An experimental study of the effectiveness of film cooling following secondary air injection through a porous section into a turbulent free stream is presented. Boundary-layer velocity and temperature profiles are described. The adiabatic -wall temperatures are presented in terms of the film-cooling effectiveness. The effects of varying the secondary air temperature, the blowing rate, and the free-stream velocity are studied. It is found that the protection given to a surface downstream of a porous section through which air is injected compares favorably to earlier studies where the secondary air was injected nearly tangential to the surface.