Patent Publication Number: US-9418561-B2

Title: System and method for displaying predictive conformal configuration cues for executing a landing

Description:
TECHNICAL FIELD 
     Embodiments of the subject matter described herein relate generally to avionics flight display systems and, more particularly, to a flight display system that displays predictive conformal configuration cues for executing a landing after an aircraft engine failure. 
     BACKGROUND 
     The spectrum of flight operations includes routine operations, such as take-off, en route cruising, landing, and taxiing, as well as anticipated non-routine operations. An example of an anticipated non-routine operation is an engine failure operation. As used herein, “engine failure” includes a plurality of events that result in the aircraft losing thrust from the engine, such as fuel exhaustion, routine practice operations, bird or debris interference, and mechanical or electrical failures. The aforementioned flight operations are supported by aircraft design features, pilot training, and an on-board avionics display system. 
     Aircraft design features assure that modern single engine aircraft are able to glide to a safe landing in the event of an engine failure. Without the thrust from the engine, the aircraft is flown at the best glide airspeed, and with sufficient altitude, the pilot may turn the aircraft around, locate an airfield, and execute a controlled and safe landing. In order to execute the safe glide landing, pilots are trained to make various aircraft configuration changes, such as deploying flaps, deploying or extending landing gear, and, in the case of a single engine plane, feathering the propeller. Each of these configuration changes affects glide speed and the lift-to-drag ratio of the aircraft, therefore each configuration may cause the landing to occur at a different location. 
     Although modern avionics display systems display a considerable amount of useful information, such as vehicle position, speed, altitude, attitude, navigation, target, and terrain information, and the like, predictive assistance to pilots during a glide landing is desirable. Specifically, visual guidance that cues or informs a pilot of the predicted landing sites resulting from various potential aircraft configurations is needed. 
     Accordingly, a system and method for displaying predictive cues on an aircraft display system for executing a landing after an engine failure is desirable. It would further be desirable if the system and method displayed cues for a variety of aircraft configurations, and displayed the cues in perspective (conformally) on a three dimensional graphical display of the surrounding terrain. 
     BRIEF SUMMARY 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     A method for displaying, on an avionics display system, cues for executing an aircraft landing after an engine failure is provided. The method comprises receiving avionics data and processing the avionics data to (i) determine current aircraft configuration, (ii) predict a first landing site based on the current aircraft configuration, and (iii) predict a second landing site associated with altering the current aircraft configuration. The method also comprises displaying a first cue representative of the first landing site and a second cue representative of the second landing site. 
     An avionics display system is also provided. The avionics display system comprises a flight deck display coupled to receive display commands and is configured, upon receipt thereof, to render images. The avionics display system also comprises a processor operatively coupled to the flight deck display and adapted to receive avionics data, the processor is configured, upon receipt of the avionics data, to (i) determine current aircraft configuration, (ii) predict a first landing site based on the current aircraft configuration, (iii) predict a second landing site associated with an alternate aircraft configuration, and (iv) supply display commands to the flight deck display that cause the flight deck display to render a first cue representative of the first landing site and a second cue representative of the second landing site. 
     Another method for displaying, on an avionics display system, configuration cues for executing a single engine aircraft landing after engine failure is provided. The method comprises receiving avionics data and processing the avionics data to (i) determine the terrain, (ii) determine current aircraft lift-to-drag ratio, (iii) predict a first landing site based on the current aircraft lift-to-drag ratio, (iv) predict a second landing site associated with a first alteration in the aircraft lift-to-drag ratio, and (v) predict a third landing site associated with a second alteration in the aircraft lift-to-drag ratio. 
     Other desirable features will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and background. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the subject matter may be derived by referring to the following detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures: and 
         FIG. 1  is a schematic representation of an embodiment of a avionics display system; 
         FIG. 2  illustrates a typical aircraft display system graphic with a 3D graphical display in accordance with an exemplary embodiment; 
         FIG. 3  is a simplified illustration of the 3D graphical display of  FIG. 2 , in accordance with the exemplary embodiment; 
         FIG. 4  is a simplified illustration of the 3D graphical display of  FIG. 3  after some time has elapsed, in accordance with the exemplary embodiment; 
         FIG. 5  is a simplified illustration of the 3D graphical display of  FIG. 4  after more time has elapsed, in accordance with the exemplary embodiment; and 
         FIG. 6  flow chart that illustrates an exemplary embodiment of a process for displaying predictive conformal configuration cues. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. 
