Definition: (DOD) Reaction propulsion in which the propulsion unit
obtains oxygen from the air, as distinguished from rocket propulsion in which
the unit carries its own oxygen-producing material. In connection with aircraft
propulsion, the term refers to a gasoline or other fuel turbine jet unit that
discharges hot gas through a tail pipe and a nozzle which provides a thrust that
propels the aircraft. See also rocket propulsion.

