Abstract: A system and method for controlling compressor inlet guide vanes of a gas turbine engine in an aircraft includes supplying, to a compressor inlet guide vane control algorithm, an inlet temperature value that is at least representative of sensed engine inlet total temperature. One or more gas turbine engine parameters are sensed with one or more sensors during operation of the gas turbine engine. The one or more gas turbine engine parameters are processed in the engine control unit to determine an inlet temperature modifier value that is an estimate of a difference between the sensed engine inlet total temperature and actual engine inlet total temperature. The inlet temperature modifier value is added to the inlet temperature value to derive a modified engine inlet total temperature. The modified engine inlet total temperature is used in the compressor inlet guide vane control algorithm, which controls the compressor inlet guide vanes.

Abstract: A system and method for controlling compressor inlet guide vanes of a gas turbine engine in an aircraft includes supplying, to a compressor inlet guide vane control algorithm, an inlet temperature value that is at least representative of sensed engine inlet total temperature. One or more gas turbine engine parameters are sensed with one or more sensors during operation of the gas turbine engine. The one or more gas turbine engine parameters are processed in the engine control unit to determine an inlet temperature modifier value that is an estimate of a difference between the sensed engine inlet total temperature and actual engine inlet total temperature. The inlet temperature modifier value is added to the inlet temperature value to derive a modified engine inlet total temperature. The modified engine inlet total temperature is used in the compressor inlet guide vane control algorithm, which controls the compressor inlet guide vanes.

Abstract: A system and method of reducing engine induced aircraft cabin resonance includes sensing the core engine speed of a first turbofan gas turbine engine, and sensing the core engine speed of a second turbofan gas turbine engine. In a control system, the core engine speed of the first turbofan gas turbine engine and the core engine speed of the second turbofan gas turbine engine are processed to determine a core engine speed difference between the first and second turbofan gas turbine engines. The core engine speed difference is processed to supply a variable inlet guide vane (VIGV) offset value. The VIGV offset value is applied to a VIGV reference command associated with one of the first or second turbofan gas turbine engine to thereby cause the VIGVs of one of the first or second turbofan gas turbine engine to move to a more closed position.

Abstract: A system and method for calculating aircraft total air temperature from bypass flow temperature in a turbofan gas turbine engine having a bypass flow duct includes sensing aircraft speed (M), sensing engine fan speed (N1), sensing core engine speed (N2), and sensing bypass air flow temperature (T15) in the bypass flow duct. Total air temperature (TAT) is calculated as a function of the sensed aircraft speed, the sensed engine fan speed, the sensed core engine speed, and the sensed bypass air flow temperature. In some embodiments, fan bleed airflow is determined, and a correction is applied to the sensed bypass airflow temperature, and aircraft total air temperature (TAT) is further based on the corrected bypass airflow temperature.

Abstract: An anti-ice system for an aircraft is provided. The system includes one or more sensors that are configured to generate data indicative of one or more of the size, shape, density and type of air borne particles in the vicinity of the aircraft. The one or more sensors are coupled to a data conditioner that is configured to prepare the data for processing. The data conditioner is coupled to a reasoner that is configured to determine from the data, the severity of an icing threat to an airframe, at least one engine and at least one air data probe. One or more controllers are coupled to the reasoner. The one or more controllers automatically operate an anti-icing mechanism for at least one of the at least one engine, the airframe, and the at least one air data probe depending on the icing threats determined by the reasoner.

Abstract: A system and method of accommodating an uncontrolled high thrust condition in a turbofan gas turbine engine includes processing engine data from the turbofan gas turbine engine to determine when a potential for an uncontrolled high thrust condition exists. When the potential for an uncontrolled high thrust condition exists, the engine data are processed to determine whether corrective action for the uncontrolled high thrust condition should be implemented by varying turbofan gas turbine engine effective geometry to (i) increase turbofan gas turbine engine rotational speed or (ii) decrease turbofan gas turbine engine rotational speed. The determined corrective action is automatically implemented.

Abstract: A system method of reducing engine induced aircraft cabin resonance in an aircraft includes sensing a parameter representative of current aircraft flight conditions, and sensing a parameter representative of current engine operating conditions of at least one of a first turbofan gas turbine engines or a second turbofan gas turbine engine. In a control system, the parameter representative of current aircraft flight conditions and the parameter representative of current engine operating conditions are processed to supply a variable inlet guide vane (VIGV) offset value. The VIGV offset value is applied to a VIGV reference command associated with one of the first or second turbofan gas turbine engine, to thereby cause the VIGVs of one of the first or second turbofan gas turbine engine to move to a more closed position.

Abstract: A system and method for calculating aircraft total air temperature from bypass flow temperature in a turbofan gas turbine engine having a bypass flow duct includes sensing aircraft speed (M), sensing engine fan speed (N1), sensing core engine speed (N2), and sensing bypass air flow temperature (T15) in the bypass flow duct. Total air temperature (TAT) is calculated as a function of the sensed aircraft speed, the sensed engine fan speed, the sensed core engine speed, and the sensed bypass air flow temperature. In some embodiments, fan bleed airflow is determined, and a correction is applied to the sensed bypass airflow temperature, and aircraft total air temperature (TAT) is further based on the corrected bypass airflow temperature.

