Patent Publication Number: US-2023145181-A1

Title: Embedded display automatic flight controls distributed architecture

Description:
TECHNICAL FIELD 
     The present invention generally relates to avionics aircraft controls systems, and more particularly to architectures for Automatic Flight Control Systems. 
     BACKGROUND 
     Prior designs for Automatic Flight Control Systems relied upon multiplexing Flight Control functions in a common processor. Furthermore, prior designs for Automatic Flight Control Systems used processing resources housed in an Integrated Processing Computer (IPC) cabinet and/or in a Data Concentrator Unit (DCU) Module Cabinet (DMC). Such prior designs may require various cabinetry to host the functions, raising to size and weight considerations. Therefore, it would be advantageous to provide one or more of a device, system, or method that cures the shortcomings described above. 
     SUMMARY 
     Embodiments of the present disclosure are directed to a flight display. In one embodiment, the flight display includes a display screen configured to display a plurality of images representing avionics data. In another embodiment, the flight display includes a physical network interface. In another embodiment, the flight display includes a plurality of processors communicatively coupled by an inter-processor communication bus. In another embodiment, one of the plurality of processors receives the avionics data and executes a display function causing the display screen to display the plurality of images. In another embodiment, at least some of the plurality of processors execute a plurality of automatic flight control system functions causing the flight display to send a command by way of the physical network interface. In another embodiment, each of the at least some of the plurality separately execute at least one of the plurality of automatic flight control system functions. In another embodiment, the flight display is a line replaceable unit configured to interface with a flight deck of an aircraft by the physical network interface. In another embodiment, the command causes at least one actuator communicatively coupled to the flight display by way of the physical network interface to adjust at least one of a flight control surface or a throttle of the aircraft. 
     Embodiments of the present disclosure are also directed to an automatic flight control system of an aircraft. In one embodiment, the automatic flight control system includes at least two flight displays. In another embodiment, the at least two flight displays are each a line replaceable unit configured to interface with a flight deck of the aircraft by a physical network interface. In another embodiment, each of the at least two flight displays include a display screen configured to display a plurality of images representing avionics data. In another embodiment, each of the at least two flight displays include a physical network interface. In another embodiment, each of the at least two flight displays include a plurality of processors communicatively coupled by an inter-processor communication bus. In another embodiment, one of the plurality of processors receives the avionics data and executes a display function causing the display screen to display the plurality of images. In another embodiment, at least some of the plurality of processors execute a plurality of automatic flight control system functions causing the flight display to send a command by way of the physical network interface. In another embodiment, each of the at least some of the plurality of processors separately execute at least one of the plurality of automatic flight control system functions. In another embodiment, the commands from the at least two flight displays cause at least one actuator communicatively coupled to the at least two flight displays by way of the physical network interfaces to adjust at least one of a flight control surface or a throttle of the aircraft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the inventive concepts disclosed herein may be better understood when consideration is given to the following detailed description thereof. Such description makes reference to the included drawings, which are not necessarily to scale, and in which some features may be exaggerated and some features may be omitted or may be represented schematically in the interest of clarity. Like reference numerals in the drawings may represent and refer to the same or similar element, feature, or function. In the drawings: 
         FIG.  1 A  depicts a simplified control diagram of a flight display, in accordance with one or more embodiments of the present disclosure. 
         FIG.  1 B  depicts a simplified control diagram showing functions executed by processors of a flight display including five processors executing the functions, in accordance with one or more embodiments of the present disclosure. 
         FIG.  1 C  depicts a simplified control diagram showing functions executed by processors of a flight display including seven processors executing the functions, in accordance with one or more embodiments of the present disclosure. 
         FIG.  2    depicts a perspective view of an exemplary flight deck of an aircraft including flight displays, in accordance with one or more embodiments of the present disclosure. 
         FIG.  3 A  depicts a simplified control diagram of an automatic flight control system with two flight displays, in accordance with one or more embodiments of the present disclosure. 