     Techniques and technologies 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. Such operations, tasks, and functions are sometimes referred to as being computer-executed, computerized, software-implemented, or computer-implemented. In practice, one or more processor devices can carry out the described operations, tasks, and functions by manipulating electrical signals representing data bits at memory locations in the system memory, as well as other processing of signals. 
     The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to the data bits. It should be appreciated that the various block components shown in the figures may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, an embodiment of a system or a component may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. 
     The system and methods described herein can be deployed with any aircraft. The embodiments of the system and methods described herein represent an intelligent way to present visual guidance to a pilot or flight crew during a landing operation of an aircraft that has experienced engine failure. 
       FIG. 1  is functional block diagram illustrating an avionics display system  100  in accordance with an exemplary embodiment. Avionics display system  100  includes at least one processor  102 , at least one monitor  104 , memory  107 , and a user input device  101 , each of which is operatively coupled to processor  102 . During operation of avionics display system  100 , processor  102  drives monitor  104  to produce a display  106  that visually provides a pilot and crew with a composite of navigation information pertaining to the host aircraft, weather, navigational aids (NAVAID), terrain, and aircraft traffic. Processor  102  may provide the display  106  with a composite image in a two dimensional format (e.g., as a moving map display), or a three dimensional format (e.g., as a perspective display), or in a hybrid format (e.g., in a picture-in-picture or split screen arrangement). 
     Processor  102  may comprise, or be associated with, any suitable number of individual microprocessors, flight control computers, navigational equipment, memories, power supplies, storage devices, interface cards, and other standard components known in the art. Processor  102  may be included within a Flight Management Computer of the type commonly deployed within a Flight Management System (FMS). 
     The processor  102  may include or cooperate with an appropriate amount of memory  107  which can be realized as RAM memory, flash memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In this regard, the memory  107  can be coupled to the processor  102  such that the processor  102  can read information from, and write information to, memory  107 . In this respect, the processor  102  may include or cooperate with any number of software programs (e.g., avionics display programs) or instructions designed to carry out the various methods, process tasks, calculations, and control/display functions described below. In the alternative, memory  107  may be integral to the processor  102 . In practice, a functional or logical module/component of the system described here might be realized using program code that is maintained in memory  107 , such as configuration data and models. Moreover, memory  107  can be used to store data utilized to support the operation of the system, as will become apparent from the following description. 
     Image-generating devices suitable for use as monitor  104  include various analog (e.g., cathode ray tube) and digital (e.g., liquid crystal, active matrix, plasma, etc.) display devices. In certain embodiments, monitor  104  may assume the form of a Head-Down Display (HDD) or a Head-Up Display (HUD) included within an aircraft&#39;s Electronic Flight Instrument System (EFIS). Monitor  104  may be disposed at various locations throughout the cockpit. For example, monitor  104  may comprise a primary flight display (PFD) and reside at a central location within the pilot&#39;s primary field-of-view. Alternately, monitor  104  may comprise a secondary flight deck display, such as an Engine Instrument and Crew Advisory System (EICAS) display, mounted at a location for convenient observation by the aircraft crew but that generally resides outside of the pilot&#39;s primary field-of-view. In still further embodiments, monitor  104  may be worn by one or more members of the flight crew. 
     In the exemplary embodiment illustrated in  FIG. 1 , the air traffic data sources  120  include a wireless transceiver  108  and a navigation system  110 , which are operatively coupled to first and second inputs of processor  102 , respectively. Navigation system  110  may be coupled to an inertial reference system (IRS)  120 , air data and attitude heading reference system (ADAHRS)  122 , and a navigation database  118 ; navigation system  110  also typically includes onboard radar  112  and onboard instrumentation  114 , such as a radio altimeter, a barometric altimeter, a global positioning system (GPS) unit, and the like. Navigation system  110  may be included within a FMS, and onboard radar  112  may be included within a Terrain Awareness and Warning System (TAWS), such as an Enhanced Ground Proximity Warning System (EGPWS). Wireless transceiver  108  is considered an air traffic data source in that wireless transceiver  108  receives broadcast data from external control sources and relays this data to processor  102 . 
     The terrain database  116  includes various types of data, including runways, areas that could be used as runways, elevation data, and other information representative of the terrain over which the aircraft is flying. The terrain data can be used to generate a three dimensional perspective view of terrain in a manner that appears conformal to the earth. In other words, the display  106  emulates a realistic view of the terrain from the flight deck or cockpit perspective. The data in the terrain database  116  can be pre-loaded by external data sources or provided in real-time by terrain sensors (not shown). 
