NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS LANGLEY FIELD VA LANGLEY AERONAUTICAL LABORATORY
Tests of 0.14-scale models of the partial-span wing and the isolated tail of the Bell XP-83 airplane Army Project MX-511 have been made in the Langley 4-by 6-foot tunnel to determine the aerodynamic characteristics in attitudes simulating spin conditions. The tests were made at a Mach number of about 0.095. The slope of the curve of aileron hinge moment against angle of attack increases negatively as the angle of attack of the wing is increased. At the higher angles of attack the slope of the curve of aileron hinge moment against aileron deflection is more negative for small aileron deflections even though the aileron hinge-moment increment from 25 to -25 deg aileron deflections is practically constant over the angle-of-attack range. The data presented indicate that in spin attitudes the yawing moment produced by the aileron is practically as much as the rolling moment. The elevator hinge-moment increment from 25 to -25 deg elevator deflections is practically constant over the angle-of-attack range and the slope of the curve of elevator hinge moment against angle of attack increases negatively as the angle of attack of the horizontal tail is increased. The elevator hinge-moment and lift-curve slopes of the isolated-tail model show close agreement with those of the complete model. As the angle of attack is increased the drag produced by elevator deflection increases while the lift produced by elevator deflection decreases. The elevator deflection has large effects on rudder hinge moments at alpha sub t 20.5 deg and angle of yaw and rudder deflection of like signs. No consistent effect of elevator deflection on rudder hinge moment is shown at alpha sub t 50.4 deg, except that negative elevator deflections usually gave the largest rudder hinge moments for the yawed conditions.