         FIG.  3 B  depicts a simplified control diagram of an automatic flight control system with two flight displays where one of the two flight displays is operating in a fail-soft configuration upon detecting a failure or power-off of the other flight display, in accordance with one or more embodiments of the present disclosure. 
         FIG.  4 A  depicts a simplified control diagram of an automatic flight control system with three flight displays where one of the three flight displays is not executing automatic flight control system functions, in accordance with one or more embodiments of the present disclosure. 
         FIG.  4 B  depicts a simplified control diagram of an automatic flight control system with three flight displays where one of the three flight displays is operating in a fail-operational configuration upon detecting a failure or power-off of a second of the three flight displays, in accordance with one or more embodiments of the present disclosure. 
         FIG.  4 C  depicts a simplified control diagram of an automatic flight control system with three flight displays each executing automatic flight control system functions with triple redundancy, in accordance with one or more embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Before explaining at least one embodiment of the inventive concepts disclosed herein in detail, it is to be understood that the inventive concepts are not limited in their application to the details of construction and the arrangement of the components or steps or methodologies set forth in the following description or illustrated in the drawings. In the following detailed description of embodiments of the instant inventive concepts, numerous specific details are set forth in order to provide a more thorough understanding of the inventive concepts. However, it will be apparent to one of ordinary skill in the art having the benefit of the instant disclosure that the inventive concepts disclosed herein may be practiced without these specific details. In other instances, well-known features may not be described in detail to avoid unnecessarily complicating the instant disclosure. The inventive concepts disclosed herein are capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     As used herein a letter following a reference numeral is intended to reference an embodiment of the feature or element that may be similar, but not necessarily identical, to a previously described element or feature bearing the same reference numeral (e.g.,  1 ,  1   a ,  1   b ). Such shorthand notations are used for purposes of convenience only, and should not be construed to limit the inventive concepts disclosed herein in any way unless expressly stated to the contrary. 
     Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive “or”. For example, a condition A or B is satisfied by anyone of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). 
     In addition, use of the “a” or “an” are employed to describe elements and components of embodiments of the instant inventive concepts. This is done merely for convenience and to give a general sense of the inventive concepts, and “a” and “an” are intended to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. 
     Finally, as used herein any reference to “one embodiment,” or “some embodiments” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the inventive concepts disclosed herein. The appearances of the phrase “in some embodiments” in various places in the specification are not necessarily all referring to the same embodiment, and embodiments of the inventive concepts disclosed may include one or more of the features expressly described or inherently present herein, or any combination or sub-combination of two or more such features, along with any other features which may not necessarily be expressly described or inherently present in the instant disclosure. 
     An automatic flight control system (AFCS) function may be executed by one or more processors based on one or more of avionics data, a desired level of integrity, or a desired redundancy. The execution of AFCS functions may generate command outputs. The command outputs may drive various actuators which are downstream of the AFCS functions. A minimum set of command outputs (i.e., instances of the functions) may be needed to cause the actuator to adjust a flight control surface or a throttle, due to various mandated safety requirements. Embodiments of the present disclosure are generally directed to executing the AFCS functions by a flight display integrated into a flight deck of an aircraft as a line-replaceable unit (LRU). The flight display may include processors which execute various avionics functions, including the AFCS functions. In this regard, the flight display may also be referred to as an Embedded Display System (EDS). Multiple of the flight displays may be communicatively coupled to form an Automatic Flight Control System (AFCS). In this regard, each of the flight displays may host the AFCS functions to provide a desired level of integrity and/or redundancy. Furthermore, various flight displays may be considered back-up displays, which are reconfigured to perform the AFCS functions upon detecting one or more of a failure or a power-off of the flight displays currently performing the AFCS functions. The system thus provides flexibility in availability and integrity of AFCS functions. In this regard, the system may implement an architecture using two or more Embedded LRU displays. Such architecture may by scalable based on the number of displays within the flight deck. 
