TOKYO - Japanese airlines welcomed US approval of test flights of the grounded Boeing 787 with prototype versions of the battery fix, holding out hopes for a resumption of its operations.
The worldwide grounding of Dreamliners has thrown airline schedules into disarray, especially in Japan where All Nippon Airways (ANA), the biggest operator of the plane, has been forced to cancel more than 3,600 flights through to the end of May.
US regulators on Tuesday approved Boeing's plan for the 787 batteries and said the company could carry out test flights with the fix.
"ANA, as the launch customer of the 787, hopes its flights will be resumed as early as possible on condition that safety is guaranteed," said the airline spokesman, which hailed the Federal Aviation Administration (FAA) approval.
"We think the approval... is a major progress towards resuming operations of the 787," he said.
A spokesman at Japan Airlines (JAL) said the company believed the issue had "entered a new stage", adding the firm would continue to work in cooperation with parties concerned.
Battery maker GS Yuasa declined to comment when contacted by AFP.
"The Federal Aviation Administration today approved the Boeing Commercial Airplane Company's certification plan for the redesigned 787 battery system... and the company's plan to demonstrate that the system will meet FAA requirements," the agency said in a statement.
The FAA said it had given the go-ahead after "thoroughly reviewing" Boeing's Feb 22 plan to address risks after lithium-ion batteries short-circuited on two 787 Dreamliner aircraft in mid-January.
A short circuit started a fire on a parked 787 at Boston's Logan Airport and smoke from a battery forced an emergency landing in Japan. The incidents led to the grounding of all 50 787s in service worldwide on January 16.