Re: 707 and KC-135 relationship and something about the 747 (was: Subsidies)

From:         shafer@ferhino.dfrc.nasa.gov (Mary Shafer)
Organization: NASA Dryden Flight Research Center, Edwards CA
Date:         02 Jun 96 23:01:53 
References:   1 2 3
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On 27 Apr 96 01:14:33 , dorfman@netcom.com (Merlin Dorfman) said:

M>      The MD-80 was originally the DC-9-80, later Super 80.  As I
M> recall three DC-9-80s prototypes were built, and two of them
M> crashed.  The FAA certified the type without hesitation.  Go
M> figure.

Part of it may have been embarassment--it was an FAA pilot who broke
the empennage off the one -80 here at Edwards by slamming it down on
the runway at about twice the maximum design sink rate.  I happened to
see this approach and was greatly concerned.  Entirely pilot error,
augmented by an "I'm the FAA pilot so screw you" attitude.
Complaining about this is like complaining that flying an airplane
into a granite cliff demonstrates some failure in the design of the
plane.  Even a carrier-qualified airplane would have been damaged, so
great was the sink rate.  (I remember this one very well; we were
trying to get an F-14 ARI flight off, but the runway was closed for
the entire day, really upsetting our schedule.)

The other one didn't crash.  It went off the runway (doing some of the
runway work like refused takeoffs) into the dirt down at Yuma.  They
decided to slide airbags under it (a standard technique) and then put
a sling around it and pick it up with a big crane.  Unfortunately the
footing for the big crane was not strong enough and the crane fell on
top of the -80 and broke its back.  Again, this is more like running a
fuel truck into a wing; it's not really a design problem.

They rebuilt the first plane but totalled the second one.  I suspect
that the insurance from the crane company may have affected this
decision.

I should mention, although this has nothing to do with airliners, that
we had a accident similar to the Yuma accident here at Edwards.  The
crane company was moving a new missile (with a wound-composite casing
instead of a metal casing) from the shipping spur to the test stand up
at the Phillips Lab.  However, instead of using oak baulks of some
amazingly large size to make the "boardwalk" that the crane would
traverse, they used something else smaller and weaker.  The crane
tipped over, dropped and broke the missile (a Titan, maybe?), and it
ignited, exploding and doing incredible damage, including killing a
worker.  This was not really a test of the new casing at all.  The
contractor ended up in really serious trouble with CalOSHA and a new
rocket was produced.  However, after they got this rocket safely into
the test stand and fired it, the case kind of unzipped and created one
of the most beautiful explosions I've ever seen, throwing chunks of
solid propellant out in a lovely starburst pattern.  Now that was a
real test of the design.  The next one worked perfectly, having some
changes in the construction.




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