Japan Air Lines Flight 123 was a scheduled domestic passenger flight from Tokyo to Osaka, Japan. On the evening of Monday, August 12, 1985, the Boeing 747 flying the route suffered a severe structural failure and explosive decompression 12 minutes after takeoff. After flying under minimal control for 32 minutes, the plane crashed in the area of Mount Takamagahara, 100 kilometres (62 mi; 54 nmi) from Tokyo.
The aircraft, featuring a high-density seating configuration, was carrying 524 people. The initial crash killed all 15 crew members and 460–490 of the 509 passengers on board. An estimated 20 to 50 passengers survived the initial crash but died from their injuries while awaiting rescue, leaving only four survivors; 520 people died as a result of the crash. The crash is the deadliest single-aircraft accident in aviation history, and it remains the deadliest aviation incident in Japan.
Japan's Aircraft Accident Investigation Commission (AAIC), assisted by the U.S. National Transportation Safety Board, concluded that the structural failure was caused by a faulty repair by Boeing technicians following a tailstrike seven years earlier. When the faulty repair eventually failed, it resulted in a rapid decompression that ripped off a large portion of the tail and caused the loss of all hydraulic systems and flight controls.
Background
Aircraft
The Boeing 747SR-46 with registration JA8119 was built and delivered to Japan Air Lines in 1974. It had accumulated slightly more than 25,000 flight hours and 18,800 cycles (one cycle consisting of takeoff, cabin pressurization, depressurization, and landing).
1978 tailstrike incident
On June 2, 1978, while operating Japan Air Lines Flight 115 along the same route, JA8119 bounced heavily on landing while carrying out an instrument approach to runway 32L at Itami Airport. The pilot then excessively flared the aircraft, causing a severe tailstrike on the second touchdown. The tailstrike cracked open the aft pressure bulkhead, and 25 of the 394 people on board were injured. The damage was repaired by Boeing technicians, and the aircraft was returned to service. The aircraft had flown for an additional 8,830 hours between the completion of bulkhead repairs and the crash.
Crew
At the time of the accident, the aircraft was on the fifth of its six planned flights of the day. The flight had 15 crew members, consisting of three cockpit crew and 12 cabin crew.
The cockpit crew consisted of:
- Captain Masami Takahama (高浜 雅己, Takahama Masami), aged 49, served as a training instructor for First Officer Yutaka Sasaki on the flight, supervising him while handling the radio communications. Takahama was a veteran pilot, having logged about 12,424 flight hours, including about 4,842 hours in 747s.
- First Officer Yutaka Sasaki (佐々木 祐, Sasaki Yutaka), age 39, was the pilot flying and was undergoing training for promotion to captain, and flew Flight 123 as one of his final training and evaluation flights. He had logged about 3,963 flight hours, including about 2,665 hours in 747s.
- Flight Engineer Hiroshi Fukuda (福田 博, Fukuda Hiroshi), age 46, was a veteran flight engineer having logged about 9,831 flight hours, including about 3,846 hours in 747s.
In 1987, when the investigation concluded, all three cockpit crew members were posthumously awarded the Polaris Award.
Passengers
The flight was during the Obon holiday period when many Japanese people travel to their hometowns or to resorts. Twenty-two non-Japanese were on board the flight, including four residents of Hong Kong, two from Italy and six from the United States, and one each from West Germany and the United Kingdom. Some apparent foreigners had dual nationality, and some of them were residents of Japan.
The four survivors, all Japanese women, were seated on the left side and toward the middle of seat rows 54–60, in the rear of the aircraft. They were Yumi Ochiai, a Japan Air Lines off-duty flight attendant; Hiroko and Mikiko Yoshizaki, a mother and her 8-year-old daughter whose relatives died in the crash; and Keiko Kawakami, a 12-year-old girl whose parents and sister also died in the crash. Among the victims were Japanese singer and actor Kyu Sakamoto, and banker Akihisa Yukawa, the father-to-be of violinist and composer Diana Yukawa, born a month after the accident.
