The YRF-4C prototype (serial number 62-12200) was used as the prototype for the F-4E, the cannon-armed Phantom. When 62-12200 was finished with its testing duties, it was selected for use as a fly-by-wire (FBW) control system testbed. The camera ports of the RF-4C nose were faired over, and a FBW system was fitted. The aircraft became known as the Precision Aircraft Control Technology (PACT) demonstrator. It made its first flight with the new FBW system on April 29, 1972. For the initial flight tests, the FBW system was backed up by conventional mechanical controls, but as confidence was obtained with continued flight testing, this backup was eventually eliminated. The PACT demonstrator made its first fully-FBW flight on January 22, 1973.
Following the successful completion of the FBW tests, 62-12200 was selected for Control Configured Vehicle (CCV) research. For this program, it was fitted with a set of canard tailplanes mounted on the upper air intakes. These tailplanes had 20 degrees of movement. The first flight in the CCV configuration took place on April 29, 1974. In order to move the center of gravity to the rear and to destabilize the aircraft in pitch, lead ballast was added to the rear fuselage. A total of 30 test flights were made.
Following the completion of the CCV program, 62-12200 was retired from service. It was donated to the US Air Force Museum at Wright-Patterson AFB on December 5, 1978. It is now on display there.