Patent Description:
Pilots, air traffic controllers, airline personnel and the like routinely monitor meteorological data, reports, and forecasts to assess any potential impacts on the current or anticipated flight plan and the intended destination. However, in situations where the aircraft needs to deviate from the original plan, such as an emergency situation, the information needs to be reanalyzed with respect to the deviation to facilitate continued safe operation. For example, in the case of an emergency landing, a pilot would ideally select an airport within range of the aircraft where landing is least likely to be compromised or complicated by weather or other factors. This requires consideration of numerous pieces of information (e.g., fuel remaining and distance to be traveled, weather radar and/or forecast information, NOTAMs, SIGMETs, PIREPs, and the like), which often is distributed across different displays or instruments, requiring the pilot to mentally piece together all the different information from the different sources, while in some instances, also manually flying the aircraft concurrently. Moreover, once a diversion airport is selected, the pilot may need to further analyze the various runways at the diversion airport and determine their relative suitability for landing. Additionally, the time-sensitive nature of aircraft operation can increase the stress on the pilot, which, in turn, increases the likelihood of pilot error. Accordingly, it is desirable to reduce the mental workload of the pilot (or air traffic controller, or the like) and provide improved situational awareness in a complex situation.

<CIT> discloses a flight assistant with automatic configuration and landing site selection. <CIT> discloses a method and system for determining landing sites for aircraft.

Methods and systems are provided for assisting operation of an aircraft en route to an airport. A first aspect of the present invention is directed to a method of assisting operation of an aircraft en route to an airport according to appended claim <NUM>.

In another embodiment, a system is provided according to appended claim <NUM>.

Embodiments of the subject matter will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and:.

Embodiments of the subject matter described herein generally relate to systems and methods for assisting operation of a vehicle en route to a destination. While the subject matter described herein could be utilized in various applications or in the context of various types of vehicles (e.g., automobiles, marine vessels, trains, or the like), exemplary embodiments are described herein in the context of an aircraft being flown en route to an airport. In particular, the subject matter is described primarily in the context of a total engine flameout (TEFO) condition when the aircraft is unable to generate or otherwise provide forward thrust.

As described in greater detail below in the context of <FIG>, when a TEFO condition or a similar anomalous condition exists, a pilot, co-pilot or other crew member operating an aircraft is provided with one or more indicia of the amount of vertical height margin that exists with respect to landing the aircraft on a runway at an airport. In this regard, the vertical height margin represents the anticipated vertical distance between the anticipated altitude of the aircraft at a runway reference point resulting from a gliding trajectory and a reference altitude at the runway reference point. Thus, the vertical margin threshold indicia provides situational awareness with respect to whether or not the aircraft is likely to be able to glide and reach the airport safely in the absence of the ability to provide further thrust, thereby providing pilot or other aircraft operator with quantitative guidance of whether the airport or other landing location within the vicinity of the aircraft is viable or otherwise likely to be within the aircraft's capability. In exemplary embodiments, the vertical height margin is dynamically determined substantially in real-time to account for the current meteorological conditions, the current lift-to-drag ratio and/or sink rate of the aircraft, the current configuration of the aircraft, the current altitude of the aircraft, the current speed of the aircraft, and/or the like to account for deviations from the originally anticipated gliding trajectory during flight.

In exemplary embodiments, determining the vertical height margin for a runway at an airport involves identifying a reference point in advance of the runway representing the start of the final approach segment, such as a final approach fix or a final approach point. Based on the lateral distance between the reference point and the runway, a reference altitude criterion associated the reference point is determined by projecting a trajectory aligned with a centerline of the runway backwards from the runway that climbs with a constant flight path angle until reaching the reference point. In some embodiments, the constant flight path angle is defined by an approach procedure associated with the runway or determined based on terrain in a vicinity of the final approach segment.

After identifying the reference point and corresponding altitude criterion, an anticipated gliding trajectory from the current location of the aircraft along an anticipated lateral trajectory to the reference point is calculated or otherwise determined based on the current altitude of the aircraft, the current speed of the aircraft, the current aircraft configuration, the current lift-to-drag ratio or sink rate of the aircraft, and the like. In exemplary embodiments, the anticipated gliding trajectory also accounts for current or forecasted meteorological conditions at the current location of the aircraft or en route to the particular airport of interest. The resulting altitude of the anticipated gliding trajectory at the location where the anticipated lateral trajectory intersects or otherwise reaches the reference point represents the predicted altitude of the aircraft upon reaching the location corresponding to the reference point when flying or otherwise executing the anticipated gliding trajectory along the anticipated lateral trajectory en route to the airport. The vertical height margin associated with the runway at the airport is then calculated or otherwise determined by subtracting the reference altitude criterion associated the reference point from the predicted aircraft altitude at the reference point. In this regard, when the difference between the predicted aircraft altitude and reference altitude criterion is positive, the aircraft is likely to be able to safely reach the airport for landing at the particular runway of interest with some potential margin for error. Conversely, when the difference between the predicted aircraft altitude and reference altitude criterion is negative, the aircraft is unlikely to be able to reach the airport for landing at the particular runway of interest.

In exemplary embodiments, the vertical height margin may be calculated or otherwise determined for one or more airports within a threshold distance of the aircraft and utilized to generate or otherwise populate an airport selection graphical user interface (GUI) display that includes indicia of the estimated vertical height margin for each of the airports within the threshold distance of the aircraft to support or otherwise assist a pilot in selecting or otherwise identifying the safest airport for landing (e.g., the runway or airport with the greatest amount of vertical height margin available). In some embodiments, the graphical indicia of the estimated vertical height margin may be presented qualitatively, for example, by depicting runways or airports having a positive estimated vertical height margin using a visually distinguishable characteristic (e.g., a green color, highlighting, bolding, or the like) to indicate viability, while runways or airports having a negative estimated vertical height margin are rendered using a different visually distinguishable characteristic (e.g., a red color, fading, shading, or the like) to qualitatively indicate lack of viability.

