Abstract: A combustion chamber including an outer casing having a flame tube within it defining an annular space between them which receives air from the engine compressor. The flame tube has diametrically opposed pairs of air inlet ports through which air from the annular space flows substantially radially into the flame tube. A flow guide on the exterior of the flame tube is associated with each air inlet port. The upstream end of each flow guide is open to air from the compressor and the downstream end extends inwardly and downstream and partitions the upstream portion of its respective air inlet port from the annular space. A fuel tube extends into each flow guide. A curved baffle may extend radially inwardly at each air inlet port and define an arcuate louver between the baffle and the downstream edge of its respective air inlet port. Each air inlet port may have a square upstream portion merging into a circular downstream portion.