Patent ID: 8601786

Claim:
A turbofan engine control system for managing a low pressure compressor operating line comprising: a low spool including a low pressure compressor housed in a core nacelle; a high spool rotatable relative to the low spool, the high spool supporting a high pressure compressor downstream from the low pressure compressor; inlet and outlet pressure sensors respectively arranged on inlet and outlet sides of the low pressure compressor; a turbofan coupled to the low spool; a fan nacelle surrounding the turbofan and core nacelle and providing a bypass flow path having a nozzle exit area; and a controller programmed to effectively change the nozzle exit area in response to an undesired stability margin for the low pressure compressor, the inlet and outlet pressure sensors in communication with the controller, which is programmed to determine the undesired stability margin corresponding to a pressure ratio across the low pressure compressor using low pressure compressor inlet and outlet pressures sensed by the inlet and outlet pressure sensors.