As depicted in <FIG>, in exemplary embodiments, one or more graphical indicia of the vertical height margin is provided on a primary flight display (PFD) or other forward-looking perspective view display to facilitate providing quantitative feedback of the vertical height margin in real-time as the aircraft travels en route to a particular airport. In this regard, as the aircraft travels, the vertical height margin may be dynamically updated and recomputed in real-time by dynamically updating the anticipated gliding trajectory to account for changes in the aircraft's speed, altitude, lift-to-drag ratio, or the like, as well as changing meteorological conditions while en route. Thus, a pilot manually flying the aircraft may adjust operation of the aircraft (e.g., by adjusting the pitch, changing the aircraft configuration, and/or the like) substantially in real-time as the amount of available vertical height margin increases or decreases while en route. In this manner, the subject matter described herein enables a pilot manually flying the aircraft to identify a viable landing location and reliably manage the vertical situation of the aircraft to facilitate safe landing of the aircraft during TEFO conditions or other anomalous conditions where the aircraft is unable to provide thrust.

<FIG> depicts an exemplary embodiment of a system <NUM> which may be located onboard a vehicle, such as an aircraft <NUM>. The system <NUM> includes, without limitation, a display device <NUM>, a user input device <NUM>, a processing system <NUM>, a display system <NUM>, a communications system <NUM>, a navigation system <NUM>, a flight management system (FMS) <NUM>, one or more avionics systems <NUM>, one or more detection systems <NUM>, and one or more data storage elements <NUM>, <NUM> cooperatively configured to support operation of the system <NUM>, as described in greater detail below.

In exemplary embodiments, the display device <NUM> is realized as an electronic display capable of graphically displaying flight information or other data associated with operation of the aircraft <NUM> under control of the display system <NUM> and/or processing system <NUM>. In this regard, the display device <NUM> is coupled to the display system <NUM> and the processing system <NUM>, and the processing system <NUM> and the display system <NUM> are cooperatively configured to display, render, or otherwise convey one or more graphical representations or images associated with operation of the aircraft <NUM> on the display device <NUM>, as described in greater detail below.

The user input device <NUM> is coupled to the processing system <NUM>, and the user input device <NUM> and the processing system <NUM> are cooperatively configured to allow a user (e.g., a pilot, co-pilot, or crew member) to interact with the display device <NUM> and/or other elements of the aircraft system <NUM>. Depending on the embodiment, the user input device <NUM> may be realized as a keypad, touchpad, keyboard, mouse, touch panel (or touchscreen), joystick, knob, line select key or another suitable device adapted to receive input from a user. In some embodiments, the user input device <NUM> is realized as an audio input device, such as a microphone, audio transducer, audio sensor, or the like, that is adapted to allow a user to provide audio input to the aircraft system <NUM> in a "hands free" manner without requiring the user to move his or her hands, eyes and/or head to interact with the aircraft system <NUM>.

The processing system <NUM> generally represents the hardware, circuitry, processing logic, and/or other components configured to facilitate communications and/or interaction between the elements of the aircraft system <NUM> and perform additional processes, tasks and/or functions to support operation of the aircraft system <NUM>, as described in greater detail below. Depending on the embodiment, the processing system <NUM> may be implemented or realized with a general purpose processor, a controller, a microprocessor, a microcontroller, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, processing core, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In practice, the processing system <NUM> includes processing logic that may be configured to carry out the functions, techniques, and processing tasks associated with the operation of the aircraft system <NUM> described in greater detail below. Furthermore, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by the processing system <NUM>, or in any practical combination thereof. In accordance with one or more embodiments, the processing system <NUM> includes or otherwise accesses a data storage element, such as a memory (e.g., RAM memory, ROM memory, flash memory, registers, a hard disk, or the like) or another suitable non-transitory short or long term storage media capable of storing computer-executable programming instructions or other data for execution that, when read and executed by the processing system <NUM>, cause the processing system <NUM> to execute and perform one or more of the processes, tasks, operations, and/or functions described herein.

The display system <NUM> generally represents the hardware, firmware, processing logic and/or other components configured to control the display and/or rendering of one or more displays pertaining to operation of the aircraft <NUM> and/or systems <NUM>, <NUM>, <NUM>, <NUM>, <NUM> on the display device <NUM> (e.g., synthetic vision displays, navigational maps, and the like). In this regard, the display system <NUM> may access or include one or more databases <NUM> suitably configured to support operations of the display system <NUM>, such as, for example, a terrain database, an obstacle database, a navigational database, a geopolitical database, a terminal airspace database, a special use airspace database, or other information for rendering and/or displaying navigational maps and/or other content on the display device <NUM>. In this regard, in addition to including a graphical representation of terrain, a navigational map displayed on the display device <NUM> may include graphical representations of navigational reference points (e.g., waypoints, navigational aids, distance measuring equipment (DMEs), very high frequency omnidirectional radio ranges (VORs), and the like), designated special use airspaces, obstacles, and the like overlying the terrain on the map. In one or more exemplary embodiments, the display system <NUM> accesses a synthetic vision terrain database <NUM> that includes positional (e.g., latitude and longitude), altitudinal, and other attribute information (e.g., terrain type information, such as water, land area, or the like) for the terrain, obstacles, and other features to support rendering a three-dimensional conformal synthetic perspective view of the terrain proximate the aircraft <NUM>, as described in greater detail below.

As described in greater detail below, in an exemplary embodiment, the processing system <NUM> includes or otherwise accesses a data storage element <NUM> (or database), which maintains information regarding airports and/or other potential landing locations (or destinations) for the aircraft <NUM>. In this regard, the data storage element <NUM> maintains an association between a respective airport, its geographic location, runways (and their respective orientations and/or directions), instrument procedures (e.g., approaches, arrival routes, and the like), airspace restrictions, and/or other information or attributes associated with the respective airport (e.g., widths and/or weight limits of taxi paths, the type of surface of the runways or taxi path, and the like). Additionally, in some embodiments, the data storage element <NUM> also maintains status information for the runways and/or taxi paths at the airport indicating whether or not a particular runway and/or taxi path is currently operational along with directional information for the taxi paths (or portions thereof). The data storage element <NUM> may also be utilized to store or maintain other information pertaining to the airline or aircraft operator (e.g., airline or operator preferences, etc.) along with information pertaining to the pilot and/or co-pilot of the aircraft (e.g., pilot preferences, experience level, licensure or other qualifications, etc.).

