ESDU AERO S.00.03.09 provides properties of an attached plane shock that forms when a supersonic flow meets a sharp two-dimensional object. Graphs show the Mach number behind the shock and the pressure ratio across the shock both as functions of upstream Mach number and flow deflection angle. Also shown are curves of the shock angle. It is noted that there may be two values of downstream Mach number for a given upstream Mach number but that in practice the higher value and the lower value of pressure ratio are obtained. A further graph plots the total pressure ratio across the shock as a function of the upstream Mach number and shock angle, values of which may be obtained from the earlier graphs.