Abstract: A high-integrity electromechanical actuator control system includes a system function controller, a plurality of actuator controllers, and at least one electromechanical actuator. Each actuator controller includes a first controller, a second controller, and a duty cycle computation circuit. The first controller receives digital actuator control commands supplied from two of the function control channels and supplies first digital duty cycle commands. The second controller receives digital actuator control commands supplied from two function control channels and supplies second digital duty cycle commands. The duty cycle computation circuit receives the first digital duty cycle commands and the second digital duty cycle commands, computes an average of the first and second duty cycle commands, and generates pulse width modulated (PWM) commutation control signals based on the computed average.

Abstract: A pressure control system includes an overboard valve in indirect communication with a first enclosed environment and in direct communication with a second enclosed environment. The first environment is suitable for human occupancy and configured to receive pressurized air from an environmental control system. The second environment is configured to receive the pressurized air from the first environment. An inboard valve is configured to supply a discharge of pressurized air from the second environment. An outflow valve is configured to regulate a discharge of air from the first environment to an area outside the first and second environments. A positive pressure relief valve configured to regulate a discharge of air from the first environment. A negative pressure relief valve configured to regulate an ingress of air into the first environment. A control valve is configured to regulator and supply pressurized air from the first environment to a compressor.

Abstract: A pressure control system for an environment to be pressurized includes a controller configured to calculate at least one of: a calculated pressure sensor rate of change error; and a calculated pressure sensor error. The calculated sensor rate of change error is based on a plurality of first environment air pressure signals over a first time period; and the calculated sensor error is based, over a second period of time, a difference between ambient air pressure signals and second environment air pressure signals. A processor in communication with the controller is configured to compare at least one of: the calculated pressure sensor rate of change error with at least one pressure sensor rate of change error control limit; and the calculated pressure sensor error with at least one pressure sensor error control limit.

Abstract: Outflow valve (OFV) assemblies including non-metallic frames and enhanced attachment features are provided. In embodiments, the OFV assembly includes a non-metallic frame to which at least one valve door is pivotally mounted. The non-metallic frame may, in turn, include a generally rectangular frame body, a central opening through the frame body, an outer peripheral flange extending around at least a portion of the frame body. Frame attachment interfaces are distributed or spaced around the outer peripheral flange of the non-metallic frame. The frame attachment interfaces include fastener openings and elevated platform regions, which project from an inboard side of the outer peripheral flange and through which the fastener openings extend. Base plates seat against the elevated platform regions. Fasteners engage the base plates and extend through the fastener openings to an outboard side of the outer peripheral flange to attach the OFV assembly to an aircraft fuselage.

Abstract: A system of pressure control for an environment to be pressurized includes a controller configured to calculate an environment leakage effective area CdALEAK according to: CdALEAK=f(Pc, Tc, Pa, WLEAK) wherein Pc is an environment pressure; Tc is an environment temperature; Pa is an ambient pressure outside of the environment; WLEAK=WECS?WOFV?WAPU; wherein WECS=air pressure inflow into the environment; WOFV=air pressure outflow to ambient that is outside of the environment; WAPU=f(Tin, Pin, APURPM, Flowfuel); wherein Tin=inlet temperature to a power source; Pin=inlet pressure to the power source; APURPM=rotational speed of the power source; Flowfuel=power source fuel flow. A processor is in communication with the controller and configured to compare a current CdALEAK value with a control limit; wherein the control limit is based on historical CdALEAK values.

Abstract: Outflow valve (OFV) assemblies including non-metallic frames and enhanced attachment features are provided. In embodiments, the OFV assembly includes a non-metallic frame to which at least one valve door is pivotally mounted. The non-metallic frame may, in turn, include a generally rectangular frame body, a central opening through the frame body, an outer peripheral flange extending around at least a portion of the frame body. Frame attachment interfaces are distributed or spaced around the outer peripheral flange of the non-metallic frame. The frame attachment interfaces include fastener openings and elevated platform regions, which project from an inboard side of the outer peripheral flange and through which the fastener openings extend. Base plates seat against the elevated platform regions. Fasteners engage the base plates and extend through the fastener openings to an outboard side of the outer peripheral flange to attach the OFV assembly to an aircraft fuselage.

Abstract: A system of pressure control for an environment to be pressurized includes a controller configured to calculate an environment leakage effective area CdALEAK according to: CdALEAK=f(Pc, Tc, Pa, WLEAK) wherein Pc is an environment pressure; Tc is an environment temperature; Pa is an ambient pressure outside of the environment; WLEAK=WECS?WOFV?WAPU; wherein WECS=air pressure inflow into the environment; WOFV=air pressure outflow to ambient that is outside of the environment; WAPU=f(Tin, Pin, APURPM, Flowfuel); wherein Tin=inlet temperature to a power source; Pin=inlet pressure to the power source; APURPM=rotational speed of the power source; Flowfuel=power source fuel flow. A processor is in communication with the controller and configured to compare a current CdALEAK value with a control limit; wherein the control limit is based on historical CdALEAK values.

Abstract: A pressure control system includes an overboard valve in indirect communication with a first enclosed environment and in direct communication with a second enclosed environment. The first environment is suitable for human occupancy and configured to receive pressurized air from an environmental control system. The second environment is configured to receive the pressurized air from the first environment. An inboard valve is configured to supply a discharge of pressurized air from the second environment. An outflow valve is configured to regulate a discharge of air from the first environment to an area outside the first and second environments. A positive pressure relief valve configured to regulate a discharge of air from the first environment. A negative pressure relief valve configured to regulate an ingress of air into the first environment. A control valve is configured to regulator and supply pressurized air from the first environment to a compressor.