Still referring to <FIG>, in an exemplary embodiment, the processing system <NUM> is coupled to the navigation system <NUM>, which is configured to provide real-time navigational data and/or information regarding operation of the aircraft <NUM>. The navigation system <NUM> may be realized as a global positioning system (GPS), inertial reference system (IRS), or a radio-based navigation system (e.g., VHF omni-directional radio range (VOR) or long range aid to navigation (LORAN)), and may include one or more navigational radios or other sensors suitably configured to support operation of the navigation system <NUM>, as will be appreciated in the art. The navigation system <NUM> is capable of obtaining and/or determining the instantaneous position of the aircraft <NUM>, that is, the current (or instantaneous) location of the aircraft <NUM> (e.g., the current latitude and longitude) and the current (or instantaneous) altitude (or above ground level) for the aircraft <NUM>. The navigation system <NUM> is also capable of obtaining or otherwise determining the heading of the aircraft <NUM> (i.e., the direction the aircraft is traveling in relative to some reference). Additionally, in an exemplary embodiment, the navigation system <NUM> includes inertial reference sensors capable of obtaining or otherwise determining the attitude or orientation (e.g., the pitch, roll, and yaw, heading) of the aircraft <NUM> relative to earth.

In an exemplary embodiment, the processing system <NUM> is also coupled to the FMS <NUM>, which is coupled to the navigation system <NUM>, the communications system <NUM>, and one or more additional avionics systems <NUM> to support navigation, flight planning, and other aircraft control functions in a conventional manner, as well as to provide real-time data and/or information regarding the operational status of the aircraft <NUM> to the processing system <NUM>. It should be noted that although <FIG> depicts a single avionics system <NUM>, in practice, the aircraft system <NUM> and/or aircraft <NUM> will likely include numerous avionics systems for obtaining and/or providing real-time flight-related information that may be displayed on the display device <NUM> or otherwise provided to a user (e.g., a pilot, a co-pilot, or crew member). For example, practical embodiments of the aircraft system <NUM> and/or aircraft <NUM> will likely include one or more of the following avionics systems suitably configured to support operation of the aircraft <NUM>: a weather system, an air traffic management system, a radar system, a traffic avoidance system, an autopilot system, an autothrust system, a flight control system, hydraulics systems, pneumatics systems, environmental systems, electrical systems, engine systems, trim systems, lighting systems, crew alerting systems, electronic checklist systems, an electronic flight bag and/or another suitable avionics system.

In the illustrated embodiment, the onboard detection system(s) <NUM> generally represents the component(s) of the aircraft <NUM> that are coupled to the processing system <NUM> and/or the display system <NUM> to generate or otherwise provide information indicative of various objects or regions of interest within the vicinity of the aircraft <NUM> that are sensed, detected, or otherwise identified by a respective onboard detection system <NUM>. For example, an onboard detection system <NUM> may be realized as a weather radar system or other weather sensing system that measures, senses, or otherwise detects meteorological conditions in the vicinity of the aircraft <NUM> and provides corresponding radar data (e.g., radar imaging data, range setting data, angle setting data, and/or the like) to one or more of the other onboard systems <NUM>, <NUM>, <NUM>, <NUM>, <NUM> for further processing and/or handling. For example, the processing system <NUM> and/or the display system <NUM> may generate or otherwise provide graphical representations of the meteorological conditions identified by the onboard detection system <NUM> on the display device <NUM> (e.g., on or overlying a lateral navigational map display). In another embodiment, an onboard detection system <NUM> may be realized as a collision avoidance system that measures, senses, or otherwise detects air traffic, obstacles, terrain and/or the like in the vicinity of the aircraft <NUM> and provides corresponding detection data to one or more of the other onboard systems <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

In one or more embodiments, an onboard detection system <NUM> may include one or more imaging devices or sensors configured to capture, sense, or otherwise obtain real-time imagery corresponding to an imaging region proximate the aircraft <NUM>, such as, for example, an infrared (IR) video camera or a millimeter wave (MMW) video camera that captures an image or frame corresponding to the imaging region at regular intervals (e.g., the refresh rate of the imaging device) for subsequent display on the display device <NUM>, as described in greater detail below. In such embodiments, the imaging device may be mounted in or near the nose of the aircraft <NUM> and calibrated to align the imaging region with a particular location within a viewing region of a primary flight display rendered on the display device <NUM>. For example, the imaging device may be configured so that the geometric center of the imaging region is aligned with or otherwise corresponds to the geometric center of the viewing region of the primary flight display. In this regard, the imaging device may be oriented or otherwise directed substantially parallel an anticipated line-of-sight for a pilot and/or crew member in the cockpit of the aircraft <NUM> to effectively capture a forward looking cockpit view of the imaging region.

In the illustrated embodiment, the processing system <NUM> is also coupled to the communications system <NUM>, which is configured to support communications to and/or from the aircraft <NUM> via a communications network. For example, the communications system <NUM> may also include a data link system or another suitable radio communication system that supports communications between the aircraft <NUM> and one or more external monitoring systems, air traffic control, and/or another command center or ground location. In this regard, the communications system <NUM> may allow the aircraft <NUM> to receive information that would otherwise be unavailable to the pilot and/or co-pilot using the onboard systems <NUM>, <NUM>, <NUM>, <NUM>. For example, the communications system <NUM> may receive meteorological information from an external weather monitoring system, such as a Doppler radar monitoring system, a convective forecast system (e.g., a collaborative convective forecast product (CCFP) or national convective weather forecast (NCWF) system), an infrared satellite system, or the like, that is capable of providing information pertaining to the type, location and/or severity of precipitation, icing, turbulence, convection, cloud cover, wind shear, wind speed, lightning, freezing levels, cyclonic activity, thunderstorms, or the like along with other weather advisories, warnings, and/or watches. The meteorological information provided by an external weather monitoring system may also include forecast meteorological data that is generated based on historical trends and/or other weather observations, and may include forecasted meteorological data for geographical areas that are beyond the range of any weather detection systems <NUM> onboard the aircraft <NUM>. In other embodiments, the processing system <NUM> may store or otherwise maintain historical meteorological data previously received from an external weather monitoring system, with the processing system <NUM> calculating or otherwise determining forecast meteorological for geographic areas of interest to the aircraft <NUM> based on the stored meteorological data and the current (or most recently received) meteorological data from the external weather monitoring system. In this regard, the meteorological information from the external weather monitoring system may be operationally used to obtain a "big picture" strategic view of the current weather phenomena and trends in its changes in intensity and/or movement with respect to prospective operation of the aircraft <NUM>.

