ESDU 81047 introduces a Fortran program (ESDUpac A8147) for calculating the buckling loads of flat rectangular orthotropic plates under combinations of uniform in-plane biaxial direct and shear loads. The program deals with symmetrical combinations of clamped and simply-supported edge conditions and takes account of out-of-plane shear deformations. The program deals strictly with specially-orthotropic plates. Most laminated fibre reinforced composites are arranged such that the plate conforms or approximates to the conditions of special orthotropy. The program is provided on disc in the software volume both uncompiled and compiled to run in ESDUview@ a user-friendly shell that prompts on screen for input data and runs under MS DOS.