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Maybe Lithium batteries in gliders not quite such a good idea yet?



 
 
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  #1  
Old January 20th 13, 06:59 PM posted to rec.aviation.soaring
RAS56 RAS56 is offline
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Default Maybe Lithium batteries in gliders not quite such a good idea yet?


My company has 787's on order, but they won't be delivered until 2014 (if then) and I'm glad I'm not having to fly the thing while this entire episode gets sorted out.
An inflight fire is one of the, if not the worst things that could happen to you. I had a cockpit fire breakout behind the engineer's panel after landing in an E-3A back in the 80's that was electrically generated and it spread with amazing speed and put out an incredible amount of smoke and fumes in a very short time. Fortunately, killing all power to the aircraft pretty much stopped the conflagration..but had it happened 10 minutes earlier while we were in hard IFR on downwind...

BTW, if you're wondering where you've heard the company named "Thales" that's mentioned in this thread and the article below, they gained prominence in the Air France 447 loss over the Atlantic some years back when the pitot tubes they manufactured iced up and were cited as a factor in that accident..

Rob
ZAP


http://www.flightglobal.com/news/art...ritory-381148/

ANALYSIS: Grounding order moves 787 into uncharted territory

By: Stephen Trimble Washington DC

02:29 17 Jan 2013

Source:

A grounding order by the US Federal Aviation Administration (FAA) moves the Boeing 787 programme into territory uncharted for a modern airliner as long as a recently discovered "battery fire risk" remains unsolved.

The order by the FAA effectively grounds six 787s operated by United Airlines and aligns the US regulator with two Japanese airlines - All Nippon Airways and Japan Airlines - that ceased 787 operations earlier on 15 January. But the action also forces five other airlines operating the 787 to reconsider the aircraft's safety for an undetermined period.

Boeing must demonstrate that it has eliminated any risk of a battery-ignited fire before the grounding will be lifted. Jim McNerney, Boeing's chief executive, says the entire resources of the company will be put at the disposal of the effort to discover the source of the battery fire risk and to correct it.

Engineering resources, meanwhile, could be diverted from other strategic efforts in 2013, such as doubling the 787's monthly production rate, completing the assembly and launch flight testing of the 290-seat 787-9 and launching the potential 320-seat 787-10.

The grounding may not have an immediate impact on aircraft valuations, as no market exists for second-hand 787-8s yet, with only 51 of the type delivered.

But the public and regulatory safety concerns growing around the programme could make it harder for some airlines and lessors to obtain financing, says Les Weal, head of valuations for the Flightglobal Ascend consultancy.

"If you were asked to finance one today, you may have to pass on the opportunity," says Weal, explaining that such financiers have no shortage of requests bearing less risk than the 787. In the hours leading up to the FAA grounding order, Flightglobal Ascend still assigned a $110 million valuation for a new 787-8 built in 2013.

On top of the programme's financial concerns, Boeing may also need to restore confidence in the 787's entire electrical architecture. It was designed as a technological leap forward, reducing fuel consumption by several percentage points, and using electricity to replace parasitic bleed-air to power onboard systems and cabin pressurisation.

But the power system with nearly 1.5MW (2,010hp) of capacity has been a source of constant headaches barely 15 months into service. A suspected batch of poorly-built circuit boards are likely to have caused a series of glitches on power distribution panels of several aircraft in December 2012, forcing United and Qatar Airways to briefly ground some aircraft to perform repairs.

Far more worrisome, however, are the newly-realised risks of fire posed by the two lithium-ion polymer batteries, a powerful chemistry is described as a "first" in commercial aviation on the 787. Boeing selected a lithium-ion-based battery proposed by electrical power conversion system supplier Thales, which packaged an industrial-grade battery designed by Japanese firm GS Yuasa and a battery charger unit made by Securaplane, based in Tucson, Arizona.

Industry and government regulators were aware of the risks of potential safety hazards posed by battery chemistries based on lithium-ion.

