Toshikazu Nagasawa, the director at the Air Line Pilots’ Association of Japan, said on Tuesday that some pilots remained concerned about the changes Boeing made to the 787’s lithium-ion batteries after two incidents involving smoke or fire led to the grounding of the fleet early this year.
Mr. Nagasawa said the pilots were also dismayed that Boeing did not adjust its cockpit displays to provide more substantial alerts if the batteries started to overheat.
Boeing officials acknowledged in interviews that they had not expanded the alerts. But they said the new battery system virtually eliminated the chance of fire or any risk to the plane. Safety regulators in the United States and Japan, and the eight airlines flying the jets, have signed off on the changes.
Two Japanese airlines, All Nippon Airways and Japan Airlines, own 27 of the 57 Dreamliners now in service. Officials at each airline said they trusted the battery repairs, and a Japan Airlines spokesman said the airline was still trying to assuage the pilots’ concerns.
The two battery incidents, both in mid-January, involved a fire on a Japan Airlines 787 parked in Boston and a smoking battery that forced an All Nippon jet to make an emergency landing in Japan.
Regulators in the United States and Japan have still not pinpointed the cause of the problems, though it is clear that the fire on the Boston plane started with a short circuit that spread through all eight of the cells on one of the plane’s batteries.
To get the planes back in the air, Boeing changed the battery manufacturing process to reduce the chances for a short circuit and added better insulation to keep a short in one cell from spreading. It also added a stainless steel box to encase the batteries and minimize the chances of a fire. And, as a last resort, it created titanium tubing to vent any hazardous residue from the plane.
“Boeing says that any battery fire will now go out on its own, so there’s no safety issue,” Mr. Nagasawa, the Japanese pilots’ union leader, said in an interview. “But that’s on paper. No pilot would ever want to keep flying with a fire on board, whether it’s in a metal box or not.”
Mike Sinnett, a Boeing vice president and the chief project engineer for the 787, said in an interview that the metal case would minimize the amount of oxygen near the battery to prevent a fire.
Boeing also received support Tuesday from the Air Line Pilots Association in the United States.
“A.L.P.A. is very satisfied with the B787 product improvements, and we have not heard any concerns from our members,” the union said in a statement.
The Japanese pilots first expressed their concerns in meetings with Boeing engineers in Tokyo in late March. Several pilots from All Nippon Airways raised about 30 safety concerns, according to a written account provided by the union.
Other more recent problems with the planes have added to the worries and irritated Japanese officials.
A loose fastener on an electrical panel caused a small part of that panel to char last month, though that occurred on a test flight without paying customers. On Sunday, two days after the Japanese airlines resumed 787 passenger flights, a sensor that detects uneven pressures near the batteries malfunctioned on one jet, forcing Japan Airlines to change planes for a flight to Beijing.
Mr. Sinnett said both problems were caused by maintenance errors by Boeing personnel. But Akihiro Ota, the Japanese transport minister, rebuked Boeing and Japan Airlines on Tuesday for the latest blunder. That the companies “failed to take all possible safety measures is deplorable,” Mr. Ota told reporters.
The 787 carries two lithium-ion batteries. The main battery provides backup power for the cockpit displays. The other battery starts a small engine that provides power to the plane on the ground.
According to the memorandum describing the meeting with Boeing in March, the Japanese pilots expressed concern that they would receive only a general warning of a battery malfunction, with no indication of its severity. The pilots were also worried about whether Boeing had provided enough proof that the jets could fly safely if the batteries failed.
Mr. Sinnett said on Tuesday that the planes had multiple backup systems and could still fly if the batteries failed.
He said the cockpit alerts were ranked in descending order by urgency — as warnings, cautions, advisories or status notices. He said that various problems with the batteries would only set off an advisory or status alert.
He added that the airlines had not asked Boeing to upgrade the alert system.
(Hiroko Tabuchi and Christopher Drew - New York Times)
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