It should be understood that <FIG> is a simplified representation of the aircraft system <NUM> for purposes of explanation and ease of description, and <FIG> is not intended to limit the application or scope of the subject matter described herein in any way. It should be appreciated that although <FIG> shows the display device <NUM>, the user input device <NUM>, and the processing system <NUM> as being located onboard the aircraft <NUM> (e.g., in the cockpit), in practice, one or more of the display device <NUM>, the user input device <NUM>, and/or the processing system <NUM> may be located outside the aircraft <NUM> (e.g., on the ground as part of an air traffic control center or another command center) and communicatively coupled to the remaining elements of the aircraft system <NUM> (e.g., via a data link and/or communications system <NUM>). In this regard, in some embodiments, the display device <NUM>, the user input device <NUM>, and/or the processing system <NUM> may be implemented as an electronic flight bag that is separate from the aircraft <NUM> but capable of being communicatively coupled to the other elements of the aircraft system <NUM> when onboard the aircraft <NUM>. Similarly, in some embodiments, the data storage element <NUM> may be located outside the aircraft <NUM> and communicatively coupled to the processing system <NUM> via a data link and/or communications system <NUM>. Furthermore, practical embodiments of the aircraft system <NUM> and/or aircraft <NUM> will include numerous other devices and components for providing additional functions and features, as will be appreciated in the art. In this regard, it will be appreciated that although <FIG> shows a single display device <NUM>, in practice, additional display devices may be present onboard the aircraft <NUM>. Additionally, it should be noted that in other embodiments, features and/or functionality of processing system <NUM> described herein can be implemented by or otherwise integrated with the features and/or functionality provided by the display system <NUM> or the FMS <NUM>, or vice versa. In other words, some embodiments may integrate the processing system <NUM> with the display system <NUM> or the FMS <NUM>; that is, the processing system <NUM> may be a component of the display system <NUM> and/or the FMS <NUM>.

Referring now to <FIG>, in an exemplary embodiment, the aircraft system <NUM> is configured to support a vertical margin display process <NUM> to display, present, or otherwise provide graphical indicia of the relationship between a predicted aircraft altitude in advance of a landing location and a reference altitude for the landing location and perform additional tasks, functions, and operations described below. The various tasks performed in connection with the illustrated process <NUM> may be implemented using hardware, firmware, software executed by processing circuitry, or any combination thereof. For illustrative purposes, the following description may refer to elements mentioned above in connection with <FIG>. In practice, portions of the vertical margin display process <NUM> may be performed by different elements of the system <NUM>, such as, the processing system <NUM>, the display system <NUM>, the communications system <NUM>, the navigation system <NUM>, the FMS <NUM>, the onboard avionics systems <NUM> and/or the onboard detection systems <NUM>. It should be appreciated that the vertical margin display process <NUM> may include any number of additional or alternative tasks, the tasks need not be performed in the illustrated order and/or the tasks may be performed concurrently, and/or the vertical margin display process <NUM> may be incorporated into a more comprehensive procedure or process having additional functionality not described in detail herein. Moreover, one or more of the tasks shown and described in the context of <FIG> could be omitted from a practical embodiment of the vertical margin display process <NUM> as long as the intended overall functionality remains intact.

Still referring to <FIG>, and with continued reference to <FIG>, in an exemplary embodiment, the illustrated vertical margin display process <NUM> begins by receiving or otherwise obtaining current status information pertaining to the aircraft (task <NUM>). The current status information pertaining to the aircraft <NUM> generally represents the instantaneous, real-time or most recent available values for one or more parameters that quantify the current operation of the aircraft <NUM>. For example, the processing system <NUM> may obtain (e.g., from FMS <NUM>, navigation system <NUM> and/or other avionic systems <NUM>) one or more of the following: the current location of the aircraft <NUM>, the current altitude (or above ground level) of the aircraft <NUM>, the current heading (or bearing) of the aircraft <NUM>, the current amount of fuel remaining onboard the aircraft <NUM>, the current engine status, the current aircraft configuration (e.g., the current flap configuration, the current landing gear configuration, and/or the like). Additionally, the processing system <NUM> may obtain, either from the onboard detection systems <NUM> or an external system via communications system <NUM>, current meteorological conditions at or near the current location of the aircraft <NUM> (e.g., the current temperature, wind speed, wind direction, atmospheric pressure, turbulence, and the like).

The vertical margin display process <NUM> continues by identifying or otherwise determining a potential landing location for analysis (task <NUM>). In some embodiments, the vertical margin display process <NUM> may identify the runway at the destination airport set forth in the flight plan programmed into the FMS <NUM> as the landing location to be analyzed. In other embodiments, in the event of a diversion or another situation where the aircraft needs to deviate from the original flight plan, such as an emergency situation, the vertical margin display process <NUM> may automatically identify one or more airports within a vicinity of the aircraft for analysis. For example, by default, the processing system <NUM> and/or the FMS <NUM> may utilize the current location of the aircraft <NUM> to identify the closest airport to the current location of the aircraft <NUM> from a database <NUM> for analysis. As described in greater detail below in the context of <FIG>, in some embodiments, the vertical margin display process <NUM> is performed with respect to any airports identified within a geographic area of interest, such as the geographic area corresponding to the currently displayed area of a navigational map on the display device <NUM>, a geographic area within a threshold distance of the current aircraft location, a user-selected geographic area, and/or the like. For example, as described in U. PatentNo. <NUM>,<NUM>,<NUM>, the processing system <NUM> and/or the FMS <NUM> may generate an airport selection graphical user interface (GUI) display on the display device <NUM> that depicts airports within a vicinity of the aircraft <NUM> for analysis and selection by a pilot, co-pilot or other crew member in the event of a diversion. A pilot may utilize his or her discretion to select or otherwise indicate the desired runway at his or her desired airport based on any number of factors (e.g., the estimated landing weight and/or required runway length, etc.).

