January 25, 2013 | 4 Comments
No Boeing 787 Dreamliners have crashed or burned to the ground, but lithium ion technology is back in the news with a vengeance. The lithium ion batteries that are used in the Boeing 787 are not good enough – they have runaway overheating and discharge smoke and fumes. In flight this would be very alarming and cause for rapid descent and landing.
This will not do, it’s not like pulling the electric vehicle over and hopping out on the side of the road. Boeing and airlines with 787s in the fleet have to be very concerned and quite angry with the battery supplier, Yuasa. Admirably, so far Boeing is taking all this squarely on its own chin.
At a briefing on the progress in the NTSB investigation of the lithium ion battery fire on-board a JAL Boeing 787 at Logan Airport in Boston, NTSB Chairman Deborah Hersman revealed (via a pdf download) that the investigating team had found signs of electrical short circuiting and thermal runaway in the cells. The NTSB is working to determine the cause.
The next steps in what appears will be a lengthy investigation will be to complete the in-house laboratory examinations; conduct examinations and testing of exemplar batteries; and to synthesize lab examination findings with fire forensics and aviation systems investigation.
No batteries are likely to have ever been subjected to such forensic intensity.
As the forensics are reported at this writing NTSB has performed an exam and teardown of the JAL battery at its Materials Laboratory. Boeing and its various suppliers have also performed component exams and teardowns:
- Securaplane Technologies, Battery Charger Unit and Start Power Unit
- United Technology Aerospace Systems, APU Controller
- Boeing, Two General Purpose Modules
- Kanto Aircraft Instrument, Battery Monitoring Unit
The battery itself comprises 8 GS Yuasa prismatic Li-ion cells each with a nominal capacity of 75 Ah, with a nominal voltage of 3.7 V. So far, NTSB has performed:
- CT scan of the entire assembly.
- Cell 1: CT scan
- Cell 2: disassembly
- Cell 3: CT scan
- Cell 4: CT scan
- Cell 5: CT scan, disassembly, scanning electron microscopy, energy dispersive electroscopy
- Cell 6: CT scan, disassembly
- Cell 7: CT scan, disassembly, SEM
- Cell 8: disassembly
Boeing said in part after the update, welcoming the progress:
In order to ensure the integrity of the process and in adherence to international protocols that govern safety investigations, we are not permitted to comment directly on the ongoing investigations. Boeing is eager to see both investigative groups continue their work and determine the cause of these events, and we support their thorough resolution.
Your humble writer has not seen any comment from Yuasa.
This is a serious economic matter for many, the airlines with grounded planes, Boeing with another tense delay on deliveries, thousands of jobs in limo, and passengers with a bit of apprehension. There is also the expense of figuring out the problem, how to fix it and dealing with a set of government safety agencies and personnel.
Still, the Dreamliner is a big technological jump in materials, construction, applications of new technologies, fuel efficiency and passenger comfort.
The lithium ion technology that Yuasa used to win the supply contract is now very suspect and the question of what the technology type selected is or would be applied to other applications is of great interest.
This bears watching – and one hopes the reporting stays on track so we can learn what changes will be coming. First the Chevy Volt had some issues, now the Dreamliner, we’re working through the issues of new technology adoption, it will work out – hopefully before the strain damages Boeing and the tens of thousands of people involved or anyone gets hurt. It’s time for Yuasa and other battery manufacturers to man up and get squared away.