NACA-RM-H56C20

Abstract

<strong>INTRODUCTION</strong> <br>This paper presents an application of the time-vector method of analysis in the determination of static and dynamic lateral derivatives of a 45 swept-wing fighter-type airplane. Details of the application of the time-vector method of analysis employed are also included in this paper as are some considerations of the limitations of the method. All data were obtained as part of a comprehensive investigation, conducted at the NACA High-Speed Flight Station at Edwards, Calif., of the lateral characteristics of this airplane. <br>The quantity of data obtained from the flight test program provided the first opportunity to perform a fairly detailed investigation of the stability characteristics of an airplane in the transonic and supersonic regions and to provide some comparison with available wind-tunnel data (ref. 1). Previous reports have presented the directional stability as determined by simple relationships (ref. 2) and the results of roll coupling investigations (refs. 3 to 6). <br>The flight rudder-pulse data for the determination of the lateral stability characteristics were obtained for four configurations. Three configurations employed the original wing and three different vertical-tail areas (original, extended, and large) while the fourth configuration employed an extended wing and the large tail. The data were obtained at altitudes between 30,000 and 43,000 feet over a Mach number range extending to 1.448. Most of the tests were performed at a nominal value of 1 g load factor, but for a few tests at nominal Mach numbers of 0.83 and 1.14 load factors within the range of 0.5g to 1.8g were used to investigate the influence of angle of attack on the lateral stability characteristics. <br>The results of the analysis of the data are compared with available wind-tunnel data and calculated derivatives.