 In the 1960s and 1970s when the U.S. and Iran were on friendly terms , the U.S. sold 225 F @-@ 4D , F @-@ 4E , and RF @-@ 4E Phantoms to Iran . The Imperial Iranian Air Force saw at least one engagement , resulting in a loss , after an RF @-@ 4C was rammed by a Soviet MiG @-@ 21 during Project Dark Gene , an ELINT operation during the Cold War . 
