Thai Airways International Flight 620

Thai Airways International Flight 620
	HS-TAE, the aircraft involved, photographed in 2012
Accident
Date	26 October 1986
Summary	Accidental hand grenade explosion
Site	Tosa Bay, while en-route Manila to Osaka
Aircraft
Aircraft type	Airbus A300B4-601
Aircraft name	Sukhothai
Operator	Thai Airways International
Registration	HS-TAE
Flight origin	Don Mueang International Airport, Bangkok, Thailand
Stopover	Ninoy Aquino International Airport; Manila, Philippines
Destination	Osaka International Airport, Osaka, Japan
Passengers	233
Crew	14
Fatalities	0
Injuries	109
Survivors	247 (all)

Thai Airways International Flight 620 was a scheduled Thai Airways International passenger flight from Bangkok to Osaka via Manila. The Airbus A300B4-601 aircraft, originating in Bangkok, suffered an explosion mid-flight. The aircraft was later repaired and there were no fatalities. The cause was a hand grenade brought onto the plane by a Japanese gangster of the Yamaguchi-gumi. 109 of the 239 people on board were injured. The aircraft descended rapidly and was able to land safely at Osaka.^[1]^[2]^[3]^[4]^[5]^[6]^[7]^[8]^{[excessive citations]}

Incident

At around 8PM of October 26, 1986, Thai Airways International Flight 620 (Airbus A300-600, Registration HS-TAE) was cruising above Tosa Bay off the coast of Kochi Prefecture, carrying 14 crews and 233 passengers, when the rear of the aircraft suddenly suffered an explosion, resulting in rapid decompression and damage to the rear pressure bulkhead, severing two of the three hydraulic pipes. As a result, the aircraft veered off course for about 100 kilometers and into restricted air space of the Japan Air Self Defense Force, as well as going into a dutch roll at one point, but the aircraft managed to make an emergency landing at Osaka Itami Airport at 8:40 PM.^[9]^[10]

As a result of the explosion and the aircraft's violent turbulence, a total of 109 passengers and crew suffered injuries, with 14 of them suffering severe injuries.^[11]

Investigation

Initially, it was believed that, like Japan Air Lines Flight 123 a year before, some sort of a mechanical problem was to blame for the incident.^[12] While the aircraft was delivered less than three weeks before the incident, the pressurization devices were having issues in the week leading up to the incident, with reports being made that warning lights were turning on.^[12]

However, it was quickly revealed after the aircraft was examined by the Osaka Prefectural Police [ja] that the explosion was caused by some sort of an explosive that was brought in, rather than the aircraft itself.^[4]^[13] Ultimately, a 43-year-old yakuza of the Yamaguchi-gumi admitted to smuggling the hand grenade into the aircraft. The yakuza stated that he "accidentally pulled the safety pin off in the toilet that was at the rear left area of the toilet" and that "he tried to put the pin back in, but it didn't work, so he left it behind in the toilet and let it blow up".^[2]^[3]^[5]^[10]^[14]

Aftermath

The yakuza who brought in the hand grenade was not arrested until after he was discharged from the hospital, because the man had suffered severe burns all over his body as oil from a broken hydraulic pipe poured over him during the incident.^[3]

The aircraft involved, HS-TAE, was delivered less than three weeks before the incident on October 9.^[11]^[12]

References

^ Ranter, Harro. "Thai Airways International Flight 620". aviation-safety.net. Aviation Safety Network.
^ ^a ^b Snyder, Janet (29 October 1986). "Police check gangster grenade blast theory". UPI. Archived from the original on 4 August 2017. Retrieved 8 July 2017.
^ ^a ^b ^c "Gangster's grenade causes jet scare". Japan Times. 30 October 1986. Archived from the original on 3 August 2017. Retrieved 8 July 2017.
^ ^a ^b "Police say grenade caused Airbus blast". China Daily. 31 October 1986. Archived from the original on 3 August 2017. Retrieved 8 July 2017.
^ ^a ^b Haberman, Clyde (4 November 1986). "Thai Plane Incident Prompts a New Look at Japan Gangs". The New York Times. ISSN 0362-4331. Archived from the original on 24 May 2015. Retrieved 8 July 2017.
^ "Yakuza Branches Out". Associated Press. 2 November 1986. Retrieved 8 July 2017.
^ "Passengers Tell of Plunge in Jetliner". Los Angeles Times. 27 October 1986. Archived from the original on 18 November 2022. Retrieved 14 July 2017.
^ "Criminal Acts Against Civil Aviation 1986" (PDF).^{[permanent dead link‍]}
^ "事故のタイ機、油圧系統2つまで切断". Asahi Shimbun (in Japanese). 1986-10-28.
^ ^a ^b Kaoru, Murano (July 2002). 明治・大正・昭和・平成事件・犯罪大事典 (1st ed.). Tokyo. p. 432. ISBN 4808940035.{{cite book}}: CS1 maint: location missing publisher (link)
^ ^a ^b "タイ航空機、圧力隔壁破壊で緊急着陸". Asahi Shimbun (in Japanese). 1986-10-27.
^ ^a ^b ^c "最新鋭機が「なぜ」タイ機事故、首ひねる航空関係者". Asahi Shimbun (in Japanese). 1986-10-27.
^ "だれがタイ機に爆発物". Asahi Shimbun (Evening Edition) (in Japanese). 1986-10-29.
^ "タイ機爆発、故意ほのめかす供述". Asahi Shimbun (Evening Edition) (in Japanese). 1986-10-29.