     Referring now to  FIGS.  1 A- 1 C , a flight display  100  is described, in accordance with one or more embodiments of the present disclosure. The flight display  100  may be configured to function as one or more of a primary flight display (PFD) or a multifunction display (MFD). Such PFD and MFDs may be mounted in front of both a pilot and a copilot. The MFD may be mounted between the PFD of the pilot and the PFD of the copilot. To allow for the failure of either the PFD or the MFD, the flight display  100  may be capable of being configured between PFD and MFD formats. Thus, the flight display  100  may provide instrumentation for the operation of an aircraft. The flight display may include one or more integrated components, such as, but not limited to, screen  102 , a memory  104 , a physical network interface  106 , a power supply  108 , and one or more processors  110 . In this regard, the flight display  100  may be considered an Embedded Display System (EDS) which may be installed within a flight deck as a line-replaceable unit. It is noted herein that the one or more components of the flight display  100  may be communicatively coupled to the various other components of the flight display  100  in any manner known in the art. For example, the processor(s)  110  may be communicatively coupled to other components (e.g., screen  102 , a memory  104 , a physical network interface  106 , a power supply  108 , and the like) by a physical connection (not depicted). The flight display  100  may further comply with various Aeronautical Radio Inc. (ARINC) standards, such as, but not limited to ARINC 661. 
     The screen  102  of the flight display  100  may include any screen known in the art. For example, the screen  102  may include, but is not limited to, a liquid crystal display (LCD). The screen are not limited to LCD devices as it is contemplated additional display technologies (e.g., OLED) may be suitable for implementation in the present invention. The screen  102  may be implemented using any of a variety of display technologies, including CRT, LCD, organic LED, dot matrix display, and others. The screen  102  may further display various images generated by the processor(s)  110 . The images shown on the screen  102  may include monochrome or color graphical representations of various avionics data, such as, but not limited to, an indication of altitude of other aircraft, weather conditions, terrain, the altitude and/or location of such information relative to the aircraft, and so on. In some embodiments, the screen may further include a touch screen. For example, the screen  102  may include a capacitive touchscreen, a resistive touchscreen, or another touchscreen known in the art. 
     The memory  104  of the flight display  100  may include any storage medium known in the art. For example, the memory  104  may include a non-transitory memory medium. For instance, the memory  104  may include, but is not limited to, a read-only memory (ROM), a random-access memory (RAM), a magnetic or optical memory device (e.g., disk), a solid-state drive and the like. It is further noted that memory  104  may be housed in a common controller housing with the one or more processor(s)  110 . In an alternative embodiment, the memory  104  may be located remotely with respect to the physical location of the processor  110 . In another embodiment, the memory  104  maintains program instructions for causing the processor(s)  110  to carry out the various steps described through the present disclosure. 
     The physical network interface  106  (also referred to as input/output (I/O)) of the flight display  100  may allow the flight display  100  to interface with a flight deck of an aircraft. In this regard, the physical network interface  106  may include any standard interface, such as, but not limited to, ARINC 429, ARINC-664, ethernet, AFDX, serial, CAN, TTP, Military Standard (MIL-STD) 1553, peripheral component interconnect (PCI) express, digital interfaces, analog interfaces, discrete interfaces, or the like. The physical network interface  106  may be configured to receive data from various sensors and/or user interfaces of the aircraft. The physical network interface  106  may also be configured to send commands to various actuators of the aircraft. In this regard, various inputs and outputs may be received and sent by the flight display  100 . 
     The power supply  108  of the flight display  100  may include any suitable power supply known in the art. In this regard, any distributed or local power supply that provides conditioned power suitable for implementation in the context of avionics (e.g., 28 VDC) capable of meeting the requirements of the flight display may be implemented. 
     The processors  110  of the flight display  100  may include any processing unit known in the art. For example, the processors  110  may include a multi-core processor, a single-core processor, a reconfigurable logic device (e.g., FPGAs), a digital signal processor (DSP), a special purpose logic device (e.g., ASICs)), or other integrated formats. Those skilled in the art will recognize that aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software/and or firmware would be well within the skill of one skilled in the art in light of this disclosure. Such hardware, software, and/or firmware implementation may be a design choice based on various cost, efficiency, or other metrics. In this sense, the processor(s)  110  may include any microprocessor-type device configured to execute software algorithms and/or instructions. In general, the term “processor” may be broadly defined to encompass any device having one or more processing elements, which execute program instructions from memory  104 , from firmware, or by hardware implemented functions. It should be recognized that the steps described throughout the present disclosure may be carried out by the processors  110 . 
