Re: Ping Ed Rasimus

Ken S. Tucker said...

On Jan 4, 1:08 pm, Ed Rasimus <rasimusSPAML...@xxxxxxxxxxx> wrote:
On Fri, 04 Jan 2008 11:56:28 -0800, "C. Jacob Underwood" wrote:

[ snip ]

Thanks, Ed. I was impressed by his documentation with numbers; that took
some digging, all of those figures for hardware successes and failures, and
the other stats with which the book was full. He seemed to me to be
painting a fair picture, if a somewhat dark one with respect to, say, the
failure rate of the air-to-air missiles. But if the failures were that
rife, a dark picture is a truthful picture.

Several factors at work here. Probably the first is the poor training
with regard to the firing envelope of the AIM-7E. Lots of shots taken
with partial lock-ons or outside of parameters.

Second is the limited engagments and the number of flight "cycles" the
missiles were subjected to prior to employment. Jolts of takeoffs,
landings and G-forces cause degradation of circuit boards and wiring
over time. Upload and download of missiles also causes wear and tear
on connections.

IMHO the hardware was ok, the Theory of Operation
of Semi Active Homing is difficult, and is based, as any
shot is, on probability.

I'm sorry - but none of that is true. Ed is right: the hardware
had some serious reliability issues back then (though I feel
that the standard "interlocks out" operational employment
was most significant in the out-of-the-envelope launches).

While constantly yo-yo'd missiles (across years), and even FOD-shakers
took a toll on reliability, the biggest problems for good AIM-7 shots
were in the launching aircraft: the Weapons Control (radar) System.
The test equipment to *accurately* diagnose the full range of problems
which might occur just didn't exist in the field until 1975.

The difference in reliability/accuracy between 1967 and 1977 was
profound; we could see the differences daily, because of the type
and range of faults we encountered and fixed. Those same types of
fault were there in the earlier days; we just couldn't see them.

The (still classified) specific Theory of Operation for these babies
isn't difficult - unless some prognisticator is trying to assign
silly parameters to it which really do not apply - such as "probability".
Pk and similar after-the-fact determinations play no role at all in
how the missile gets to the target; they are instead projected measures
of *observed* accuracy during tests and in actual use.

Dweezil Dwarftosser, WCS - former MSgt USAF of the 1st, 4th, 15th,
36th, 50th, 56th, 86th, and 388th (Korat) TFWs

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