Patent Publication Number: US-11398159-B2

Title: Method and system for reducing aircraft fuel consumption

Description:
FIELD 
     This application generally relates to aircraft routing at an airport. In particular, this application describes a method and system for reducing aircraft fuel consumption. 
     BACKGROUND 
     The cost of aircraft fuel is a significant consideration in the operation of a fleet of aircraft. For example, by some estimates, airlines in the United States collectively consume 17 billion gallons of j et fuel annually. 
     The majority of aircraft fuel consumption occurs while aircraft are flying. However, an appreciable amount of fuel can be consumed while aircraft are waiting to take off from an airport. For example, aircraft may be consuming fuel while waiting at a gate or while taxiing towards the runway. 
     Some airports face chronic congestion problems, which results in aircraft spending a considerable amount of time waiting on various taxiways and runway entranceways to take off. The chronic delay can impact aircraft and crew scheduling related to particular aircraft. When considering a fleet of aircraft, time spent in such cases can significantly impact the operating costs of an airline. 
     SUMMARY 
     In a first aspect, a computer-implemented method to reduce aircraft fuel consumption is disclosed. The method includes determining, by a computer, whether a particular aircraft belongs to a runway queue associated with one or more aircraft waiting to take-off from a runway of an airport based on (i) real-time aircraft geographic location information associated with the particular aircraft and (ii) a graph associated with features of the airport. The method further includes, responsive to determining that the particular aircraft belongs to the runway queue, determining, by the computer, an amount of time the particular aircraft spends in the runway queue before taking off from the runway. The computer may determine a runway queue take-off delay associated with the runway queue based at least in part on the amount of time the particular aircraft spends in the runway queue. The computer may communicate the runway queue take-off delay to a controller terminal of the airport to facilitate routing a different aircraft to a different runway queue associated with a shorter runway queue take-off delay to reduce fuel consumption by the different aircraft. 
     In a second aspect, a system to reduce aircraft fuel consumption is disclosed. The system includes a memory that stores instruction code; and a processor in communication with the memory. The instruction code is executable by the processor to perform acts that include determining whether a particular aircraft belongs to a runway queue associated with one or more aircraft waiting to take-off from a runway of an airport based on (i) real-time aircraft geographic location information associated with the particular aircraft and (ii) a graph associated with features of the airport. Responsive to determining that the particular aircraft belongs to the runway queue, the processor determines an amount of time the particular aircraft spends in the runway queue before taking off from the runway. The processor determines a runway queue take-off delay associated with the runway queue based at least in part on the amount of time the particular aircraft spends in the runway queue. The processor communicates the runway queue take-off delay to a controller terminal of the airport to facilitate routing a different aircraft to a different runway queue associated with a shorter runway queue take-off delay to reduce fuel consumption by the different aircraft. 
     In a third aspect, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium has stored thereon instruction code executable to perform acts to facilitate a reduction in aircraft fuel consumption. The instruction code is executable by a processor of a computer to perform acts that include determining whether a particular aircraft belongs to a runway queue associated with one or more aircraft waiting to take-off from a runway of an airport based on (i) real-time aircraft geographic location information associated with the particular aircraft and (ii) a graph associated with features of the airport. Responsive to determining that the particular aircraft belongs to the runway queue, an amount of time the particular aircraft spends in the runway queue before taking off from the runway is determined. A runway queue take-off delay associated with the runway queue is determined based at least in part on the amount of time the particular aircraft spends in the runway queue. The runway queue take-off delay is communicated to a controller terminal of the airport to facilitate routing a different aircraft to a different runway queue associated with a shorter runway queue take-off delay to reduce fuel consumption by the different aircraft. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying drawings are included to provide a further understanding of the claims, are incorporated in, and constitute a part of this specification. The detailed description and illustrated examples described serve to explain the principles defined by the claims. 
         FIG. 1  illustrates an environment that facilitates reducing aircraft fuel consumption, in accordance with an example. 
         FIG. 2  illustrates a polygon topology that may represent information stored in an airport mapping database of an aircraft runway queue detection system of the environment, in accordance with an example. 
         FIG. 3  illustrates a computer-implemented method to reduce aircraft fuel consumption, in accordance with an example. 
         FIG. 4  illustrates an example of a graph that may be utilized in determining whether a particular aircraft belongs to a runway queue, in accordance with an example. 
         FIG. 5A  illustrates an airport map with an instantiated runway queue, in accordance with an example. 
         FIG. 5B  illustrates the addition of a second aircraft to the instantiated runway queue, in accordance with an example. 
         FIG. 5C  illustrates the addition of a third aircraft to the instantiated runway queue, in accordance with an example. 
         FIG. 5D  illustrates the addition of a fourth aircraft to the instantiated runway queue, in accordance with an example. 
         FIG. 5E  illustrates the addition of a fifth aircraft to the instantiated runway queue, in accordance with an example. 