     Processor  102  includes one or more inputs operatively coupled to one or more avionics data sources, which continually provide processor  102  with data input from user input device  101 , terrain database  116 , and air traffic data services  120 . In operation, an avionics display system  100  as described herein is suitably configured to process the current real-time avionics data (such as geographic position data, current real-time heading data, airport feature data, aircraft body mass acceleration data, configuration data, terrain data, and the like) to generate image rendering display commands to achieve the display  106 . 
       FIG. 2  illustrates a typical aircraft display system graphic of a 3D graphical display  106  in accordance with an exemplary embodiment. Pilots rely on 3D graphical displays such as display  106  to depict target runways, such as runway  201 , and surrounding terrain. Graphical displays such as display  106  provide relevant, time sensitive information; for example, flight path marker  204  depicts the direction of travel, lateral and wind drift information  206 , and flight path marker  208 , indicates the direction that the aircraft is traveling. 
     At the moment of detecting the engine failure, the exemplary embodiment determines performance computations based on temperature, pressure, altitude, real time lift-to-drag ratio, aircraft weight, and aircraft configuration information. Responsive to the performance computations, the exemplary embodiment adds simple, unique, predictive conformal cues (symbols  210 ,  214  and  218 ) to the display  106 . The predictive conformal cues inform the pilot of potential landing sites associated with alterations in the aircraft lift-to-drag ratio. The alterations in the aircraft lift-to-drag ratio may be predetermined configurations of aircraft equipment (for example, landing gear, flaps, spoilers, and the like) that alter the lift-to-drag ratio, or they may be aircraft maneuvers (for example, a slip). Alternate aircraft configuration data is stored in memory  107  and may be customized via user input at user input device  101 . Each cue, described hereinbelow, is predictive as to the location that the aircraft will land (a landing site) for a given configuration of aircraft equipment. Each cue is unique in its combination of a symbol and associated text. 
     Symbol  210  is shown as a chevron with its point at the predicted best landing site, runway  201 , and the text “clean”  212  is displayed proximate to symbol  210 . Typically, the best or “clean” landing site is also the landing site associated with the “current” aircraft configuration and lift-to-drag ratio. Regardless of the current configuration, landing at the best or “clean” landing site is typically accomplished when the pilot does not alter the aircraft configuration (i.e., does not extend the landing gear or deploy flaps), and aligns the flight path marker  204  with the “clean” chevron (symbol  210 ), extending the glide of the aircraft as much as possible and achieving the maximum lift-to-drag ratio (L/D) for the aircraft. As previously mentioned, altering the L/D may also comprise an aircraft maneuver, like a slip. 
     Symbol  214  is a chevron pointing to the predicted landing site that would result if the pilot altered the aircraft lift-to-drag ratio by deploying/extending only the landing gear. The optionally selected text “gear”  216  is displayed proximate to symbol  214 . In the exemplary embodiment, the location of symbol  214  is continuously being updated and displayed to reflect a landing site that results from deploying the landing gear. Likewise, symbol  218  is a chevron pointing to a predicted landing site that would result if the pilot altered the aircraft lift-to-drag ratio by deploying both landing gear and flaps. The optionally selected text “G+F”  220  is displayed proximate to symbol  218 . The location of symbol  218  is also continuously updated and displayed to reflect a landing site that results from deploying the landing gear and flaps. The symbols  210 ,  214  and  218  are optionally illustrated as chevrons, and oriented so that the point (for example, point  222 ) is located on the landscape  202  at the location of the predicted landing site for the associated configuration of the aircraft. 
     The symbols  210 ,  214  and  218  are rendered in perspective form (also referred to as “conformal”) on the landscape, which is reflected in the relative size decrease from symbol  218  to symbol  214 , to symbol  210 . In other words, symbol  218  is more near to the aircraft and symbol  210  is farther away from the aircraft. The symbols may be visually distinguishable by means of various techniques, such as highlighting, color variations, flashing, etc.; symbols, text labels and visual distinguishability techniques may be customized via user input at the user input device  101  during any part of the flight or landing operation. 
     Using the exemplary embodiment, the pilot, without reducing the lift-to-drag ratio of the aircraft, aligns the flight path marker  204  with the “clean” chevron to affect aircraft movement toward runway  201 . As the aircraft moves closer to runway  201 , the runaway appears larger on display  106 . At the point in time when runway  201  is even with, or slightly overlapped with, the “G+F” chevron, symbol  218  on display  106 , the pilot decreases the lift-to-drag ratio (for example, lowers the gear and flaps), and aligns the flight path marker  204  with the “G+F” chevron, symbol  218 .  FIGS. 3, 4 and 5  illustrate these concepts in more detail. 
