The transport ministry on April 26 permitted All Nippon Airways and Japan Airlines to resume flights of Boeing 787 Dreamliners, following the U.S. Federal Aviation Administration's approval of Boeing's modification of the jetliner's battery system, which had developed "thermal runaway" problems. Boeing claims that the changes to the airliner's battery system will ensure the aircraft's safety. But the cause of the overheating problems has not been pinpointed. The aircraft maker and airlines cannot be too careful in ensuring that the Dreamliner's battery system is operating without trouble.
On Jan. 7, a fire ignited in the battery pack for an auxiliary power unit of a JAL 787 at Boston's Logan International Airport. On Jan. 16, an ANA 787 made an emergency landing at Takamatsu airport in Kagawa Prefecture after smoke from the battery system was detected in the cockpit.
The batteries involved in these accidents were lithium-ion batteries manufactured by Kyoto-based GS Yuasa Corp. Shortly after the Jan. 16 emergency landing incident, the FAA grounded all 787s, and the transport ministry told ANA and JAL to stop flying the jetliner. Since Japanese makers are responsible for 35 percent of the aircraft's parts and components, the grounding had a significant effect on them. Eight airlines have introduced 50 Boeing 787s, with ANA owning 17 and JAL seven, expecting that Dreamliners will contribute to increasing their profitability.