         FIG. 5F  illustrates the first aircraft taking off from the runway, in accordance with an example. 
         FIG. 5G  illustrates the second aircraft moving to the head of the runway queue, in accordance with an example. 
         FIG. 5H  illustrates the second aircraft taking off from the runway, in accordance with an example. 
         FIG. 5I  illustrates the fourth aircraft as being at the head of the runway queue, followed by the fifth aircraft, in accordance with an example. 
         FIG. 5J  illustrates the fifth aircraft moving to the head of the runway queue and the fourth aircraft moving to the second position in the runway queue, in accordance with an example. 
         FIG. 5K  illustrates the fourth aircraft moving to the head of the runway queue after the fifth aircraft takes off from the runway, in accordance with an example. 
     
    
    
     DETAILED DESCRIPTION 
     Various examples of systems, devices, and/or methods are described herein. Words such as “example” and “exemplary” that may be used herein are understood to mean “serving as an example, instance, or illustration.” Any implementation, and/or feature described herein as being an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over any other embodiment, implementation, and/or feature unless stated as such. Thus, other embodiments, implementations, and/or features may be utilized, and other changes may be made without departing from the scope of the subject matter presented herein. 
     Accordingly, the examples described herein are not meant to be limiting. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations. 
     Further, unless the context suggests otherwise, the features illustrated in each of the figures may be used in combination with one another. Thus, the figures should be generally viewed as component aspects of one or more overall embodiments, with the understanding that not all illustrated features are necessary for each embodiment. 
     Additionally, any enumeration of elements, blocks, or steps in this specification or the claims is for purposes of clarity. Thus, such enumeration should not be interpreted to require or imply that these elements, blocks, or steps adhere to a particular arrangement or are carried out in a particular order. 
     Moreover, terms such as “substantially,” or “about” that may be used herein, are meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including, for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of ordinary skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide. 
     To the extent that terms “includes,” “including,” “has,” “contains,” and variants thereof are used herein, such terms are intended to be inclusive in a manner similar to the term “comprises” as an open transition word without precluding any additional or other elements. 
     INTRODUCTION 
     As noted above, chronic congestion problems at airports result in aircraft spending a considerable amount of time on various taxiways and runway entranceways waiting to take off. When considering a fleet of aircraft, time spent in such cases can significantly impact the operating costs of an airline. 
     Examples of systems and methods are disclosed herein that address this problem. According to examples, a polygon topology that represents features of an airport is provided. A graph that includes nodes and edges is generated based on the polygon topology. Locations of aircraft on the grounds of the airport are determined in relation to the polygon topology. The polygon topology and the graph are utilized to identify aircraft waiting in a runway queue. The amount of time aircraft spend in the runway queue (i.e., take-off delay) is determined and communicated to air traffic controllers of the airport. The communicated take-off delay associated with the runway queue facilitates routing aircraft to runway queues having a shorter take-off delay. 
       FIG. 1  illustrates an example of an environment  100  that facilitates reducing aircraft fuel consumption. Illustrated entities of the environment  100  include an aircraft runway queue detection system (ARQDS)  102 , a controller terminal  104 , and aircraft  106 . The various entities of the environment  100  can communicate with one another via a network  107 , such as the Internet. 
     The ARQDS  102  includes a memory device  127  that stores instruction code and a processor  125  that is in communication with the memory device  127 . An example of the ARQDS  102  can further include an I/O subsystem  110  and an airport mapping database (AMDB)  130 . 
     The processor  125  executes instruction code stored in the memory device  127  for coordinating activities performed between the various subsystems of the ARQDS  102 . As an example, the processor  125  can correspond to a stand-alone processor such as an Intel®, AMD®, or PowerPC® based processor or a different processor. The ARQDS  102  can include an operating system, such as Microsoft Windows®, Linux, Unix®, or another operating system that operates on the processor  125 . Operations performed by the ARQDS  102  are describe in further detail below. 
     The I/O subsystem  110  can include one or more input/output interfaces configured to facilitate communications with entities outside of the ARQDS  102 . In this regard, the I/O subsystem  110  can be configured to communicate information using a communication methodology such as, for example, a RESTful API or a Web Service API. In some cases, the I/O subsystem  110  can implement a web browser to facilitate generating one or more web-based interfaces through which users of the ARQDS  102 , controller terminal  104 , and/or other systems can interact with the ARQDS  102 . 
     The AMDB  130  can store information that specifies the locations of various features of an airport. The information in the AMDB  130  can be specified in Geographic Javascript Object Notation (GeoJSON). 
       FIG. 2  illustrates a polygon topology  200  that can represent information stored in the AMDB  130  of the ARQDS  102 . Referring  FIG. 2 , the polygon topology  200  can specify the spatial layout of an airport. The geometry of features of the airport can be described as points, lines, and polygons. Within examples, polygons  205 A and  205 B can represent runways of the airport. Polygons  210 A and  210 B can represent different runway entranceways. Polygons  212 A,  212 B,  212 C, and  212 D can represent portions of a taxiway. Polygons  215 A and  215 B can represent gates of an airport. Other information stored in the AMDB  130  can specify additional aspects of the features, such as surface type, name/object identifier for the features, runway slope, etc. 
