NASA-TN-D-7149

Abstract

A force-test investigation has been conducted in the Langley full-scale tunnel to determine the static longitudinal and lateral stability and control characteristics of a full-scale mockup of a light single-engine high-wing airplane. Hinge moments were measured on all control surfaces during the investigation and downwash surveys were made at the horizontal tail. The investigation was made over an angle-of-attack range of -4&#176; to 24&#176; at various angles of sideslip between &#177;8&#176; for various power and flap settings. The power conditions were a thrust coefficient T_&#263; of zero which represents either a low-power or a high-speed condition (where the thrust coefficient approaches zero), T_&#263; = 0.14 which corresponds to a climb condition, and T_&#263; = 0.30 which corresponds to a take-off condition. <br>The investigation showed that the model has both stick-fixed and stick-free longitudinal stability up to the stall for all configurations tested with the center of gravity located at 13.7 percent of the mean geometric chord. Power generally has a small destabilizing effect, but at worst the model could become no more than neutrally stable with the center of gravity as far aft as 40 percent of the mean geometric chord. The model has positive effective dihedral and directional stability for all test conditions. The aileron and rudder effectiveness was maintained up to the stall and was powerful enough to trim out all model moments up to the stall.