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From: hplabs!ham@hpsmtc1.hp.com (Bob Hamilton)
Newsgroups: sci.military
Subject: Re: F111 ride: an E ticket? Bye bye lunch...
Message-ID: <5792@cbnews.ATT.COM>
Date: 21 Apr 89 03:28:31 GMT
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From: hplabs!ham@hpsmtc1.hp.com (Bob Hamilton)

I was in the Air Force 1965 - 1972, and involved with the FB-111 weapon
system for the last four of those years (simulator maintenance).

The FB-111 could be navigated (in pitch) during low altitude flight by a
terrain-following radar (TFR).  The TFR had three clearance settings: 200
feet, 500 feet, and 1,000 feet, as I recall, and three "ride" settings:
hard, medium, soft.  1,000-soft was the smoothest, 200-hard was the
roughest.

Normally, the autopilot was slaved to the TFR duing low altitude flight,
and the plane "flew itself" (quite well, too).  It was possible to change
this to "manual" mode, in which the TFR issued "commands" which the pilot
followed manually.  At 200'-hard setting, this required considerable skill.

During the time I was involved, 2 or 3 F-111's flew into the ground.  In
each case in which the results of the post-crash investigation were
published, the TFR was found to have been in the MANUAL mode.

My associates and I felt that this was a very foolish way to fly the
F-111 at low altitude.

--Bob Hamilton
  Software Methods Lab
  Hewlett Packard Company
  Cupertino, California
  (408) 447-5113  ham@hpda