Japan Airlines Flight 123

**Japan Airlines Flight 123**
Summary
CG render:JA8119, missing most of the vertical stabilizer
Date	August 12 1985
Cause	Structural failure, loss of hydraulic controls
Site	Mount Osutaka-no-one, Gunma, Japan
Origin	Tokyo International Airport (Haneda)
Destination	Osaka International Airport (Itami)
Passengers	509
Crew	15
Fatalities	520
Survivors	4
Aircraft
Aircraft type	Boeing 747-SR46
Operator	Japan Airlines
Tail number	JA8119

Japan Airlines Flight 123 was a Japan Airlines domestic flight from Tokyo International Airport to Osaka International Airport. The Boeing 747-SR46 that made this route, registered JA8119, crashed into the ridge of Mount Takamagahara in Gunma Prefecture, 100 kilometres from Tokyo, on Monday August 12, 1985. The crash site was on Osutaka Ridge (おすたかのおね, Osutaka-no-One^?), near Mount Osutaka.

All 15 crew members and 505 out of 509 passengers died: a total of 520 deaths. It remains the deadliest single-aircraft disaster in history, and the second-deadliest aviation accident in history, after the Tenerife disaster (not counting ground victims).

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 Yoshizaki, who were trapped in an intact section of the fuselage; and a 12-year-old girl, Keiko Kawakami, who was found wedged between branches in a tree.^[1] Among the dead was the famous singer Kyu Sakamoto.

Sequence of events

Photograph taken by a witness of the crippled 747

The flight took off at 6:12 p.m. About 12 minutes after takeoff, as the aircraft reached cruising altitude over Sagami Bay, the rear pressure bulkhead failed, causing an explosive decompression at the rear of the fuselage which tore the vertical stabilizer from the aircraft and severed the lines of all four of the aircraft's hydraulic systems. A photograph (shown) taken from the ground some time later showed that the vertical stabilizer was missing. The pilots set their transponder to broadcast a distress signal to air traffic control in Tokyo, who directed the aircraft to descend and gave it heading vectors for an emergency landing. Continued control problems required them to first request vectors back to Haneda, then to Yokota (a U.S. military air base), then back to Haneda again as the aircraft wandered uncontrollably. With the loss of all control surfaces, the aircraft began to oscillate up and down in what is known as a phugoid cycle, a flight mode typical of accidents that disable an aircraft's controls. After descending to 13,500 feet (4100 m), the pilots reported that the aircraft was uncontrollable. It flew over the Izu Peninsula, headed for the Pacific Ocean, then turned back toward the shore and descended to below 7,000 feet (2100 m) before the pilots managed to return to a climb. The aircraft reached an altitude of 13,000 feet (4000 m) before entering a wild descent into the mountains and disappearing from radar at 6:56 p.m. and 6,800 feet (2100 m). During the oscillations that preceded the crash, the pilots managed a small measure of control by using engine thrust. The final moments of the plane occurred when it hit a mountain as a result of this loss of control, flipped, and landed on its back.

Thirty-two minutes elapsed from the time of the accident to the time of the crash, long enough for some passengers to write farewells to their families. Some passengers, not having access to writing instruments, cut themselves and used their own blood to write farewell messages.^[2]

Rescue operations

Because of mountainous terrain and darkness, rescue crews did not reach the crash site until the following morning, more than twelve hours after the crash. Most of the passengers' remains were identified, and were enshrined at the nearby village of Ueno.

There was some confusion about who would handle the rescue in the immediate aftermath of the crash. A U.S. Air Force helicopter was the first to the crash site, some 20 minutes after impact. The crew radioed Yokota Air Base to assemble rescue teams and offered to help guide Japanese forces to the site immediately. Japanese government representatives ordered the U.S. crew to return to Yokota Air Base because the Japan Self-Defense Forces (JSDF) were going to handle the rescue.

Although a JSDF helicopter spotted the wreck during the night, poor visibility and difficult terrain prevented it from landing at the site. The helicopter pilot reported no signs of survivors. As a result, JSDF forces did not get to the site as quickly as they might have, spending the night in a village 63 kilometers from the wreck, and not arriving until the following morning. Medical staff found a number of bodies whose injuries indicated that they had survived the crash but died from shock or exposure while awaiting rescue.^[1]

The off-duty flight attendant who survived the crash recounted from her hospital bed that she recalled bright lights and the sound of helicopter rotors shortly after she awoke amid the wreckage, and while she could hear screaming and moaning from other survivors, this gradually died down during the night.^[1]

Cause

The official cause of the crash according to the 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".^[3] 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.

Aftermath

The Japanese public's confidence in JAL took a dramatic downturn in the wake of the disaster, passenger numbers on domestic routes dropping by one-third. Rumours persisted that Boeing had admitted fault to cover up shortcomings in the airline's inspection procedures and thus protect the reputation of a major customer.^[1] Without admitting liability, JAL paid 780 million yen to the victims' relatives in the form of "condolence money". Its president, Yasumoto Takagi, resigned, while a maintenance manager working for the company at Haneda committed suicide to "apologize" for the accident.^[1]

The crash also led to the 2006 opening of the Safety Promotion Center near Haneda Airport, directed by Yutaka Kanasaki.^[4]^[5] This center was created for training purposes to alert employees of the importance of airline safety and their personal responsibility to ensure safety. The center, which has displays regarding air safety, the history of the crash, and selected pieces of the aircraft and passenger effects (including handwritten farewell notes), is also open to the public by appointment made one day prior to the visit.

References

^ ^a ^b ^c ^d ^e
^ Cineflix, Stone City Films. (2006). Mayday: Out of Control [documentary TV series].
^ Air Board findings. Retrieved 2 March 2007.
^ The worst crash in Japan's aviation history. Retrieved 2 March 2007.
^ Why Japan Airlines Opened a Museum to Remember a Crash. Retrieved 2 March 2007.

External links

Coordinates: 36°0′5″N, 138°41′38″E

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