Gas turbine auroengine control system which estimates engine inlet conditions

In a control system for a gas turbine aero engine, without using the engine inlet sensors, the engine inlet condition data including the intake air temperature and the intake air pressure is estimated based at least on the detected rotational speed of the turbine, the detected inlet pressure of the turbine and the detected atmospheric pressure, etc. through reasoning. Thus, the system can remove the engine inlet sensors (which are generally expensive) and instead, enables to estimate the engine inlet condition data necessary for controlling the engine with a relatively simple configuration.