     The controller terminal  104  can correspond to a computer system operated, for example, by an air traffic control operator at an airport. The controller terminal  104  can be located in a control tower of the airport and can be configured to provide real-time status information regarding aircraft on the ground. For example, the controller terminal  104  can depict a map of the airport that shows the relative location of aircraft on the ground. 
     The aircraft  106  correspond to any aircraft that can be located at the airport, such as commercial jets, passenger jets, helicopters, unmanned aerial vehicles (UAVs), etc. The aircraft  106  can be located on one several runways, taxiways, and runway entranceways. The aircraft  106  can be parked at gates, etc. Particular aircraft  106  can include aircraft location tracking hardware, such as global positioning system (GPS) hardware that facilitates determining the speed and location of the particular aircraft in real-time. The aircraft  106  can further include communication hardware that facilitates communicating the information regarding the speed and location of the aircraft to other entities of the environment, such as the controller terminal  104  and the ARQDS  102 . An example of such communication hardware can correspond to an ADS-B (Automatic Dependent Surveillance-Broadcast) transponder. 
       FIG. 3  illustrates a computer-implemented method to reduce aircraft fuel consumption. The operations of the method of  FIG. 2  can be implemented by one or more of the subsystems of the ARQDS  102 . In this regard, the memory device  127  can include instruction code that is executed by the processor  125  of the ARQDS  102  to cause the processor  125  to perform, and/or control other subsystems of the ARQDS  102  to perform, the operations. 
     Referring to  FIG. 3 , block  300  of the method involves determining, by a computer, whether a particular aircraft belongs to a runway queue associated with one or more aircraft waiting to take-off from a runway of an airport based on (i) real-time aircraft geographic location information associated with the particular aircraft and (ii) a graph associated with features of the airport. 
     The runway queue corresponds to a group of one or more aircraft that line up to take off from a particular runway. In this regard, each runway of an airport can be associated with a single runway queue. That is, there can be multiple queues at a given airport. The first aircraft in a particular runway queue can be the next aircraft expected to take off from the runway. The second aircraft the runway queue can be expected to take off from the runway after the first aircraft, and so on. 
     The real-time aircraft geographic location can correspond to GPS information communicated from the aircraft to the ARQDS  102 . In some examples, the real-time aircraft geographic location facilitates determining the speed of aircraft. In other examples, the aircraft can communicate speed information along with the GPS information. As noted above, aircraft can include communication hardware (e.g., ADS-B) that facilities communicating the real-time aircraft geographic location to other entities of the environment. 
       FIG. 4  illustrates an example of a graph  400  that is associated with the polygon topology  200  of  FIG. 2 . Information in the graph  400  can be utilized by the processor  125  of the ARQDS  102  to determining whether aircraft belong to a runway queue. More specifically, the graph  400  facilitates determining the shortest route and distance between polygons of the polygon topology, which in turn facilitates determining the shortest route and distance between features of the airport, such as taxiways, runway entranceways, runways, etc. 
     Referring to  FIG. 4 , the graph  400  includes an arrangement of nodes and edges that are associated with the features of  FIG. 2 . The nodes correspond to centroids or geometric centers of the polygons of the features of  FIG. 2 . For example, nodes  410 A and  410 B correspond respectively to the centroids of polygons  210 A and  210 B (See  FIG. 2 ), which are illustrated in  FIG. 2 , which are associated with runway entranceways of the airport. Nodes  412 A,  412 B,  412 C, and  412 D correspond respectively to the centroids of polygons  212 A,  212 B,  212 C, and  212 D (See  FIG. 2 ), which are associated with a taxiway of the airport. The centroid in a given polygon generally corresponds to the arithmetic mean position of all the points in the polygon. The centroid for each polygon can be computed by the processor  125  using various techniques. An example of one technique implemented by the processor  125  for determining the centroid can involve representing all the points of the polygon as:
 
 S ={( x   1   ,y   1 ),( x   2   ,y   2 ), . . . ( x   n   ,y   n )}
 
     The processor  125  can then compute the centroid C x,y  of the points in S according to: 
     
       
         
           
             
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     Edges in the graph connect the centroids of polygons that are connected to one another. For example, edge  415 A connects centroids/nodes  412 A and  412 C, which are associated with polygons  212 A and  212 C. Edge  415 B connects the centroid  412 D, which is associated with taxiway polygon  212 D, with centroid  410 B, which is associated with runway entranceway polygon  210 B. 
     The length of each edge represents the distance between the centroids of related polygons. The length of each edge can be computed by the processor  125  using various techniques. For example, the processor  125  can compute the length of the edge according to the Euclidian distance between centroids of related polygons. Determination of the length of each edge facilitates determining the shortest route and distance between polygons of the polygon topology, which in turn facilitates determining the shortest route and distance between features of the airport, such as taxiways, runway entranceways, runways, etc. 
