In January of 2013 a relatively new Boeing 787 Dreamliner operated by Japan Airlines caught fire while on the ground at Boston’s Logan International Airport. Fortunately, all passengers had deplaned from a 13 hour nonstop flight from Tokyo, while ground crews were making preparations for a return flight. The fire was traced to the aft electrical equipment bay and was believed to originate in the aircraft’s auxiliary power system, where a lithium ion battery later exploded, causing a secondary fire. This was the second incident involving a fire condition with the auxiliary batteries.
That incident triggered a subsequent six month grounding of all existing operational 787 aircraft while government safety agencies and Boeing searched for the cause. At the time, Supply Chain Matters featured a series of ongoing commentaries reporting on subsequent program developments. The aircraft was later approved for service after Boeing initiated a complete redesign of the battery housing unit containing lithium-ion batteries.
Last week, the U.S. National Transportation Safety Board (NTSB) issued its final accident report regarding the 2013 incident. (The investigative actions of government agencies tend to be elongated)
In its report, the NTSB states: “The NTSB determines that the probable cause of this incident was an internal short circuit within a cell of the APU lithium-ion battery, which led to thermal runaway that cascaded to adjacent cells, resulting in the release of smoke and fire. The incident resulted from Boeing’s failure to incorporate design requirements to mitigate the most severe effects of an internal short circuit within an APU battery cell and the FAA’s failure to identify this design deficiency during the type design certification process.”
That conclusion pretty much summarizes what business and other industry media was suspecting all along. The accident report further identified “cell manufacturing defects and oversight of cell manufacturing processes” within lithium-ion battery supplier GS Yuasa’s manufacturing facilities. The NTSB identified several concerns, including “foreign object debris (FOD) generation during cell welding operations and a post assembly inspection process that could not reliably detect manufacturing defects, such as FOD and perturbations (wrinkles) in the cell windings, which could lead to internal short circuiting.” In addition, the NTSB specifically cited the U.S. Federal Aviation Administration’s (FAA) oversight of Boeing and its power sub-systems contractor Thales, oversight of GS Yuasa which did not ensure that the cell manufacturing process was consistent with established industry practices.
The good news is that since Boeing’s re-design of the auxiliary power unit (APU) installation configuration there have been no major additional incidents involving battery short circuiting or thermal runaway. Boeing obviously responded and took appropriate action.
As with previous incidents related to the 787, there are obvious common themes of learning. Earlier this year, the U.S. FAA released the results of its comprehensive joint study of the 787 program. That report concluded that the 787 is soundly designed and that processes exist to identify and correct manufacturing issues. However, the report noted areas that required attention. The most notable was the two-way flow of product design, specification, testing information among various tiers of the global supply chain along with proper oversight of supplier manufacturing processes. At the time of the release of the FAA report Boeing senior executives acknowledged to business media that they lost some control of the manufacturing process because of the nature of the global supply chain, and placing too much reliance on suppliers for the overall quality of 787 components and systems.
From our lens, this latest NTSB accident investigation report adds more credence to the reality that globally extended aerospace and complex equipment supply chains need to consider more timely two-way integration of product lifecycle management (PLM) and manufacturing process test information across B2B supply chain networks. Similar to supply chain planning or execution synchronization, product management information synchronization is equally important.
Last week, Boeing announced that it had initiated the manufacturing of the larger 787-9 (Dash Nine) configuration at its South Carolina assembly facility. The North Charleston, S.C., site joins Boeing’s Everett, Wash., final assembly, which began 787-9 production in May 2013. United Airlines will be the designated customer that takes delivery of the first South Carolina-built 787-9. The overall 787 global supply chain needs to scale-up to meet unfulfilled airline customer orders.
The Dash Nine is designed to be 20 feet longer than the previous 787 models and can accommodate up to 290 passengers. This model was originally due to be delivered in 2010 but its production has been dramatically pushed back due to changes in design, most notably Boeing taking on more responsibility for key major component design and manufacturing.
When it comes to extended global supply chain sourcing of major sub-systems, it often takes time and acquired learning to uncover problem areas. The industry learning is that as commercial aerospace supply chains continue to scale-up to higher volumes of production, network-wide product design and manufacturing process information and oversight is just as crucial as other supply chain business process needs. B2B supply chain business networks include the need for synchronization of PLM information elements.