     The processors  110  may also be communicatively coupled by an inter-processor communication bus  112 . The inter-processor communication bus  112  may allow the processors  110  to pass various information. The inter-processor communication bus  112  may include any inter-processor communication bus known in the art. 
     One or more of the processors  110  may run one or more operating systems. The operating system may include any operating system known in the art. The operating system may act as a kernel between the various hardware components and the software functions further described herein. In some embodiments, the operating system may partition applications or functions by time division multiplexing or other suitable process. In this regard, resources may be guaranteed for the various functions. 
     The processors  110  may execute various functions. For example, one or more of the processors  110  may execute a display function causing the screen  102  to display the images. The display function may include any display function known in the art, such as displaying various avionics data. By way of another example, one or more of the processors  110  may execute an external communication bus function. The external communication bus function may cause the flight display  100  to handle signals received from the physical network interface  106  and further send various signals by way of the physical network interface  106 . The external communication bus function may include any external communication bus function known in the art. In some embodiments, a first processor executes both the display function and the external communication bus function. 
     According to various exemplary embodiments of the inventive concepts disclosed herein, the flight display  100  may also provide automatic flight control system (AFCS) functionality. 
     The processors  110  may execute one or more automatic flight control system (AFCS) functions. The AFCS functions may receive various sensor data and aircraft configuration data (e.g., by way of the physical network interface  106 ) as inputs. Such received data may include, but is not limited to, data from navigation sensor data, attitude sensor data, air data sensor data, aircraft configuration data, or other flight control input data known in the art. The AFCS functions may further cause the flight display  100  to send one or more commands by way of the physical network interface  106 . The commands may cause actuators which are communicatively coupled to the flight display  100  (e.g., by way of the physical network interface  106  and various other networks) to adjust a flight control surface or a throttle of the aircraft. The signals may control a servo connected to a control cable for directly adjusting the flight control surface or controlling an actuator (e.g., hydraulic actuator) coupled to the flight control surface. The signals may also be transmitted to a fly-by-wire system, which in turn moves the flight surfaces using an interfaces with the aircraft actuators. The signals may also control a servo that moves a column or wheel of the aircraft, with such movement then being sensed by a fly-by-wire system which transmits a signal to command the actuator to adjust the flight control surface. The command may be provided to the actuator by a direct connect or a data concentration (i.e., routed through a different box). Such actuators may include any actuator known in the art. Similarly, such flight control surfaces may include any flight control surface known in the art, such as, but not limited to, an elevator, an aileron, a rudder, or a trim. 
     It is contemplated that by hosting the AFCS functions on the processors  110  within the flight display  100 , no IMA cabinet may be required to perform said AFCS functions. This may be advantageous in implementing AFCS functions in an aircraft which otherwise does not include sufficient cabinet space and/or for reducing a weight or cost of the aircraft. Furthermore, as the number of displays housed within the aircraft increases, an integrity and availability of the AFCS functions may similarly increase. It is further contemplated that one or more IMA cabinets and/or an additional flight display may host the AFCS functions in tandem with the flight display  100 . 
