Boeing’s 787 chief engineer says the solution the manufacturer has come up with for the aircraft’s lithium ion battery guarantees there will never be a battery-related fire onboard a Dreamliner.
And in the same media briefing, given Friday morning in Tokyo, Boeing Commercial Airplanes president and CEO Ray Conner said he expects the 787 to be flying again in weeks, not months, and he fully intends to be on the first flight of a Dreamliner after the aircraft grounding is lifted.
Boeing 787 VP and chief project engineer Mike Sinnett gave a detailed description of the redesigned lithium ion battery system for which FAA on Wednesday approved a certification plan.
The Dreamliner has been grounded since mid-January after two safety incidents related to the aircraft’s lithium ion battery, one at Boston Airport and the other during a flight over Japan. A total of 50 787s around the world have been grounded since.
Sinnett said the combination of fixes for the battery and charger design and a new enclosure for the battery system was important “because it eliminates all possibility of fire.” Asked directly by an AFP reporter if he could guarantee there is no risk of fire, Sinnett responded, "Yes, I can. If we have a cell event, I am very, very confident that we will not have a fire as a result.”
The three-part solution addresses the battery design to further mitigate the possibility of cell failure, the charger operation, and also containment of the battery should a failure occur. A new enclosure for the battery system will ensure there is never sufficient oxygen for a fire to break out, Sinnett said.
The three layers of protection are designed to prevent the initiation of an event, its propagation and any impact on the aircraft. This involves battery and charger design improvements, a tighter voltage range, and enhanced battery and cell manufacturing processes and testing.
Conner gave strong apologies to the airlines impacted by the grounding and those passengers affected by the safety events. He said he anticipated the certification process to take weeks rather than months and added, “I fully intend to be on the first flight when that occurs.”
Sinnett acknowledged that a root cause for the two failures that occurred in January was still not known. “When we go back four or five years or even longer, the history of lithium ion batteries was very good and so I don’t think that our basic design assumptions for failure probability were incorrect.”
But having seen two events occur within the space of a few days, Sinnett said Boeing had taken the decision to develop a much safer solution that provides multiple layers of redundancy rather than look for a specific root cause fix.