After identifying the landing location of interest, the vertical margin display process <NUM> identifies or otherwise determines the location of a reference point in advance of the landing location that defines or otherwise demarcates a final approach segment en route to the landing location (task <NUM>). In this regard, the final approach reference point represents the location in advance of landing at the runway at which the aircraft is aligned with the runway heading (or centerline) and the aircraft configuration would be expected to be adjusted for landing at the runway (e.g., flap extension, landing gear deployment, etc.). In one or more embodiments, the processing system <NUM> and/or the FMS <NUM> utilizes an airport database <NUM> to identify the geographic location associated with a final approach fix associated with a runway at the airport of interest which defines the final approach segment aligned with the runway heading (or runway centerline). In other embodiments, in the absence of a defined final approach fix for a given runway or airport, the processing system <NUM> and/or the FMS <NUM> may calculate or otherwise determine a final approach reference point for a final approach segment by projecting a segment aligned with the runway backwards towards the current location of the aircraft by a predetermined distance (e.g., <NUM> nautical mile).

After identifying the location of a final approach reference point, the vertical margin display process <NUM> calculates or otherwise determines a target altitude for the aircraft upon reaching the final approach reference point (task <NUM>). In exemplary embodiments, the vertical margin display process <NUM> generates or otherwise constructs a vertical trajectory that climbs at a constant flight path angle (e.g., <NUM>° from the horizontal) backwards from the runway at the airport until reaching the location of the final approach reference point. In practice, the flight path angle may vary depending on the runway and/or airport, for example, if terrain or approach procedures associated with a particular runway prescribes a particular flight path angle. Otherwise, a standard default angle of <NUM>° from the horizontal may be utilized.

Still referring to <FIG>, the vertical margin display process <NUM> constructs or otherwise determines a lateral trajectory from the current location of the aircraft to the location of the final approach reference point, and then calculates or otherwise determines a gliding vertical trajectory for the aircraft along the lateral trajectory using gliding characteristics associated with the aircraft (tasks <NUM>, <NUM>). In exemplary embodiments, the processing system <NUM> and/or FMS <NUM> identifies a lateral trajectory that includes one or more segments between the current geographic location of the aircraft <NUM> and the location associated with the final approach reference point. The lateral trajectory accounts for the turning radius of the aircraft <NUM> and provides a feasible lateral trajectory that the aircraft <NUM> is capable of flying given the aircraft's current airspeed, the current aircraft configuration, and potentially other factors (e.g., meteorological conditions or the like).

Once the lateral trajectory is determined, the processing system <NUM> and/or the FMS <NUM> calculates or otherwise determines the gliding vertical trajectory that represents the expected behavior or performance of the aircraft <NUM> vertically while gliding along the lateral trajectory. The gliding vertical trajectory starts at the current altitude of the aircraft <NUM> at the current location of the aircraft and descends along the lateral trajectory en route to the final approach reference point at a rate that reflects the gliding characteristics of the aircraft <NUM>, such as, for example, the optimal glide speed for the aircraft <NUM> that minimizes the sink rate, the current sink rate (or lift-to-drag ratio) for the aircraft, the current weight of the aircraft <NUM>, the current configuration of the aircraft <NUM>, and/or the like. In exemplary embodiments, the processing system <NUM> and/or the FMS <NUM> identifies or otherwise determines the current sink rate (or lift-to-drag ratio) and projects the gliding vertical trajectory forward from the current aircraft altitude and location by initially using the current sink rate and current speed of the aircraft <NUM> and constructing a descent path that reflects the current and/or anticipated airspeed, sink rate, winds, and/or the like while en route to the final approach reference point and assuming the current aircraft configuration state is maintained until reaching the final approach reference point. In various embodiments, the vertical margin display process <NUM> also identifies or otherwise obtains forecasted or real-time meteorological information associated with the runway (e.g., via communications system <NUM>), the current location of the aircraft (e.g., via an onboard detection system <NUM>), or other navigational reference points or geographic areas relevant to the lateral trajectory so that the resulting gliding vertical trajectory accounts for meteorological impacts on the descent of the aircraft <NUM> (e.g., wind speed and direction, etc.). For example, a tailwind or headwind along the anticipated flight path can increase or decrease the airspeed above or below the optimal gliding speed and thereby increase the sink rate and reduce the predicted altitude at the final approach reference point.

After constructing the gliding vertical trajectory en route to the final approach reference point, the vertical margin display process <NUM> identifies or otherwise determines the predicted altitude of the aircraft expected upon arrival at the final approach reference point in accordance with the gliding vertical trajectory (task <NUM>). In this regard, the processing system <NUM> and/or the FMS <NUM> identifies the altitude along the gliding vertical trajectory at the geographic location of the final approach reference point that is expected to result from the aircraft <NUM> gliding from its current location en route to the final approach reference point along the lateral trajectory. The vertical margin display process <NUM> generates or otherwise provides a graphical indication of the difference between the predicted aircraft altitude at the final approach reference point and the target altitude at the final approach reference point (task <NUM>). For example, the processing system <NUM> and/or the FMS <NUM> may subtract the target altitude from the predicted aircraft altitude at the final approach reference point and provide a graphical representation of the estimated vertical height margin available to the aircraft <NUM>. In some embodiments, the processing system <NUM> and/or the FMS <NUM> may provide qualitative indicia of whether the estimated vertical height margin is positive or negative, for example, by rendering the runway or airport using one visually distinguishable characteristic to indicate when sufficient margin exists (e.g., a green color when the estimated vertical height margin is positive) and a different visually distinguishable characteristic when the estimated vertical height margin is insufficient (e.g., a red color when the estimated vertical height margin is negative). Thus, a pilot, co-pilot, or other crew member operating the aircraft <NUM> may be quickly apprised of the anticipated vertical situation of the aircraft <NUM> with respect to landing at the particular runway or airport of interest and manually fly the aircraft <NUM> in a manner that is informed by the estimated vertical height margin.

For example, the estimated vertical height margin appears to be too high, the pilot can take actions to increase the descent rate (e.g., by increasing speed above the glide speed) or alter the lateral flight path (e.g., by adding turns closer to the runway) to increase the lateral distance to be traveled and thereby reduce the estimated vertical height margin upon reaching the reference point. Conversely, if the estimated vertical height margin is too low, the pilot may jettison fuel or initiate other actions to decrease the descent rate or otherwise alter the aircraft trajectory to attempt to increase the vertical height margin (or alleviate the potential absence thereof).

