Methods and apparatus for operating gas turbine engines

A gas turbine engine (10) including a temperature sensor assembly (110) that continuously monitors an operating temperature within a multi-stage rotor assembly (18) of the turbine engine is described. A plurality of cavities (100) are defined within the multi-stage rotor assembly. The temperature sensor assembly includes a plurality of temperature sensor assemblies that monitor the temperature within each of the rotor assembly cavities. Each temperature sensor assembly includes a plurality of support guide tubes (140,142) attached to the engine and extending from an outer casing (72) of the engine to each cavity. A temperature sensor (121) is inserted through the guide tubes and positioned within each cavity.