     As described in more detail below, the determination of the shortest route and distance between features of the airport facilitates determining whether aircraft are arranged in a runway queue. For example, instantiation of a runway queue can occur when the distance between a particular aircraft and a runway and/or a runway entranceway is below a predefined threshold and/or when the particular aircraft slows or comes to a stop on a runway and/or a runway entranceway. 
       FIG. 5A  illustrates an airport map with an instantiated runway queue  507 . Referring to  FIG. 5A , a first aircraft  510 A can move into a first runway entranceway  517 A of a runway. The first aircraft  510 A can move at a speed that is below a threshold such as, for example, 2 knots and/or the first aircraft  510 A can come to a complete stop in the first runway entranceway  517 A of the runway. The processor  125  can then determine, based on the distance between the first aircraft  510 A and the first runway entranceway  517 A, and the speed of the first aircraft  510 A, that the be the first aircraft  510 A is in a runway queue  507  of one or more aircraft that will take off from the runway. That is, the runway queue  507  can be instantiated and initialized with the first aircraft  510 A. The instantiated queue is illustrated in the table of  FIG. 5A . 
     Determining that the first aircraft  510 A is in the first runway entranceway  517 A can involve measuring the distance between the first aircraft  510 A and the centroid associated with the polygon in the AMDB that is associated with the first runway entranceway  517 A. If the distance is below a threshold (e.g., 100 ft), the first aircraft  510 A can be determined to be on the first runway entranceway  517 A. In one example, an adapted Dijkstra algorithm can be utilized to measure the shortest route between the first aircraft  510 A and the first runway entranceway  517 A. For example, in the graph  400 , there can be various combinations of paths/edges that connect the polygon associated with the location of the first aircraft  510 A and the polygon associated with the first runway entranceway  517 A. The adapted Dijkstra algorithm can determine the combination of paths/edges having the shortest overall length. That is, the combination of paths/edges for which the sum of the lengths of all the edges is minimized. The length associated with the combination having the shortest overall length can be considered as the shortest distance between the first aircraft  510 A and the first runway entranceway  517 A. 
     In addition or alternatively, the first aircraft  510 A can be determined to be within the first runway entranceway  517 A if the location of the first aircraft  510 A falls within the polygon associated with the first runway entranceway  517 A. 
       FIGS. 5B-5E  illustrate the addition of aircraft to an instantiated runway queue  507 . Referring to  FIGS. 5B-5D , in some examples, aircraft can be added to the runway queue  507  when they slow down and/or stop in proximity to other aircraft in the runway queue  507 . For example, a second aircraft  510 B can be added to the runway queue  507  when the distance between the second aircraft  510 B and the first aircraft  510 A, previously determined to be in the runway queue  507 , is below a threshold, such as 100 ft, and the second aircraft  510 B slows or comes to a complete stop. Similarly, a third aircraft  510 C can be added to the runway queue  507  when the distance between the third aircraft  510 C and the second aircraft  510 B, previously determined to be in the runway queue  507 , is below a threshold, and the third aircraft  510 C slows or comes to a complete stop. A fourth aircraft  510 D can be similarly added to the runway queue  507 . Adding of the various aircraft to the queue is illustrated in the tables of  FIGS. 5B-5D . 
     Determining the distance between the particular aircraft and aircraft in the runway queue  507  can involve accumulating the length of the edges that connect the centroid associated with the polygon within which the particular aircraft is located, and one or more centroids associated with polygons within which the aircraft in the runway queue  507  are located. For example, the adapted Dijkstra algorithm described above can be utilized to determine the shortest path between the particular aircraft and aircraft in the runway queue  507 . When the accumulated length of the edges is below a threshold (e.g., 100 ft), the particular aircraft can be added to the runway queue  507 . 
     Referring to  FIG. 5E , in some examples, aircraft can be added to the runway queue  507  when they stop in proximity to other runway entranceways. For example, a fifth aircraft  510 E can be determined to be stopped within a threshold distance of the second runway entranceway  517 B and, therefore, added to the runway queue  507  associated with the runway. The distance can be determined via the adapted Dijkstra algorithm. In addition or alternatively, the fifth aircraft  510 E can be determined to be within the second runway entranceway  517 B if the location of the fifth aircraft  510 E falls within the polygon associated with the second runway entranceway  517 B. Adding of the fifth aircraft to the queue is illustrated in the table of  FIG. 5E . 
     Returning to  FIG. 3 , block  305  involves determining, by the computer and responsive to determining that the particular aircraft belongs to the runway queue  507 , an amount of time the particular aircraft spends in the runway queue  507  before taking off from the runway. For example, the processor  125  can measure an elapsed time between a time when a particular aircraft enters the runway queue  507  and a time when the particular aircraft takes off from the runway. 
