Effect of Horizontal-tail Position on the Hinge Moments of an Unbalanced Rudder in Attitudes Simulating Spin Conditions

An investigation was made in the Langley 15-foot free-spinning tunnel to determine the effect of horizontal-tail position on rudder hinge-moments at attitudes simulating spinning conditions. Hinge-moment measurements were made on an unbalanced rudder on a rectangular vertical tail for six positions of the horizontail tail. The hinge-moment measurements were supplemented by tuft tests to determine the air flow about the vertical tail.