As Japan Airlines Flight 516 was landing, it collided with the Coast Guard plane,[2] immediately igniting fires that destroyed both aircraft.

[4] Investigations have determined that Japan Airlines Flight 516 was given landing clearance, while the Coast Guard aircraft did not have permission to be on the runway.

[13][14][15] The Japan Coast Guard aircraft involved was a De Havilland Canada DHC-8-315Q MPA, manufacturer serial number 656, nicknamed Mizunagi-1 (Japanese: みずなぎ1号), and registered as JA722A.

[14][17][18] The Japan Coast Guard aircraft, carrying six crew members, was transporting emergency supplies to an airbase in Niigata in response to the 2024 Noto earthquake, which had occurred the day before.

[14] At approximately 17:47 JST (08:47 UTC), JAL516 collided with a Japan Coast Guard Dash 8, identified by its call sign and registration number JA722A, while landing on runway 34R at Haneda Airport.

[41] According to a statement by a JAL spokesman, the three pilots felt a sudden shock immediately after landing and lost control of the aircraft while trying to maintain its course along the runway.

[50] Paul Hayes, the director of air safety at Ascend, a British-based aviation consultancy, told Reuters, "The cabin crew must have done an excellent job.

[8] Another factor cited in the survival of those on board was that the aircraft, one of the first commercial models to be made of composite carbon fiber materials, appeared to have withstood the initial impact of the collision and fire relatively well.

[22] The aircraft following immediately behind Flight 516—JAL166, a Boeing 737-800 approaching runway 34R—had to perform a go-around at 1,150 feet (350 m) before diverting to Narita International Airport.

[34] At around 21:30 JST (12:30 UTC), Haneda Airport's remaining three runways were reopened according to the Ministry of Land, Infrastructure, Transport and Tourism (MLIT).

The MLIT also warned of additional aircraft flying over Chiba Prefecture at low altitudes after the collision rendered low-altitude routes over central Tokyo unusable.

[64] On 12 January, the Japan Coast Guard suspended personnel at the Haneda Air Station [ja], which has jurisdiction over the coastal waters between Ibaraki and Shizuoka Prefectures, from operating the facility's two helicopters and three remaining fixed-wing aircraft as part of efforts to ensure safety and psychological care to the staff, delegating the operation of the station's air assets to personnel from other Coast Guard facilities.

[69] The use of the phrase "number 1" in air traffic control parlance was also prohibited after the investigation suggested that the usage of the term led the Coast Guard pilot to think he had clearance to enter the runway.

[72] Japanese Prime Minister Fumio Kishida extended his condolences to the dead, referring to their service to the victims of the 2024 Noto earthquake.

It also apologized for the inconvenience and distress caused to passengers, friends, families, and everyone affected by the accident, and gave assurances that it would cooperate with the investigation.

[80] The Japan Federation of Civil Aviation Workers' Union for Air Safety (JFAS) said that, in line with ICAO Annex 13, finding out the facts should be the first priority, adding that in many cases police intervention prevented the identification of the cause of aircraft accidents.

[84] The French Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) announced on Twitter that they will be cooperating with Airbus during the investigation.

[30] Air traffic controllers later told MLIT officials that they had not noticed the Coast Guard plane moving onto the runway, adding that they were preoccupied with assisting other aircraft.

[97] Another MLIT official also said that the Coast Guard was not informed of measures introduced by a government task force to prevent airport runway incursions following similar accidents in 2007.

Moreover, it was revealed that over 100 emergency vehicles were waiting to enter the airport and several ambulances carrying injured passengers were unable to leave for about 30 minutes.

The report added that neither the controller in charge nor the JAL pilots noticed that the Coast Guard aircraft entered the runway, and that the three circumstances combined resulted in the accident.