Investigators in Japan said yesterday they had found a hole in the fuel tank of a China Airlines (CAL) plane that could explain why it burst into a fireball moments after landing.
All 165 passengers and crew fled to safety, sliding down emergency chutes with minutes to spare as the Boeing 737-800 burst into fire and then exploded after landing on Monday on Okinawa.
As investigators from Japan, Taiwan and the US sifted through the jet's charred remains, the Japanese side said it discovered the fuel tank had been pierced.
"We spotted a hole in a fuel tank," the Ministry of Land, Infrastructure and Transportation's investigative division said in a brief statement.
"We suspect that oil leaked from this hole and spilled from the right wing to the outside," it said.
Chief investigator Kazushige Daiki pointed to a bolt that was part of the plane's structure.
"It is believed that the hole was made as the tank was pierced by the bolt," Daiki told a news conference in Okinawa.
Jiji Press reported that Boeing Co issued a warning to airlines last year to check for bolts piercing the tank as there were previous incidents. Officials at the Boeing offices in Tokyo and Hong Kong declined to comment, citing the ongoing investigation into the incident.
The bolt came off from a movable flap on the front of the right wing called a slat, but the investigators could not determine why the bolt came off, Japanese media reports said. Public broadcaster NHK said the hole measured 2cm or 3cm in diameter.
Investigators have already recovered the plane's black box to analyze the pilots' conversations.