Japan’s Transport Safety Board (JTSB) has confirmed that is preparing to resume limited flight tests of the 787 as part of initial efforts to characterize the operating environment of the battery during typical flight cycles.
Boeing, which declines to confirm reports in numerous media that it has requested permission from theto conduct the data-gathering flights, is known to be evaluating several potential modifications to the battery system as part of urgent attempts to restore the 787 to service. The aircraft has been grounded since mid-January following two separate battery failures on aircraft in the U.S. and Japan earlier last month.
The FAA tells Aviation Week, “We are evaluating the request,” but declines further comment.
The JTSB, meanwhile, is providing new details about the extent of the damage sustained by the main battery, which failed on the787 on Jan. 16. The agency says its investigation has found evidence of the same type of thermal runaway event that the U.S. says occurred on the 787 APU battery at International Airport on Jan. 7. CT scans and other analysis conducted by the JTSB found damage to all eight cells in the battery as well as indications of short-circuiting and thermal runaway—a condition in which the failure of a single cell rapidly leads to overheating and a spillover to the surrounding cells.
According to media reports, the initial flight tests will focus on measuring the impact of temperature and vibrations on the battery as experienced during typical flight cycles. As previously revealed by Aviation Week, the report also indicates Boeing is evaluating potential means of improving the battery containment and venting system.