Thursday 12 August 2021

Remembering Japan Airlines Flight 123

JAPAN AIR B787-9 JA865J (MSN 38138) 

Japan Airlines Flight 123 was a scheduled domestic passenger flight from Tokyo's Haneda Airport (HND/RJTT) to Osaka International Airport (ITM/RJOO). On the 12th August 1985, the Boeing 747SR operating this route suffered a sudden decompression twelve minutes into the flight and crashed, killing 520 out of the 524 passengers. Flight 123 pushed back from gate 18 at 6:04pm. and took off from Runway 15L at Haneda Airport at 6:12pm.. About 12 minutes after takeoff, while climbing through 23,900 feet at a speed of 300 knots, an unusual vibration occurred., then the aircraft had a rapid decompression, bringing down the ceiling around the rear lavatories, damaging the unpressurized fuselage aft of the plane, unseating the vertical stabilizer, and severing all four hydraulic lines. When the decompression occurred the crew got indications of problems with the R5 door. In fact, the rear pressure bulkhead had ruptured, causing serious damage to the rear of the plane. A portion of its vertical fin, measuring 5 metres together with the section of the tailcone containing the auxiliary power unit (APU) were ripped off the plane. Due to the damage, the hydraulic pressure dropped and ailerons, elevators and yaw damper became inoperative. Controlling the plane was very difficult as the airplane experienced dutch rolls and phugoid oscillations (unusual movement in which altitude and speed change significantly in a 20-100 seconds cycle without change of angle of attack). Japan's Aircraft Accident Investigation Commission officially concluded that the rapid decompression was caused by a faulty repair by Boeing technicians after a tailstrike incident during a landing at Osaka Airport seven years earlier in 1978. A doubler plate on the rear bulkhead of the plane had been improperly repaired, compromising the plane's airworthiness. Cabin pressurization continued to expand and contract the improperly repaired bulkhead until the day of the accident, when the faulty repair finally failed, causing the rapid decompression that ripped off a large portion of the tail and caused the loss of hydraulic controls to the entire plane. The aircraft, configured with increased economy class seating, was carrying 524 people. Casualties of the crash included all 15 crew members and 505 of the 509 passengers. Some passengers survived the initial crash but subsequently died of their injuries hours later, mostly due to the Japan Self-Defense Forces' decision to wait until the next day to go to the crash site, after declining an offer from a nearby United States Air Force base to start an immediate rescue operation. It is the deadliest single-aircraft accident in aviation history. The aircraft was a Boeing 747-100 (Short Range) The Boeing 747 Series 100 was aircraft specifically configured for domestic flights with a high density seating arrangement.

Aircraft Details
Airline: Japan Air
Code: JL/JAL
Aircraft: Boeing 747SP46
Registration: JA8119
Serial Number: 20783
Engines: 4 Pratt & Whitney JT9D-7A
First Flew: 28/01/1974
Age: 11Yrs 7 Mts

No comments:

Post a Comment