“determined that overcharging was the only known failure mode that could result in cell venting with fire”.

It’s not a calculation of a probability, it’s just them saying that the only way they think batteries could catch fire is if they overcharged them.

“But that probability is most likely valid” The difference between never/1-in-a-billion and 1-in-29,000-hours is not a matter a confusion of statistical probability for observed occurrences, it is a difference between “most likely valid” and “not valid at all”. That is, between right and demonstrably wrong.

@TimWorstall:

Fenyman did lead the overall Challenger review (a national treasure, he was). Edward Tufte later expanded on Feynman’s description of the O-ring decisions, and focused on the failures of engineering communications methods that lead to the bad decisions to begin with. Tufte showed the charts created by Morton about the O-rings, and used by NASA engineers to overrule a few Morton engineer’s objections to launch, were terrible and misleading. Literally, a better chart would have probably saved the Challenger.

If you had bothered to spend about 5 seconds reading up, you would discover that the last time new battery technology was brought on board – when lead acid was replaced by nicad – there were all sorts of problems; thats what happens with new technology.
Planes used to fall out of the sky regularly; recently, disasters have been few so we are accustomed to a much lower failure rate

know what etops means ?
the LI batteries are important because they allow thie plane to fly a route where they can be up to 5 hours from a airport.
if you bother to look at a globe you see that , esp in the pacific, this opens up all sorts of new routes for this plane..which is a big point to the customers, with theability to fly a route where the plane is 5 hours from any availalbe runway, they can do all sorts of new direct flughts…

” Edward Tufte’s analysis of how the Challenger disaster happened: engineers being careful, and managers overruling them. ”

Yup. The Li-ion disaster at Boeing is a management disaster, of outsourcing at all costs and shriveling the in-house know-how for the sake of managerial ideology. Nothing to do with engineers.

When engineers are in charge at Boeing, you get the 747 and the B52 (introduced in February 1955 ans still in use and irreplaceable 58 years later). When managers run the show, you get nightmares like the “Dreamliner”.

If only it were that simple then they’d have solved the problem months ago.

You can’t get NiCd or lead acid batteries of the required power into the space that they’ve designed for the batteries. They’d need to redesign the actual plane to make enough space to get such batteries in there. That’s why they’re all fiddling around with lithium still.”

First of all, all battery types can cause fires. Take your car battery, put a wrench across both terminals, and it will short-circuit with one hell of a flash. Batteries, like fuel tanks, are bombs simply waiting for the proper fuse to come along and detonate them (or, technically, deflagrate them).

The space available is not the issue at this point. Any redesign of the electrical system would require lots of time, with additional time for recertification. And it would lots heavier, cutting into payload. There were lots of problems when Ni-Cad batteries began to be used in aviation as well; now it’s the safe and proven technology.

The APU is NOT a lithium-ion battery. The APU is the auxiliary power unit.

The batteries are not operating in flight, unless there is an electrical failure.

There is lithium-ion battery and lithium-ion battery. Depending on the chemical interface used, they have different flamability. The one used by Boeing was very aggressive. It doesn’t mean that all lithium-ion batteries are bad.

There is not such a thing as a 100% fullproof system. Fuel can explode, composites can and will delaminate, navigation equipment will fail.

All I see here is some free Boeing bashing. Trust me, I’m not a big fan of them, but there are so many technical mistakes in your article that putting a finger at their engineers is quite hilarious.

If only it were that simple then they’d have solved the problem months ago.

You can’t get NiCd or lead acid batteries of the required power into the space that they’ve designed for the batteries. They’d need to redesign the actual plane to make enough space to get such batteries in there. That’s why they’re all fiddling around with lithium still.

“Edward Tufte’s analysis of how the Challenger ”

??

Feynman and O Rings wasn’t it?

They already did.

;)

In flight, the batteries power critical systems only in the event that neither engine, or the APU is capable of generating electrical power – an extremely unlikely event. Batteries can fail in flight. What they can’t do is catch on fire, firstly because any inflight fire is dangerous, and secondly because Li-ion battery fires burn very hot and are extremely hard to extinguish.

The problem with Boeing is not, as Felix implies, that engineers are making decisions. It appears that Boeing had an extremely strong engineering culture, extending all the way to the top, prior to its merger with McDonnell Douglas – a merger that’s been described as MD buying Boeing with Boeing’s money. The old Boeing would never had outsourced so much of the airplane as the new Boeing did with the 787.

In flight, the batteries power critical systems only in the event that neither engine, or the APU, is capable of generating electrical power – an extremely unlikely event. Batteries can fail in flight with no impact on the airplane so long as the generators are working. What they can’t do is catch on fire, firstly because any inflight fire is dangerous, and secondly because Li-ion battery fires burn very hot and are extremely hard to extinguish.

The problem with Boeing is not, as Felix implies, that engineers are making decisions. It appears that Boeing had an extremely strong engineering culture, extending all the way to the top, prior to its merger with McDonnell Douglas – a merger that’s been described as MD buying Boeing with Boeing’s money. The old Boeing would never had outsourced so much of the airplane as the new Boeing did with the 787.

But hey, maybe they can outsource it.

1) Its not about ‘engineers’ hubris’. Too many of them (with experience) have been heaved overboard, by Boeing ‘management’, in its misguided strategy to become a civil aerospace maquiladora. Of greater concern is their completely clueless response to this near catastrophe, replete with shameless lies. Take this Boeing exec, for example: http://blogs.crikey.com.au/planetalking/ 2013/03/06/boeings-mr-conner-has-some-fi guring-out-to-explain/
2) And, Ken G. : Being expert on all the technologies deployed in civil airliners is PRECISELY the FAA’s job.