System and method for detecting a shaft event on an engine

A system for detecting a shaft event of a gas turbine engine, the system comprising:

• a processing unit;
• and
• a non-transitory computer-readable medium having stored thereon program instructions executable by the processing unit for:
• monitoring at least one engine parameter and comparing the at least one engine parameter to a schedule for the at least one parameter defining a first threshold and a second threshold greater than the first threshold;
• applying a limit to the at least one engine parameter when the at least one engine parameter is inside a parameter limiting region between the first threshold and the second threshold, the first threshold separating the parameter limiting region from a normal operating region, the second threshold separating the parameter limiting region from a hazardous operating region;
• and
• detecting the shaft event when the at least one engine parameter crosses the second threshold and issuing a signal in response to the detecting.

A method for reducing a likelihood of a false-positive shutdown of a multi-spool gas turbine engine of an aircraft, the method comprising:

• operating the engine;
• monitoring operation of the engine at a plurality of points in time, and based on the monitoring, at each point in time of the plurality of points in time, determining a value for at least one engine parameter and comparing the value to a first threshold and a second threshold defining a parameter limiting region, the first threshold separating the parameter limiting region from a normal operating region, the second threshold separating the parameter limiting region from a hazardous operating region;
• and
• in response to the at least one parameter being in the parameter limiting region, applying a limit to the at least one engine parameter.