Fox is a brevity code used by NATO pilots to signal the simulated or actual release of an air-to-air munition or other combat function,  'Fox' is short for 'foxtrot', the phonetic designation for the letter 'F', which is short for 'fire', the International Radiotelephony Spelling Alphabet, commonly known as the ICAO phonetic alphabet, sometimes called ?
Fox (code word) Fox is a brevity code used by NATO pilots to signal the simulated or actual release of an air-to-air munition or other combat function. Army aviation elements may use a different nomenclature, as the nature of helicopter-fired weapons is almost always air-to-surface. 'Fox' is short for 'foxtrot', the phonetic designation for the letter 'F', which is short for 'fire'. The radio call announcing that a weapon has been fired is intended to help avoid friendly fire, cueing other pilots to ensure that they do not maneuver into the path of harm.
Active radar homing Active radar homing (ARH) is a missile guidance method in which a missile contains a radar transceiver (in contrast to semi-active radar homing, which uses only a receiver) and the electronics necessary for it to find and track its target autonomously. NATO brevity code for an air-to-air active radar homing missile launch is Fox Three.