A mechanic who went to the electronics bay to investigate saw two distinct flames about three inches long at the front of the case holding the plane’s lithium-ion battery, according to a report released Thursday by the National Transportation Safety Board.
Firefighters, who were quickly called, found “a white glow with radiant heat waves” coming from the battery. The battery was hissing loudly and leaking liquids, and it seemed to be reigniting. Standard fire suppressants had little effect. A fire captain’s neck was burned, he said, when the battery “exploded.”
The new details about the fire aboard the technologically advanced aircraft were in a preliminary report from the safety board that provided the most comprehensive picture so far of the battery fire in the 787 that was parked at the airport and burst into flame on Jan. 7.
The 48-page report, supported by nearly 500 pages of technical documents, gave a detailed chronology of the investigation, and graphic descriptions of what took place aboard the airplane. What it did not say, however, is what caused the fires in the battery cell in the first place.
The report also gave more details about the steps Boeing took to test and certify the first large-scale use of lithium batteries aboard a commercial passenger jet. Some of those details raised questions about how Boeing could have misjudged the risks.
In broad terms, the report echoed what Deborah A. P. Hersman, the board’s chairwoman, told reporters last month — that the problems seemed to have originated in the battery, where one of the eight cells had a short circuit and the fire spread to the rest of the cells.
The incident in Boston was the first serious sign of trouble with the new batteries on the 787. All 50 planes in service were grounded nine days later after another aircraft, operated by All Nippon Airways, made an emergency landing in Japan when the pilots smelled smoke. The inquiry into that incident is being conducted by Japanese investigators.
The safety board released its report a day after federal officials said that the Federal Aviation Administration was close to approving the testing of battery fixes that were proposed by Boeing. That decision is likely to be made next week, and the tests could begin immediately.
Boeing officials said they had identified the most likely ways in which the batteries could fail. They contend that the proposed changes would minimize the odds of future incidents and protect the plane and its passengers if a problem does arise. Meanwhile, the safety board plans to continue its investigation, and said Thursday that it would hold a hearing on the hazards of lithium-ion batteries next month.
The report said the airplane involved in the Boston incident was delivered to Japan Airlines on Dec. 20. At the time of the fire, it had logged 169 flight hours and 22 flight cycles.
The plane had flown from Narita, Japan, and touched down in Boston at 10 a.m.
The flight data recorder showed that at 10:04 a.m., the pilots started the auxiliary power unit, which provides power while the plane is on the ground and is energized by one of the plane’s two lithium batteries.
That battery is in the electronics bay, which is under the main cabin, near the middle of the plane. The other lithium-ion battery, located in the front of the plane, provides power to the cockpit. It was that battery that emitted smoke in the incident in Japan.
The possibility that there could be a fire in the advanced plane was so surprising that the airline’s station manager in Boston, Ayumu Skip Miyoshi, could not initially believe the radio call he got from a maintenance employee who reported smoke in the cabin.
“I wasn’t sure what he meant, therefore I replied, ‘So you mean one passenger smoked in the lavatory?’ ” he said in a witness statement. He rushed from his office and tried to enter the cabin but could not see more than 10 feet from the door because the smoke was so intense.
Article source: http://www.nytimes.com/2013/03/08/business/safety-board-reports-little-progress-in-787-inquiry.html?partner=rss&emc=rss