Re: AA flight 587: Bikefanclub.com

Skuke:

It is a fact that AA flight 587 was brought down by a carbon failure. You can read the NTSB report, you can read any account of the investigation, or, if you have a barf bag handy, you can look at this photo:

http://pubs.acs.org/cen/topstory/7948/7948notw4.html

"Questions are also arising about composite materials, which entered flight-critical applications some 15 to 20 years ago and have been used increasingly ever since: Are composites subject to fatigue like metals are? Can delamination, where layers of carbon fiber fabric lose the resin matrix bond, lead to such failures?"

If you saw Bode Miller's crash at the Birds of Prey Downhill at Beaver Creek this year, or Chad Fleischer's famous blow-over crash at Kitzbuehel, a picture is worth 1K words. In both cases, their carbon skis simply crumbled, almost vaporized. Metal tends to fail progessively, i.e. it usually bends, then cracks, then fails. Usually. In the bending and cracking phase, it may still function. Maybe. Carbon seldom gives you that chance.

F1 designers such as Patrick Head of Williams and Adrian Newey of McLaren have both been extensively quoted about the heaven and hell of carbon race car suspensions. They're lighter and stiffer than aluminum or magnesium suspensions. But the hell part is that if the car "kisses" a wall or another car, there is no chance of it limping home on a bent suspension. The suspension, once overstressed, simply folds. Head, in particular, rued carbon suspensions in print when Michael Schumacher purposely barged into Damon Hill's Williams in a fatally damaged Benetton in the final race (Adelaide) of the 1994 World Driving Championship. Head specifically said that if Hill's Williams had an aluminum suspension, Hill might have been able to limp home to the World Championship.

Perhaps I draw false comfort from the above, but after having had carbon fiber windsurfing booms vaporize in my hands out on the water (thrice), and having a carbon snow ski turn into a piece of carpet under me (twice), I'll stick to metal, thanks. I race bikes a fair amount, crash occasionally, and riding on carbon frames that have been crashed or even boxed and air-shipped gives me the willies.

Oh yeah, and one more thing in the interests of full disclosure. I've owned three carbon bikes and never had a problem with two of them. The third one had some electrolysis problems where the carbon tubes were bonded to aluminum lugs, but that never affected its performance, and the Trek factory repaired it under warranty.

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"I haven't failed. I've just managed to find 100,000 ways that don't work"

--Albert Einstein

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