Posted on 02/13/2013 9:20:08 PM PST by rawhide
Two test flights of Boeing Co's (BA.N) 787 Dreamliner have not revealed the cause of the battery malfunctions that grounded the jets, leaving it to focus on low-tech interim fixes, the Wall Street Journal said, citing government and industry officials.
More test flights are planned, including efforts to assess potential fixes, although no significant new clues emerged to help pinpoint the cause of the problem, the Journal said.
Boeing is now considering putting the lithium ion batteries in a sturdier container to stop heat, flames and toxic chemicals from escaping if the power packs overheat, the newspaper said.
People familiar with the design of the container told the Journal that titanium is a possible material for its construction.
(Excerpt) Read more at reuters.com ...
This has to be one the most asinine thing I have ever heard! The FAA cannot allow this happen!
Me too.
The FAA cannot allow this happen!
Wanna bet?
An “interim fix”? Like giving all passengers a bus ticket?
Why not use aircraft rated lead acid batteries?
They seem to work on fighter aircraft...
Singular faults that cannot be recreated are the bane of some industries; aviation and space vehicles are among them, but even down to the Earth Toyota got plenty of flak for the stuck accelerator pedal in some cars.
Given what we know, there is only one obvious solution, short of canceling the 787 project and refunding the purchase price. That solution would be:
They don’t meet the RoHS requirements?
Plastic piece of CRAP.
This is going to be the end of Boeing.
If I was Boeing, I might consider scrapping the lithium in favor of more proven cadmium, weight and space penalty and all.
(Note: I am not a chemical engineer, so I reserve the privilege to be in complete ignorance on this topic.)
.
Boeing is running these 2-3 hours tests.
What they need to do is fly the 787 on a overseas flight, with all the electronics going full blast, tv’s and cooking appliances and the such, as in the real world. And weigh the plane down as if you have a full load of people, then fly halfway out into the Pacific and then return home. That will tell you more than these short-hop tests they are running.
Which they couldn't re-create because it had never happened in the first place. The "stuck accelerator pedal" turned out to be a hoax.
Boeing lawyers Management to have fireproof business suits at the ready
“Plastic piece of CRAP.”
Far exceeds the life and strength of aluminum!!!
Its a spark that "jumps" (cough 800 cough).
Don't worry...this will be just fine.
In a 2010 article, Gizmag quoted Professor Clare Grey as saying, "Fire safety is a major problem that must be solved before we can get to the next generation of lithium-ion batteries and before we can safely use these batteries in a wider range of transportation applications."
I guess we are lucky that nobody was reckless enough to stuff a car with half a ton of those Li-Ion firebombs. Otherwise it might be bad news for owners of those cars.
If I was Boeing, I might consider scrapping the lithium in favor of more proven cadmium, weight and space penalty and all.
Boeing may simply not have that extra space. Otherwise sure, there are tens of proven chemistries that are inherently safe (from fire, at least.) But they are not as capable. If Boeing depends on a certain discharge current from these batteries, retrofit might take a while (months) and you'd have to recertify, which will take even longer. Electrical failure in an airplane can be an unpleasant surprise in the air, especially if all your controls are electrically actuated.
I just looked up aircraft lead acid battery. Apparently the NiCad batteries might be banned because they are to hazardous to the health of recyclers. The article I found talked about the pitfalls of the Lithium batteries and seemed to suggest (air craft) lead acid batteries are the way to go.
Nah uh!
I is the inspector!
The engineers right out of high school don’t know shisa!
My next plane will be a Lancair P4, all glass!!
I understand, from very knowledable family sources, is that the Dreamliner is an electrical hog, as all normally hydraulic systems have been replaced by electric motors.
I also understand that the Japanese airlines are very, very power consious, and may be depleting the batteries excessively, which may then cause generator recharging of the batteries exceeding rates that they can accept charge, leading to heat.
In a short time, Boeing will get to the bottom of this problem! Crisis over!
Actually, all they have to do is change from cobalt li-ion to manganese or nickle li-ion. They took a huge gamble with the slightly higher performance of cobalt and lost big.
“Examine the recorded fault conditions and try to recreate them. Make the battery fail on the ground. Once that happens you have solved 90% of the problem.”
The answer is known:
These batteries fail in a catastrophic manner due to internal or external shorts. External shorts can be protected against by proper fusing. Internal shorts are not so easy...
Think of it this way. These batteries, although not the power density of a hydrocarbon fuel, still hold an immense amount of energy. And they are capable of extremely high discharge rates, much higher than a lead acid or nickel cadmium battery.
For example, I have one of these on my electric bike. It is rated at 20 amp hours at 36 volts. My battery is capable of delivering 120 amps into a load in 10 minutes. In the case of my battery, it would explode if you tried that. Like I said, fuses can mitigate that risk...
However, internal shorts are another matter. These batteries are the functional equivalent of a gas tank on your lawnmower (or your car) where the oxygen is stored in the same tank, separated by a thin plastic membrane possibly a couple of thousandth of an inch thick.
If one cell fails, the resulting thermal damage will rupture the other cells in the battery and all of a sudden you have a bomb. A KWH of energy released in 10 seconds is 360 kilowatt seconds.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.