As pointed out the power an Engine produces is limited by it's core strength, rotational forces and ability to withstand high temperature. As the atmospheric temperature increases beyond the flat rated temperature the density decreases and if the fuel flow is kept constant the EGT starts rising beyond the limit EGT so fuel flow is progressively reduced to keep EGT at limit. The reverse is happening at temperatures below the flat rated temperature. As the air density is increasing the EGT is not limiting but more fuel cannot be added as the core strength is limiting. Therefore fuel flow is kept constant to limit thrust below that.
Last edited by vilas; 6th Jul 2020 at 06:32.