       FIG. 3  is a simplified illustration of the 3D graphical display of  FIG. 2 , in accordance with the exemplary embodiment.  FIG. 3  is not to scale, but may be relied upon to understand the relative size and locational relationships of the objects. The flight path marker  204  is aligned with the “clean” chevron, symbol  210 . Aircraft travel is in the direction of arrow  302 . The terrain appears to move in the direction of arrow  304 . 
       FIG. 4  is a simplified illustration of the 3D graphical display of  FIG. 3  after some time has elapsed, in accordance with the exemplary embodiment. Flight path marker  204  is aligned with the “clean” chevron, symbol  210 . The aircraft has flown closer to runway  201 , resulting in runway  201  appearing larger. 
       FIG. 5  is a simplified illustration of the 3D graphical display of  FIG. 4  after more time has elapsed, in accordance with the exemplary embodiment. At the point when runway  201  is slightly overlapped with the “G+F” chevron, symbol  218 , the pilot alters the lift-to-drag ratio by, for example, deploying the gear and flaps, and lands. The pilot lowers the flight path marker  204  from its initial position  502  to align it with the “G+F” chevron, symbol  218 , thereby moving flight path marker  204  through position  504 , position  506 , and position  508  before bringing it to rest in alignment with the “G+F” symbol  218 . 
       FIG. 6  is a flow chart that illustrates an exemplary embodiment of a process  600  for displaying predictive conformal configuration cues. While STEP  602 -STEP  608  are arbitrarily shown as occurring in a sequence, in practice, these steps may be rearranged, customized, or have additional steps added. In addition, user input that customizes symbol shapes, symbol colors, text for aircraft configurations, techniques for displaying the objects in a visually distinguishable manner, and the like, may be accepted at any step in process  600 . Typically, at the moment of detecting the engine failure, the aircraft does not have landing gear extended and does not have flaps deployed; therefore, when process  600  starts, the “current” aircraft configuration and associated lift-to-drag ratio is generally referred to as the configuration that would lead to a “best” or “clean” landing site. The details are described in more detail hereinbelow. 
     At STEP  602  avionics data (such as geographic position data, current real-time heading data, airport feature data, aircraft body mass acceleration data, configuration data, terrain data, and the like) is received by process  600 . Avionics data also includes related data from aircraft subsystems such as wireless transceiver  108 , navigation system  110 , terrain data, and the various sensors and broadcast data. In STEP  602 , configuration data and/or models (i.e., data corresponding to landing equipment that affects L/D, such as aircraft landing gear data, aircraft flap data, and aircraft maneuver data) are also retrieved from memory  107  or determined from avionics data. Configuration data and/or models may be uploaded once or may be altered in the course of process  600 , according to user input data received at user input device  101 . 
     In STEP  604 , processor  102  has the required data, and process  600  processes the data to determine a predicted landing site for various alterations of the lift-to-drag ratio that may be predetermined aircraft configurations. In the exemplary embodiment, process  600  predicts landing sites for three predetermined configurations: 1) a best or “clean” glide (first) landing site, 2) a second landing site that would result from a first alternate aircraft configuration (with a first alteration in L/D), and 3) a third landing site that would result from a second alternate aircraft configuration (with a second alteration in L/D). For example, in the exemplary embodiment, the first alternate aircraft configuration may be deploying only the landing gear, and the second alternate aircraft configuration may be deploying the landing gear and the flaps. 
     In STEP  606 , the predicted landings sites are indicated using optionally selectable cue symbols (see,  FIG. 2 - FIG. 5 , symbol  210 , symbol  214  and symbol  218 ) that are displayed in perspective form on the landscape  202 . Any user selected visual distinguishability, text, and symbol selection is incorporated into the display of the conformal configuration cues in STEP  606 . At STEP  608 , process  600  determines whether or not the aircraft has landed. If the aircraft has not landed, process  600  continuously cycles and updates display  106  until the aircraft has landed. 
     Thus, there has been provided a system and method for displaying predictive cues on an aircraft display system for executing a landing after an engine failure. The system and method displays the cues for various aircraft configurations, and each cue is displayed in perspective (conformally) on a three dimensional graphical display of the surrounding terrain. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.