anti-misting additive for jet fuel to avoid explosion in crashes

From:         thornbur@physics.ubc.ca (Jonathan Thornburg)
Organization: The University of British Columbia
Date:         07 Apr 95 03:09:13 
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Fire is probably the #1 hazard in (jet) aircraft crashes.  Puddles
of spilled fuel aren't very flammable, but the mechanical and wind
shearing of a high-speed crash tends to atomize spilled fuel, and a
fine mist of fuel is highly explosive due to its huge surface/volume
ratio.

Some years ago, I read in some aviation magazine (nice ambiguous
reference there :-) ) about an FAA project to develop an anti-atomizing
fuel additive to reduce this fire hazard.  As I recall, the additive
was a long-chain polymer (sort of like spagetti) which greatly increased
the fuel's effective viscosity when rapidly sheared.  The system
incorporated a "degrader" (I don't recall how it worked) to remove
the polymer within the engines just before the fuel was burned.

The additive and the equipment involved were fairly cheap (I recall
~$50K per aircraft, and less than 1% increase in the fuel cost),
light (I think ~50 kg per aircraft), and worked well in tests.  Alas,
when the FAA staged a test crash of a remote-controlled B720, the
crash turned out to be a lot more violent than they planned, and the
aircraft exploded in a fireball despite the additive.  (I remember
a photo of the test crash in the article I read.)

Can anyone give more details on this scheme?  What ever happened to
it?  Is it still being worked on?  Why isn't it in use today?

(((I only get to read news once a month or so, so if you post a
followup to this article, please E-mail me a copy.  Thanks.)))

- Jonathan Thornburg
  University of British Columbia / Physics Dept / <thornbur@physics.ubc.ca>
  "In a study of schoolboys, an educator discovered a correlation between
   size of feet and quality of handwriting.  The boys with the larger feet
   were, on the average, older."  Wallis/Roberts, "The Nature of Statistics"