[SystemSafety] 787 Groundings

[Peter Bernard Ladkin]

Just in case y'all missed it, the FAA has grounded US 787 aircraft because of the battery issues.
http://www.flightglobal.com/news/articles/analysis-grounding-order-moves-787-into-uncharted-territory-381148/ 
EASA followed suit, which grounded LOT's two: 
http://www.flightglobal.com/news/articles/european-regulator-adopts-faas-787-grounding-381166/ and 
various other countries.

The 32V 8-cell lithium-ion batteries are made by the Japanese company GS Yuasa. I didn't know that a 
building in Tucson "burned to the ground" during a "botched" test of one of the batteries in 2006.

Flight International in its paper edition this week has an article, also by Stephen Trimble, (p15) 
written before the latest incident, including a diagram source to Boeing of "787 lithium-ion battery 
locations". There are two; the APU-starter battery in the aft bay by the aft cargo door, and the 
main battery in a bay under the aft cockpit, accessed through an "equipment access door" in the 
aircraft. I can't find this article on the FlightGlobal WWW site.

The ground explosion in Boston was the APU battery, and the latest smoke-in-flight incident was 
reported to have been associated with the Main Battery.

Bernd and I have been questioning why and how on earth a battery technology known to be susceptible 
to thermal runaway, with consequences fire and explosion, made it into an aircraft. Yes, Boeing went 
to extra lengths and the FAA required specific justification and so on. But why take the chance just 
to save a few kilos? Does anyone here have a handle on the economics of it?

I found out an interesting tidbit on Tuesday at a meeting of the German 
electrotechnical/informatiotechnical standardisation organisation DKE in Frankfurt (in a committee I 
chair). We did get around to a little chat about the news. Apparently the DKE standardises the 
individual cells of batteries, but another standardisation organisation, VDA, which standardises 
stuff to do with automation, has the battery remit. I guess there was a time when automation had 
little to do with electrotechnics, but all that has changed in the last half-century. I imagine 
there was some horse-trading in the recent past as the two areas converged, but I don't know any of 
that yet. The car people have their own, NA-Automobil, and there is the overall 
industrial-standardisation body DIN.

PBL

-- 
Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany
Tel+msg +49 (0)521 880 7319  www.rvs.uni-bielefeld.de