On January 31, 2001, Japan Airlines Flight 907, a Boeing 747-400 en route from Haneda Airport, Japan, to Naha Airport, Okinawa, narrowly avoided a mid-air collision with Flight 958, a McDonnell Douglas DC-10-40 en route from Gimhae International Airport, South Korea, to Narita International Airport, Japan. The event became known in Japan as the Japan Airlines near miss incident above Suruga Bay (日本航空機駿河湾上空ニアミス事故, Nihonkōkūki surugawan jōkū niamisu jiko).
The incident was attributed to errors made by air traffic controller trainee Hideki Hachitani (蜂谷 秀樹, Hachitani Hideki) and trainee supervisor Yasuko Momii (籾井 康子, Momii Yasuko). The incident caused Japanese authorities to call upon the International Civil Aviation Organization (ICAO) to take measures to prevent similar incidents from occurring. Had the collision occurred, given the 677 people on board both aircraft combined, this could have potentially been the deadliest aviation accident in the world, surpassing the Tenerife airport disaster, which killed 583 people. It would also have been the world's deadliest mid-air collision, surpassing the Charkhi Dadri mid-air collision which killed 349 people.
The Boeing 747-446 Domestic, registration JA8904, was operating flight 907 from Tokyo Haneda International Airport to Naha Airport with 411 passengers and 16 crew. The flight departed Haneda airport at 15:36 local time.
The McDonnell Douglas DC-10-40, registration JA8546, was operating flight 958 from Gimhae International Airport to Narita International Airport with 237 passengers and 13 crew.
According to the flight plan, both aircraft were supposed to pass each other while 2,000 feet apart.
The mid-air incident occurred as flight attendants began to serve drinks onboard Flight 907. JA8904's TCAS sounded 20 minutes after its departure as the jet climbed towards 39,000 feet. The DC-10, JA8546, cruised at 37,000 feet. The pilots of both planes had received instructions from their TCAS, but Flight 907 received conflicting instructions from the flight controller at the Tokyo Area Control Center in Tokorozawa, Saitama Prefecture. Flight 907, headed by 40-year-old pilot Makoto Watanabe (渡辺 誠, Watanabe Makoto), followed an order to descend issued by the flight controller while Flight 958, headed by pilot Tatsuyuki Akazawa (赤沢 達幸, Akazawa Tatsuyuki), descended as instructed by the TCAS, meaning that both planes remained on a collision course.
The trainee for the aerospace sector, 26-year-old Hideki Hachitani (蜂谷 秀樹, Hachitani Hideki), handled ten other flights at the time of the near miss. Hachitani intended to tell Flight 958 to descend. Instead, at 15:54, he told Flight 907 to descend. When the trainee noticed that JAL 958 cruised at a level altitude instead of descending, the trainee asked JAL 958 to turn right; the message did not get through to the JAL 958 pilot. The trainee's supervisor, Yasuko Momii (籾井 康子, Momii Yasuko), ordered ″JAL 957″ to climb, intending to tell JAL 907 to climb. There was no "JAL 957" in the sky.
The aircraft avoided collision using evasive maneuvers once they were in visual proximity, and passed within about 135m of each other. An unidentified passenger told NHK, "I have never seen a plane fly so close. I thought we were going to crash." Alex Turner, a passenger on Flight 907 and a student at Kadena High School, a school for children with parents stationed at Kadena Air Base in Okinawa Prefecture, estimated that the avoidance maneuver lasted for two seconds.
Seven passengers and two crew members of the 747 sustained serious injuries; additionally, 81 passengers and 10 crew members reported minor injuries. Some unbelted passengers, flight attendants, and drink carts hit the ceiling, dislodging some ceiling tiles. The maneuver threw one boy across four rows of seats. Most of the injuries to occupants consisted of bruising. The maneuvers broke the leg of a 54-year-old woman. In addition, a drink cart spilled, scalding some passengers. No passengers on the DC-10 sustained injuries. Flight 907, with the 747's cabin bearing minor damage, returned to Haneda, landing at 16:45.
By 18:00 on February 1, eight Flight 907 passengers remained hospitalized, while 22 injured passengers had been released. Two passengers remained hospitalized at Kamata General Hospital (蒲田総合病院, Kamata Sōgō Byōin). Two passengers remained hospitalized at Ichikawa No. 2 Hospital (市川第2病院, Ichikawa Daini Byōin). In addition, the following hospitals each had one passenger remaining: Takano Hospital (タカノ病院, Takano Byōin), Kitasato University, Horinaka Hospital (堀中病院, Horinaka Byōin), and Tokyo Rosai Hospital (東京労災病院, Tōkyō Rōsai Byōin). All injured passengers recovered.
JAL sent apology letters to the passengers on the 747; injured passengers directly received messages, and uninjured passengers received messages via the mail.
In its report on the accident, published in July 2002, the Aircraft and Railway Accidents Investigation Commission called on the International Civil Aviation Organization (ICAO) to make it clear that TCAS advisories should always take precedence over ATC instructions. A similar recommendation was made three months later by Germany's accident investigation body (the BFU) in light of the Überlingen mid-air collision. ICAO accepted these recommendations and amended its regulations in November 2003.
The Tokyo Metropolitan Police Department and Ministry of Land, Infrastructure and Transport investigated the incident.
In May 2003, Tokyo police filed an investigative report concerning Hideki Hachitani (ATC trainee), Yasuko Momii (ATC Supervisor), and Makoto Watanabe (Pilot of flight 907), suspecting them of professional negligence. In March 2004, prosecutors indicted Hachitani and Momii for professional negligence.
Hachitani, then 30 years old, and Momii, then 35 years old, pleaded not guilty to the charges at Tokyo District Court in 2004. During the same year, the lawyer for Hachitani and Momii said that the pilots of the aircraft bore the responsibility for the near miss.
By November 16, 2005, 12 trials had been held since the initial hearing on September 9, 2004. The prosecution argued that the two defendants neglected to provide proper separation for the two aircraft, the instructions issued were inappropriate, and that the supervisor failed to correct the trainee. The defense argued that the lack of separation would not immediately have led to a near miss, that the instructions issued were appropriate, that the TCAS procedure was not proper, and that the Computer Navigation Fix (CNF) had faulty data.
In 2006, prosecutors asked for Hachitani, then 31, to be sentenced to one year in prison and for Momii, then 37, to be sentenced to one and a half years. On March 20, 2006 the court ruled that Hachitani and Momii were not guilty of the charge. The court stated that Hachitani could not have foreseen the accident and that the mixup of the flight numbers did not have a causal relationship with the accident. Hisaharu Yasui, the presiding judge, said that prosecuting controllers and pilots would be "unsuitable" in this case. The Tokyo District Public Prosecutor's Office filed an appeal with the Tokyo High Court on March 31. During the same year, the Japanese government agreed to pay Japan Airlines and Tokio Marine & Nichido Fire Insurance a total of ¥82.4 million to compensate for the near miss.
On April 11, 2008, on appeal, a higher court overturned the decision and found Hachitani and Momii guilty. The presiding judge, Masaharu Suda (須田 賢, Suda Masaharu), sentenced Hachitani, then 33, to confinement for one year, and Momii, then 39, for one year and six months. Both were placed on probation. Each of the two sentences was suspended for three years. Suda described the mixing of the flight numbers as a "rudimentary error". The lawyers representing the controllers appealed, but the convictions were upheld on October 26, 2010 by the Supreme Court.