FAA has approved Boeing’s certification plan for the redesigned 787 Dreamliner battery system, the first step in the process to return the aircraft to commercial service.
The agency grounded all in-service Boeing 787s in January, following several incidents involving malfunctioning of the plane’s lithium ion battery system and other critical components while it was being operated on commercial flights.
In a statement, FAA said the internal battery components have been redesigned to minimize initiation of a short circuit within the battery, better insulation of the cells and the addition of a new containment and venting system.
During its ongoing investigation of the Japanese Airlines 787 battery fire that occurred at Boston’s Logan International Airport in January, the National Transportation Safety Board (NTSB) discovered that the origin of the fire was a short circuit occurring within one of the battery’s eight cells.
"Our proposal includes three layers of improvements. First, we've improved design features of the battery to prevent faults from occurring and to isolate any that do. Second, we've enhanced production, operating and testing processes to ensure the highest levels of quality and performance of the battery and its components," said Ray Conner, president and CEO of Boeing's commercial airplanes unit.
"Third, in the unlikely event of a battery failure, we've introduced a new enclosure system that will keep any level of battery overheating from affecting the airplane or being noticed by passengers," Conner added.
The redesign of the battery system will be approved only if the battery system completes all required tests and analysis to comply with FAA requirements. The airworthiness directive issued by the agency in January is still in effect, although two 787s have been approved to perform limited test flights. Those two planes will have the new versions of the battery containment system installed.
“We are confident the plan we approved today includes all the right elements to conduct a comprehensive evaluation of the battery system redesign,” said FAA Administrator Michael Huerta. “Today’s announcement starts a testing process which will demonstrate whether the proposed fix will work as designed.”
The agency did not disclose a possible return to service date for the 787.