The flight connected two of the largest cities of Japan, and a number of other celebrities initially booked the flight but ultimately had either switched to another flight or used the Tokaido Shinkansen instead. These include Sanma Akashiya, Masataka Itsumi and his family, Johnny Kitagawa, and the then–cast of Shōten. Some members of the Shonentai were also scheduled to travel with Kitagawa but had stayed in Tokyo.
Accident
Take-off and decompression
The aircraft landed as JL366 at Haneda Airport in Ōta, Tokyo, from Fukuoka Airport at 17:12. After almost an hour on the ground, Flight 123 pushed back from gate 18 at 18:04 and took off from Runway 15L at 18:12, 12 minutes behind schedule. Twelve minutes after takeoff, at 18:24, at near cruising altitude over Sagami Bay 3.5 miles (3.0 nmi; 5.6 km) east of Higashiizu, Shizuoka, the aircraft underwent explosive decompression, bringing down the ceiling around the rear lavatories, damaging the unpressurised fuselage aft of the plane, unseating the vertical stabilizer, and severing all four hydraulic lines. A photograph taken from the ground shows the vertical stabilizer missing.
The pilots set their transponder to broadcast a distress signal. Captain Takahama contacted Tokyo Area Control Center to declare an emergency and request a return to Haneda Airport, descending and following emergency landing vectors to Oshima. Tokyo Control approved a right-hand turn to a heading of 090° back toward Oshima, and the aircraft entered an initial right-hand bank of 040°, several degrees greater than observed previously. Captain Takahama ordered First Officer Sasaki to reduce the bank angle, and expressed confusion when the aircraft did not respond to the control wheel being turned left. The flight engineer reported that hydraulic pressure was dropping. The captain repeated the order to reduce the bank angle, as the autopilot had disengaged. He ordered the first officer to bank it back, then ordered him to pull up. None of these attempted maneuvers produced a response. The pilots realised the aircraft had become virtually uncontrollable, and Captain Takahama ordered the copilot to descend.
18:27–18:34
Heading over the Izu Peninsula at 18:26, the aircraft turned away from the Pacific Ocean and back toward the shore, but only turned right far enough to fly a north-westerly course. Seeing that the aircraft was still flying west away from Haneda, Tokyo Control contacted the aircraft again. After confirming that the pilots were declaring an emergency, the controller asked the nature of the emergency. At this point, hypoxia appeared to have begun setting in, as the pilots did not respond. Also, the captain and co-pilot asked the flight engineer repeatedly if hydraulic pressure had been lost, seemingly unable to comprehend it. Tokyo Control contacted the aircraft again and repeated the direction to descend and turn to a 090° heading to Oshima. Only then did the captain report that the aircraft had become uncontrollable. (Tokyo: "Japan Air 124 [sic] fly heading 090 radar vector to Oshima." JAL123: "But now uncontrol." Tokyo: "Uncontrol, roger understood.")
The aircraft traversed Suruga Bay and passed over Yaizu, Shizuoka, at 18:31:02. Tokyo Control asked if they could descend, and Captain Takahama replied that they were now descending, stating that their altitude was 24,000 feet (7,300 m). Captain Takahama declined Tokyo Control's suggestion to divert to Nagoya Airport 72 nautical miles (83 mi; 133 km) away, instead preferring to land at Haneda, which had the facilities to handle the 747. The flight data recorder shows that the flight did not descend, but was rising and falling uncontrollably. With the total loss of hydraulic control and non-functional control surfaces, the aircraft entered phugoid oscillations lasting about 90 seconds, in which airspeed decreased as it climbed and increased as it fell. The rise in airspeed increased the lift over the wings, resulting in the aircraft climbing and slowing down, then descending and gaining speed again. Almost immediately after the separation of the stabiliser and rudder removed the only means of damping yaw, the aircraft began to exhibit Dutch roll, simultaneously yawing right and banking left, before yawing back left and banking right. At some points the banking motion became very profound, with large arcs of around 50° in cycles of 12 seconds.
