Abstract: In accordance with one aspect of the present invention, a combustor is disclosed having three separate domes, each dome having disposed therein a plurality of circumferentially spaced mixers for uniformly mixing air and fuel. The combustor utilizes a high percentage of the total available combustion air at the dome area in order to maintain a lean mixture of air and fuel during all levels of engine output. Besides providing an unobstructed area in the diffuser dump region upstream of the mixers for the combustion air, sealing means is included to prevent cooling air from entering the combustion chamber until downstream of the primary combustion zone. Heat shields having radial centerbodies are also included between each dome to isolate each primary combustion zone.