In 2006, Securaplane's administration building "burned to the ground" because of a botched laboratory test involving a GS Yuasa battery designed for the 787. In 2007, the FAA imposed a set of special conditions for Boeing to prove the safety of lithium-ion batteries before the agency would grant airworthiness certification for the new aircraft.

The certification tests appeared to show that Boeing had passed the FAA's test. The lithium-ion battery allowed Boeing to start the auxiliary power unit with a device half the size of comparable nickel-cadmium or lead acid batteries used in previous aircraft designs.

Last week, Michael Sinnett, the 787's chief project engineer, said lithium-ion is not the only acceptable solution, but it was still the best option for the 787.

Any future design must show that the battery is safe, even if something fails and heat builds up to dangerous levels, says Hans Weber, head of the Tecom aviation consultancy.

Such a design must ensure that a fire is contained and is quickly extinguished by being deprived of oxygen, he says. Moreover, most, if not all, of the smoke generated by the flames must be vented outboard, rather than be allowed to circulate inside the pressurised cabin, he says.

Speaking hours before the FAA imposed by the grounding order, Weber said the public and regulatory response to the ANA and JAL battery incidents had been surprising.

"It's been driven by emotion, which is understandable," he says. "The emotion generated by a fire on board is high. That's one of the scariest things to contemplate."

  #2  
Old January 20th 13, 07:33 PM posted to rec.aviation.soaring
Dave Nadler
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Posts: 1,610
Default Maybe Lithium batteries in gliders not quite such a good idea yet?

On Sunday, January 20, 2013 1:59:45 PM UTC-5, RAS56 wrote:
.... In 2006, Securaplane's administration building "burned to the ground"
because of a botched laboratory test involving a GS Yuasa battery designed
for the 787. In 2007, the FAA imposed a set of special conditions for Boeing
to prove the safety of lithium-ion batteries before the agency would grant
airworthiness certification for the new aircraft.


http://www.reuters.com/article/2013/...90J06I20130120
  #3  
Old January 20th 13, 09:28 PM posted to rec.aviation.soaring
RAS56 RAS56 is offline
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First recorded activity by AviationBanter: Dec 2010
Posts: 85
Default Maybe Lithium batteries in gliders not quite such a good idea yet?

Interesting.

This article:

http://seattletimes.com/html/busines...gpainsxml.html

Has a Japanese safety investigator opining that it COULD BE overcharging that led to the event(s). Boeing and the US NTSB saying one thing, Japanese Safety Board saying "...not so fast." These batteries are so big, I'm wondering if there is the possibility of developing localized internal "hot spots" during charging that the sensors cannot detect that result in the explosions/fire? It seems too early to unequivocally state it is or is not one thing or another.

I'm a huge fan of Boeing products, having flown most of my career in them, but I am cynical enough to remember that according to Boeing, there wasn't anything wrong with the 737 rudder system either, but "we'll redesign it anyways".

There is a gigantic financial interest in seeing these things get flying again, ASAP.
  #4  
Old January 21st 13, 02:20 AM posted to rec.aviation.soaring
Dave Nadler
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Posts: 1,610
Default Maybe Lithium batteries in gliders not quite such a good idea yet?

I love part about the former Securaplane employee who sued them,
claiming he was dismissed for raising concerns about their chargers:
http://www.reuters.com/article/2013/...90J06I20130121

I bet he is in demand at the moment ;-)
  #5  
Old January 21st 13, 11:42 AM posted to rec.aviation.soaring
Peter Higgs
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Posts: 47
Default Maybe Lithium batteries in gliders not quite such a good idea yet?

Some Aero-Modelers, who use Li-Poly batteries to power their aircraft,
leave ventilation space between adjacent cells to aid cooling.
Looking at the burnt out 787 battery pack, their cells don't seem to have
any ventilation space, and are just packed together. Maybe they don't
want a pathway for any fumes to get into the cabin, so make the unit as
sealed-up as possible.

phiggs

 




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