China airlines Boeing 747-209B plane crash
off Penghu, Taiwan
The aircraft was on a passenger flight from Taiwan's Chiang Kai Shek Airport to Hong Kong. The flight duration was expected
to be 1h20. About 20 minutes after takeoff, while cruising at FL350, the aircraft disappeared from radar screens and
crashed into the Taiwan Strait between Taiwan and China. Radar data suggests that the aircraft broke into four pieces
while at FL350. This theory is supported by the fact that articles, which would have been found inside the aircraft
(magazines, etc.) were found up to 80 miles (150 kilomètres) from the crash site.
There was no sign of an explosion on the recovered debris, and no distress call was received from the flight crew. Weather around the time of the accident was clear.
The final investigation report found that the accident was the result of "metal fatigue" due to inadequate maintenance after a previous incident. The report finds that on February 7, 1980, the accident aircraft suffered a tail strike occurrence in Hong Kong. The aircraft was then ferried back to Taiwan on the same day un-pressurized and a temporary repair was conducted the day after. A permanent repair was conducted on May 23 through 26, 1980. However, the permanent repair of the tail strike was not accomplished in accordance with the Boeing SRM (Structure Repair Manual), in that the area of damaged skin in Section 46 was not removed and the repair doubler did not extend sufficiently beyond the entire damaged area to restore the structural strength. Consequently, after repeating cycles of depressurization and pressurization during flights, the weakened hull started to crack gradually and finally broke open in flight on that flight, exactly 22 years after the faulty repair has been applied to the damaged tail. An explosive depressurization of the aircraft occurred once the crack was broken, causing the complete disintegration of the aircraft mid-air.
All the 225 passengers and crew members were killed.
This accident is the 7th worst plane crash since year 2000 in terms of the number of combined onboard and ground fatalities.