The
combat radius of an
aircraft is a distance. It represents the maximum distance that aircraft can fly from its base while armed for combat while retaining enough fuel to perform its mission at the end of the leg and then return home. This is in contrast to an aircraft's maximum
range, which is a straight-line,
one-way number. For aircraft intended to perform patrols once on station, the combat radius is usually expressed along with their intended
loiter time on station.
Bombers (and strike aircraft in general) tend to have a combat radius quite close to half their range, since they have a direct and active task to perform before getting the heck back to the barn. Interceptors, as well, as they are usually only launched in direct response to a particular threat. Air superiority fighters, however, or ground attack aircraft intended for air support operations, or patrol aircraft usually have such 'qualified' radius ratings.
The term arises from the fact that it can be plotted on a map as a circle centered on the aircraft's base, with the length of the radius of that circle the given distance.
See also: range, ferry range.