     One or more automatic flight control system (AFCS) functions are now described. The AFCS functions may include a flight guidance (FG) function. The flight guidance function may provide an outer loop that converts position error into one or more of an attitude or an attitude error command. The attitude or attitude error command may further be provided for use by an autopilot function. The AFCS functions may also include an autopilot (AP) function. The autopilot function may provide aircraft stability and control, while at the same time, process the attitude or attitude error command from the flight guidance function to position the aircraft as desired. The AFCS functions may also include a yaw damper (YD) function. The yaw damper function may provide yaw axis control for stability of Dutch Roll and turn coordination. The AFCS functions may also include a trim function. The trim function may provide control of secondary systems to alleviate forces on a control column in one or more axes of control. The AFCS functions may also include an auto-throttle (AT) function. The auto-throttle function may control aircraft engines either directly or indirectly via the engine throttles, to maintain aircraft speed or thrust. The AFCS functions may also include a flight control system (FCS) monitor function. The monitor function may provide independent safety and design assurance over safety critical functions, such as, but not limited to, the autopilot function, the yaw damper function, the trim function, and/or the auto-throttle function. The AFCS functions may also include a stall warning (SW) function. The stall warning function may detect an impending stall condition. The AFCS functions may also include a stall protection function. The stall protection function may actively force the aircraft out of a potential stall condition. The AFCS functions may include various additional or alternative functions as known in the art of flight control. 
     In some embodiments, a signal may be received by way of the physical network interface. The received signal may indicate a failure or a power-off of another component of the aircraft (e.g., a second flight display or an IMA cabinet). One or more of the processors  110  may detect the failure or power-off based on the received signal. One or more of the processors  110  may further be reconfigured in response to the detection. In this regard, the functions executed by the processors  110  may be dynamically reconfigurable. The processors  110  may reconfigure the images displayed on the screen  102 . For example, where the flight display  100  is a multi-function display, the images may be reconfigured to display primary flight display imagery, in response to detecting failure of one of the primary flight displays. The processors  110  may also be reconfigured to execute the AFCS functions. For example, the processors  110  may be reconfigured to execute the AFCS functions, such that the flight display  100  may be considered a secondary AFCS function host (i.e., in the event of a primary AFCS function host) or a tertiary AFCS function host (i.e., in the event of failure of power-off of a secondary AFCS function host). Such reconfiguration may cause the flight display  100  to operate in a fail-operational configuration, where each of the AFCS functions is fully operational even upon failure of the primary or secondary function host. It is further contemplated that the flight display  100  may be considered the primary AFCS function host. By way of another example, the processors  110  may be reconfigured to provide the command outputs to the aircraft actuator based on the AFCS functions executed by the processors. 
     The flight display  100  may include a number of the processors  110  (e.g., between five and seven, or more). Parallel processing the AFCS functions among the processors  110  may raise various certification issues with flight authority. In some embodiments, each of the processors  110  execute separate AFCS functions, such that no AFCS function is parallelly processed and do not share processing resources for performing the AFCS functions. Various permutations of AFCS function allocation among the processors  110  may exist. Such allocations may be based on the number of processors  110  embedded within the flight display  100 , various certification requirements, resource availability, or other suitable reasons. An exemplary permutation allocating the AFCS functions among five processors is depicted in  FIG.  1 B  (see flight display  100   a ). An exemplary permutation allocating the AFCS functions among seven processors is depicted in  FIG.  1 C  (see flight display  100   b ). 
     In some embodiments, one or more of the processors  110  may execute two or more AFCS functions. For example, one of the processors  110  may execute the autopilot function, the yaw damper function, and the trim function (See  FIG.  1 B ). Said processor may further execute the stall protection function (See  FIG.  1 C ). By way of another example, one of the processors  110  may execute the flight guidance function and the auto-throttle function (See  FIG.  1 B ). 
     In some embodiments, one or more AFCS functions are hosted on separate processors from others of the AFCS functions. For example, the stall warning function may be executed by a separate processor than the stall protection function. By way of another example, the flight control system monitoring function may be executed by a separate processor from one or more of the autopilot function, the yaw damper function, the trim function, and the auto-throttle function. As may be understood, a number of the AFCS functions may be executed by separate processors. 
     Referring now to  FIGS.  2   , a system  200  of an aircraft is described, in accordance with one or more embodiments of the present disclosure. The system  200  may be embodied as a cockpit of an aircraft. The system  200  may include one or more the flight displays  100  each being a line replaceable unit interfacing with a flight deck of the aircraft by the physical network interface  106 . By executing the AFCS functions within the flight displays  100 , the system  200  may be considered an automatic flight control system. The system  200  may provide a high level of integrity and availability for the AFCS functions. The flight displays  100  may further meet a design assurance such that no single point failure may result in loss of all AFCS functions. 
