Add to ORKGHere, it is shown that the construction of an airplane model can and should be simplified in order to obtain the most reliable test data. General requirements for model construction are given, keeping in mind that the general purpose of wind tunnel tests on a model airplane is to obtain the aerodynamic characteristics, the static balance, and the efficiency of controls for the particular combination of wings, tail surfaces, fuselage, and landing gear employed in the design. These parts must be exact scale reproductions. Any appreciable variation from scale reproduction must be in the remaining parts of the model, i.e., struts, wires, fittings, control horns, radiators, engines, and the various attachments found exposed to the wind in specia...