A detailed quasiclassical trajectory study of the O-2+N --> NO+O reaction is performed based on ab initio potential-energy surfaces of the (2)A' and (4)A' states. The study is aimed at generating a database of thermally averaged and O-2 state-specific rate constants needed for accurate simulations of NO kinetics in high-temperature flow processes. The rate constants obtained show good agreement with the available experimental data and with other quasiclassical trajectory calculations. It is found that the reactant internal energy of the O-2+N --> NO+O reaction is less effective in enhancing the rate than in the N-2+O --> NO+N reaction. An analysis of the product vibrational energy shows that NO formed by the O-2+N --> NO+O reaction has a non-Boltzmann distribution. It is also found that the most populated NO vibrational level is determined by the reactant vibrational energy, while the terminal slope of the NO vibrational distribution is a strong function of the reactant translational temperature. (C) 1997 American Institute of Physics.