TOKYO Boeing Co (BA.N) expressed confidence on Friday that it could have its grounded 787 Dreamliner jets flying again in a matter of weeks, after it unveiled its proposed fix for the aircraft's battery system that it says would eliminate the risk of fire.
Regulators grounded all 50 of the carbon-composite Dreamliners in use by airlines worldwide in January after a battery caught fire on a Japan Airlines Co Ltd (9201.T) 787 jet at Boston's Logan airport and a battery melted on an All Nippon Airways Co Ltd (9202.T) flight in Japan.
In its first detailed explanation of the proposed changes to the battery system, Boeing said it would encase the 787's lithium-ion battery in stainless steel casing and fit the power pack with extra insulation, spacers and heat-resistant sleeving.
"If we look at the normal process and the way in which we work with the FAA, and we look at the testing that's ahead of us, it is reasonable to expect that we could be back up and going in weeks, not months," Mike Sinnett, chief project engineer for the 787 programme, told reporters at a briefing in Tokyo.
Earlier this week, the U.S. Federal Aviation Administration approved Boeing's plan to fix the battery system, starting what could be a rigorous testing regimen. The company also faces U.S. public hearings in April on the safety of its lithium-ion batteries.
Japan's Civil Aviation Bureau said on Friday that it was too early to estimate when the 787 could resume operations.
"At this time we are not yet in a position to say when flights will restart," said Shigeru Takano, air transport safety director at the bureau, following Boeing's comments.
Takano said it was "inappropriate" for Boeing to say that the investigation might not find the root cause of the battery incidents.
Japan is Boeing's biggest customer for the fuel-efficient aircraft, which has a list price of $207 million, with Japan Airlines and All Nippon Airways accounting for almost half of the Dreamliners delivered to date.
Boeing is now about a third of a way through the certification process of the new battery, the company said.
"This enclosure keeps us from ever having a fire to begin with," Sinnett said of the new battery's casing.
Boeing said it has asked Japan's GS Yuasa Corp (6674.T), which makes the battery for the airplane, and France's Thales SA (TCFP.PA), which produces the battery system for the aircraft, to improve production standards to eliminate "variation" in battery cell production.
"Because we did not find the single root cause, we looked at everything that could impact a battery and set a broad set of solutions," Sinnett said.
Boeing also intends to replace the battery chargers for the airplane.
Shares in Japan Airlines and All Nippon Airways have risen 20 percent and 16 percent, respectively, in Tokyo trading since January 7 - the day of the JAL battery fire in Boston - in line with an 18 percent rise in the broader market .N225. Boeing's stock has gained 11 percent.
Boeing has said the proposed changes to the battery and its testing plans are a final fix. But it remains unknown what effect the 787 problems have had on public perception of the plane's safety.
"I get often asked if I believe the airplane is still safe. My answer is simple, 'Absolutely'," Sinnett said.
"I've flown on the 787 more than 100 times, and I never once had any concern about my safety. I would gladly have my family, my wife and my children, fly on this airplane," he said. (Additional reporting by James Topham, Dominic Lau and Yoko Kubota; Editing by Chris Gallagher)