Non-equilibrium state-to-state vibration-chemical kinetics and transport properties in a supersonic nozzle flow of five-component air mixture are studied. State-to-state vibrational distributions and macroscopic flow parameters are calculated for various nozzle profiles and reservoir conditions. These distributions arc then used for the evaluation of transport properties and heat transfer in expanding flows. Contribution of different dissipative processes to the total heat flux is estimated. While the role of state-to-state kinetics in the formation of non-Boltzmann vibrational distributions is found to be important, the influence of vibrational excitation on the total energy flux appears to be weak. This peculiarity is discussed, and the contribution of different vibrational levels to the heat transfer is analyzed.