Earlier this week the Federal Aviation Administration took the first steps towards approving a set of proposed battery fixes for the Boeing 787 Dreamliner, and today the company took the opportunity to detail the changes — as well as try to downplay the severity of the issue. During a press conference, Boeing's vice president and chief project engineer Mike Sinnett struck back at media reports about the Dreamliner's problems, saying that the planes were never in any real danger. The problems, said Sinnett, were "limited to the function of the battery in the immediate area of the battery, but the airplane was not at risk."
The Dreamliner caught mainstream attention due to several incidents, with reports indicating that the plane's lithium-ion batteries had either caught fire or started smoking in the midst of flight. Sinnett said such reports were untrue. "In the factual report you can see that the only report of flame was two small three-inch flames on the front of the battery box on the connector," he said, "There were no flames inside the battery, and in the Takamastu event there was no fire at all."
"There were no flames inside the battery."
Descriptions of the batteries smoking, he said, were the result of the cells in the battery "venting" as designed. "This is a protective mechanism that is designed into the battery cells," Sinnett said. "When they vent, they vent vaporized electrolyte, which to you and I looks like smoke... it is not the product of combustion." In the case of the Dreamliner, he said, the cells got hot, began the venting process, and that process itself led to other cells overheating and venting themselves. This trickle-down process eventually led to the entire battery failing.
To resolve the issue, Boeing has put together a number of fixes. The individual battery cells will be wrapped in electrical isolation tape, in order to help heat from one cell spreading to another, and drain holes have been added to the battery enclosure for any moisture to drain without affecting the battery as a whole. A key aim, Sinnett explained, was to modify the design of the enclosure to ensure that any heat and pressure within the battery enclosure could be safely released, and that any vapors or odors would be vented overboard.
"It eliminates the possibility for fire."
However, he struck out again at the press when it came to the design aims of the enclosure. "It has been misreported that all we're doing is building an enclosure around a potential fire," Sinnet stated. "This enclosure keeps us from ever having a fire to being with. It eliminates the possibility for fire." He said Boeing has been designing the new features for over six weeks.
Sinnett was careful, however, to note that the lithium-ion battery technology was included only after a thought-out design process where positive and negative attributes were all considered. Ultimately, he said, "it earned its way on" the Dreamliner, noting that lithium-ion batteries already used in the aerospace industry.
That said, he acknowledged that the company has yet to find a definitive cause for what kicked off the process of the battery failures in the first place. "We may never get to the single root cause," Sinnett said, but that wouldn't prevent him from flying on a 787 himself when the FAA ban is lifted. "This airplane is among the safest airplanes our company has ever produced."
As far as steps forward, Boeing needs to complete the certification testing per the FAA, which the company hopes can be finished within a number of weeks — should everything go smoothly. Once the fixes are approved, Boeing will install the new batteries in current 787 aircraft, which would allow them to return to normal flight operation. At that point Boeing can resume production of new aircraft for customers still awaiting delivery.