On July 23, 1999, an All Nippon Airways Boeing 747-481D with 503 passengers on Flight 61, including 14 children and 14 crew members on board, took off from Tokyo Haneda Airport in Ōta, Tokyo, Japan and was en route to New Chitose Airport in Chitose, Japan, near Sapporo[1] when it was hijacked by Yūji Nishizawa.

[a] About 25 minutes after takeoff at 11:48 A.M. JST,[2] Nishizawa used a kitchen knife which was 20 centimetres (7.9 in) long,[3] to force a flight attendant to allow him access into the cockpit.

He then forced 34-year-old First Officer Kazuyuki Koga out,[b] remaining in the cockpit with 51-year-old captain Naoyuki Nagashima,[c] who managed to notify Air Traffic Control (ATC) about the hijacking.

Nishizawa stabbed Nagashima in the chest and took control of the plane, at one point descending to an altitude of 300 metres (980 ft).

Nishizawa had discovered the security flaw a month before the hijacking, and after confirming it on a round-trip flight to Kumamoto, sent letters to the Ministry of Transport, All Nippon Airways, and other agencies, in addition to major newspapers, notifying them of it.

After the incident, the Japanese Transport Ministry ordered more strict checks with hand-carried baggage brought through security checkpoints before boarding any aircraft.

[9] Due to issues of criminal insanity, the mass media had not initially revealed Nishizawa's name when reporting on the case.