Report presenting the dimensional parameters of ram-compression power plants as related to their thrust and economy performance and an investigation of the speed and range performance possibilities of a family of pilotless airplanes powered with one of the power plants. The analysis of the power plants includes the power-plant configuration, aerodynamic and thermodynamic cycle, constants used in the computations, power-plant performance, and operation of the power unit with fixed areas at various flight speeds. The investigation of the aircraft included a description of its characteristics, speed, range, effect of wing selection of speed, and effect of size on performance.