armed service, and was not used on any aircraft other than the F-14. Iranian combat experience On January 7, 1974 as part of Project Persian King, the Imperial Iranian Air Force placed an order for 424 AIM-54As, later increasing it by 290 missiles that June. Of the initial order, 274 missiles and 10 training rounds were delivered for US$150 million, until the 1979 Revolution ended deliveries and left the remaining 150 missiles embargoed and the additional order of 290 cancelled. According to Tom Cooper and Farzad Bishop, during the Iran–Iraq War AIM-54s fired by IRIAF Tomcats achieved 78 victories against Iraqi MiG-21/23/25s, Tu-22s, Su-20/22s, Mirage F 1s, Super Étendards, and even two AM-39 Exocets and a C-601. This includes two occasions where one AIM-54 was responsible for the downing of two Iraqi aircraft, as well as an incident on January 7, 1981 where a Phoenix fired at a four-ship of MiG-23s downed three and damaged the fourth. The US refused to supply spare parts and maintenance after the 1979 Revolution, except for a brief period during the Iran-Contra Affair. According to Cooper, the Islamic Republic of Iran Air Force kept its F-14 fighters and AIM-54 missiles in regular use during the entire Iran–Iraq War, though periodic lack of spares grounded large parts of the fleet at times. During late 1987, the stock of AIM-54 missiles was at its lowest, with fewer than 50 operational missiles available. The missiles needed fresh thermal batteries that could only be purchased from the US. Iran found a clandestine buyer that supplied it with batteries, which cost up to US$10,000 each. Iran received spares and parts for both the F-14s and AIM-54s from various sources during the Iran–Iraq War, and has received more spares after the conflict. Iran started a program to build spares for the planes and missiles, and although there are claims that it no longer relies on outside sources to keep its F-14s and AIM-54s operational, there is evidence that Iran continues to procure parts clandestinely. Both the F-14 Tomcat and AIM-54 Phoenix missile continue in the service of the Islamic Republic of Iran Air Force. Iran claimed to be working on building an equivalent missile and in 2013 unveiled the Fakour-90, an upgraded and reverse-engineered version of the Phoenix. Variants Original model that became operational with the U.S. Navy in about 1974, and it was also exported to Iran before the