File photo of a United Boeing 787-8 Dreamliner (N45905). Image courtesy of Oliver Holzbauer, and shared under the CC BY-SA 2.0 license.
When the Boeing 787 Dreamliner first launched, It was hailed as a revolutionary aircraft that would shake up the industry. To an extent, the aircraft has done exactly that, opening up the so-called "long and thin" routes that previously weren't economically feasible. Now, with a low-capacity, long-range jetliner, you can take a direct flight from California to a secondary city in Asia, without having the hassle of connecting at a major hub. By using exotic carbon fiber in its fuselage, the Boeing 787 ultimately became one of the most fuel efficient and innovative jetliners in the industry, captivating airlines and passengers alike.
Despite this, the entry of the 787 into commercial service was not without its hiccups. In 2013, ANA (All Nippon Airways) suffered a battery failure in flight on one of its 787-8 Dreamliners, prompting an emergency landing and evacuation at Takamatsu airport. Earlier that month, a Japan Airlines 787-8, parked at Boston's Logan International Airport, also suffered a serious battery fire in a well-publicized incident. Furthermore, numerous other incidents concerning the 787's battery occurred within that same year, and as a result, the entire 787 fleet was grounded. After Boeing and its subcontractors made changes to the 787's battery system, the issue appeared to be solved. Or was it?
Infographic of the Boeing 787 Dreamliner's battery system. Image courtesy of Tested.
On November 13, 2017, United Airlines flight 915 was on its descent into Paris - Charles de Gaulle International Airport (CDG) when the main lithium-ion battery was found to be overheating. Upon inspection after landing, engineers found that the battery system was "venting fluid" out of the forward vent relief system, essentially a box installed by Boeing as part of its corrective measures for the 787 in order to prevent a battery meltdown from becoming catastrophic.
The 787's lithium-ion batteries, manufactured by Japanese battery manufacturer GS Yuasa, has been known to suffer serious overheating problems both in-flight and on the ground. Fortunately, nothing serious happened during this flight as the aircraft was able to land without incident. This also comes as a slight relief to Boeing engineers, as the battery containment system worked to prevent the overheating battery cell from affecting other systems in the aircraft. However, a repeated string of battery failures points to a problem within the battery itself. This is not Boeing's fault, as GS Yuasa designed and manufactured the 787's battery. For Boeing, the lithium-ion batteries are clearly a win-win, as they provide a high amount of energy for extremely low weight. Despite this, GS Yuasa needs to come up with a fix for these batteries, as there is obviously still a recurring overheating issue with the lithium-ion batteries that needs to be addressed immediately, in order to prevent future occurrences.
A schematic showing how Boeing implemented a fix to the battery's overheating problems. Image courtesy of Engineering & Technology Magazine/ Graphic News.