A method of controlling a gas turbine engine capable of operating in at least a high, medium-high, medium, medium-low, and low output power ranges. The method includes during the medium-high output power range varying the angle of the variable guide vanes so that a third predetermined temperature of the combustor is maintained, during the medium output power range the variable guide vanes are closed and bleeding a gas from a downstream part of the compressor to an upstream part of the compressor so that a first predetermined temperature of the combustor is maintained, during the medium-low output power range the variable guide vanes are closed and bleeding a gas from a downstream part of the compressor to an upstream part of the compressor and bleeding a gas from the downstream part of the compressor to the exhaust so that a second predetermined temperature of the combustor is maintained.