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Boeing Dreamliner Safety Concerns Are Specious
SoyChemist writes in to note his article at Wired Science on the uproar Dan Rather has stirred up with his claim that Boeing's new 787 Dreamliner aircraft may be unsafe. "Dozens of news agencies have jumped on the bandwagon. Most of them are reporting that the carbon fiber frame may not be as sturdy as aluminum. Few have bothered to question Rather's claims that the composite materials are brittle, more likely to shatter on impact, and prone to emit poisonous chemicals when ignited. While there is a lot of weight behind the argument that composite materials are not as well-studied as aircraft aluminum, the reasoning behind the flurry of recent articles may be faulty. The very title of Rather's story, Plastic Planes, indicates a lack of grounding in science. Perhaps the greatest concern should be how well the plane will hold up to water. Because they are vulnerable to slow and steady degradation by moisture, the new materials may not last as long as aluminum. Testing them for wear and tear will be more difficult too."
Carbon fiber more brittle than Aluminum? So's diamond...What's your point? Carbon fiber is also a lot more flexible than aluminum and it's lighter. There are pros and cons of every material. It produces chemicals when it burns? Like inhaling toxic smoke is going to be your big worry if the PLANE is ON FIRE.
This kind of crap is infuriating for airline companies...It doesn't take much at all to kill a whole line of planes, just the vague reputation for being unsafe. A report like this, based on a flawed understanding of Carbon vs Aluminum where the "reporter" doesn't even grasp the real issue, could do real harm.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
If you go "this is unsafe!" and you were right, and you can go I told you so, and score a political victory.
If you go "this is unsafe!" and you were wrong, you can go well my conserns were addressed and score a political victory.
If you go "this is safe!" and it is safe. Nothing really happends no creditability loss or gained.
If you go "this is safe!" and it was found unsafe. You get fired, invistagations, rumors you were in colution with with contrators....
So if you were trying to run or stay in office what will you demmand.
Government is a failure driven buisness it is what you do wrong that hurts you and if enough people above you were fired then you finally get promoted. So Screamming and yelling and making false accuasations and make the world seem like an unbarable place to live is the best thing you can do for your job.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
And it was built in the early 1980's. You would think that in a plane whose computers limit turns to 9g's -- not because of the airframe, but because of the stresses on the pilot -- they would have concerns over strength. But that is not so.
One concern the USAF had with the F-16 was that in the event of a crash, a cloud of electrically conductive carbon fibers would settle over the base, shorting out anything electrical. Judging by the F-16 we had burn on the taxiway at Hahn AB in 1985, that wasn't the case.
Chip H.
The documents were not only forged, they were incompetently forged. Rather blew it, and whether he did so because he hated GWB, or just wanted to be Woodward and Bernstein so bad he could taste it, doesn't change his guilt.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
True, it's not about if Dan Rather made it up or not, it's about if he did proper investigative journalism to determine if the allegations have merit out side of a disgruntled employee trying to stir up some FUD.
Or maybe Dan's just gone of the deep end. Of course, should a jumbo jet fall from the sky and crash, I don't think it's going to matter it it's made of, it's going to be destroyed. Now, in situations such as crashes on the runway, that might has some merit.
Courage.
Cheers,
Fozzy
It only works that way in different load directions. You can take a sheet of CF in a typical layer configuration (say a 45/90/135) and bend it 45 degrees or more and it won't break or even look like it was bent when you return it to its former shape. But if you pull on it it doesn't stretch like aluminum. What people misunderstand is that because it doesn't stretch, they think it is more prone to failure which just isn't true. It is absorbing the same (or more) energy but it doesn't exhibit the same behavior while doing so. Aluminum will fail and snap also, but people are more comfortable with it stretching first because that's what they are used to seeing. It doesn't make it better, just different.
The types of CF composite that degrade faster are the ones where the resin doesn't have a UV inhibitor in it. UV degrades the resin just like it does to any plastic but with proper protection that isn't a problem. Once this was understood companies developed UV inhibitors for the resins to make them resistant to UV degradation. And you can bet the farm on a $150+ million dollar plane being adequately protected. There is no reason to think that they won't last just as long as an aluminum plane. Never mind that the resin only carries a tiny fraction of the load, in the directions the fibers aren't laid up for. Meaning the resin is mainly there to keep the material from delaminating.
Though some may not know it, but as aluminum oxidizes over time it becomes aluminum oxide which is more brittle and prone to fracture. So you face the same problem with aluminum, but it is adequately protected and hasn't been a problem for the many many years that commercial aircraft have been flying. Just like fiberglass boats, adequately protected and maintained they last a long time.
But what do I know, I'm just an aerospace engineer with some composite materials training. I should leave the science to Dan Rather.
BS - the FAA does not examine the plane and "decide" if it is airworthy.
The FAA has set some tests that must be completed by all aircraft manufacturers - and the tests have extremely simple, impossible to fake criteria. For example, the fully loaded plane must go at full throttle on the runway up to the no return line, and slam on the brakes. The plane must stop before the end of the runway, sit for 5 minutes (worst case overheating of the brakes), and then taxi to the terminal. The tires are expected to blow, and the brakes may catch on fire, but other than that no damage is allowed.
There are many tests like this. They have to pass them all. If you build a plane from glass and it passes these tests, it is just as safe as a solid steel one - it would just be a lot harder to design.
Materials do not give a plane safety. Engineering is what gives a plane safety.
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Yeah, because if he is racist/personality challenged, he can't be any good in engineering either.
This isn't Shockley we're talking about, it's someone who was fired for cause, who didn't raise these issues before he was fired. If his former colleagues refuse to get on that plane, then I might give some credence to his claims, but until and unless that happens, I think he's full of shit.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."