Abstract: A system and method of accommodating an uncontrolled high thrust condition in a turbofan gas turbine engine includes processing engine data from the turbofan gas turbine engine to determine when a potential for an uncontrolled high thrust condition exists. When the potential for an uncontrolled high thrust condition exists, the engine data are processed to determine whether corrective action for the uncontrolled high thrust condition should be implemented by varying turbofan gas turbine engine effective geometry to (i) increase turbofan gas turbine engine rotational speed or (ii) decrease turbofan gas turbine engine rotational speed. The determined corrective action is automatically implemented.

Abstract: A system method of reducing engine induced aircraft cabin resonance in an aircraft includes sensing a parameter representative of current aircraft flight conditions, and sensing a parameter representative of current engine operating conditions of at least one of a first turbofan gas turbine engines or a second turbofan gas turbine engine. In a control system, the parameter representative of current aircraft flight conditions and the parameter representative of current engine operating conditions are processed to supply a variable inlet guide vane (VIGV) offset value. The VIGV offset value is applied to a VIGV reference command associated with one of the first or second turbofan gas turbine engine, to thereby cause the VIGVs of one of the first or second turbofan gas turbine engine to move to a more closed position.

Abstract: A system and method of reducing engine induced aircraft cabin resonance includes sensing the core engine speed of a first turbofan gas turbine engine, and sensing the core engine speed of a second turbofan gas turbine engine. In a control system, the core engine speed of the first turbofan gas turbine engine and the core engine speed of the second turbofan gas turbine engine are processed to determine a core engine speed difference between the first and second turbofan gas turbine engines. The core engine speed difference is processed to supply a variable inlet guide vane (VIGV) offset value. The VIGV offset value is applied to a VIGV reference command associated with one of the first or second turbofan gas turbine engine to thereby cause the VIGVs of one of the first or second turbofan gas turbine engine to move to a more closed position.

Abstract: A system and method for controlling aircraft anti-ice bleed air flow in an anti-ice system. The system includes a modulating shut-off valve that is moveable between a closed position and a plurality of open positions. Bleed air pressure upstream of the modulating shut-off valve is measured when the modulating shut-off valve is in the closed position. When an anti-ice initiation signal is received in a processor, the processor determines, based on at least the measured bleed air pressure when the anti-ice initiation signal was received, an initial open position of the modulating shut-off valve. The processor also commands the modulating shut-off valve to move to the initial open position, determines when a predetermined event occurs, and commands the modulating shut-off valve to remain in the initial open position until the predetermined event occurs period.

Abstract: A system and method for controlling aircraft anti-ice bleed air flow in an anti-ice system. The system includes a modulating shut-off valve that is moveable between a closed position and a plurality of open positions. Bleed air pressure upstream of the modulating shut-off valve is measured when the modulating shut-off valve is in the closed position. When an anti-ice initiation signal is received in a processor, the processor determines, based on at least the measured bleed air pressure when the anti-ice initiation signal was received, an initial open position of the modulating shut-off valve. The processor also commands the modulating shut-off valve to move to the initial open position, determines when a predetermined event occurs, and commands the modulating shut-off valve to remain in the initial open position until the predetermined event occurs period.

Abstract: An ice protection system and method of implementing ice protection for a vehicle includes a plurality of segmented sub-areas each including a leading edge surface subject to the formation of ice thereon. The system further includes a plurality of air ducts, each in fluid communication with at least one of the segmented sub-areas and a source of heated air. A cyclic diverter valve is configured to provide a cyclic flow of heated air via the plurality of air ducts to each of the plurality of segmented sub-areas to protect the leading edge surface from the formation of ice.

Abstract: An ice protection system and method of implementing ice protection for a vehicle includes a plurality of segmented sub-areas each including a leading edge surface subject to the formation of ice thereon. The system further includes a plurality of air ducts, each in fluid communication with at least one of the segmented sub-areas and a source of heated air. A cyclic diverter valve is configured to provide a cyclic flow of heated air via the plurality of air ducts to each of the plurality of segmented sub-areas to protect the leading edge surface from the formation of ice.

Abstract: A method for selecting a setpoint for a turbofan engine having a fan speed and a core idle speed scheduling includes determining a weighting factor based upon a throttle lever position, the weighting factor being zero in an idle region and ranging from zero to one in a dead band region and applying the weighting factor to an output of a fan speed governor and to an output of a core speed governor to select the setpoint.

Abstract: A method for generating a power setting parameter table. The method includes the steps of generating an index from a plurality of first and second inputs and determining a power setting parameter corresponding to each index and second input. The first inputs may include flight speed and temperature values and the second inputs may include altitude values.

Abstract: A turbofan engine throttle control system and method for eliminating dead bands in the throttle control by decreasing and increasing the fuel flow to the engine during transition from the scheduled core speed to scheduled fan speed of the engine to effect a smooth and continuous transition from the core speed to the fan speed and vice-versa. A signal is generated to open and close a valve system to augment and decrease the fuel flow in response to sensing different throttle lever angles.

Abstract: A method for generating a power setting parameter table. The method includes the steps of generating an index from a plurality of first and second inputs and determining a power setting parameter corresponding to each index and second input. The first inputs may include flight speed and temperature values and the second inputs may include altitude values.

Abstract: A method for selecting a setpoint for a turbofan engine having a fan speed and a core idle speed scheduling includes determining a weighting factor based upon a throttle lever position, the weighting factor being zero in an idle region and ranging from zero to one in a dead band region and applying the weighting factor to an output of a fan speed governor and to an output of a core speed governor to select the setpoint.