A low-cost, RPRV (Remotely-Piloted Research Vehicle) flight experiment system for the study of the aerodynamic characteristics of airplanes has been developed. The cost has been kept to a minimum by utilizing devices and techniques of radio-controlled models. Severe limitations on size and weight have to be met by all airborne components. On the ground, computerized data processing and test-sequence handling have been necessary. It has been necessary to select appropriate sensors, especially for the airdata sensors working in very low dynamic pressures, and to make careful calibrations both in the laboratory and on the field. Attentions have been paid to keep errors of the measured data within 1% of maximum variation to enable meaningful comparison with other measurements and calculations.