     The number of the flight displays  100  within the system  200  may be based on a configuration of the associated flight deck. For example, some cockpit configurations may include between two and six, or more flight displays  100 . Commonly, three of the flight displays  100  may be provided within the flight deck (e.g., two PFDs and one MFD). A level of integrity and availability may increase as additional flight displays host the AFCS functions. In some instances, the flight deck may be reconfigurable. The flight displays  100  may handle the addition or removal of AFCS function hosts (e.g., additional fight displays or IMA cabinets) by receiving a signal by way of the physical network interface  106 . 
     The system  200  may also include one or more user interface (UI) elements  202 . The UI elements  202  may include, for example, dials, switches, buttons, touch screens, keyboards, a mouse, joysticks, cursor control devices (CCDs) or other multi-function key pads certified for use with avionics systems. The UI elements  202  may be configured to, for example, allow an aircraft crew member to interact with various avionics applications and perform functions such as data entry, manipulation of navigational maps, and moving among and selecting checklist items. For example, the UI elements  202  may be used to adjust features of the flight displays  100 , such as contrast, brightness, width, and length. The UI elements  202  may also (or alternatively) be used by an aircraft crew member to interface with or manipulate the displays of the flight displays  100 . For example, the UI elements  202  may be used by aircraft crew member to adjust the brightness, contrast, and information displayed on the flight displays  100 . The UI elements  202  may additionally be used to acknowledge or dismiss an indicator provided by the flight displays  100 . Further, the UI elements  202  may be used to correct errors on the flight displays  100 . Other UI elements  202 , such as indicator lights, displays, display elements, and audio alerting devices, may be configured to warn of potentially threatening conditions such as severe weather, terrain, and obstacles. 
     In some embodiments, the UI elements  202  include a flight control mode panel. The flight control mode panel may be communicatively coupled to the flight displays  100 . The AFCS functions executed by the flight displays  100  may be reconfigurable based on a signal from the flight control mode panel. The flight control mode panel may further allow for selective engagement of the automatic flight control system functions, based on a control mode selected on the flight control mode panel. The flight control mode panel may include any number of control modes known in the art. 
     Referring now to  FIGS.  3 A- 3 B , a system  300  (e.g., system  300   a , system  300   b ) is described in accordance with one or more embodiments of the present disclosure. The system  300  may be similar to the system  200 , with the exception that the system  300  includes two of the flight displays  100 . 
     The system  300  may include two of the flight displays  100 . The flight displays  100  may receive various data by way of the physical network interfaces  106  and various communication buses. The communication buses may include any communication bus known in the art. 
     The flight displays  100  may receive data from aircraft sensors  302 . The aircraft sensors  302  may include, but are not limited to, navigation sensors, attitude sensors, and air data sensors. For example, the navigation sensors may include data from one or more of very high frequency omnidirectional range systems (VOR), instrument landing system (ILS), or global positioning systems (GPS) and the like. By way of another example, the attitude sensors may include one or more of attitude or inertial reference sensor values used to perform closed loop attitude stability and control of the aircraft. By way of another example, the air data sensors may include one or more of air data or angle of attack sensor data used in closed loop control or for further control loop closure. 
     The flight displays  100  may also receive aircraft configuration data  304 . The aircraft configuration data  304  may be received by sensors which supply the aircraft configuration data and/or may be based on data stored in memory. The aircraft configuration data  304  may include, but is not limited to, flap position, spoiler position, gear position, weight on wheels, surface positions, trim position, engines, and the like. Although the aircraft sensors  302  and the aircraft configuration data  304  are each depicted by one block diagram, this is not intended as a limitation on the present disclosure. Commonly, aircraft sensors data and aircraft configuration data may be separated into various subsets (e.g., subsets based on the side of the aircraft, sensor type, etc.). 
