초록 ▼

A control system and method of controlling a propeller aircraft engine during takeoff limits the amount of engine power developed at the very beginning of the takeoff in order to maximize thrust and minimize rollout distances. The control system limits the amount of power developed by the engine, ev

A control system and method of controlling a propeller aircraft engine during takeoff limits the amount of engine power developed at the very beginning of the takeoff in order to maximize thrust and minimize rollout distances. The control system limits the amount of power developed by the engine, even in the face of a nominal demand by the pilot for maximum engine power. Instead, the control system provides something significantly less than full power at the beginning of takeoff and gradually increases the power developed by the engine to full power as the airspeed increases. This gradual increase from partial engine power toward full power helps prevent stalling of the propeller, thereby maximizing the effectiveness of the propeller and engine in assisting the aircraft to takeoff quickly. The control system is particularly helpful for taking off from high-altitude runways.

대표청구항 ▼

1. A control system for controlling an engine of an aircraft of the type piloted by a pilot and having at least one propeller powered by the engine, the control system being operative to control the engine during take off and comprising: an electronic controller operative for controlling the engine

1. A control system for controlling an engine of an aircraft of the type piloted by a pilot and having at least one propeller powered by the engine, the control system being operative to control the engine during take off and comprising: an electronic controller operative for controlling the engine while the aircraft is in take off mode and, if so, the electronic controller being operative to provide less than full engine power at the initiation of take off and gradually increases engine power as air speed increases during take off so as to provide substantially maximum thrust for take off despite any pilot demands for maximum engine power during take off, thereby minimizing rollout distance for take off, the electronic controller providing substantially maximum thrust for take off and avoiding stalling of the propeller during take off by determining a maximum effective power to apply to the propeller and comparing the power demanded from the pilot of the aircraft with the maximum effective power, the electronic controller applying the power demanded from the pilot when the power demanded is less than the maximum effective power and applying the maximum effective power when the power demanded from the pilot exceeds the maximum effective power. 2. The control system of claim 1 wherein the maximum effective power of the engine is determined by determining the maximum thrust that can be developed by the propeller at the present air speed and ambient air pressure or altitude, and determining the appropriate engine power level for producing that maximum thrust. 3. The control system of claim 1 wherein the maximum effective power is determined based on air speed of the aircraft and ambient conditions. 4. The control system of claim 3 wherein the ambient conditions comprise air pressure. 5. The control system of claim 3 wherein the ambient conditions comprise altitude. 6. The control system of claim 3 wherein the maximum effective power is determined by accessing a lookup table containing performance data for the engine and propeller over a wide range of take off conditions. 7. The control system of claim 6 wherein the lookup table contains performance data for the engine and propeller operating at different power output levels over a variety of altitudes or air pressures, whereby for a given altitude or air pressure, the engine power level that develops maximum thrust for the present air speed can be determined, thereby maximizing thrust while avoiding stalling the propeller. 8. The control system of claim 1 wherein the maximum effective power is determined based on air speed and propeller blade angle. 9. The control system of claim 1 wherein the maximum effective power is determined according to the formula PME=PMAX(X)+(1−X)(AS/TOAS), where PME is the maximum effective power to apply to the propeller, PMAX=maximum available power, X is a fraction between 0 and 1 representing an initial power level to apply at the beginning of take off, AS is air speed, and TOAS is the aircraft's rated take off air speed. 10. The control system of claim 1 wherein the maximum effective power is determined based on elapsed time from the initiation of take off. 11. The control system of claim 1 wherein the maximum effective power is determined according to the formula PME=PMAX(X)+(1−X)(T/TOT), where PME is the maximum effective power to apply to the propeller, PMAX=maximum available power, X is a fraction between 0 and 1 representing an initial power level to apply at the beginning of take off, T is elapsed time from the initiation of take off, and TOT is the aircraft's rated time for take off. 12. A method of controlling an engine in an aircraft for take off, the aircraft being of the type having at least one propeller powered by the engine, the method comprising: monitoring air speed and an ambient condition during take off;determining a maximum effective engine power level that can be applied to the propeller at that moment without stalling the propeller under the circumstances of the air speed and the ambient condition; andcontrolling the engine to deliver no more than the maximum effective power to the propeller, thereby limiting the power applied to the propeller to the maximum effective power that can be applied without stalling the propeller, despite a nominal pilot demand for substantially full power. 13. The method as claimed in claim 12 wherein the ambient condition and the airspeed are compared with a lookup table to determine the appropriate engine power level that produces maximum thrust for the present ambient condition and airspeed. 14. The method as claimed in claim 13 wherein the ambient condition is air pressure or a condition that varies with or is indicative of air pressure. 15. The method of claim 12 wherein the method is operative to provide less than full engine power at the initiation of take off and gradually increases engine power as air speed increases during take off so as to provide substantially maximum thrust for take off, thereby minimizing rollout distance for take off. 16. A method of controlling an engine of an aircraft during take off, the aircraft having at least one propeller powered by the engine, the method comprising: using the airspeed of the aircraft and an ambient condition as inputs to limit engine power so as to maximize propeller thrust, rather than maximizing engine power or engine speed during take off, despite a nominal pilot demand for full engine power during take off, wherein the propeller is provided with less than full engine power at the initiation of take off and engine power is gradually increased as air speed increases during take off so as to provide substantially maximum thrust for take off, thereby minimizing rollout distance for take off. 17. The method of claim 16 wherein the ambient condition is altitude. 18. The method of claim 16 wherein the ambient condition is air pressure or another ambient condition that varies with or is indicative of air pressure.