Japan Airlines flight 123 (JAL123, JL123), a Boeing 747-100SR-46, JA8119, crashed into Mount Osutaka in Gunma Prefecture, Japan, on August 12, 1985.

It was the worst single-aircraft disaster in history, with all 15 crew members dead, and 505 out of 509 passengers dead (including the famous singer Kyu Sakamoto) for a total of 520 deaths. There were four survivors, all passengers.

The flight took off at 6:12 PM, bound from Tokyo International Airport, Haneda, Tokyo to Osaka International Airport, Itami, Hyogo. About 12 minutes after takeoff, as the aircraft reached cruising altitude over Sagami Bay, its tailplane buckled, shedding 15 feet of leading edge into the sea, depressurizing the cabin, and disabling the aircraft's hydraulics. The pilots set their transponder to broadcast a distress signal to air traffic control in Tokyo, who allowed the aircraft to descend and gave it heading vectors for an emergency landing.

After descending to 13,500 feet, the pilots reported that the aircraft was "uncontrollable." It flew over the Izu Peninsula, headed for sea, then turned back toward shore and descended to below 7,000 feet before the pilots managed to return to a climb. The aircraft reached an altitude of 13,000 feet before entering a wild descent and disappearing from radar at 6:56 PM and 6,800 feet.

Some thirty minutes elapsed from the time the tailplane buckled to the time of the crash, long enough for some passengers to scribble shaky farewells to their families.

Because of rain, unfavorable terrain, and the lack of sunlight, rescue crews were unable to reach the site until the following morning. Most of the passengers' remains were unidentifiable, and were enshrined at a nearby village.

Cause

The cause of the crash according to the offical report published by the Japanese Aircraft and Railway Accidents Investigation Commission , is as follows:

1. The aircraft was involved in a tailstrike incident at Itami airport on June 2, 1978, which damaged the aircraft's rear bulkhead.
2. 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%.
3. 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.

JAL accepted partial responsibility for the disaster because the tail had been making intermittent whistling noises (suggesting a flaw in the fuselage) for years, without action by company maintenance personnel.

Several higher and lower ranking employees of Japan Airlines committed suicide in the aftermath. Some of these people had absolutely no connection to the disaster, but they could not bear the shame that fell on the entire company.

See also

• List of accidents and incidents on commercial airliners

External links

• The record of JAL123 (Japanese)
• Accident Accident Report(PDF)（Aircraft and Railway Accidents Investigation Commission）