R-27   An advanced Russian air-to-air guided missile.
R-60   A second-generation Russian heat-seeking missile.
R-73   A third-generation Russian heat-seeking missile.
radar   Radio Detection And Ranging.
radar altimeter   An altimeter which determines the altitude of the aircraft
    above the terrain directly beneath it through the use of radar.
radio  beacon   A radio transmitter which emits distinctive signals used for
    the determination of bearings, courses or location.
radar cross-section   A measure of an aircraft's detectability by radar,
    which is not necessarily proportional to its physical size.  (See also  low
    observable technology.
RAM   Radar Absorbent Material.
RCS   Radar Cross Section.
recon   Reconnaissance.
red shirt   A deckhand who handles ordnance on an aircraft carrier.
redout   A loss of vision (or consciousness) due to pulling too many
    negative g's.
remote magnetic indicator   RMI -- Aircraft instrument that displays
    heading information and magnetic bearing to one or two radio beacon
    stations.