F-16 co-designer blames stealth ‘skin’ for F-22 problems | tyndall – The News Herald

Pierre Sprey, who helped develop the A-10 and F-16 jets, said he believes the glues that hold the F-22 stealth “skin” in place is emanating chemicals that are making the pilots sick.

According to Sprey, the Air Force has overlooked, or ignored, the potential stealth skin problems because it has not been able to test successfully for adhesive toxins in the pilot’s bloodstream. He said the Air Force doesn’t talk about the stealth adhesives because the chemical makeup of the compounds that make up the stealth skin are considered “classified information.”

via F-16 co-designer blames stealth ‘skin’ for F-22 problems | tyndall – The News Herald.

I’m having a hard time reconciling what this guy is saying with the Air Force report saying that the possible diisocyanate toxins haven’t been found in the pilots’ blood. The diisocyanate adhesives I work with do not outgas that long, though I have to say I don’t use anything classified. If the faulty adhesive is used on the skin, and therefore the outside of the plane, how would a pilot breathe that? There should also be a pattern of more pilot illness with more recent re-application of the adhesive, or a demonstrable sensitivity to diisocyanates.

If all else fails, apply a little heat and make it offgas faster.

6 thoughts on “F-16 co-designer blames stealth ‘skin’ for F-22 problems | tyndall – The News Herald”

  1. It might be plausible, the flowpath being from the skin at the front of the plane -> boundary layer -> engine intake -> bleed air -> OBOGS. If the outgassed toxins had the right chemical or physical properties they could either be concentrated along with the O2 or damage the OBOGS in some way.

    I agree with your skepticism on how long the glue outgasses, but I don’t know enough (read: anything) about the F-22 glue or OBOGS, so I’d file this under “possible, but unlikely.”

  2. Stranger things have happened. NASA employs people with chemical sensitivities to test for things like this since in a space craft you obviously can’t pop open a window. Strange that the Chair Force missed this one.
    I’m guessing that it hits some people harder than others. It happens with glues and paints, some people can develop an allergy.

    1. I don’t know what you mean by employing people with chemical sensitivities. It’s a standard block of tests for offgassing, toxicity, and odor. I could bore you to tears with what’s involved in NASA-STD-6001.

    2. We usually perform the toxicity test first, and if it passes with flying colors, i.e. you could safely use 100 lbs of the material in a habitable volume, then we skip the odor test entirely, since that is dependent on people and not calibrated equipment.

  3. Yeah, I don’t buy it. The hypoxia symptoms aren’t evident at low Gs and altitudes, but if it were outgassing of the adhesives, you’d think you’d see it in every flight profile coming through the O2 system. I’m just a dumb grunt, and can’t claim to be a structural engineer, but I’m pretty sure that symptoms of sniffing glue don’t really only become evident at high G.

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