The Boeing 747-SR46 that made this route, registered JA8119, crashed into the ridge of Mount Takamagahara in Gunma Prefecture, Japan 100 km ...
The Boeing 747-SR46 that made this route, registered JA8119, crashed into the ridge of Mount Takamagahara in Gunma Prefecture, Japan 100 km from Tokyo, on Monday August 12, 1985. The crash site was on Osutakano-O'ne (Osutaka Ridge), near Mount Osutaka. It remains the worst single-aircraft disaster in history, and the second-worst aviation accident of all time, second only to the Tenerife disaster. All 15 crew members and 505 out of 509 passengers died (including the famous singer Kyu Sakamoto): a total of 520 deaths. The four female survivors were seated towards the rear of the plane: Yumi Ochiai, an off-duty JAL flight attendant, age 25, who was jammed between a number of seats; Hiroko Yoshizaki, a 34-year-old woman and her 8-year-old daughter Mikiko, who were trapped in an intact section of the fuselage; and a 12-year-old girl, Keiko Kawakami, who was found sitting on a branch in a tree. -- The cause of the crash according to the official report published by the Japanese Aircraft and Railway Accidents Investigation Commission, is as follows: The aircraft was involved in a tailstrike incident at Itami Airport on June 2, 1978, which damaged the aircraft's rear pressure bulkhead. The subsequent repair performed by Boeing was flawed. Boeing's procedures called for a doubler plate with two rows of rivets to cover up the damaged bulkhead, but the engineers fixing the aircraft used two doubler plates with only one row of rivets. This reduced the part's resistance to metal fatigue by 70%. According to the FAA, the one "doubler plate" which was specified for the job, (the FAA calls it a "splice plate" - essentially a patch), was surprisingly cut into two pieces parallel to the stress crack it was intended to reinforce, "to make it fit". This negated the effectiveness of one of the two rows of rivets. During the investigation Boeing calculated that this incorrect installation would fail after approximately 10,000 pressurizations; the aircraft accomplished 12,319 take-offs between the installation of the new plate and the final accident. When the bulkhead gave way, it ruptured the lines of all four hydraulic systems. With the aircraft's control surfaces disabled, the aircraft was uncontrollable. Less
