Abstract: A disclosed example non-transitory machine readable storage medium includes instructions to cause programmable circuitry to at least determine, based on output from at least one sensor, (i) a first parameter corresponding to a first position in a casing of a gas turbine engine, the first position at or downstream of a volume at which flows from respective ones of bleed offtakes are combined, and (ii) a second parameter corresponding to a second position in a casing of a gas turbine engine, the second position upstream from the first position, determine a status of at least one of the bleed offtakes or the at least one sensor based on the first and second parameters, and provide or indicate the status in response to the status indicating improper operation of at least one of the bleed offtakes or the at least one sensor.

Abstract: Methods and apparatus to determine engine status with plenum measurements are disclosed. A disclosed example apparatus for use with a gas turbine engine having bleed offtakes includes at least one sensor on or within the gas turbine engine, the at least one sensor to measure at least one parameter corresponding to: a first plenum within a casing of the gas turbine engine, the first plenum positioned at or downstream of a volume at which flows from respective ones of the bleed offtakes are combined, and a second plenum within the casing, the second plenum positioned upstream of the first plenum, and an interface to communicatively couple the at least one sensor to a controller, the controller to determine a status of the bleed offtakes based on the at least one parameter.

Abstract: A system includes a plurality of actuators and a control system operably associated with the plurality of actuators. The control system having a control logic architecture having a dynamic command input shaping model associated with an input command, a robust inner loop associated with the dynamic command input shaping model, and a time delay cancellation model. The method includes selecting a control law based upon a flight performance of an aircraft, decoupling the control law into a first individual component and a second individual component of the aircraft flight motion, analyzing each individual component separately, regrouping the component of flight motion, analyzing the control law with a time delay cancellation model and providing the necessary dynamic flight quickness with a different command input condition.

Abstract: A system includes a plurality of actuators and a control system operably associated with the plurality of actuators. The control system having a control logic architecture having a dynamic command input shaping model associated with an input command, a robust inner loop associated with the dynamic command input shaping model, and a time delay cancellation model. The method includes selecting a control law based upon a flight performance of an aircraft, decoupling the control law into a first individual component and a second individual component of the aircraft flight motion, analyzing each individual component separately, regrouping the component of flight motion, analyzing the control law with a time delay cancellation model and providing the necessary dynamic flight quickness with a different command input condition.

Abstract: One embodiment of the present invention is a main rotor helicopter blade for generating higher lift with less drag and delaying stall at high Mach numbers. A cross-section of this blade includes aft camber. The difference between a chord line of the cross-section and a camber line of the cross-section increases from a leading edge of the cross-section to a maximum between a trailing edge of the cross-section and a midpoint of the chord line and decreases to the trailing edge producing the aft camber of the blade. The aft camber generates higher lift with less drag and delays stall at high Mach numbers.

Abstract: One embodiment of the present invention is a main rotor helicopter blade for generating higher lift with less drag and delaying stall at high Mach numbers. A cross-section of this blade includes aft camber. The difference between a chord line of the cross-section and a camber line of the cross-section increases from a leading edge of the cross-section to a maximum between a trailing edge of the cross-section and a midpoint of the chord line and decreases to the trailing edge producing the aft camber of the blade. The aft camber generates higher lift with less drag and delays stall at high Mach numbers.