     The amount of time the first aircraft  510 A spends in the runway queue  507  can correspond to the elapsed time between the time the first aircraft  510 A was assigned to the runway queue  507 , as illustrated in  FIG. 5A , and the time at which the first aircraft  510 A was determined to have taken off from the runway. For example, the elapsed time between when the first aircraft  510 A entered the runway queue  507  and when the first aircraft  510 A took off from the runway can be 5 minutes. In this regard, the first aircraft  510 A can be considered to have taken off from the runway when the first aircraft  510 A is within a threshold distance of an end position  505  of the runway, and/or if the ground speed of the first aircraft  510 A exceeds a predefined threshold speed (e.g., 60 knots) that is greater than a typical maximum taxiing speed (e.g., 30-35 knots), as illustrated in  FIGS. 5F and 5G . For example, referring to  FIG. 5F , the first aircraft  510 A can begin moving down the runway, but can still be assigned to the runway queue  507 . As shown in  FIG. 5G , the first aircraft  510 A can be removed from the runway queue  507  when the first aircraft  510 A is within a threshold distance of the end position  505  of the runway. For example, the first aircraft  510 A can be removed when the first aircraft is within 500 ft of the end position  505  of the runway. After removal of the first aircraft  510 A from the runway queue  507 , the second aircraft  510 B can be moved to the head of the runway queue  507 . That is, the second aircraft  510 B can be expected to be the next aircraft to take off from the runway. Removal of the first aircraft from the queue is illustrated in the table of  FIG. 5G . 
     Block  310  involves determining, by the computer, a take-off delay associated with the runway queue  507  based at least in part on the amount of time the particular aircraft spends in the runway queue  507 . Following the example above, the runway queue take-off delay associated with the runway queue  507  can be determined to be 5 minutes because the first aircraft  510 A spent 5 minutes in the runway queue  507 . 
     In some examples, the runway queue take-off delay can correspond to the average of the amount of time aircraft in the runway queue  507  spend in the runway queue  507 . For example,  FIG. 5H  illustrates the second aircraft  510 B taking off from the runway. Removal of the second aircraft from the queue is illustrated in the table of  FIG. 5H . As soon as the second aircraft  510 B is within a threshold distance (e.g., 500 ft) of the end position  505  of the runway and/or the ground speed of the second aircraft  510 B exceeds a predefined threshold speed (e.g., 60 knots), the second aircraft  510 B can be removed from the runway queue  507 . At this point, the elapsed time the second aircraft  510 B had spent in the runway queue  507  can be determined to be the time between removal of the second aircraft  510 B from the runway queue  507  and the time at which the second aircraft  510 B was added to the runway queue  507  (See  FIG. 5B ). For example, the elapsed time can be 10 minutes. In this case, the average runway queue take-off delay can be determined to be 7.5 minutes, which corresponds to the average time spent by the first aircraft  510 A and the second aircraft  510 B in the runway queue  507 . 
     Block  315  involves communicating, by the computer, the runway queue take-off delay to a controller terminal  104  of the airport to facilitate routing different aircraft to a different runway queue associated with a shorter runway queue take-off delay to reduce fuel consumption by the different aircraft. For example, the ARQDS  102  can communicate the runway queue take-off delay associated with several runway queues  507  to the controller terminal  104 . An air traffic controller at the controller terminal  104  can choose to assign aircraft departing the gates to runway queues  507  having shorter take-off delays. Assigning the aircraft to runway queues  507  having shorter take-off delays results in the aircraft spending less time on the taxiway, which reduces aircraft fuel consumption. 
     As noted above, aircraft are assigned to an existing and/or new runway queue  507  when they are determined to have stopped or slowed down on a runway entranceway or runway, or when they slow down or stop in proximity to other aircraft previously determined to be in a runway queue  507 . In some examples, the runway queue order/sequence in which the aircraft entered the runway queue  507  can be maintained. For example, as noted above, the first aircraft used to instantiate the runway queue  507  can correspond to the first aircraft in the runway queue  507 . The runway queue order/sequence of other aircraft entering the runway queue  507  can be set according to a time at which the other aircraft enter the runway queue  507 . 
     Referring to  FIGS. 5G-5I , the position of a particular aircraft in the runway queue  507  moves as other aircraft in the runway queue take off from the runway. For example, after the first aircraft  510 A takes off from the runway, the second aircraft  510 B moves to the head of the runway queue  507 , as illustrated in  FIG. 5G . After the second aircraft  510 B takes off from the runway queue  507 , the third aircraft  510 C moves to the head of the runway queue  507 , as illustrated in  FIG. 5H . After the third aircraft  510 C takes off from the runway queue  507 , the fourth aircraft  510 D moves to the head of the runway queue  507 , as illustrated in  FIG. 5I . 
