Bolt pierced fuel tank of 737 that exploded, officials say

TOKYO — Investigators today found that a bolt had pierced the fuel tank of a Taiwanese jetliner that caught fire after landing in Japan, forcing all 165 people aboard to evacuate the plane seconds before it exploded, officials said.

A fuel leak through that hole likely caused Monday's fire on the China Airlines Boeing 737-800, said Kazushige Daiki, chief investigator at Japan's Aircraft and Railway Accidents Investigation Commission.

All 157 passengers and eight crew evacuated safely at the airport on the resort island of Okinawa before the explosion. The pilots jumped from the cockpit window just before the jet erupted in a fireball.

Daiki said aviation officials investigating the wreckage found a bolt from a right wing slat piercing the fuel tank. The hole was about 0.8-1.2 inches in diameter. Investigators were still trying to determine how the bolt got into the tank.

"The bolt pierced through the fuel tank, and we believe that caused fuel to leak out," Daiki said.

Following today's findings, Japan's Transport Ministry ordered three Japanese airlines that own Boeing 737-800s to inspect the leading edge slats on the main wings to ensure bolts are in place before their first flight takes off Friday morning, said ministry spokesman Yusuke Asakura.

Slats slide out from the frontal edge of the main wings during takeoff and landing to stabilize the aircraft, along with flaps that come out of the wings' rear edge.

Aircraft maker Boeing Co. has in the past received reports of several similar cases in which the bolt penetrated the fuel tank and instructed airlines in December 2005 to inspect their 737-800s, Kyodo News agency reported, citing Japanese transport officials.

Boeing spokesman Mark Hooper declined to comment on the report because the "investigation has not concluded."

Ground engineers had said they saw fuel leaking from the plane's right engine as it pulled into a parking spot after arriving from Taiwan.

Investigators had earlier suspected damage to the pylon connecting the engine to the right wing. But Harumi Tsurumi, a spokesman for the Accidents Investigation Commission, said the experts took apart the pylon and found no major problems so far.

The explosion was a blow to the Taiwan-based airline, which has been struggling to shake off its reputation for having a poor safety record.

In 2002, a China Airlines 747 crashed during a flight from Taipei to Hong Kong, killing 225 people. Some 450 people died in China Airlines accidents in the 1990s.