The Japan Airlines Flight 123 (JAL 123) Disaster

How many people are familiar with the story of Japan Airlines Flight 123? Not many. Yet, the August 12, 1985 accident 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, resulting in a total of 520 deaths.

Below is a picture of the doomed airplane that was taken in 1984:

The Boeing 747-SR46 took off from Tokyo International Airport in Ōta, Tokyo, Japan 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.

The pilots, including Captain Masami Takahama, 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, 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 before the pilots managed to return to a climb. The aircraft reached an altitude of 13,000 feet before entering a wild descent into the mountains and disappearing from radar at 6:56 p.m. and 6,800 feet. 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.

Below is a transcript of the final seconds captured on the flight data recorder:

18:55:55 CA: Power, power.
?: URV
CA: Flap.
FO: I am retracting it.
CA: URV
18:56:05 CA: Raise nose.
CA: Raise nose.
CA: Power.
18:56:14 GPWS: Sink rate, pull up, pull up, pull up, pull up
18:56:19 CA: URV
GPWS: Pull up pull up
18:56:23 (sound of collision with first peak)
GPWS: Pullup, pullup
18:56:26 (sound of impact on the second peak)
18:56:28 (tape ends)

Thirty-two minutes elapsed from the time of the first problems to the time of the crash, long enough for some passengers to write farewells to their families.

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 personnel 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.

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. Among the dead was the famous singer Kyu Sakamoto.

Ochiai 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.

Below is a photo of the crash site:

A more gruesome series of images from the crash site can be found here.

Cause

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

1. The aircraft was involved in a tailstrike incident at Osaka International Airport on June 2, 1978, which damaged the aircraft’s rear pressure bulkhead.

2. The subsequent repair performed by Boeing was flawed in order “to make it fit”, reducing the part’s resistance to metal fatigue by 70%. 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 “repair” and the final accident.

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.

*** The JAL Union disagrees with the offical investigation, stating there was not rapid depressurization (seen as the cause of the crash by the official report).***

Aftermath

Rumors 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. Without admitting liability, JAL paid 780 million yen to the victims’ relatives in the form of “condolence money”. Its president, Yasumoto Takagi, resigned and a number of JAL employees and one Boeing employee committed suicide to “apologize” for the accident.

Below is a picture of the crash site today:

The video clip below (which I highly recommend viewing) contains more details and uses a flight simulator to recreate portions of the last flight. The clip concludes with the cockpit audio from the final 40 seconds of the flight.

As an interesting “oh by the way”, the last 38 seconds of the cockpit voice recording appear on certain pressings of the album Reise, Reise by Rammstein.