Maximum filter flow predictor

A rotorcraft, comprising:

• a body;
• a power train coupled to the body and comprising one or more power sources, a drive shaft coupled to the one or more power sources, and an air filter with an inlet and an exhaust associated with the one or more power sources;
• a rotor system coupled to the power train comprising a plurality of rotor blades;
• and
• a filter condition measurement device at least partially disposed within the body, the filter condition measurement device comprising:
• an engine data repository configured to store an engine data set comprising a plurality of stored flow values and a plurality of stored engine power values corresponding to the plurality of stored flow values;
• one or more sensor units associated with the power train and configured to receive, during operation of the rotorcraft, a sensed delta-pressure value and a sensed engine power value corresponding to the sensed delta-pressure value, the sensed delta-pressure value representing a difference in pressure between the inlet and the exhaust of the air filter;
• a measurement unit configured to:
• identify a first flow value corresponding to the sensed engine power value from the engine from the engine data repository;
• determine a filter coefficient for the filter as a function of the first flow value and the sensed delta-pressure value;
• identify a second engine power value from the plurality of stored engine power values and a second flow value corresponding to the second engine power value;
• and
• determine a second delta-pressure value for the air filter as a function of the filter coefficient and the second flow value;
• and
• a filter condition indicator configured to provide an indication representative of the second delta-pressure value.