In exemplary embodiments, the vertical margin display process <NUM> continually repeats the loop defined by tasks <NUM>, <NUM>, <NUM> and <NUM> to dynamically update the graphical indicia of the vertical height margin as the aircraft <NUM> travels en route to a particular airport. In this regard, as the manually flown aircraft <NUM> deviates from the previously determined lateral trajectory or gliding vertical trajectory, the estimated vertical height margin is dynamically updated to reflect the changing state of the aircraft <NUM> and provide feedback to the pilot, co-pilot, or other crew member operating the aircraft <NUM> regarding the vertical situation of the aircraft <NUM> with respect to landing at the particular runway or airport of interest. Thus, the pilot can dynamically adjust manual flight of the aircraft <NUM> substantially in real-time in response to fluctuations in the estimated vertical height margin and take anticipatory actions that are likely to improve future operation of the aircraft <NUM> with respect to landing at the airport.

<FIG> depicts an exemplary vertical profile <NUM> depicting the relationship between a gliding vertical trajectory and a final approach reference point in connection with an exemplary embodiment of the vertical margin display process <NUM>. As described above, after identifying a runway <NUM> at an airport of interest in a vicinity of the aircraft <NUM>, the vertical margin display process <NUM> identifies the location for a final approach reference point <NUM> in advance of the runway <NUM> and constructs a reference vertical trajectory <NUM> backwards along the runway heading from the runway <NUM> to the approach reference point <NUM> at a constant flight path angle <NUM> to arrive at a target altitude <NUM> at the final approach reference point <NUM>. The vertical margin display process <NUM> then calculates or otherwise determines a gliding vertical trajectory <NUM> that descends from the current altitude of the aircraft <NUM> at the current location of the aircraft <NUM> in a manner that is influenced based at least in part on the current aircraft speed, the current sink rate, the current aircraft configuration, and/or other factors as described above to arrive at a predicted aircraft altitude <NUM> upon reaching the final approach reference point <NUM> when being flown manually and gliding en route from the current aircraft location to the final approach reference point <NUM> along the expected lateral trajectory. In this regard, the lateral distance associated with the gliding vertical trajectory between the current location of the aircraft <NUM> and the final approach reference point <NUM> corresponds to the lateral distance associated with the constructed lateral trajectory between the current aircraft location and the final approach reference point <NUM>. The vertical margin display process <NUM> calculates or otherwise determines the estimated vertical height margin <NUM> for landing at the runway <NUM> by subtracting the target approach altitude <NUM> from the predicted aircraft altitude <NUM>. Graphical indicia of the magnitude and/or sign of the estimated vertical height margin <NUM> may then be provided on the display device <NUM> to indicate to the pilot that sufficient vertical height margin is expected for the runway <NUM>.

Referring now to <FIG>, and with continued reference to <FIG>, in one or more exemplary embodiments, the processing system <NUM> and the display system <NUM> are cooperatively configured to control the rendering of a flight deck display <NUM> on the display device <NUM> and provide graphical indicia of the estimated vertical height margin on the flight deck display <NUM>. In an exemplary embodiment, the flight deck display <NUM> includes a primary flight display <NUM> capable of being utilized by a pilot or other user for guidance with respect to manually flying the aircraft <NUM>, that is, the pilot's primary reference for flight information (e.g., speed and altitude indicia, attitude indicia, lateral and vertical deviation indicia, mode annunciations, and the like). It should be appreciated that flight deck display <NUM> as depicted in <FIG> represents the state of a dynamic display frozen at one particular time, and that the flight deck display <NUM> may be continuously refreshed during operation as the aircraft <NUM> travels to reflect changes in the attitude, altitude and/or position of the aircraft <NUM> with respect to the Earth.

In the illustrated embodiment, the primary flight display <NUM> includes several features that are graphically rendered, including, without limitation a synthetic perspective view of terrain <NUM>, a reference symbol <NUM> corresponding to the current flight path of the aircraft <NUM>, an airspeed indicator <NUM> (or airspeed tape) that indicates the current airspeed of the aircraft <NUM>, an altitude indicator <NUM> (or altimeter tape) that indicates the current altitude of the aircraft <NUM>, a zero pitch reference line <NUM>, a pitch ladder scale <NUM>, a compass <NUM>, and an aircraft reference symbol <NUM>, as described in greater detail below. The embodiment shown in <FIG> has been simplified for ease of description and clarity of illustration - in practice, embodiments of the primary flight display <NUM> may also contain additional graphical elements corresponding to or representing pilot guidance elements, waypoint markers, flight plan indicia, flight data, numerical information, trend data, and the like. For the sake of clarity, simplicity, and brevity, the additional graphical elements of the primary flight display <NUM> will not be described herein.

In an exemplary embodiment, the terrain <NUM> is based on a set of terrain data that corresponds to a viewing region proximate the current location of aircraft <NUM> that corresponds to the forward-looking cockpit viewpoint from the aircraft <NUM>. As described above, the processing system <NUM> and/or the display system <NUM> includes or otherwise accesses a terrain database <NUM>, and in conjunction with navigational information (e.g., latitude, longitude, and altitude) and orientation information (e.g., aircraft pitch, roll, heading, and yaw) from one or more onboard avionics systems <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, the processing system <NUM> and/or the display system <NUM> controls the rendering of the terrain <NUM> on the display device <NUM> and updates the set of terrain data being used for rendering as needed as the aircraft <NUM> travels. As shown, in an exemplary embodiment, the processing system <NUM> and/or the display system <NUM> renders the terrain <NUM> in a perspective or three dimensional view that corresponds to a flight deck (or cockpit) viewpoint. In other words, terrain <NUM> is displayed in a graphical manner that simulates the flight deck viewpoint, that is, the vantage point of a person in the cockpit of the aircraft (e.g., a line of sight aligned with a longitudinal axis of the aircraft). Thus, features of terrain <NUM> are displayed in a conformal manner, relative to the Earth. For example, the relative elevations and altitudes of features in terrain <NUM> are displayed in a virtual manner that emulates reality. Moreover, as the aircraft <NUM> navigates (e.g., turns, ascends, descends, rolls, etc.), the graphical representation of terrain <NUM> and other features of the perspective display can shift to provide a continuously updated virtual representation for the flight crew that reflects the current state of the aircraft <NUM> with respect to the Earth. It should be appreciated that the perspective view associated with primary flight display <NUM> need not always include a perspective view of terrain <NUM>. For example, in the absence of terrain data, the perspective view of the display may appear flat, blank, or otherwise void of conformal terrain graphics.

