from the Yom Kipper War, in October 1973, led to the development
and installation of the AN/ALR-62 Compass Sail antenna. Installation
of the Compass Sail mod caused the removal of the AN/ALR-41 system
and its small antenna, which had previously been located under the
nose. As with most fleet-wide modifications, order of installation
was SAC FB-111s first, followed by USAFE F-111E/Fs and finally stateside
F-111A/Ds. In this instance, SAC installations began in 1980, with
USAFE beginning the following year and so forth. Completion of this
program took about a year at each base, so all aircraft had probably
received ALR-62s by 1983 or so.
On the F-111D, the Compass Sail antenna was located under the nose,
to the right of centerline and next to the KB-18 strike camera (which
was installed only a year or two earlier). On the F-111A, F-111C,
F-111E, and F-111F the antenna was on the centerline, staggered
slightly in front of the KB-18. It was also in this location on
the FB-111A/F-111G (which had no KB-18).
The EF-111A had neither the AN/ALR-62 Compass Sail antenna nor KB-18.
In addition, the retractable anti-collision beacon was moved from
between the speed brake and converted bomb bay to just to the left
of the centerline-mounted UHF antenna, which was located farther
forward on the nose.
The large TACAN antenna just behind the escape capsule on all variants
began to be replaced by a smaller one starting in the spring of
1991. Also, during 1989, some F-111Fs were observed with raked-back
lower front UHF antennas. This change was made to some, but not
F-111D antenna positions as of
1981 are shown in these photos. Note that strip lights were not
GPS antenna installation used on an F-111E AMP is shown in these
photos. This same installation was also used on Pacer Strike F-111Fs
and EF-111A AMP aircraft. Only one F-111E was AMP-modified in
time for the 1991 Gulf War.
F-111E AMP antenna positions
as of 1995 are shown in the above photo. There was no external
difference in antenna positions between the E and F.
F-111F with the raked-back UHF antenna installed on some
aircraft in the late 1980s is shown in the left photo. The right
photo shows F-111F Pacer Strike antenna positions as of 1995.
antenna positions as of 1990 are shown above. Note the additional
pitot-probe on the right side that was not found on other variants.
antenna positions as of 1993 are shown above. Note how the UHF
antenna was shifted forward to the location of the KB-18 on other
left photo shows the normal antenna arrangement on the top of
the fuselage with the small IFF antenna in the front and the larger
UHF/TACAN antenna behind. The aircraft is an F-111F in about 1982.
The right photo shows the secondary antenna arrangement, with
the IFF using a UHF/TACAN-sized antenna. This configuration was
standard on the EF-111 and frequently used by F-111As in Vietnam
and stateside F-111s. It was seen less frequently on European-based
the left is a close up of an anti-collision beacon, this one mounted
in the non-standard EF-111A position slightly ahead and left of
the lower UHF/TACAN antenna. The right photo shows the location
of various antennas and lights on the top of the aircraft (in
this case an F-111F). The light non-standard markings behind the
strip lights are the hinge line of the over-wing fairings.
Anti-collision lights were located on the top and bottom of the
aircraft. On the belly they were mounted between the weapon bay
and main landing gear door except in the EF-111 where it was located
to the left of the UHF antenna under the nose. They were turned
on and off at the same time as the ground roll spoiler switch,
so were normally retracted into the fuselage and not seen on the
While normally used throughout the flight, the anti-collision
beacons were turned off prior to combat, automatically retracting
into the fuselage. Also turned off prior to night combat were
the electro luminescent strip-lights, fitted during
the early 1980s to provide better visual references for night
Chaff and flares were carried in the aircrafts internal
countermeasures dispenser set (CMDS), located in the bullet fairings
for the horizontal tail. The older AN/ALE-28 dispensers were gradually
replaced between 1990 and 1992 with the USAF-standard AN/ALE-40
(but few, if any Desert Storm aircraft had this modification).
AN/ALE-28 (left) countermeasures dispenser was used by the F-111 for
most of its service. At about the time of the 1991 Gulf War, the much
more reliable AN/ALE-40 (right) was adopted. Generally, the AMP/Pacer
Strike aircraft had this modification.
Edited by Assistant
David de Botton - Flash@F-111.net
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