Abstract: A pressure control system for an environment to be pressurized includes a controller configured to calculate at least one of: a calculated pressure sensor rate of change error; and a calculated pressure sensor error. The calculated sensor rate of change error is based on a plurality of first environment air pressure signals over a first time period; and the calculated sensor error is based, over a second period of time, a difference between ambient air pressure signals and second environment air pressure signals. A processor in communication with the controller is configured to compare at least one of: the calculated pressure sensor rate of change error with at least one pressure sensor rate of change error control limit; and the calculated pressure sensor error with at least one pressure sensor error control limit.

Abstract: A thrust recovery outflow valve includes a valve frame for mounting on an aircraft exterior skin and a bi-fold valve door that is mounted within the valve frame. The bi-fold valve door includes an aft door section, a forward door section, and a ram air flap. The aft door section is rotatable between an aft door closed position and an aft door full-open position and has a ram air opening formed therein. The forward door section is rotatable between a forward door closed position and a forward door full-open position. The ram air flap is rotationally mounted on the aft door section and is rotatable between a flap closed position, which prevents air flow through the ram air opening, and a flap open position, which allows air flow through the ram air opening.

Abstract: A thrust recovery outflow valve includes a valve frame for mounting on an aircraft exterior skin and a bi-fold valve door that is mounted within the valve frame. The bi-fold valve door includes an aft door section, a forward door section, and a ram air flap. The aft door section is rotatable between an aft door closed position and an aft door full-open position and has a ram air opening formed therein. The forward door section is rotatable between a forward door closed position and a forward door full-open position. The ram air flap is rotationally mounted on the aft door section and is rotatable between a flap closed position, which prevents air flow through the ram air opening, and a flap open position, which allows air flow through the ram air opening.

Abstract: A bi-fold valve door and method for controlling aircraft cabin pressure are provided. The bi-fold valve door includes an aft door section and a forward door section, and only the forward door section is selectively rotated about one rotational axis to a position between a closed position and a full-open position, while the aft door section is maintained in its closed position. The forward door section is selectively rotated about the rotational axis to a full-open position to engage the aft door section, while the aft door section is maintained in its closed position. When the forward door section is in the full-open position, the aft door section and the forward door section are simultaneously rotated about another rotational axis.

Abstract: A thrust recovery outflow valve and method for controlling the transfer of air between a cabin in an aircraft and atmosphere outside of the aircraft are provided. An outflow valve is mounted on the aircraft that includes a valve frame, a first valve door, and a second valve door. The first valve door is rotated to a first predetermined open position while the second valve door is in the second door closed position to thereby open first and second flow passages that place the aircraft cabin in fluid communication with the atmosphere. When the first valve door is at a first predetermined open position, a flap is rotated, relative to the first valve door, to at least partially cover the second flow passage and thereby at least inhibit flow through the second flow passage.

Abstract: An aircraft cabin pressure control system outflow thrust recovery valve includes a frame, a valve element, and actuation hardware. The frame, valve element, and at least a portion of the actuation hardware are made of composite material. The actuation hardware is disposed external to the frame.

Abstract: A single valve door thrust recovery outflow valve is provided that does not rely on a relatively large and expensive actuator to move it, and does not create unwanted drag during aircraft cruise operations. The valve includes a valve frame, a valve door, and an aerodynamic flap. The valve door is rotationally coupled to the valve frame, is adapted to receive a drive torque, and is configured, upon receipt of the drive torque, to rotate between a closed position, a full-open position, and a plurality of partial-open positions between the closed position and the full-open position. The aerodynamic flap is coupled to the valve door. When the valve door is in the closed position and in numerous partial-open positions, the aerodynamic flap makes the thrust recovery outflow valve aerodynamically clean.

Abstract: A multiple outflow valve control system for an aircraft is provided having a plurality of outflow valves that may be controlled independently via an all electrical control system. The outflow valves may be located in various locations in an aircraft. The control system may have a control loop controlling the outflow valve motors via open-loop PWM commands and may not have a motor speed feedback in the control loop. The cabin pressure control system may have manual and auto controls controlling separate motors on each outflow valve. Auto motor control may be performed via software biasing command logic included in the control laws in the control system. Air flow may be biased through selected outflow valves and the degree of biasing may be automatically or manually set.

Abstract: An aircraft cabin pressure control system outflow thrust recovery valve includes a frame, a valve element, and actuation hardware. The frame, valve element, and at least a portion of the actuation hardware are made of composite material. The actuation hardware is disposed external to the frame.

Abstract: A method of calibrating an outflow valve on an aircraft may include determining if the aircraft has reached a predetermined cruise condition. The outflow valve may be moved until a closed position is reached, if the aircraft has reached the predetermined cruise condition. An actual position feedback value of the outflow valve may be determined while the aircraft is in the predetermined cruise condition. An offset calibration factor may be determined from the actual position feedback value of the outflow valve relative to a theoretical value.

Abstract: An aircraft cabin pressure control system outflow thrust recovery valve includes a frame, a valve element, and actuation hardware. The frame, valve element, and at least a portion of the actuation hardware are made of composite material. The actuation hardware is disposed external to the frame.

Abstract: A method of calibrating an outflow valve on an aircraft may include determining if the aircraft has reached a predetermined cruise condition. The outflow valve may be moved until a closed position is reached, if the aircraft has reached the predetermined cruise condition. An actual position feedback value of the outflow valve may be determined while the aircraft is in the predetermined cruise condition. An offset calibration factor may be determined from the actual position feedback value of the outflow valve relative to a theoretical value.