In the illustrated embodiment, the primary flight display <NUM> and/or the terrain <NUM> includes a graphical representation of a runway <NUM> (e.g., a runway outline) that the aircraft <NUM> is en route to. In this regard, the runway indicator <NUM> is depicted with respect to the terrain <NUM> in a manner that reflects the altitude of the runway and the orientation of the runway heading with respect to the surrounding terrain <NUM>.

As illustrated in <FIG>, the flight path reference symbol <NUM>, the airspeed indicator <NUM>, the altitude indicator <NUM>, the zero pitch reference line <NUM>, the pitch ladder scale <NUM>, the compass <NUM>, and the aircraft reference symbol <NUM> are displayed or otherwise rendered overlying the terrain <NUM>. During flight, the flight path reference symbol <NUM> moves within primary flight display <NUM> such that it generally indicates the direction the aircraft <NUM> is currently moving. The pitch ladder scale <NUM> includes a number of parallel marks and/or alphanumeric characters that indicate the pitch of the aircraft <NUM> relative to a reference orientation for the body of the aircraft <NUM> using any convenient scale, where a pitch angle of zero degrees with respect to the reference orientation for the body of the aircraft <NUM> (i.e., zero pitch on pitch ladder scale <NUM>) corresponds to the zero pitch reference line <NUM>. In an exemplary embodiment, the zero pitch reference line <NUM> is rendered in a conformal manner such that it moves (up and down) and rotates (clockwise and counterclockwise) within the primary flight display <NUM> in accordance with the current orientation (e.g., pitch, roll, and yaw) of the aircraft <NUM>. In this regard, the rendering and display of zero pitch reference line <NUM> is influenced by the actual zero pitch orientation of the aircraft. It will be appreciated that the zero pitch reference line <NUM> generally corresponds to an artificial horizon line (e.g., an angle of zero degrees for the aircraft <NUM> nose to pitch up or down with respect to the real horizon parallel to the local earth surface), such that portions of the primary flight display <NUM> (e.g., portions of terrain <NUM>) above the zero pitch reference line <NUM> correspond to real-world features that are above the current altitude of the aircraft <NUM> portions of the primary flight display <NUM> below the zero pitch reference line <NUM> correspond to real-world features that are below the current altitude of the aircraft <NUM>. Thus, the zero pitch reference line <NUM> may be utilized to discern relative altitude and/or attitude of the terrain <NUM> with respect to the aircraft <NUM>. Markings of pitch ladder scale <NUM> that appear above zero pitch reference line <NUM> correspond to positive pitch of the aircraft, and markings of pitch ladder scale <NUM> that appear below zero pitch reference line <NUM> correspond to negative pitch of the aircraft. The "intersection" of an aircraft reference symbol <NUM> with pitch ladder scale <NUM> represents the current pitch of the aircraft <NUM>, as indicated on pitch ladder scale <NUM>.

Still referring to <FIG>, in exemplary embodiments, when the vertical margin display process <NUM> is active, the primary flight display <NUM> includes a graphical indication <NUM> that the primary flight display <NUM> is in a display mode other than a normal or managed operating mode. For example, in one or more embodiments, the vertical margin display process <NUM> may be automatically initiated in response to the processing system <NUM> and/or the FMS <NUM> detecting a TEFO condition, with the primary flight display <NUM> being automatically updated to include a TEFO display mode indicator <NUM> that notifies the pilot or other aircraft operator of the automated change to the primary flight display <NUM>.

In the TEFO display mode, the processing system <NUM> generates or otherwise provides a graphical indication <NUM> of the estimated vertical height margin calculated with respect to a final approach reference point in advance of the runway <NUM> in accordance with the vertical margin display process <NUM> of <FIG> as described above. In this regard, the estimated vertical height margin indicator <NUM> includes a graphical representation of the estimated vertical height margin (e.g., vertical height margin <NUM>) corresponding to the difference between the altitude of the aircraft <NUM> expected to result from a gliding trajectory (e.g., vertical gliding trajectory <NUM>) en route to the final approach navigational reference point in advance of the runway <NUM>, thereby providing the pilot or other aircraft operator with quantitative feedback regarding the current state of the aircraft <NUM> with respect to landing at the runway <NUM>. Additionally, in exemplary embodiments, the estimated vertical height margin indicator <NUM> is rendered in different visually distinguishable characteristics depending on whether the estimated vertical height margin is positive or negative to provide qualitative feedback regarding the current state of the aircraft <NUM> with respect to landing at the runway <NUM>. For example, the estimated vertical height margin depicted within the estimated vertical height margin indicator <NUM> may be rendered using blue when it is positive or rendered in red when the estimated vertical height margin is negative. The visually distinguishable or distinctive characteristics are preferably chosen to allow a pilot or crew member to quickly and intuitively ascertain the qualitative state of the aircraft <NUM> (e.g., without requiring prolonged focus on the indicator). While the subject matter is described herein in the context of the visually distinguishable characteristic being a color, depending on the embodiment, the "visually distinguishable characteristics" or "visually distinctive characteristics" may be realized by using one more of the following characteristics, individually or in any combination thereof: different colors, different hues, different tints, different levels of transparency, translucency, opacity, contrast, brightness, or the like, different shading, texturing, and/or other graphical effects.

