A control system for a gas turbine engine comprising an engine core comprising combustion equipment , a first turbine , a second turbine, a first compressor , a second compressor , a first core shaft connecting the first turbine to the first compressor, and second core shaft connecting the second turbine to the second compressor , the second turbine , second compressor , and second core shaft are arranged to rotate at a higher rotational speed than the first core shaft ; the first compressor comprising at least one variable stator vane configured to move between an open position and a closed position for controlling the angle at which gas enters the engine core ; and a bypass passage provided within the engine core for directing gas flow from the second compressor to the second turbine to bypass the combustion equipment , comprising at least one valve for controlling the amount of air that enters the bypass passage ; wherein the control system is configured to adjust the at least one variable stator vane according to a nominal schedule so as to control the angle at which gas enters the engine core , the nominal schedule being dependent on the semi-dimensional rotational speed of the first compressor , wherein the adjustment of the at least one variable stator vane is configured to be biased to a more open position from the nominal schedule in response to a first input which indicates that the engine core temperature T41 is above or at a first predetermined threshold; and wherein the control system is configured to adjust the at least one valve according to a nominal schedule so as to control the amount of air that enters the bypass passage , the nominal schedule being dependent on a power setting parameter and/or the altitude of the gas turbine engine , wherein the control system is configured to bias biased the at least one valve from the nominal schedule in response to a second input; wherein the second input indicates that the compressor delivery temperature T30 is above or at a second predetermined threshold. the first compressor comprising at least one variable stator vane configured to move between an open position and a closed position for controlling the angle at which gas enters the engine core ; and a bypass passage provided within the engine core for directing gas flow from the second compressor to the second turbine to bypass the combustion equipment , comprising at least one valve for controlling the amount of air that enters the bypass passage ; wherein the control system is configured to adjust the at least one variable stator vane according to a nominal schedule so as to control the angle at which gas enters the engine core , the nominal schedule being dependent on the semi-dimensional rotational speed of the first compressor , wherein the adjustment of the at least one variable stator vane is configured to be biased to a more open position from the nominal schedule in response to a first input which indicates that the engine core temperature T41 is above or at a first predetermined threshold; and wherein the control system is configured to adjust the at least one valve according to a nominal schedule so as to control the amount of air that enters the bypass passage , the nominal schedule being dependent on a power setting parameter and/or the altitude of the gas turbine engine , wherein the control system is configured to bias biased the at least one valve from the nominal schedule in response to a second input; wherein the second input indicates that the compressor delivery temperature T30 is above or at a second predetermined threshold. <EOS>