aircraft were stood down from this dual role due to cost and this capability was removed. After the reduction of conventional forces in Europe, the Luftwaffe began phasing out the RF-4Es in 1993–94. The surplus aircraft were supplied to Allied NATO nations, with 32 sent to Turkey and 20 to Greece. AG 51 received Panavia Tornados as a replacement, while AG 52 was disbanded. F-4F upgrades and disposal A total of 12 F-4Fs were initially modified for dual controls and were later de-modified. In 1980–83, the F-4F fleet was fitted with air-refueling probes, utilizing USAF tankers to make longer flights to Canada and Spain. The AIM-9B and F were replaced with the "L" version Sidewinder. The "ICE" (Improved Combat Efficiency) program commenced in 1983 to upgrade the F-4F's air-to-air capabilities. This involved the APG-65 radar and AIM-120 AMRAAM as the main elements, along with many minor upgrades. The original plan was to upgrade 75 F-4Fs, but the number was increased to 110 in the late 1980s. Initially, the ICE upgrades were intended only for the interceptor wings, but more were upgraded due to delays in the Eurofighter Typhoon program. Phase 1 of ICE commenced in 1989–90 and included upgrades such as the ALR-68 Radar warning receiver, the Honeywell H-423 laser gyro inertial navigation system, the GEC Avionics CPU-143/A digital central air data computer, and the Mil Std 1553R digital data bus. In July 1989, the first F-4F ICE Phase 2 aircraft was completed, and on 22 November 1991 the first firing of an AIM-120 AMRAAM took place. In 1992, the first batch of six upgraded aircraft was delivered to JG 71 (Fighter Wing 71), but the AIM-120 AMRAAM missiles were not available at that time. The F-4Fs were employed to fill operational gaps twice; the first time due to Panavia Tornado delays, while the F-4F ICE was needed due to the Eurofighter Typhoon delays. The units equipped with F-4F ICE were JG 71, JG 72, JG 74 and JG 73. This latter was a mixed unit, sent to Preschen airbase and had one staffel of F-4s and one with MiG-29s. This was a unique situation, until the phasing out of the Fulcrums. The F-4F ICE program offered a reasonably inexpensive and capable aircraft for the interceptor role, albeit with limitations. Apart from natural deficiencies of the air frame design itself, the greatest drawbacks of the F-4F ICE were the lack