I recieved an email on this news story:
Air Force warns not to pick up F-22 debris if found
which includes this:
Any debris discovered by snowmachiners or others should not be handled because the aircraft was built with materials that can present health risks if they are mishandled.
The email questioned if I knew what those materials could be. Of course the warning could be a bluff; the F-22, while a pretty old design, is undoubtedly loaded with classified components made out of advanced materials that various foreign powers might like to get their paws on. But there is a real health concern, given that the F-22 is built out of a whole lot of carbon fiber composites.
One day back in California I worked at a rocket test stand that had, some time earlier, played host to a carbon fiber rocket case that went *foom*. It was a hot, long, sunny day, and I took a moment to sit on a step in the shade.
Long story short: shouldn’t’ve sat there. All the clothes I was wearing wound up being thrown away, from shoes to lab coat to undies. I got to go home early, wearing someone else’s lab coat for modesty, spending not just the rest of the day, but several *weeks* pulling little carbony needles out of my ass. That drive home was… uncomfortable. There was a necessary tradeoff between driving as quickly as possible in order to reduce travel time… and not travelling so fast as to arouse the greed of the innumerable state troopers on the road.
When a metal aircraft crashes, there is an immediate danger from shrapnel, as bits of metal go flying. But once they’ve landed, their dangerousness is largely over. While there is a risk of getting cut from large pieces of torn metal, the risk is easily understandable, and generally restricted to larger pieces. Tiny little bits are generally not much more dangerous than sand or pebbles. But when carbon fiber fails spectacularly, you get *clouds* of little needles. They are evil little bastards… they can easily be too small to see with the naked eye, but you can sure feel ’em when they dig in. If you get them in your eyes or lungs, you are in for a world of hurt.
8 Responses to “Fun Personal Anecdote”
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I wrote my e-mail to you before I read this,ironically. weird,huh?
It was about the F-22.
Carbon fibre inhalation is reason enough to avoid the chunks.
Jim
I also wrote him an email about it yesterday.
If the F-22 burned on impact (I assume it did), then the resin matrix that the carbon fiber was embedded in probably burnt away, leaving a lot of it exposed and ready to cause problems.
It’s interesting that they say if you come across parts of the aircraft you shouldn’t handle them, as they have the whole crash site cordoned off at the moment. Did the aircraft start to come apart before it hit, scattering parts over a wide area? Engine explosion from ingesting a Kee Bird*?
A friend of mine brought up a sparkplug cable made out of carbon fiber once, I took one look at that stuff, one look at all my electronic sound and video equipment, and told him to get that stuff out of here ASAP.
I wonder if the stuff they unspooled from the drones over the Iraqi power stations during the first gulf war is still causing problems?
Glass fiber is also a lot of fun to get into your skin.
*Alaskan native bird who’s haunting call of “kee-kee-keerist but it’s cold.”
became well known to American troops stationed up there in WW II.
I e-mailed Scott about how the Sukhoi T-50 is so similar to the F-22 and
how they are in their own way taking advantage of our discards as far as
design goes and how Italy copied our B-17 and gave it their own designation.
Doing a quick check of the SCCA and IMSA to see if they have handling procedures for carbon fiber debris. Bupkis. Will continue to search the FIA and elsewhere.
Imagine it’s like coming into contact with prickly pear, only moreso. I did that once in Texas; itched maddeningly. I don’t want to think about inhaling carbon fibers.
Hello, Patrick Flannery, you crazy Mick! OM Jr. here.
Having had the joy of handling fiberglass insulation many times, I can see where carbon fiber would be even worse.
How can you tell the difference between coughing up a tiny piece of fiberglass and a bit of frothy blood? Rub it on someone else’s skin, and if they scratch, it’s fiberglass.
Bruce, I still have a paperback book called MiG Pilot (http://www.amazon.com/Mig-Pilot-Final-Escape-Belenko/dp/0380538687), about a pilot who defected to Japan in a MiG 25. In some of the design descriptions I found it interesting how the Russians worked with what they had- when flush rivets were difficult, they didn’t bother with them where the air flow was minimal and laminar flow was less important. We Americans tend to overdo a lot of stuff, like building race car-like engines with maximum performance for a space truck.
I’ll bet there isn’t a lot of danger of flying carbon fibers when a MiG-25 crashes 🙂
Though you could get silver out of it; the engines were surrounded by a layer of silver-plated steel mesh, this in turn covered with glass fiber insulation. Each aircraft used eleven pounds of silver in this way.
We thought the aircraft was mainly built of titanium, and some parts were (wing, tail, and intake leading edges as well as parts of the rear fuselage) but the majority of it was built of low-creep stainless steel.