SYSTEM AND METHOD FOR SELECTIVELY MODULATING THE FLOW OF BLEED AIR USED FOR HIGH PRESSURE TURBINE STAGE COOLING IN A POWER TURBINE ENGINE

A method (401) for selectively modulating bleed air used for cooling a downstream turbine section in a gas turbine engine. The method including: measuring (403) an engine and/or aircraft performance parameter by an engine sensor device; comparing (405) the engine and/or aircraft performance parameter to a performance threshold; determining a bleed trigger condition (409), if the engine and/or aircraft performance parameter crosses the performance threshold; determining a non-cooling condition (411), if the engine and/or aircraft performance parameter is below the performance threshold; actuating a flow control valve to an open position (413), in response to the bleed trigger condition, so that bleed air is extracted from the compressor section and flowed to the downstream turbine section; and terminating (415), in response to the non-cooling condition, the flow of the bleed air to the downstream turbine section of the engine by actuating the flow control valve to a closed position.