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From: eachus@aries.mitre.org (Robert I. Eachus)
Newsgroups: sci.military
Subject: Re: why F-4's as Wild Weasels?
Message-ID: <1991Feb6.033735.23238@cbnews.att.com>
Date: 6 Feb 91 03:37:35 GMT
References: <1991Feb4.072034.23521@cbnews.att.com>
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From: eachus@aries.mitre.org (Robert I. Eachus)
In article <1991Feb5.044941.7360@cbnews.att.com> ron@hpfcso.fc.hp.com (Ron Miller) writes:

     One additional reason for using an F-4 as a Wild Weasel platform:
acceleration.  Since the goal of the Wild Weasel is to 1) get an enemy
missile fired AT you, 2) fire a HARM at the radar guiding the missile,
3) stay a live target until the HARM reaches the radar (afterward, as
well, but once the radar is out, it's not such an iffy thing).  So you
amble in toward a protected target and eventually the radar lights up
and you get a missile launch warning...time to light off the HARM,
turn around, and GET THE FUCK OUTTA THERE, jinking on the way.

     The limit on turning radius is the crew tolerance for G forces,
but the limit on thrust change is spoolup time (long) or the amount of
afterburner available (NOW).  As I have mentioned before, the F-4 has
(two) humongous afterburners that can get you from cruise to Mach 2 in
a few seconds. (And use up your fuel in a few minutes, but that's not
the problem here.)

     The F-14 might not be bad in the Wild Weasel role, but the F-4
seems to have been designed for it.  Planes like the F-16 and F-18 get
high-speed performance by using a very low drag airframe...the F-4 has
often been described as a proof that a barn door can be made to fly
given a big enough engine--then they stuffed a second engine in. Since
the engines are working fairly hard at cruise, kicking in the burners
can give you a really big kick in the seat.  As one pilot described it
to me: "the damn thing accelerates more as it goes faster...you've got
another guy sitting on your chest every few seconds until around
{Mach} 1.8 one of them finally gets off." The engines actually are
losing power--as more air gets rammed in the front, the engines have
to spin faster to generate the same amount of power, and the plane is
accelerating about as fast as the engines can spool, but the
afterburners more than make up for it--more, and colder, air is more
thrust as long as you have fuel to mix with it.

     I think I remember it as under 10 seconds from Mach 0.9 to Mach
2.0, and the engines RPMs still increasing as he got there.


--

					Robert I. Eachus

     Our troops will have the best possible support in the entire
world.  And they will not be asked to fight with one hand tied behind
their back.  President George Bush, January 16, 1991