ESDU 11007 describes an alternative procedure for implementing viscous effects using a method to add a frozen boundary layer to the wing surface in the form of a displacement thickness with corrections for sweep. The method is subsonic with compressibility corrections and has been enhanced to give an improved calculation of sectional viscous drag. The addition of this item enables the FP method to be used as a rapid assessment tool to provide initial aerodynamic qualities of wings as part of the design process.