Cracks, poor maintenance caused CAL crash: report

An official with the Aviation Safety Council yesterday displays the investigation report of the China Airlines flight CI-611 crash in May 2002 at a press conference yesterday. The reports said that cracks in the plane's tail section caused the crash. PHOTO: CNA

On May 25, 2002, the CAL flight CI-611, a Boeing 747-200 jumbo jet, broke apart and plunged into the Taiwan Strait 23 nautical miles northeast of Penghu County shortly after takeoff from CKS International Airport.

After more than two years of analyzing information gathered from the plane's flight data recorder, air traffic control, wreckage distribution and a reconstructed section of the fuselage, the ASC concluded that a 180.34cm crack on the fuselage resulted in the in-flight breakup at the altitude of 10,668m, killing 206 passengers and 19 crew members.

According to the ASC, the fatigue crack in the aircraft could be dated back to an accident that took place 25 years ago. On Feb. 7, 1980, the aircraft suffered damage when its tail touched the ground while landing in Hong Kong. Although the damaged plane was shipped back to Taiwan and underwent temporary repairs the day after the incident, permanent repairs conducted by the nation's largest carrier, China Airlines, were flawed.

"China Airlines did not repair the [damage] in accordance with Boeing's [structural repair manual]. The damaged skin should have been either trimmed or removed as the standard procedure required. But the repairs did not extend sufficiently beyond the damaged area and thus, did not restore structural strength," said ASC Chairman Kay Yong at a press conference yesterday.

The ASC believes that the pre-existing fissures on scratched surface, and after not having been properly fixed, deepened and grew to a 180.34cm crack as a result of pressurization and de-pressurization during flights.

"A crack measuring 180.34cm in length is long enough to cause structural separation in the fuselage. It is the root cause of the in-flight breakup of the aircraft," said Thomas Wang head of the ASC's investigation team.

Although the ASC could not confirm exactly when the fuselage came apart, the Cabinet-level aviation authority criticized the air carrier for not finding the damage to the aging aircraft in regular checkups over the past 25 years.

CAL officials, however, rebuked the ASC's report and questioned its findings.

"Since the section of the aircraft that is suspected of causing the crash was not found, the information is not conclusive enough to determine the exact cause of the accident," CAL said in a statement.

"The ASC said that they have found 75 percent of the aircraft, but they actually collected only 50 percent of the damaged section 46, the key part needed to determine the cause of the crash," said CAL spokesman Roger Hen.

While openly disputing the ASC's findings, the air carrier objected to the claim that maintenance oversight was also to blame.

"Our checkups are conducted in compliance with the SRM [structural repair manual]. Boeing stated clearly that if repairs are done in accordance with the SRM, there is no need to report it to the aircraft manufacturer," Hen said.

According to the regulations of Boeing's Repair Assessment Program, aircraft should have undergone inspections upon reaching of 22,000 flights. Yet the accident occurred when the jet completed its 21,398th flight, a few times of landing and take-off away from the maintenance program's maximum threshold.

Civil Aeronautics Administration (CAA) slammed that the ASC's report, accusing the agency of failing to find the actual cause of the crash.

"How could the ASC jump hastily its conclusions when half of the [section in question] has yet to be found?" said CAA director-general Billy Chang.

CAMERAS? (cctv external and internal)
 

Report Vol 1 (25.3mb pdf file)  Link1

Report Vol 2 (11.3mb pdf file)  Link2

Report (Press Conf Slides 7 mb pdf) Link3