OF LEADINGEDGEAT SUBSONIC AND

The results of a wind-tunnel investigation are presented which show the effect of the variation of taper ratio on the-lift, drag, and pitching-moment characteristics of tplin wings of aspect.ratio 3 with 53.1 ° sweepback of the leading edge. Three wings, tith taper ratios of 0, 0.2, and 0.4, in combination with a high-ftieness-ratio body were studied ti the investigation. Measurements of the forces and momenta on the wing-body combfna-tions were obtained throughout an angle-of-attack range from-4 ' to a maximum of +17O at Mach numbers of 0.6 to 0.9 and 1.2 to 1.9. All models were tested at a Reynolds number of.3.0 tillion per foot at all Mach numbers. (This corresponds to Reynolds numbers varying from 2.9 to 3.6 million when baaed on the mean aerodynamic chords of the models.) In addition, the models were tested at Reynolds numbers of 4.0 million per foot at all subsonic Mach numbers and 6.0 million per foot at Mach numbers of 0.8 and 0.9. Static longitudinal stability at subsonic speeds was reduced near a lift coefficient of 0.5 for the wings with taper ratios of 0.2 and 0.4. Variation of taper ratio did not affect the minimum drag coeffi-cient at subsonic speeds. At supersonic speeds increasing the taper ratio resulted in a slight reduction in the minimum drag coefficient. Drag due to lift was decreased at all Mach numbers by an increase Fn taper ratio from 0 to 0.2. 2 NACA RM A5452