NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

suMMARY Pressure distributions on a semispan rectangular wing model having an NACA 0015 airfoil section and a moderate aspect ratio were measured at one spanwise station in tests made on a transonic bump in the Ames 16-foot high-speed wind tunnel. The free-stream Mach number range was from 0.4 to 1.o6. The results showed that at a fixed angle of attack a region developed over the airfoil wherein the Mach number at each point remained essentially constant as the free-stream Mach number was increased above the critical. This region covered essentially the whole chord of the airfoil at free-strea