In exemplary embodiments, the estimated vertical height margin indicator <NUM> is positioned on the primary flight display <NUM> adjacent to the altitude indicator <NUM>, so that the pilot can conveniently reference the estimated vertical height margin indicator <NUM> when evaluating the current altitude of the aircraft <NUM>. As described above in the context of <FIG>, during flight en route to the runway <NUM>, the gliding vertical trajectory <NUM> is dynamically updated as the aircraft <NUM> travels to reflect changes to the altitude, location, and/or speed of the aircraft <NUM> substantially in real-time, which, in turn, results in the estimated vertical height margin <NUM> depicted within the estimated vertical height margin indicator <NUM> being correspondingly updated to provide the pilot with feedback substantially in real-time. Thus, by virtue of the improved situational awareness provided by the estimated vertical height margin indicator <NUM>, a pilot can quickly ascertain how manual operation of the aircraft <NUM> is influencing the ability of landing at the runway <NUM> and proactively respond to changes in real-time to improve the likelihood of a safe landing at the runway <NUM> under a TEFO condition or other anomalous condition of the aircraft <NUM>. For example, a pilot may utilize the estimated vertical height margin indicator <NUM> to manually fly the aircraft <NUM> in a manner that results in the estimated vertical height margin converging towards a value of zero upon reaching the final approach reference point (e.g., to avoid having either excess energy upon landing or insufficient energy to land at the runway). In this regard, when the estimated vertical height margin toggles from positive to negative or vice versa, the estimated vertical height margin indicator <NUM> dynamically updates to provide qualitative and quantitative feedback of any manual overcorrections substantially in real-time.

<FIG> depicts an exemplary airport selection GUI display <NUM> that may be presented in accordance with one or more embodiments of the vertical margin display process <NUM> of <FIG>. For example, in response to the processing system <NUM> and/or the FMS <NUM> detecting a TEFO condition or other anomalous condition, the processing system <NUM> may automatically update a lateral map display (or navigational map display) to include graphical representations of different airports <NUM> within a currently displayed geographic area around the current location of the aircraft <NUM> from which the pilot may select a desired diversion airports, in a similar manner as described in <CIT>.

For each potential airport within a threshold distance of the current location of the aircraft <NUM> defined by the currently displayed geographic area, the vertical margin display process <NUM> identifies a respective final approach reference point <NUM> in advance of the respective airport <NUM>, identifies a target altitude at the respective final approach reference point <NUM>, constructs a respective lateral trajectory <NUM> en route to the respective final approach reference point <NUM>, and determines respective gliding vertical trajectory en route to the respective final approach reference point <NUM> along the respective lateral trajectory <NUM> for each respective airport <NUM> (e.g., tasks <NUM>, <NUM>, <NUM>, <NUM>). For each respective airport <NUM>, an estimated vertical height margin associated with the respective airport <NUM> is determined based on the difference between the predicted aircraft altitude resulting from the gliding vertical trajectory en route to the respective final approach reference point <NUM> for that airport <NUM> and the identified target altitude at the respective final approach reference point <NUM> for that airport <NUM> (e.g., task <NUM>). A graphical indication <NUM> of the estimated vertical height margin associated with each respective airport <NUM> is depicted adjacent to or otherwise in visual association with the graphical representation of the respective reference point <NUM> and/or the graphical representation of the respective airport <NUM> (e.g., task <NUM>), thereby allowing the pilot to concurrently assess and analyze the potentially available (or unavailable) vertical height margin with respect to each of the airports <NUM> in a vicinity of the aircraft. In this regard, the qualitative feedback provided by rendering the estimated vertical height margin indicator <NUM> using different visually distinguishable characteristics may allow the pilot to quickly identify the subset of the airports <NUM> that are most likely to be viable, and from which the pilot may then utilize the quantitative estimated vertical height margin, potentially in addition to other factors, to identify or otherwise select the airport <NUM> that the pilot would like to select. Upon selection of a particular airport <NUM>, the primary flight display rendered on the display device <NUM> onboard the aircraft <NUM> may then automatically update to the TEFO display mode to depict the estimated vertical height margin for the selected airport and dynamically update the estimated vertical height margin while the pilot navigates the aircraft <NUM> en route to the selected airport <NUM>.

For the sake of brevity, conventional techniques related to approach procedures, aerodynamics, aircraft modeling, graphics and image processing, avionics systems, and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. It should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the subject matter.

The subject matter may be described herein in terms of functional and/or logical block components, and with reference to symbolic representations of operations, processing tasks, and functions that may be performed by various computing components or devices. It should be appreciated that the various block components shown in the figures may be realized by any number of hardware components configured to perform the specified functions. Furthermore, embodiments of the subject matter described herein can be stored on, encoded on, or otherwise embodied by any suitable non-transitory computer-readable medium as computer-executable instructions or data stored thereon that, when executed (e.g., by a processing system), facilitate the processes described above.

The foregoing description refers to elements or nodes or features being "coupled" together. As used herein, unless expressly stated otherwise, "coupled" means that one element/node/feature is directly or indirectly joined to (or directly or indirectly communicates with) another element/node/feature, and not necessarily mechanically. Thus, although the drawings may depict one exemplary arrangement of elements directly connected to one another, additional intervening elements, devices, features, or components may be present in an embodiment of the depicted subject matter. In addition, certain terminology may also be used herein for the purpose of reference only, and thus are not intended to be limiting.

The foregoing detailed description is merely exemplary in nature and is not intended to limit the subject matter of the application and uses thereof. Furthermore, there is no intention to be bound by any theory presented in the preceding background, brief summary, or the detailed description.

Claim 1:
A method of assisting operation of an aircraft en route to an airport, the method comprising:
identifying a reference point in advance of a runway at the airport using a procedure database, the reference point comprising a final approach fix associated with the runway;
dynamically determining a gliding vertical trajectory for the aircraft en route to the reference point based at least in part on a current altitude of the aircraft at a current aircraft location and gliding characteristics of the aircraft, the gliding vertical trajectory resulting in a predicted altitude of the aircraft at a location corresponding to the reference point;
constructing a reference vertical trajectory having a constant flight path angle backwards from the runway to the final approach fix;
and
providing, on a primary flight display, a graphical indication of a vertical height margin comprising a difference between the predicted altitude at the location corresponding to the reference point resulting from the gliding vertical trajectory and an altitude criterion associated with the reference point, the altitude criterion comprising a target altitude at the final approach fix identified as an altitude of the reference vertical trajectory at a distance in advance of the runway corresponding to the location of the final approach fix, wherein the graphical indication of the difference dynamically updates as the aircraft travels, and wherein the graphical indication comprises a graphical representation of the difference between the predicted altitude at the location corresponding to the final approach fix resulting from the gliding vertical trajectory and the target altitude at the final approach fix, wherein the graphical representation of the difference is rendered in a visually distinguishable characteristic influenced by a sign of the difference.