Abstract : A theory concerning the drag coefficient for the flat plate at zero angle of attack in slip flow was extended to include the aerodynamic coefficients for drag, lift, and moment at very small angles of attack. The lift coefficient may be taken to equal the skin-friction coefficient. The skin-friction stresses tend to reduce the lift coefficient at high-altitude, high-speed conditions. The moment coefficient will not be significantly greater than 2 alpha/square root of M sub infinity to the 2nd power - 1, the value derived from the ideal linearized 2-dimensional supersonic continuum-flow theory, where is angle of attack and M sub infinity is the free-stream Mach number. Except for the skin-friction coefficient, the corrections to be applied to the aerodynamic formulas of linearized supersonic theory, which account for viscosity and slip, will not generally be significant in the slip-flow region.