ESDU 89025 treats the transient condition of the variation of the surface stresses in a thick plate insulated on one side when the aerodynamic heating temperature on the other side is changing@ from an initially constant temperature condition@ linearly with time. Curves are given that allow the stresses to be obtained at both the heated and insulated surfaces at any time for a plate with completely free edges. The curves can be applied when there is a thin insulating layer at the heated surface. A fully worked example illustrates the use of the method.