Fast,
In WW2, the US used codenames for the Japanese planes. Fighters were given male names (i.e. Zeke for A6M and George for N1K) and bombers/patrol planes and the like were given female names (such as Kate for B5N or Judy for D4Y). The reason for this was mainly that it made plane identification easier and the US had little information on the Japanese planes.
There is a modern equivalent. NATO calls Russian planes by other names. Flanker, Fulcrum, Flogger, etc...