Japan Airlines said it temporarily grounded one of its 787 Dreamliners after white smoke was spotted outside the plane, warning lights in the cockpit indicated possible faults with the main battery and charger, and one battery cell appeared to be leaking. Boeing Co said it was "aware of the 787 issue that occurred at Narita, which appears to have involved the venting of a single battery cell." The incident comes nearly a year to the day after Japan Airlines and All Nippon Airways grounded their 787 fleets after two 787 batteries overheated on two different planes in less than two weeks. Global regulators grounded the worldwide fleet on January 16, 2013. The planes remained grounded for more than three months while Boeing redesigned the battery, charger and containment system to ensure battery fires would not put the airplane at risk. The cause of the battery problems has not been determined.  Japan Airlines said maintenance engineers who were in the cockpit saw white smoke from the cockpit. When they went outside the aircraft the smoke had dispersed. On returning to the cockpit the engineers found warning lights indicating possible faults with the main battery and charger. When checking the battery they found one of the eight cells to be active with a liquid coming out. The plane, due to depart from Tokyo Narita airport for Bangkok, was taken out of service and the 158 passengers due to board the plane were put aboard a separate 787, JAL said. (Reuters)