Abstract: An augmented mixed flow gas turbine engine is provided with a variable area bypass injector system which varies the area through which the bypass stream is injected into the core stream and which also selectively obtrudes cooling airflow to the augmentor liner. The ability to vary the area through which the bypass stream is injected into the core stream permits the mixed flow gas turbine engine of this invention to operate efficiently over a wide range of bypass ratios and further permits the total pressure of the bypass stream to be maintained at a level which will keep the engine inlet airflow matched to an optimum design level throughout a wide range of engine thrust settings. The ability to selectively obtrude cooling flow to the augmentor liner allows the augmentor cooling flow to be optimized for development of engine thrust during the augmented and non-augmented modes of operation and thereby further improve the operating range and efficiency of the engine of this invention.