board (JTSB) examined flight data from the Digital Flight Data Recorder (DFDR) and Cockpit Voice Recorder (CVR), alongside air traffic control communications and crew statements. The investigation focused on the deceleration process, the crew's interpretation of air traffic control (ATC) instructions, and the visibility of runway markings during the night landing. Investigators analyzed the sequence of braking, including the moment the captain disarmed the autobrakes, and reviewed the specific wording used by the Niigata Tower controller regarding taxi clearances.
Findings
The investigation established that the primary cause of the overrun was that the captain failed to reduce the aircraft's speed sufficiently before reaching the runway threshold lights. The crew mistakenly identified these threshold lights as stop bar lights for the intersecting runway 04/22. This misidentification was driven by a misunderstanding of the ATC instruction "cross runway 04/22," which the crew interpreted as permission to cross the intersection during the landing roll rather than a taxi clearance to be executed after vacating the runway.
Contributing factors included:
- The captain disarmed the autobrakes at approximately 70 knots with the intention of rolling to the end of the runway, which prevented effective speed control via manual braking.
- The crew was unfamiliar with the specific layout of Niigata Airport, particularly the intersection with runway 04/22.
- Limited visibility of ground objects and runway markers during the night landing made it difficult for the crew to judge their speed and position accurately.