From: Mary Shafer <shafer@reseng2.dfrc.nasa.gov>
Newsgroups: alt.disasters.aviation,alt.aviation.safety,rec.aviation.military
Subject: Re: Air Tran Incident
Date: 19 May 1998 09:29:18 -0700

This Air Tran accident isn't the first time weather has managed to
ruin a radome.  About 10-15 years ago, an F-111 radome came completely
apart, damaged by hail or lightning, as I recall.  I saw the pictures
and it was incredible.  These radomes are made of layers of
composites, some wound in a spiral, some running longitudinally.

This radome had come apart, with the various strands of fiber
separated.  It looked like a bundle of yarn.  The tip of the nose was
pointed aft, not forward.  I was astounded that it was flyable; the
drag and change in flying characteristics had to be much greater than
those produced by the loss of the radome in the Air Tran accident.

There was other damage, too, but it wasn't so graphic and I don't
remember what it was.  Maybe something about the canopy?

The crew got medals for bringing that one back.

Regarding hail damage, I've also seen pictures of a USN Harrier that
got caught in hail in the last year or two--the wing and tail leading
edges are gone, the nose is a funny shape, the plane looks too damaged
to fly.  Again, the crew brought it back.

A friend of mine told me of seeing a DC-3 that had just landed after
flying through hail; he said it looked like the whole plane had been
gone over by mad mechanics with ball peen hammers.  The pilot said it
flew just fine, though, and was quite surprised to see the extent of
the damage once he got it on the ground.

I'm a little dismayed by all the comments saying, or implying, that
the Air Tran crew shouldn't have flown through the hail.  These are
the sort of remarks I'd expect from people who know nothing about
flying or weather, but I'm disappointed to read them here, where
people should know better.  Believe me, the crew didn't fly through
that hail on purpose.  By the time they discovered it was hail they
were in it and had no way to get out except to keep flying.  There's
no magic way to tell hail from rain and, often, no way to dodge every
storm cell.  Thunderstorms are extremely dynamic and very fast-moving.
I've spent a lot of time listening to ATC on United flights and the
aircrews and controllers work really hard at vectoring planes around
what looks like the worst cells, but it's not possible to do so
perfectly.  Any article describing weather radar will make it very
clear that this has its limitations.

--
Mary Shafer               NASA Dryden Flight Research Center, Edwards, CA
SR-71 Flying Qualities Lead Engineer     Of course I don't speak for NASA
shafer@reseng.dfrc.nasa.gov                               DoD #362 KotFR
URL http://www.dfrc.nasa.gov/People/Shafer/mary.html
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