The Federal Aviation Administration said Tuesday that it has approved Boeing’s certification plan for the redesigned 787 battery system and will allow two Dreamliner planes to begin test flights with the revamped protections against overheating batteries and damaging fires.
“We are confident the plan we approved today includes all the right elements to conduct a comprehensive evaluation of the battery system redesign,” FAA chief Michael Huerta said. “Today’s announcement starts a testing process which will demonstrate whether the proposed fix will work as designed.”
Transportation Secretary Ray LaHood said regulators “won’t allow the plane to return to service unless we’re satisfied that the new design ensures the safety of the aircraft and its passengers.”
As earlier unofficial reports indicated, Boeing’s proposed improvements include “a redesign of the internal battery components 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,” according to the FAA.
The agency said its certification plan requires a series of tests that must be passed before the 787 could return to service, with specific pass/fail criteria and testing methodology. FAA engineers will be present for the testing and will be closely involved in all aspects of the process, the agency said.
Boeing Commercial Airplanes President Ray Conner described the planned measures as “a comprehensive set of solutions designed to significantly minimize the potential for battery failure while ensuring that no battery event affects the continued safe operation of the airplane.”
In a Boeing statement, Conner outlined “three layers of improvements.”
One involves a redesign of the battery “to prevent faults from occurring and to isolate any that do.”
Another involves “enhanced production, operating and testing processes” for the battery. Reports this month said battery supplier GS Yuasa had been advised by outside experts to tighten inspections and reject more batteries from its production line to ensure the highest levels of quality and performance of the battery and its components.
The third level of protection is an improved system for channeling smoke and volatile liquids out of the airplane “in the unlikely event of a battery failure,” Conner said. He said the “enclosure system . . . will keep any level of battery overheating from affecting the airplane or being noticed by passengers.”
The Dreamliners have been grounded since mid-January after battery failures caused a battery fire in a jetliner on the ground in Boston and then a smoldering battery on a flight in Japan. The grounding has halted deliveries of new planes as well as flights by the 50 already delivered to customers.
A Boeing team led by Conner presented the company’s proposed solution on Feb. 22 to Huerta, deputy Transportation Secretary John Porcari and other FAA officials.