       FIG. 5I  illustrates the fourth aircraft  510 D as being at the head of the runway queue  507 , followed by the fifth aircraft  510 E. In addition, a sixth aircraft  510 F is added to the runway queue  507  because the sixth aircraft  510 F slows or stops in proximity to the fifth aircraft  510 E. The order of the various aircraft in the queue is illustrated in the table of  FIG. 5I  As noted above, the fifth aircraft  510 E was added to the runway queue  507  when the fifth aircraft  510 E entered the second runway entranceway  517 B, which was after the fourth aircraft  510 D was assigned to the runway queue  507 . In this scenario, the fourth aircraft  510 D would be expected to be the next aircraft to take off from the runway. 
     In some examples, however, an aircraft can be moved to the head of the runway queue  507  after the aircraft moves to the runway. For example, as illustrated in  FIG. 5J , the fifth aircraft  510 E can be moved from the second position in the runway queue  507  (See  FIG. 5I ), to the first position in the runway queue  507  and the fourth aircraft  510 D can be moved to the second position in the runway queue  507 . Additionally, the sixth aircraft  510 F can be removed from the runway queue  507  because the sixth aircraft  510 F moved away from the runway entranceway in which the fifth aircraft  510 E. The swapping of the fifth aircraft and the fourth aircraft within the queue is illustrated in the table of  FIG. 5J . The removal of the of the sixth aircraft from the queue is also illustrated in the table of  FIG. 5J . 
     In some examples, when two aircraft simultaneously enter the runway, the position of the aircraft in the runway queue  507  can be based on the distance of the aircraft to, for example, the end position  505  of the runway. For example, as illustrated in  FIG. 5J , the fourth aircraft  510 D and the fifth aircraft  510 E appear to enter the runway at the same time. The fifth aircraft  510 E is closer to the end position  505  of the runway and, therefore, can be moved to the head of the runway queue  507 . After the fifth aircraft  510 E takes off from the runway, the fourth aircraft  510 D can be moved to the head of the runway queue  507 , as illustrated by the table in  FIG. 5K . 
     As previously noted,  FIG. 3  illustrates a computer-implemented method to reduce aircraft fuel consumption. Block  300  can involve determining, by a computer, whether a particular aircraft belongs to a runway queue  507  associated with one or more aircraft waiting to take-off from a runway of an airport based on (i) aircraft geographic location information associated with the particular aircraft and (ii) a graph associated with features of the airport. 
     Block  305  can involve responsive to determining that the particular aircraft belongs to the runway queue  507 , determining, by the computer, an amount of time the particular aircraft spends in the runway queue  507  before taking off from the runway. 
     Block  310  can involve determining, by the computer, a runway queue take-off delay associated with the runway queue  507  based at least in part on the amount of time the particular aircraft spends in the runway queue  507 . 
     Block  315  can involve communicating, by the computer, the runway queue take-off delay to a controller terminal  104  of the airport to facilitate routing a different aircraft to a different runway queue associated with a shorter runway queue take-off delay to reduce fuel consumption by the different aircraft. 
     In some examples, determining whether the particular aircraft belongs to the runway queue  507  can involve measuring, by the computer, a distance from the particular aircraft to an entrance of the runway; and in response to determining that the distance is below a threshold distance, assigning, by the computer, the particular aircraft to the runway queue  507 . 
     In some examples, determining whether the particular aircraft belongs to the runway queue  507  the method can involve measuring, by the computer, a distance from the particular aircraft to another aircraft of the runway queue  507 ; and in response to determining that the distance is below a threshold distance, assigning, by the computer, the particular aircraft to the runway queue  507 . 
     In some examples, determining the runway queue take-off delay can involve computing, by the computer, an average of the amount of time at least some of the one or more aircraft spend in the runway queue  507 ; and setting, by the computer, the runway queue take-off delay associated with the runway queue  507  to be the computed average. 
     In some examples, determining the amount of time the particular aircraft spends in the runway queue  507  before taking off from the runway can involve measuring, by the computer, an elapsed time between a first time when the particular aircraft enters the runway queue  507  and a second time when the particular aircraft takes off from the runway. 
     In some examples, determining whether the particular aircraft belongs to the runway queue  507  can involve specifying, by the computer and in the graph, (i) centroids of a plurality of polygons specified in Geographic Javascript Object Notation (GeoJSON) data and (ii) edges between the centroids, wherein the plurality of polygons correspond to geographic outlines associated with the features of the airport; determining a distance between the particular aircraft and the runway queue  507  is based on an accumulated length of one or more edges of the graph that connect a polygon associated with a geographic location associated with the particular aircraft with a polygon associated with the runway queue  507  is below a threshold distance; and responsive to determining the distance to be below a threshold, assigning, by the computer, the particular aircraft to the runway queue  507 . 
     Some examples of the method can involve specifying, by the computer, a runway queue order or sequence within the runway queue  507  for at least some of the one or more aircraft. 
     Some examples of the method can involve specifying, by the computer, a runway queue order associated with aircraft positioned on the runway to be lower than the runway queue order associated with aircraft positioned either a runway entranceway or a taxiway. That is, the position in the queue of aircraft located on a runway or runway entranceway can be lower than that of aircraft located on taxiway. 
