The 501-KH engine is a single shaft gas turbine engine utilizing a 14-stage axial flow compressor; six combustion chambers within an annular combustor; a 4-stage turbine, of which the first stage is air cooled; and five main anti-friction pressure lubricated bearings. The compression ratio is approximately 9.3:1 at standard continuous rating conditions. Manifold flanges are provided on the outer combustion case for steam injection. The 501-KH engine is available in two configurations: (1) for operation with liquid fuel, (2) for operation with gaseous fuel. The specific fuel shall be reviewed by Allison prior to acceptance of the order. The fuel use shall be as specified in the purchase order.