This installation of the Applied Technology Inc (ATI) AN/APR-25 S/C/X-band radar homing and warning system seems to be a stopgap installation giving time for the development of the total Project Shoehorn fit with the AN/APR-30.  It is seen only in aircraft of VF-142 and VF-143 on CVA-64 USS Constellation during its 1967 Vietnam cruise.

These aircraft sported a single fairing on the tail's fin cap similar to the F-4Cs of the period to accommodate the rear facing antennas of the APR-25 RHAW system. The chin fairing IR seeker equipment originally installed in many of the Constellations late production aircraft was removed and replaced by the AN/APR-25's forward facing antenna set.  It is unclear how much of the ATI equipment was used in this installation.  Later AN/APR-25 installations which were part of Shoehorn Mod 2 and 3 used only the RHAW equipment, choosing to retain the Navy developed AN/APR-27 missile warning set instead of using ATI's AN/APR-26 missile warning equipment.

F-4B - AN/APR-25 Rear Cockpit Installation (Typical)

F-4B Rear Cockpit
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1 - AN/APR-25 Azimuth Display

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2 - AN/APR-25 Sensitivity Reduction

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3 - AN/APR-25 Threat Display Panel

F-4B - AN/APR-25 External Antenna Locations (Typical)

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1 - AN/APR-25 Fwd Hemisphere Antennas
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1 - AN/APR-25 Aft Hemisphere Antennas

  • 26 MAR 2014 - Original Post
  • Artwork by Kim Simmelink
  • Michael France and Craig Kaston