TOKYO (AP) -- Japan's transport minister said Friday the government will allow Japanese airlines to resume flying grounded Boeing 787s once they complete installation of systems to reduce fire risk in problematic lithium ion batteries.
The ministry gave the official approval Friday evening following a formal safety order from U.S. Federal Aviation Administration.
"We have reached a conclusion that there is no problem with the judgment by the FAA," Transport Minister Akihiro Ohta told reporters. "We believe all possible safety measures would be taken to prevent recurrence of similar problems."
The 50 Dreamliner jets in service worldwide were grounded in mid-January after incidents with smoldering batteries occurred aboard two different planes. Japan's All Nippon Airways was the launch customer for the technologically advanced airliner and has 17 of the jets. Japan Airlines has seven.
The groundings have led to hundreds of canceled flights and big revenue losses.
A resumption of Dreamliner commercial flights would be around June, as safety improvements are expected to take several weeks to finish, airline officials said.
The FAA posted a safety order online Thursday allowing 787 flights to resume once the batteries are replaced with a revamped system that manufacturer Boeing Co. says sharply reduces the risk of fire.
Japan is requiring ANA and JAL to take additional safety measures, including installation of a system that allows monitoring of battery voltage on the ground and test flights of all 787 aircraft. A first test flight is expected Sunday.
ANA said Friday it plans to complete the safety improvement work, which would require about one week per aircraft, by the end of May for its entire 787 fleet.
Engineering crews are working to retrofit new systems on each of its 17 Dreamliner aircraft, ANA said. The measures involve replacing existing batteries with new ones, installing new chargers, containment boxes and a venting system.
AP writer Malcolm Foster contributed.