JAL 787 is grounded by glitch in battery bay

Kyodo

A Japan Airlines’ Boeing 787 Dreamliner scheduled to fly Sunday from Tokyo to Beijing experienced a problem with an air pressure sensor for its battery container, prompting JAL to use another aircraft for the flight.

The incident came just a day after JAL and All Nippon Airways resumed regular flights using 787s after the aircraft was grounded for more than four months due to a series of battery problems.

JAL said the problem was found during a safety check at around 6 a.m. The flight was scheduled to depart Haneda airport at 9:10 a.m.

The pressure sensor for the battery container in the electrical equipment bay at the back of the aircraft showed a difference in air between outside and inside the container.

JAL said there was no abnormality found in the battery itself.

According to the airline, Boeing may have caused the problem through faulty maintenance, as two small holes in the container were mistakenly sealed during repairs to the battery system. The holes are necessary for air ventilation to prevent overheating, JAL said.

JAL swapped in a Boeing 767 for the flight, which left about an hour behind schedule.

In a similar incident, a power switchboard was partially damaged by heat during a 787 training flight conducted by ANA on May 4 due to faulty maintenance by Boeing.

A Boeing mechanic had left a nut loose during a checkup of the switchboard before modifying the aircraft’s battery, so it is believed heat was generated by increased electrical resistance, ANA said, adding it has asked the airplane maker to prevent any recurrence.

The root cause of the battery defect that grounded all 787s for several months has yet to be identified.