NACA-ARR-3F23

Abstract

<strong>INTRODUCTION</strong> <br>Considerable data are available for the evaluation of the effect of aerodynamic interference between wing, fuselage, and vertical tail on lateral-stability characteristics (references 1, 2, and 3). These data indicate that the vertical-tail effectiveness Is greater with the wing in a low position on the fuselage than with the wing In a high position. Air-flow surveys in the region of the vertical tail showed that the change in tall effectiveness with wing position resulted from a sidle flow the magnitude and direction of which were functions of wing position (reference 4). Because the data of references 1 to 4 were obtained for models without q horizontal tall, the question arises as to whether a horizontal tail will modify these results. The horizontal tail has been known to increase the effectiveness of the vertical tail by acting as an end plate. A theoretical analysis of this end- Plate effect was made in reference 5. <br>The present report continues the .investigation of lateral-stability characteristics by adding a fourth part, the horizontal tail, to the previous model consisting of a wing, fuselage, and vertical tall. The purpose of the present report" is to determine to what extent the horizontal tail Influences the effect of wing-fuselage interference on the vertical tail and to determine equip mentally the end-plate effort of the horizontal tail on the vertical tail.