Deadliest single-aircraft accident in history

Speed ... Reliability... Comfort... Air Transportation is considered as one of the safest modes of travel worldwide. Plane crashes rarely happen but when they do, it usually involves serious injuries and death due to the speed and height that planes travel at. The deadliest single-aircraft accident in history happened with Japan Airlines Flight 123 on August 12, 1985. It was a domestic flight from Tokyo International Airport (Haneda) to Osaka International Airport (Itami).

The Boeing 747-SR46 that made this route, registered JA8119, suffered mechanical failures, the rear pressure bulkhead failed, the part that separates cabin and tail. It is meant to seal the aircraft and maintain the cabin pressure. When it failed, an explosive decompression blew the vertical stabilizer off the tail. This made the aircraft uncontrollable, and eventually making the Boeing 747-SR46 crash into 12 minutes into the flight and 32 minutes later crashed into two ridges of Mount Takamagahara in Ueno, Gunma Prefecture, 100 kilometers from Tokyo. Only four people survived the crash. The four women were lucky to be seated in the rear part of the plane. All 15 crew members and 505 out of 509 passengers died, resulting in a total of 520 deaths The crash site was on Osutaka Ridge near Mount Osutaka. and 4 survivors.


Cause of accident
The plane was involved in a tailstrike incident in 1978. The repairs done were substandard and later lead to the plane's explosive decompression. Boeing conducted research after the crash and calculated the incorrect installation of repairs would handle approximately 10,000 pressurizations. The accident occurred on the 12,319th flight after the repair.

Source: Wikipedia