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vololiberista

fix or Cover-up!

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http://www.ibtimes.co.uk/articles/438563/20130223/boeing-dreamliner-787-battery-fix-faa-airbus.htm

 

I vote cover-up! I for one won't be on that a/c when the battery explodes possibly ruptiring the hull etc etc etc.

l-ion batteries are too much of a risk. They don't take kindly to high charge rates. Overheating is a common problem during high charges.

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Flew out of Qatar two days ago, was a sad sight looking at a row of brand new 787 dreamliners gathering dust on the ramp.

 

Regards

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DC10 = cargo door heaven! An example of marketing an a/c that they knew would crash!

As for the 787 they seem to be cutting too many corners and have unresolved issues that should have been sorted "years ago!"

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http://www.ibtimes.c...-faa-airbus.htm

 

I vote cover-up! I for one won't be on that a/c when the battery explodes possibly ruptiring the hull etc etc etc.

l-ion batteries are too much of a risk. They don't take kindly to high charge rates. Overheating is a common problem during high charges.

 

If Li-Ion batteries are such a risk I take it you don't own a cellphone, tablet, lap-top or high-end camera then? Speaking of which, have you checked out the explosive properties of kerosene lately? It's also pretty prone to going boom (see also TWA800). It's a case of designing your system properly to mitigate the risk, which Boeing obviously didn't do properly the first time round. Both Boeing and the FAA know that they will lose all credibility if they let through a fix that is less than perfect though. I'm also pretty sure that the FAA will make public the results of the certification process for this fix, so why call it a cover up?

 

Id rather fly a Dc10 any day than some darn plastic toy

 

Plastic that's up to three times as strong as aluminium for the same weight ;).

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DC10 = cargo door heaven! An example of marketing an a/c that they knew would crash!

 

I was thinking the same thing, safe is not the first word that springs to mind when I think of the DC10

 

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If Li-Ion batteries are such a risk I take it you don't own a cellphone, tablet, lap-top or high-end camera then? Speaking of which, have you checked out the explosive properties of kerosene lately? It's also pretty prone to going boom (see also TWA800). It's a case of designing your system properly to mitigate the risk, which Boeing obviously didn't do properly the first time round. Both Boeing and the FAA know that they will lose all credibility if they let through a fix that is less than perfect though. I'm also pretty sure that the FAA will make public the results of the certification process for this fix, so why call it a cover up?

 

 

 

Plastic that's up to three times as strong as aluminium for the same weight ;).

 

Mobile phone batteries are notorious for getting hot especially if you both charge and use them at the same time. Older mobiles with the fast charge rates had to be turned off to avoid getting too hot. Now with the modern appliances the charge rates are slower so it's not such a problem. As I said L-ion batteries don't take kindly to being put under heavy load and charge simultaneously. The behaviour of l-ion batteries is well documented and many people are questioning Boeing's decision process.

Boeing had years to resolve this problem. Instead they went with "predictions" rather than actual results. Their fix smells a little of "We don't want to spend any more on this problem" or "We don't know what to do". Airbus have "seen the light" and gone back to nicad. This whole problem arose just to save a little weight. Not resolving a problem and instead putting that problem into a box is dangerous in the aviation industry. There have already been too many accidents as a result of that approach. They could be creating a time bomb!

If the 787 were to fail Boeing would be in serious trouble.

 

You're other point regarding strength of composites. Yes it's stronger weight for weight but it has another problem in that when it goes "it goes!!!" Whereas alluminium will deform first. Use of composities in aviation is still in its infancy. No one can yet predict the "life" of a composite fuselage. Having batteries leak all over it certainly doesn't do it any good!

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You're other point regarding strength of composites. Yes it's stronger weight for weight but it has another problem in that when it goes "it goes!!!" Whereas alluminium will deform first. Use of composities in aviation is still in its infancy. No one can yet predict the "life" of a composite fuselage. Having batteries leak all over it certainly doesn't do it any good!

 

Well nothing could be farther from truth. :smile: A spitfire with a composite fuselage was built in 1940, but then the traditional metallic solution was more apt to rapid industrialization during wartime. However composite use saw widespread use in the military aviation since 1960's: F-111, F-4, F-14, F-15 had structural parts (mainly tail surfaces) made of composites. AV-8B main wing is made of composites. Regarding airliners, the use of composites for control surfaces and other parts has began more than 30 years ago (all control surfaces of the 767 are composites).

 

And Burt Rutan has been building all-composites aircraft for nearly 40 years, and I wouldn't be surprised if some of the oldest Rutan's aircrafts are still flying.

 

And then the most significant testimony to the strenght of the composites: most of the unlimited aerobatics aircrafts have a composite wing (_including the wing spar_): Extra 300, MX2, SU-31, Sbach 300, CAP232, Zivko Edge 540.

 

Yes, it's true that the aluminium is more ductile than composites. But the important thing is how the structural part has been designed and its final strenght: is it better an aluminium wing that bends at, say, 4g and breaks at 6g, or a composite wing that doesn't bend at all but breaks at 8g?

 

Finally, composites are much less prone to the issue of fatigue. An aluminium structural part, _whatever small is the load_, will break after a certain number of cycles. Most of structural failures in aviation (and not only) are caused by fatigue.

 

Aluminium is also much more prone to corrosion compared to composites (although the latter have issues with umidity absorption).

 

Marco

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