     The system  300  may further include a communication bus  308 . The communication bus  308  may communicatively couple the flight displays  100  (e.g., by way of the physical network interfaces  106 ). In this regard, the flight displays  100  may detect when one or more of the other flight displays has experienced a failure or a power-off. Optionally, the flight displays  100  may share the command outputs from the AFCS functions. In this regard, the flight displays  100  may receive the command outputs for comparison purposes (e.g., to determine agreement prior to controlling the actuator). The communication bus  308  may include any communication bus known in the art. 
     In some embodiments, a minimum set of command outputs (i.e., instances of the functions) may be needed to meet a mandated safety requirement. For example, one instance of the flight guidance function, the stall warning function, the monitoring function, and the auto-throttle function may be required to meet the safety requirement. By way of another example, two instances of the auto-pilot function, the yaw damper function, and the stall protection function may be required to meet the safety requirement. In this regard, the command outputs from the two instances of the auto-pilot function must be in agreement. Further instances of the functions may be provided to meet a desired level of redundancy. As depicted in  FIG.  3 A , the flight displays  100  may include processors which execute two instances of the AFCS functions. In this regard, the system  300   a  may meet the requirements for the auto-pilot functions, the yaw damper functions, and the stall protection functions. 
     The flight displays  100  may further send the commands output to one or more actuators  306 . The actuators  306  may be communicatively coupled to the flight displays  100  by way of the physical network interface  106  and one or more communication buses. In some embodiments, the actuators  306  are in a direct connection with the flight displays  100 . In other embodiments, the actuators  306  are further communicatively coupled by way of a data concentration unit (e.g., for comparing the commands). In response to receiving the commands, the actuators  306  may adjust a flight control surface or a throttle of the aircraft. The flight control surface may include any flight control surface known in the art, such as, but not limited to, an elevator, an aileron, a rudder, or a trim. Similarly, the actuator may include any actuator known in the art. Thus, the two flight displays may provide the two instances of autopilot, trim, stall Protection and yaw damper commands required to drive the downstream actuators. 
     In some embodiments, only one instance of the flight guidance function is hosted by the two flight displays  100 . The one instance of the flight guidance function may be dynamically configured to the either of the flight displays (e.g., pilot or co-pilot side) depending on which flight display is currently in manual control. 
     Referring specifically now to  FIG.  3 B , a second of the flight displays  100  has failed or otherwise been powered-off. A first of the flight displays  100  may detect the failure or power-off of the second flight display. The first flight display may then be dynamically reconfigured into a fail-soft configuration upon detecting the failure or the power-off. In this regard, the actuator  306  may receive insufficient numbers of autopilot, trim, yaw damper, and stall protection commands. The active flight display may further reconfigure the AFCS functions. Optionally, the processors of the active flight display may continue to execute one or more of the flight guidance function, the stall warning function, the flight control system monitor function, or the auto-throttle function. Similarly, the processors of the active flight display may continue to execute display functions and communication bus functions. Similarly, the autopilot function, the yaw damper function, the trim function, and the stall protections functions may continue to execute. However, the aircraft host may lose the functionality of the yaw damper function, the trim function, and the stall protections functions due to only one instance of each function being executed in the flight deck. Upon regaining functionality of the second flight display, the first flight display may be reconfigured from a stand-by mode to an active mode where the commands from the autopilot function, the yaw damper function, the trim function, and the stall protections functions are provided (with additional commands from the second flight display) to the actuator, causing the actuator to adjust the flight control surface or the throttle. 
     Referring now to  FIGS.  4 A- 4 C , a system  400  (e.g., system  400   a , system  400   b , system  400   c ) is described in accordance with one or more embodiments of the present disclosure. The system  400  may be similar to the system  200  and the system  300 , with the exception that the system  400  includes three of the flight displays  100 . As depicted, a middle flight display may be in an inactive AFCS function (or mode) and the two outside flight displays may be in an active AFCS function (or mode). The active AFCS function may include executing the AFCS functions by the processors. The inactive AFCS function may include no execution of the AFCS functions by the processors or otherwise a stand-by mode of the functions which run in the background but are not outputting commands to the actuator. The two outside flight displays may thus provide the required number of AFCS commands outputs without a need for the middle flight display. For example, the middle flight display may be a multi-function display and the two outside displays may be primary flight displays, where the MFD is disposed between the PFDs. The MFD may provide AFCS function commands upon detecting a failure of one of the PFDs. 
