Boeing and federal regulators told U.S. lawmakers on Wednesday they learned crucial lessons from the 787 Dreamliner's battery problems, but they defended the certification process as "quite robust" and safe enough.
The Federal Aviation Administration also said at a hearing on Capitol Hill that it would release results of its review of Boeing's design, manufacturing and assembly of the 787, a new high-tech jet that uses lithium-ion batteries for backup power. The agency declined to specify a date, but said it would release the review results this summer.
The FAA launched its review after one battery caught fire in a parked 787 in Boston in January. A second battery overheated and smoked during a flight in Japan about a week later, prompting regulators to ground the worldwide fleet for four months while Boeing altered and recertified the battery system.
The incidents caused no injuries or loss of aircraft, but did focus worldwide attention on the 787 and on the FAA's practice of delegating some regulatory oversight to manufacturers. The FAA said it has adopted new testing standards as one lesson from the battery experience.
The hearing, called by House Aviation Subcommittee Chairman Frank LoBiondo (R-NJ), comes almost three months after the FAA approved Boeing's improved battery system, allowing the 787 to resume carrying passengers and Boeing to resume delivering the aircraft to customers. Boeing expects to deliver more than 60 this year, adding to 50 already in service.
The exact cause of both battery problems remains under investigation by the National Transportation Safety Board.
Rick Larsen, the U.S. congressman who has Boeing Co's biggest factory in his district, said the grounding of the jet raised "legitimate questions" about how well the FAA certification process worked.
He questioned the FAA practice of delegating oversight of aircraft certification to the companies themselves. "Can you help us understand why the FAA would argue that this is not self-certification?" Larsen asked.
Peggy Gilligan, associate administrator for aviation safety at the FAA, said the agency oversees the performance of people and companies authorized to perform oversight on the FAA's behalf. She said this was necessary because of the large number of approvals required to certify an airplane and a limited FAA staff. The system has been in place since the late 1930s.
The FAA said it spent about 7,000 hours working with Boeing on recertifying the redesigned battery system.
Gilligan defended the FAA's decision not to apply its new, tougher standard for lithium-ion batteries developed by an industry group. She noted that the FAA had already approved the use of the batteries in the 787, provided the plane met special conditions. She said it was difficult to go back and apply new standards to products that were already approved unless there was evidence of an unsafe condition.
Gilligan said the FAA also learned that it should draw on more outsiders to review certification plans for new technology.
Boeing's chief engineer for the 787, Mike Sinnett, told the panel that the plane had logged a reliability rating of 98.2 percent over its first 15 months of service, meaning that mechanical problems delayed only 0.8 percent of flights. "That is better than the (Boeing) 777, which had been considered the best in its class," Sinnett said.
Sinnett disagreed with suggestions that the FAA certification process was deficient. He said planes are designed to fly and land even if certain components fail, and the FAA certifies to that standard. The system worked, he said, because while the battery failed, the plane and its safe operation were not compromised.
He said Boeing's additional tests on the battery after the two failures had "advanced the state of the art" in testing.
Sinnett said Boeing engineers working on behalf of the FAA are "completely independent...That's deeply rooted in our culture."
(Reporting by Alwyn Scott; Editing by Gerald E. McCormick and David Gregorio)