Counterflow diffusion flame experiments and modeling results are presented for a fuel mixture consisting of N, C H, and C2H4 flowing against decomposition products from a solid AP pellet. The flame zone simulates the diffusion flame structure that is expected to exist between reaction products from AP crystals and a hydrocarbon binder. Quantitative species and temperature profiles have been measured for one strain rate, given by a separation of 5 mm, between the fuel exit and the AP surface. Species measured include C2H2, CH4, N-2, CN, NH, OH, CH, C-2, NO, NO2, O-2, CO2, H-2, CO, HCl, H2O, and soot volume fraction. Temperature was measured using a combination of a thermocouple at the fuel exit and other selected locations, spontaneous Raman scattering measurements throughout the flame, NO vibrational populations, and OH rotational population distributions. The burning rate of the AP was also measured for this flame's strain rate. The measured eighteen scalars are compared with predictions from a detailed gas-phase kinetics model consisting of 105 species and 660 reactions. Model predictions are found to be in good agreement with experiment and illustrate the type of kinetic features that may be expected to occur in propellants when AP particles burn with the decomposition products of a polymeric binder. (c) 2004 The Combustion Institute. Published by Elsevier Inc. All rights reserved.