     Some examples of the method can involve specifying, by the computer, an order within the runway queue  507  of at least some of the one or more aircraft positioned on the runway according to a distance of the at least some of the one or more aircraft positioned on the runway to a particular position of the runway; and specifying, by the computer, the order within the runway queue  507  of at least some of the one or more aircraft positioned on a runway entranceway and at least some of the one or more aircraft positioned on a taxiway according to a time at which the at least some of the one or more aircraft positioned on the runway exit and the at least some of the aircraft positioned on the taxiway are determined to be in the runway queue  507 . 
     Further, the disclosure comprises embodiments according to the following clauses: 
     Clause 1. A computer-implemented method, comprising: determining, by a computer, whether a particular aircraft belongs to a runway queue associated with one or more aircraft waiting to take-off from a runway of an airport based on (i) aircraft geographic location information associated with the particular aircraft and (ii) a graph associated with features of the airport; responsive to determining that the particular aircraft belongs to the runway queue, determining, by the computer, an amount of time the particular aircraft spends in the runway queue before taking off from the runway; determining, by the computer, a runway queue take-off delay associated with the runway queue based at least in part on the amount of time the particular aircraft spends in the runway queue; and communicating, by the computer, the runway queue take-off delay to a controller terminal of the airport to facilitate routing a different aircraft to a different runway queue associated with a shorter runway queue take-off delay. 
     Clause 2. The computer-implemented method according to any of the preceding clauses, wherein determining whether the particular aircraft belongs to the runway queue comprises: measuring, by the computer, a distance from the particular aircraft to an entrance of the runway; and in response to determining that the distance is below a threshold distance, assigning, by the computer, the particular aircraft to the runway queue. 
     Clause 3. The computer-implemented method according to any of the preceding clauses, wherein determining whether the particular aircraft belongs to the runway queue comprises: measuring, by the computer, a distance from the particular aircraft to another aircraft of the runway queue; and in response to determining that the distance is below a threshold distance, assigning, by the computer, the particular aircraft to the runway queue. 
     Clause 4. The computer-implemented method according to any of the preceding clauses, wherein determining the runway queue take-off delay further comprises: computing, by the computer, an average of the amount of time at least some of the one or more aircraft spend in the runway queue; and setting, by the computer, the runway queue take-off delay associated with the runway queue to be the computed average. 
     Clause 5. The computer-implemented method according to any of the preceding clauses, wherein determining the amount of time the particular aircraft spends in the runway queue before taking off from the runway comprises: measuring, by the computer, an elapsed time between a first time when the particular aircraft enters the runway queue and a second time when the particular aircraft takes off from the runway. 
     Clause 6. The computer-implemented method according to any of the preceding clauses, wherein determining whether the particular aircraft belongs to the runway queue further comprises: specifying, by the computer and in the graph, (i) centroids of a plurality of polygons specified in Geographic Javascript Object Notation (GeoJSON) data and (ii) edges between the centroids, wherein the plurality of polygons correspond to geographic outlines associated with the features of the airport; determining a distance between the particular aircraft and the runway queue based on an accumulated length of one or more edges of the graph that connect a polygon associated with a geographic location associated with the particular aircraft with a polygon associated with the runway queue is below a threshold distance; and responsive to determining the distance to be below a threshold, assigning, by the computer, the particular aircraft to the runway queue. 
     Clause 7. The computer-implemented method according to any of the preceding clauses, further comprising: specifying, by the computer, an order within the runway queue for at least some of the one or more aircraft. 
     Clause 8. The computer-implemented method according to any of the preceding clauses, further comprising: specifying, by the computer, an order within the runway queue of at least some of the one or more aircraft positioned on the runway to be lower than an order within the runway queue of at least some of the one or more aircraft positioned on a runway entranceway and an order within the runway queue of at least some of the one or more aircraft positioned on a taxiway. 
     Clause 9. The computer-implemented method according to any of the preceding clauses, further comprising: specifying, by the computer, an order within the runway queue of at least some of the one or more aircraft positioned on the runway according to a distance of the at least some of the one or more aircraft positioned on the runway to a particular position of the runway; and specifying, by the computer, the order within the runway queue of at least some of the one or more aircraft positioned on a runway entranceway and at least some of the one or more aircraft positioned on a taxiway according to a time at which the at least some of the one or more aircraft positioned on the runway entranceway and the at least some of the aircraft positioned on the taxiway are determined to be in the runway queue. 
