In this article we examine the spread of a flame along a flat, combustible, thermally thick solid against an opposed shear flow resembling a fluid-dynamic boundary layer. The model of [7, 8] is reexamined to produce a correlation formula, with all parameters fixed and determined. The parameters of the correlation substantially corroborate previous results. The flame-spread models considered here assume infinitely fast kinetics; these are called heat transfer models. The implications for the general problem with finite-rate chemistry are discussed.