The Federal Aviation Administration has signed off on Boeing's certification plan for the lithium-ion battery system aboard the 787 Dreamliner and approved flight testing the solution to a problem that has grounded the jets since January.
Getting federal authority to proceed with the modifications - which include redesigning the eight cells within the 63-pound battery -- is a big step forward for Boeing, which has been working nonstop to get the Dreamliner airborne again. All 50 Dreamliners worldwide have been grounded since Jan. 16 after batteries aboard two planes started smoking in an incident called thermal runaway.
"This comprehensive series of tests will show us whether the proposed battery improvements will work as designed,” Transportation Secretary Ray LaHood said in a statement from the FAA. “We 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."
According to the FAA, the 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.” The FAA could demand further changes if problems persist in laboratory or flight tests.
"Our team has been working around the clock to understand the issues and develop a solution based on extensive analysis and testing following the events that occurred in January,” Boeing CEO Jim McNerney said in a statement from the company. “Today's approval from the FAA is a critical and welcome milestone toward getting the fleet flying again and continuing to deliver on the promise of the 787."
The decision comes just days after the National Transportation Safety Board, investigating a January 6 fire aboard a 787 parked in Boston, issued a preliminary report questioning testing by suppliers and Boeing, noting the battery and its charging system were not tested a complete system, either in a lab or aboard an airplane.
The NTSB is investigating one of thermal runaway events, a Jan. 7 fire aboard a 787 at the gate in Boston. A week later, a second Dreamliner making a domestic flight in Japan made an emergency landing after the crew smelled smoke from an overheating battery. The two incidents prompted the Federal Aviation Administration to ground all Boeing 787 aircraft registered in the United States. Aviation agencies worldwide quickly followed suit in what was the first grounding of an American-built airliner in more than 30 years.
Neither federal investigators nor their counterparts in Japan have determined the root cause of the problem. Earlier indications from the NTSB suggest a short circuit of a single cell within the 63-pound battery as the earliest known problem. Ray Conner, Boeing's commercial airplanes president and CEO, said the company has been working with in-house battery technology experts as well as those from outside the company.
“We have proposed a comprehensive set of solutions designed to significantly minimize the potential for battery failure,” Conner said, “while ensuring that no battery event affects the continued safe operation of the airplane.”
In addition to the three improvements mentioned by the FAA, Boeing added there will be “enhanced production and testing processes” that will “include more stringent screening of battery cells prior to battery assembly.”
Boeing's certification plan includes a series of tests and outlines specifically how they will be designed and conducted and what specific parameters will be measured. It also stipulates specific criteria that must be met to pass, or fail, the tests. FAA engineers will be involved in all aspects of the testing.
The FAA also approved limited test flights for two aircraft, including Boeing workhorse ZA005. The aircraft will be fitted with prototypes of a new battery containment system, which is said to be designed to contain any smoke or fire.
Dreamliner ZA005 was used for two short test flights after the grounding earlier this year and has been in the flight-test fleet for a few years now. The company also will use line number 86 to “conduct tests to demonstrate that the comprehensive set of solutions work as intended in flight and on the ground.”
The new battery system will be tested in a wide range of normal and abnormal conditions. In addition to following FAA standards, Boeing will also adhere to test plans written based on applicable guidelines from the Radio Technical Commission on Aeronautics which were not available during the original 787 battery certification plan.
The airworthiness directive from the FAA states the company must demonstrate a new design meets and complies with the agency’s requirements. With the grounding approaching the end of its second month, Boeing is ready to return the Dreamliner fleet to the sky. A company spokesman told Wired flight testing will begin soon, "both airplanes will fly within the days ahead."
