Nine Japan Air Lines Jumbo Jets Had Patch-up Repairs on Bulkhead
TOKYO (AP) _ The Boeing Co. conducted minor ″patch-up″ repairs to the aft pressure bulkheads on nine Boeing 747 jumbo jets which were later delivered to Japan Air Lines, a JAL spokeswoman said Friday.
Some Japanese investigators believe a rupture in the pressure bulkhead caused the Aug. 12 crash of a Boeing 747SR which killed all but four of the 524 aboard the aircraft in history’s worst single-plane disaster. But that plane was not one of those that underwent the pre-delivery patchup, JAL said.
Boeing has admitted that it had conducted faulty repairs to the bulkhead of the plane involved in the crash after a 1978 incident when it scraped the runway. However, Boeing and Japanese investigators have not established a direct link between the faulty repair and the crash.
The bulkhead is a dome-shaped pressure wall made of aluminum alloy which separates the pressurized cabin from the non-pressurized tail cone.
JAL spokeswoman Megumi Nunokawa, who refused to provide the delivery dates for each of the patched-up planes, said bulkheads on the nine aircraft had suffered small dents on their surfaces on the assembly line at the Seattle- based company. One of the nine planes was delivered to a JAL subsidiary, Japan Asia Airways, which flies to Taiwan.
Jack Gamble, public relations manager for Boeing’s 747 division in Seattle, said Friday afternoon that any repairs on the nine jets were not a result of the Aug. 12 crash, because Boeing has delivered no 747s to JAL since then.
″You’d have to go back a few years to get nine airplanes,″ he added.
He also said Boeing, the customer and the Federal Aviation Administration all inspect aircraft before delivery, so ″Those things are going to get caught and they’re going to get repaired.″
The dents were ″nothing that compromised the integrity of the aircraft or the safety of operation,″ he said.
Hideo Tabuchi, a senior official of the Transport Ministry’s Airworthiness Division, said, ″They (repairs) were very minor and the ministry confirmed that there was nothing wrong through inspections conducted during the planes’ initial flights.″
The pre-shipment repairs came to light during safety checks on 49 jumbo jets operated by Japanese airline companies following an Aug. 29 Boeing request to check the bulkheads.