Deliveries occurred between October 1971 and September 1972 under Peace Alfa. At the time of delivery these F-4Cs were already obsolete, but they replaced even older aircraft, F-104Gs and F-86Fs. In Spanish Air Force use, the F-4Cs were designated "C.12" (C stood for "Caza" and 12 stood for "12th fighter type in service since the creation of the Ejército del Aire"). The F-4Cs were assigned to Escuadrones 121 and 122, Ala 12 (Wing). To support them a fleet of three KC-97Ls was acquired in 1972, equipping Escuadrón 123, being replaced by KC-130Hs (which equipped Escuadrón 301) from January 1976. While the KC-97s were fitted with a flying boom refuelling system, the Hercules that replaced them were fitted with the probe and drogue system and so could not refuel the F-4s. Further F-4 deliveries took place in October 1978, with the addition of four F-4Cs and four RF-4Cs. The RF-4Cs were given the Spanish designation CR.12. During their service, seven F-4C were lost to accidents before being replaced by EF-18s in April 1989. The RF-4Cs continued to serve in the reconnaissance role along with another eight ex-USAF RF-4C delivered in 1989 in the 123 Squadron, that operated from Torrejón airbase. This batch of RF-4Cs was updated to the highest USAF standard prior to delivery and had a completely revised avionic suite, including new radios, RWR, VOR and ILS navigation equipment and KS-86 cameras. These aircraft also had J79-GE-15E "smokeless" engines. In 1995 the older F-4s were retired and six more RF-4Cs were obtained. The new RF-4Cs had newer avionics, including Have Quick digital UHF/VHF radios, Itek AN/ARL-46 RWR, and Tracor AN/ALE-40 dispensers. The upgrades included provisions for up to four AIM-9L Sidewinder missiles, for self-defence and to provide a secondary capability as an interceptor. The existing fleet underwent a standardization program which among other changes included replacing the APQ-99 terrain-following radar by a Texas Instruments AN/APQ-172 radar, laser-ring gyro inertial navigation system and an Israeli Aircraft Industries in-flight refueling probe, while the original USAF-style refuelling receptacle was retained. These improvements allowed the Spanish RF-4C fleet to serve into the 21st century, finally being retired in 2002. Turkey One of the most prominent Phantom users is the Turkish Air Force ("Türk Hava Kuvvetleri" or THK), which operates about 233 F-4s. Under the Peace Diamond I program 40 F-4Es were ordered, with deliveries starting in June 1974, although completion of the order was