Force Tests of a 1/5-Scale Model of the McDonnell XP-85 Airplane with Conventional Tail Assembly in the Langley Free-Flight Tunnel

At the request of the Air Materiel Command, Army Air Forces an investigation of the low-speed, power-off stability and control characteristics of the McDonnell XP-85 airplane is being conducted in the Langley free-flight tunnel. The XP-85 airplane is a parasite fighter carried in a bomb bay of the B-36 airplane. As a part of the investigation a few force tests were made of a 1/5 scale model of the XP-85 with a conventional tail assembly installed in place of the original design five-unit tail assembly. The total area of the conventional assembly was approximately 80 percent of the area of the five-unit assembly. The results of this investigation showed that the conventional tail assembly gave about the same longitudinal stability characteristics as the original configuration and improved the directional and lateral stability.