     In  FIG.  4 B , one of the two outside flight displays (e.g., a pilot PFD or a copilot PFD) has undergone a failure or has been powered-off. The middle flight display may detect the failure or power-off and switch to a fail-operational configuration. In the fail-operational configuration, the middle flight display may include displaying various imagery which was previously displayed on the failed or power-off flight display. The fail-operational configuration may also include reconfiguring the processors of the middle flight display to execute the AFCS functions. In this regard, the middle flight display may now send the commands to the actuators  306  together with the lower flight display. By providing the middle flight display as a backup, the system  400   b  may include modular redundancy for the AFCS functions. The recitation of top, middle, and lower is not intended to be limiting. In this regard, any two of the flight displays may host the AFCS functions with the remaining flight display serving as the secondary AFCS function host. 
     Referring specifically to  FIG.  4 C , each of the three flight displays may host the AFCS functions. By providing the instances of the AFCS commands, the system  300   c  may include triple modular redundancy. In some embodiments, one or more of the flight displays  100  may compare the command outputs by majority voting. In other embodiments, a data concentration unit (not depicted) performs the majority voting comparison. 
     Referring generally again to  FIGS.  1 A- 4 C . 
     It is contemplated that the various systems described herein may further include one or more IMA cabinet hosting one or more of the AFCS functions. The one or more IMA cabinet may host the AFCS functions together with one or more of the flight displays. It is further contemplated, the IMA cabinet and the flight displays may both host primary AFCS functions, with dual (e.g., 2-tuple), triple (e.g., 3-tuple), or n-tuple redundancy, where the n-tuple is based on the number of IMA cabinets and the number of flight displays acting as primary hosts for the AFCS functions. It is further contemplated that one or more IMA cabinets and/or one or more flight displays may serve as a secondary AFCS function host. In this regard, the IMA cabinet and/or the flight displays may host the AFCS functions and be reconfigured to output the commands to the actuator upon failure or power-off of the primary AFCS function host. It is further contemplated that one or more IMA cabinets and/or one or more flight displays may serve as a tertiary AFCS function host. In this regard, the IMA cabinet and/or the flight displays may host the AFCS functions and be reconfigured to output the commands to the actuator upon failure of the secondary AFCS function host. For example, four of more flight displays may host the AFCS functions, with a first two displays performing primary hosting, with a third display performing a secondary hosting (e.g., upon failure of either of the first two displays), and with a fourth display performing a tertiary hosting (e.g., upon detecting failure of the third display or the remaining first two displays) such that the four flight displays are configured with quadruple redundancy for the AFCS functions. As may be understood, a variety of permutations of AFCS function hosting among a select number of flights displays and a select number of IMA cabinets may provide a select level of redundancy for the AFCS functions. Furthermore, as additional flight display and/or IMA cabinets are added to the aircraft, additional levels of redundancy for the AFCS functions may be achieved. It is further contemplated that the flight displays may include more than one channel with capability for executing the AFCS functions (e.g., a dual channel redundancy, or more). In some instances the channels will be handled by dissimilar processors to further improve a redundancy of the AFCS functions. 
     From the above description, it is clear that the inventive concepts disclosed herein are well adapted to carry out the objectives and to attain the advantages mentioned herein as well as those inherent in the inventive concepts disclosed herein. While presently preferred embodiments of the inventive concepts disclosed herein have been described for purposes of this disclosure, it will be understood that numerous changes may be made which will readily suggest themselves to those skilled in the art and which are accomplished within the broad scope and coverage of the inventive concepts disclosed and claimed herein.