     Clause 10. A system, comprising: a memory that stores instruction code; and a processor in communication with the memory, wherein the instruction code is executable by the processor to perform acts comprising: determining whether a particular aircraft belongs to a runway queue associated with one or more aircraft waiting to take-off from a runway of an airport based on (i) real-time aircraft geographic location information associated with the particular aircraft and (ii) a graph associated with features of the airport; responsive to determining that the particular aircraft belongs to the runway queue, determining an amount of time the particular aircraft spends in the runway queue before taking off from the runway; determining a runway queue take-off delay associated with the runway queue based at least in part on the amount of time the particular aircraft spends in the runway queue; and communicating the runway queue take-off delay to a controller terminal of the airport to facilitate routing a different aircraft to a different runway queue associated with a shorter runway queue take-off delay. 
     Clause 11. The system according to any of the preceding clauses starting from clause 10, wherein the instruction code is executable by the processor to perform acts comprising: measuring a distance from the particular aircraft to an entrance of the runway; if the distance is below a threshold distance, assigning the particular aircraft to the runway queue; and wherein routing the different aircraft to the different runway queue associated with the shorter runway queue take-off delay facilitates a reduction in fuel by the different aircraft. 
     Clause 12. The system according to any of the preceding clauses starting from clause 10, wherein the instruction code is executable by the processor to perform acts comprising: measuring a distance from the particular aircraft to another aircraft of the runway queue; and if the distance is below a threshold distance, assigning the particular aircraft to the runway queue. 
     Clause 13. The system according to any of the preceding clauses starting from clause 10, wherein the instruction code is executable by the processor to perform acts comprising: measuring an elapsed time between a first time when the particular aircraft enters the runway queue and a second time when the particular aircraft takes off from the runway. 
     Clause 14. The system according to any of the preceding clauses starting from clause 10, wherein the instruction code is executable by the processor to perform acts comprising: specifying, in the graph, (i) centroids of a plurality of polygons specified in Geographic Javascript Object Notation (GeoJSON) data and (ii) edges between the centroids, wherein the plurality of polygons correspond to geographic outlines associated with the features of the airport; determining a distance between the particular aircraft and the runway queue based on an accumulated length of one or more edges of the graph that connect a polygon associated with a geographic location associated with the particular aircraft with a polygon associated with the runway queue is below a threshold distance; and responsive to determining the distance to be below a threshold, assigning the particular aircraft to the runway queue. 
     Clause 15. The system according to any of the preceding clauses starting from clause 10, wherein the instruction code is executable by the processor to perform acts comprising: specifying a sequence within the runway queue for at least some of the one or more aircraft. 
     Clause 16. The system according to any of the preceding clauses starting from clause 10, wherein the instruction code is executable by the processor to perform acts comprising: specifying an order within the runway queue of at least some of the one or more aircraft positioned on the runway to be lower than an order within the runway queue of at least some of the one or more aircraft positioned on a runway entranceway and an order within the runway queue of at least some of the one or more aircraft positioned on a taxiway. 
     Clause 17. The system according to any of the preceding clauses starting from clause 10, wherein the instruction code is executable by the processor to perform acts comprising: specifying an order within the runway queue of at least some of the one or more aircraft positioned on the runway according to a distance of the at least some of the one or more aircraft positioned on the runway to a particular position of the runway; and specifying the order within the runway queue of at least some of the one or more aircraft positioned on a runway entranceway and at least some of the one or more aircraft positioned on a taxiway according to a time at which the at least some of the one or more aircraft positioned on the runway entranceway and the at least some of the aircraft positioned on the taxiway are determined to be in the runway queue. 
     Clause 18. A non-transitory computer-readable medium having stored thereon instruction code, wherein the instruction code is executable by a processor of a computer to perform acts comprising: determining whether a particular aircraft belongs to a runway queue associated with one or more aircraft waiting to take-off from a runway of an airport based on (i) real-time aircraft geographic location information associated with the particular aircraft and (ii) a graph associated with features of the airport; responsive to determining that the particular aircraft belongs to the runway queue, determining an amount of time the particular aircraft spends in the runway queue before taking off from the runway; determining a runway queue take-off delay associated with the runway queue based at least in part on the amount of time the particular aircraft spends in the runway queue; and communicating the runway queue take-off delay to a controller terminal of the airport, wherein the runway queue take-off delay is employable to route a different aircraft to a different runway queue associated with a shorter runway queue take-off delay. 
     Clause 19. The non-transitory computer-readable medium according to any of the preceding clauses starting from clause 18, wherein the instruction code is executable by the processor of the computer to perform acts comprising: measuring a distance from the particular aircraft to an entrance of the runway; and if the distance is below a threshold distance, assigning the particular aircraft to the runway queue. 
     Clause 20. The non-transitory computer-readable medium according to any of the preceding clauses starting from clause 18, wherein the instruction code is executable by the processor of the computer to perform acts comprising: measuring a distance from the particular aircraft to another aircraft of the runway queue; and if the distance is below a threshold distance, assigning the particular aircraft to the runway queue. While the systems and methods of operation have been described with reference to certain examples, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted without departing from the scope of the claims. Therefore, it is intended that the present methods and systems not be limited to the particular example disclosed, but that the disclosed methods and systems include all embodiments falling within the scope of the appended claims.