Despite the complete loss of control, the pilots continued to turn the control wheel, pull on the control column, and move the rudder pedals until the moment of the crash. The pilots also began efforts to establish control using differential engine thrust, as the aircraft slowly wandered back toward Haneda. Their efforts had limited success. The unpressurised aircraft rose and fell in an altitude range of 20,000–25,000 feet (6,100–7,600 m) for 18 minutes, from the moment of decompression until around 6:40 p.m., with the pilots seemingly unable to figure out how to descend without flight controls. This was possibly due to the effects of hypoxia at such altitudes, as the pilots seemed to have difficulty comprehending their situation as the aircraft pitched and rolled uncontrollably. The pilots possibly were focused, instead, on the cause of the explosion they had heard, and the subsequent difficulty in controlling the jet. The flight engineer suggested donning oxygen masks when word reached the cockpit that the rear-most passenger masks had stopped working. None of the pilots complied, however, but the captain simply replied "yes" to both suggestions by the flight engineer to do so. The accident report indicates that the captain's disregard of the suggestion is one of several features "regarded as hypoxia-related in [the] CVR record[ing]." Their voices can be heard relatively clearly on the cockpit area microphone for the entire duration, until the crash, indicating that they never donned their oxygen masks.
18:34–18:48: Limited control
At 18:35, the flight engineer responded for the first time to multiple calls from Japan Air Tokyo via the SELCAL (selective-calling) system. Having just been informed about the inoperative oxygen masks, the flight engineer voiced the (erroneous) assumption that the R-5 door was broken and informed the company that they were making an emergency descent. Japan Air Tokyo asked if they intended to return to Haneda, to which the flight engineer responded that they were making an emergency descent, and to continue to monitor them.
Eventually, the pilots regained limited control of the aircraft by adjusting engine thrust. In doing so, they dampened the phugoid cycle and somewhat stabilised their altitude. However, given jet engines' inertia and the resulting response time (to changes in throttle), "[s]uppressing of Dutch roll mode by use of the differential thrust between the right and left engines is estimated practically impossible for a pilot." Shortly after 6:40 p.m., they lowered the landing gear using the emergency extension system in an attempt to dampen the phugoid cycles and Dutch rolls further. This was somewhat successful, as the phugoid cycles were dampened almost completely, and the Dutch roll was damped significantly, but lowering the gear also decreased the directional control the pilots were getting by applying power to one side of the aircraft, and their ability to control the aircraft deteriorated.
Shortly after lowering the gear, the flight engineer asked if the speed brakes should be used, but the pilots did not acknowledge the request. The aircraft then began a right-hand descending 420° turn from a heading of 040° at 6:40 p.m. to a heading of 100° at 18:45, flying in a loop over Otsuki, due to a thrust imbalance created from having the power setting on Engine 1 (the left-most engine) higher than the other three engines. The aircraft also began descending from 22,400 feet (6,800 m) to 17,000 feet (5,200 m), as the pilots had reduced engine thrust to near idle from 18:43 - 18:48. Upon descending to 13,500 feet (4,100 m) at 18:45:46, the pilots again reported an uncontrollable aircraft. At this time, the aircraft began turning slowly to the left, while continuing to descend. The thicker air allowed the pilots more oxygen, and their hypoxia appeared to have subsided somewhat, as they were communicating more frequently. The pilots also appeared to understand the gravity of their situation, with Captain Takahama exclaiming, "This may be hopeless" at 18:46:33. At 18:47, the pilots recognised that they were beginning to turn toward the mountains. Despite efforts by the crew to get the aircraft to continue to turn right, it instead turned left, flying directly toward the mountainous terrain on a westerly heading.
Around 18:50 – approximately six minutes before the aircraft crashed – a photographer on the ground in Okutama captured a photograph of the 747, which showed that the vertical stabiliser was missing.