Tokyo -The grounded Dreamliner is "absolutely" safe and will be back in the air within weeks, planemaker Boeing said in Japan on Friday, as it sought to reassure airlines and passengers about its aircraft.
The 50 planes grounded around the world since two lithium-ion battery malfunctions sparked a global no-fly order in mid-January will get fixes to their systems and be operational again soon, senior executives said.
"I get often asked if I think the airplane is still safe. My answer is simple: absolutely," Mike Sinnett, the chief project engineer on the 787, told reporters.
The Dreamliner "is among the safest airplanes our company has ever produced", he added.
Ray Connor, president of Boeing Commercial Airplanes, said fixes the company had put in place and which were now undergoing flight testing meant the aircraft would be back in the skies soon.
"We are going to be dependent upon (moving) through the certification process. We will determine when we actually get back in the air in terms of flights," he said.
"Previously as I have been anticipating that in months, we are talking more along the line of weeks," he said.
The pair were speaking as part of a push by the manufacturer to explain how it planned to remedy problems that have badly knocked confidence in one of the world's most advanced aircraft.
The company chose to give its first public explanation of the fix in Japan, home to two of its biggest customers -- All Nippon Airways and Japan Airlines -- and to suppliers who make around a third of the aircraft's parts.
The Dreamliner has been lauded for its use of next-generation materials that have cut weight and slashed fuel costs.
Boeing opted to use lithium-ion batteries for the plane, which engineers say are lighter than other batteries and are capable of higher power output that they do not lose when not in use.
But the batteries have come under scrutiny after a small fire on a parked 787 at Boston's Logan Airport in January. Days later what appeared to be smoke from a battery on an ANA flight forced an emergency landing in Japan.
Sinnett said an investigation into the two incidents had proved the aircraft's safety measures had kicked in properly.
"After the battery failure the airplane responded in exactly the way we had designed and anticipated," he said.
Sinnett said there had been no fire inside the battery on either aircraft, and what appeared to the untrained eye to be smoke was electrolyte venting from the cells.
He said despite extensive testing that had involved as many as 500 engineers from a number of different disciplines, the ultimate root cause of the problems had evaded them.
However, he said, layers of safety measures, including multiple back-up systems meant the company believed the battery posed no risk to the plane or its passengers.
"Are we confident that there will never, ever be another battery failure? The answer to that is: parts fail," he said.
"We know that someday a battery may fail. We need to make sure that there is no significant impact at the airplane level when it does."
The worldwide grounding of Dreamliners threw schedules into disarray, especially in Japan where ANA, the biggest operator of the plane, has been forced to cancel more than 3,600 flights to the end of May.
The Federal Aviation Administration, the US watchdog, gave Boeing the go-ahead to begin flight testing after "thoroughly reviewing" Boeing's February 22 plan to address risks.
The US aircraft giant, which has bet heavily on its lightweight plane at a time when airlines are eager to slash fuel costs, desperately wants to get it back in the air.