This paper discusses a computer simulation of the transient, thermochemical events associated with ignition and combustion of an automotive airbag gas-generator unit. Following a brief description of the model development and physical assumptions made in the analysis, calculations are presented for a series of test cases that are characteristic of the standard, passenger-side, 60-L experiments conducted at TRW-VSSI. Pressure and temperature profiles generated by the airbag combustion program are presented and compared with experimental data for a special test case. The calculations show excellent agreement with experimental data obtained in the TRW-VSSI test apparatus. The results presented in this paper also demonstrate the usefulness of the airbag combustion program in assessing the sensitivity of airbag pressure curves to various design parameters. A short discussion is also provided on experimental data which must be collected for model development and verification requirements.