Fieseler Fi 166

In the early 1940s, Erich Bachem, Fieseler Aircraft's technical manager, developed two designs for a rocket-launched fighter that could reach high altitudes quicker than conventional fighters.

Design one
Design one involved a straight-winged jet fighter powered by two Jumo 004 jet engines. It would be launched upright by liquid-fuel rockets. After attaining an altitude of 3660 meters, the rocket would burn out, disconnect and return to Earth via parachute for re-use. The fighter would then engage Allied bombers before landing as a conventional airplane.