TAIPEI, Taiwan (AP) -- Investigators analyzing the wreckage of a China Airlines' jumbo jet that broke apart over the Taiwan Strait in a crash that killed all 225 people on board last May have found a crack seen as evidence of metal fatigue, a Taiwanese official has said.
But the official declined to speculate whether metal fatigue was the cause of the crash, saying only that it was "one of the risk factors" related to the incident.
Findings by Taiwan's Chungshan Institute of Science and Technology were recently confirmed by the aircraft's maker, Seattle-based Boeing, said Kay Yong, Taiwan's chief crash investigator.
"We can only say that metal fatigue was one of the risk factors," Yong told The Associated Press.
It is still unknown why the Boeing 747-200 broke apart about 20 minutes into a flight from Taipei to Hong Kong on May 25, said Yong, managing director of Hong Kong's Aviation Safety Council.
Investigators discovered a crack several inches (centimeters) long in the rear of the plane.
It was later determined that the crack was not caused by the impact of the crash but had grown out of a smaller crack that was previously documented and related to a minor accident in 1980, when the plane's tail hit the ground during takeoff.
The part of the aircraft damaged in that accident was covered by a metal patch measuring 23 inches (half a meter) by 125 inches (3 meters).
The findings indicated that all airlines need to conduct a more thorough inspection for signs of metal fatigue on any Boeing jets that have undergone a major repair, he said.
http://www.cnn.com/2002/WORLD/asiapcf/east/12/25/taiwan.jet.ap/index.html