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From: (Ed Rasimus)
Newsgroups: rec.aviation.military
Subject: Re: Whatever happened to IFF?
Date: Fri, 08 Jan 1999 16:32:25 GMT (SoBernardo) wrote:

>"Lt. Commander Dana Mullenhour, 34, an F-18 pilot from Michigan, N.D., was in
>the air over southern Iraq on Tuesday. His job was to hit Iraqi air-defense
>bases if they had aimed their radar at the patrolling jets.
>He called it a ``difficult mission'' because there were so many jets in the
>``You've got so many friendly aircraft around, so you've got to make sure you
>are not locking on to a friendly aircraft,'' Mullenhour said. ``Out there, you
>can't look out your windshield and say who's the good guy and who's the bad
>Whatever happened to IFF?

IFF is a transponder that allows an aircraft to "respond" by
"transmitting" a squawk when interrogated. Military aircraft usually
respond in four different modes in combat (civilians only use
one--mode 3).

But, fighter aircraft don't always have interrogators, only
transponders. And, they don't always have all the codes of all the
players. It is typically only the ground radar or AWACs that has the
equipment and capability to display IFF responses.

And, on most IFF displays the picture the operator is viewing is
called "secondary" radar which means the targets are computer
generated (usually with identifying text) NOT actual blips or returns
of the radar energy.

Primary radar which views the echos of your own radiated signal would
be the mode for the combat patrol tactical aircraft. In other words,
the F-18 driver can respond when interrogated but usually can't get
the full picture that IFF in all its modes and codes is offering to
the AWACs.

 Ed Rasimus                   *** Peak Computing Magazine
  Fighter Pilot (ret)         ***   (
                              *** Ziff-Davis Interactive
                              ***   (

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