NACA-TN-4041

Abstract

An investigation has been conducted horizontal-tail location and size on the to determine the effects of longitudinal aerodynamic characteristics of an airplane model having a triangular wing. The wing had an aspect ratio of 3 and the NACA 0003.5-63 section in the stresmwise direction. Two horizontal tails were tested which had areas of either 16.7 or 21.9 percent of the wing area. Each of the horizontal tails had an aspect ratio of 4, a taper ratio of 0.33, the NACA 0004-64 section, and no sweepback of the 50-percent-chord line. Tests were conducted with the horizontal tails located -0.10, 0, 0.10, and 0.20 wing semispans above the chord plane of the wing at longitudinal distances of 1.2 and 1.5 mean aerodynamic chord lengths behind the moment center. The wind tunnel tests were conducted at a Reynolds number of 2.5 million at Mach numbers from 0.25 to 0.95. <br>It was found that the horizontal tail was destabilizing at moderate lift coefficients when located above the plane of the wing. When placed either in or below the plane of the wing, the horizontal tail was stabilizing throughout the lift range. For the balanced condition, the drag increment due to the tail was less when "the tail was placed 0.10 wing semispan below the wing chord plane than when placed in the wing chord plane. In general, the drag due to balancing the model decreased with increases in tail size or length and increased markedly was the Mach number was increased beyond 0.90.