Boeing has started to replace battery systems on its 787s, but admitted it may never know what caused the malfunctions that resulted in the entire fleet of Dreamliners being grounded in January.
A team of 300 Boeing engineers forming 10 teams began working on the 50 aircraft, after the US Federal Aviation Administration (FAA) approved the new measures.
The news comes after three months of investigation.
The 787 is the first aircraft to be fitted with lithium ion main power batteries, which are lighter and smaller but potentially more temperamental than the nickel-cadmium sources used on most planes.
Larry Loftis, vice president and general manager of the 787 programme, explained the new safety measures at a briefing in London yesterday, while reaffirming Boeing’s commitment to using lithium ion batteries.
“We see this as the permanent fix and we have found no compelling reason for us to move away from the lithium ion battery,” he said. “The airplane has performed very well and has had over one million passengers fly on it. With the exhaustive study carried out followed by the comprehensive solutions we’ve put in place, it gives me the utmost confidence to put my own family on it.”
The batteries operate when the plane is on the ground with its engines off. They are used to power the brakes and lights.
The new batteries, located in the aircraft’s electronics bay and an auxiliary power unit in the cargo compartment, operate at a cooler temperature than their previous incarnation, essentially not working as hard.
They will be enclosed in stainless steel boxes with an added ventilation pipe going directly to the outside of the plane.
The extra steel housing and other accessories fitted to the batteries to keep them safe weighed about 150 pounds, cancelling the batteries’ weight savings.
Mr Loftis, who said he expects it will take five days per plane to do the necessary work, added that the National Transportation Safety Report and Japan National Safety Board are still conducting an investigation into what caused the problem.
The malfunctions were first reported after a battery overheated and set alight on a Japan Airlines 787 at Boston’s Logan International Airport.
An All Nippon Airways 787 had to make an emergency landing in Japan after a battery started to give off smoke nine days later, leading to the grounding of all Dreamliners.
The grounding of the 787s has already cost the company an estimated £393 million, while Japanese carrier ANA, whose grounded 787 jets were the first to be fitted with the new batteries, lost some £9.5 million in January alone.