On 6 January 2007, a Boeing B737-900 operated by Korean Airlines landed at Akita Airport on a taxiway parallel to the in-use runway after a daylight non-precision approach (NPA) using a head-up display (HUD). The crew realised their error during the landing roll.
The Investigation was begun by the Aircraft and Railway Accidents Investigation Commission which was replaced by the Japan Transport Safety Board (JTSB) during the course of the Investigation. The following extract is from the official Report (AI2008-01) into the Serious Incident investigation published by the Japan Transport Safety Board (JTSB):
"A Boeing 737-900, registered HL7724, which was operated by Korean Air Lines Co., Ltd. as scheduled flight 769, took off from Incheon International Airport (Seoul, the Republic of Korea) on January 6, 2007 (Saturday), and made an approach to Runway 10 of Akita Airport (Akita Japan), its destination, but landed on a parallel taxiway located south side of Runway 10 at about 12:16.
Of the total of 133 persons on board, consisting of the captain, the first officer, seven other crewmembers and 124 passengers, no one was injured, and there was no damage to the aircraft.
The Report provides the following analysis of the misidentification of the runway:
"[…] according to the conversation […] recorded by the CVR, it is estimated that the captain mistook the taxiway for the runway. And he said, “I’ll make a landing there” at 14m52s. It is estimated that the first officer also agreed with the captain in the course of the conversation.
[…] because the first officer said, “It looked like as though there were two runways”, it is considered that the captain saw the runway likewise. It is considered that their failure to distinguish the runway from the narrower taxiway, which is located on the right-hand side of the runway, was caused by such reasons that the captain and the first officer forgot and did not reconfirm the relative locations of the runway and the taxiway, that visibility was poor due to rain, that they saw the runway in the distance when the Aircraft was heading rightward in the strong crosswind and its flight path was nearly aligned with the taxiway, and that it was difficult to see boundary of the rain-wet taxiway.
Under such circumstance, because the captain mistakenly assumed that the VHF Omnidirectional Radio Range (VOR) approach course was heading toward the runway, and the FDGC [Flight Director Guidance Cue], LNAV [Lateral Navigation], and the like indicate direction to the runway, it is considered that he mistook the right side taxiway for the runway, assuming that the one corresponding to the flight path was the runway. Meanwhile, it is considered that although the first officer at first correctly recognized the runway based on the position of PAPI, he misunderstood that the LNAV course were leading to the runway, and agreed with the captain. Furthermore, concerning that the captain and the first officer mistakenly interpreted the indication of the instruments, it is considered contributory that they did not know that VOR No.1 approach course ran in parallel with the runway, and that its extended line was nearly superposed on the taxiway.
Because the captain continued an approach relying on HUD and ND indications when he should have made a visual approach after he got the runway in sight, it is considered that his attention to the outside view was diminished, and thereby he was unable to correct his mistake.
Even under the visual meteorological conditions, if there was any uncertainty about visual identification of the runway, the captain should have taken such measures to ensure correct identification of the runway as requesting the lighting of the runway lights or confirming the aerodrome chart, but it is considered that he did not consider it necessary to use various confirmation measures due to his misunderstanding that the indication of the instruments points to the runway."
The JTSB identified the following probable cause and contributory factors:
- "It is estimated that this serious incident was caused by that the captain and the first officer made a landing by misidentifying the parallel taxiway for the runway.
- Concerning this misidentification, such factors are considered contributory as forgetting and failing to reconfirm the relative location between the runway and the taxiway, deterioration of local visibility under the visual meteorological condition and the lack of knowledge about the fact that VOR No.1 approach course runs in parallel with the runway. In addition, it is considered that captain’s mistaken belief that the FDGC in the HUD display had indicated direction to the runway was also a contributory factor."
The Report provides no Safety Recommendations. As a result of the investigation, Korean Airlines added and modified the Company Airway Manual regarding operations into Akita Airport that upon arrival, when using VOR DME RWY 10 APP, caution must be exercised not to confuse runway with taxiway especially in poor visibility due to fog or snow.
To see the official comments and Safety Recommendations of ARAIC of Republic of Korea, see Attachment 5 to the Report (Further Reading)