Patent Description:
Conventional approaches to FANS <NUM>/A are offered by aircraft original equipment manufacturers (OEM) and are hosted in the Flight Management System (FMS). While FMS-based solutions meet operational requirements, FANS <NUM>/a functionality significantly increases resource demands on the FMS and provides only a single aircraft-specific solution for each aircraft type, resulting in increased costs to airlines and training differences in operational behavior across aircraft types.

Document "<NPL>) provides an overview of FANS (Future Air Navigation System) and details aspects of CNS (Communication Navigation Surveillance) and ATM (Air Traffic Management).

In a first aspect, an aircraft-based communications management unit (CMU) configured for real-time Automated Dependent Surveillance-Contract (ADS-C) fulfillment is disclosed. In embodiments, the CMU includes an input for receiving intent data outputs from the flight management system (FMS) via a trajectory bus, each intent data output including aircraft state data (e.g., 4D position and ETA) and trajectory intent data (e.g., trajectory points indicative of a lateral or vertical flight path transition). CMU processors independently determine a dynamic route representation based on the received intent data outputs, the dynamic route inferring and connecting flight path waypoints based on trajectory intent data. Based on the dynamic route representation, the CMU generates and transmits ADS-C reports to ground-based control station/s in fulfillment of ADS-C contracts between the aircraft and the ground station/s, each ADS-C report including at least current aircraft state data (position, altitude, ETA). The CMU received ADS-C messages and requests, and transmits ADS-C reports, via an Aircraft Communications Addressing and Reporting System (ACARS)-compatible communications interface.

In some embodiments, the intent data outputs include trajectory points corresponding to flight path waypoints, e.g., air traffic service (ATS) waypoints having a fixed location and coordinates; inserted waypoints added to the flight plan by the FMS, and dynamic or pseudo waypoints indicative of a programmed change in flight parameters.

In some embodiments, the CMU is in communication with aircraft-based navigational systems (e.g., GNSS receivers and other absolute position systems, air data inertial reference units (ADIRU) and other relative navigational systems), and queries each navigational system, e.g., for availability and/or accuracy. Accordingly, each ADS-C report including a navigational status accuracy report.

In some embodiments, the ADS-C report is a periodic ADS-C report transmitted in fulfillment of an ADS-C contract providing for transmission of ADS-C report data at a predetermined reporting rate.

In some embodiments, the ADS-C report is transmitted in fulfillment of an ADS-C event contract providing for the transmission of ADS-C report in response to one or more specific flight events, which flight events are detected by the CMU based on the received intent data outputs.

In some embodiments, the ADS-C report is transmitted in fulfillment of an ADS-C demand contract received from the ground station/s, whereby the CMU generates and transmits a specific ADS-C report demanded by the ground station.

In some embodiments, the ADS-C demand contracts requests a projected state or position of the aircraft at a subsequent time, and the CMU determines the projected position at the subsequent time based on the dynamic route.

In some embodiments, the CMU determines and transmits via ADS-C report a projected route of the aircraft to the determined projected (e.g., future) position at the subsequent time, the projected route including a set of intermediate points between the current aircraft state and the projected future position.

In a further aspect, a method for Automated Dependent Surveillance-Contract (ADS-C) fulfillment via an aircraft-based CMU is also disclosed. In embodiments, the method includes receiving, via the CMU through a trajectory bus connecting the CMU to the aircraft flight management system (FMS), intent data outputs from the FMS, each intent data output including aircraft state data (e.g., 4D position and ETA of the aircraft) and trajectory intent data (e.g., one or more trajectory points indicative of a lateral or vertical flight path transition). The method includes generating and determining, independently via the received intent data outputs, a dynamic route representation approximating the actual route of the aircraft without querying the FMS or pilot for additional data, the dynamic route connecting each received aircraft state. The method includes, based on the dynamic route, generating ADS-C reports in fulfillment of an ADS-C contract between the aircraft and one or more ground stations, each ADS-C report based at least on an aircraft state received via the set of intent data outputs. The method includes transmitting each ADS-C report to the appropriate ground station/s.

In some embodiments, the method includes identifying, within the set of received intent data outputs (e.g., the set of trajectory points included therein), flight plan waypoints including: air traffic service (ATS) waypoints having a fixed location and coordinates; inserted waypoints added to the flight plan by the FMS, and dynamic or pseudo waypoints corresponding to programmed changes in flight parameters.

In some embodiments, the method includes assessing, via the CMU, availability and accuracy of aircraft navigational systems (e.g., GNSS receivers and other absolute position receivers, air data inertial reference units (ADIRU) and other relative navigational systems) and including with each ADS-C report a navigational accuracy status report.

In some embodiments, the method includes generating and transmitting ADS-C reports at a predetermined reporting rate in fulfillment of a periodic ADS-C contract.

In some embodiments, the method includes detecting, based on the dynamic route, specific flight events and generating ADS-C reports responsive to the detected flight events in fulfillment of an ADS-C event contract.

In some embodiments, the method includes receiving, via the CMU, ADS-C demand contracts from the ground station/s and generating in response ADS-C reports fulfilling the specific information requests of the demand contract.

In some embodiments, the method includes determining, via the CMU, a projected position of the aircraft at a subsequent time requested by an ADS-C contract, and generating an ADS-C report including a projected future state or position of the aircraft at the subsequent time.

Referring to <FIG>, an aircraft <NUM> is disclosed. The aircraft <NUM> may include flight management system <NUM> (FMS); communications management unit <NUM> (CMU); datalink radios <NUM>; multifunction control and display unit <NUM> (MCDU); absolute positioning systems (e.g., Global Navigation Satellite System (GNSS) receiver <NUM>); and inertial reference systems (e.g., air data inertial reference unit <NUM> (ADIRU)). One or more of the aforementioned components, e.g., the FMS <NUM>, GNSS receiver <NUM>, and/or ADIRU <NUM>, may include backup or redundant systems aboard the aircraft <NUM>.

In embodiments, the FMS <NUM> may automate inflight tasks as necessary and manage the fulfillment of the flight plan by the aircraft <NUM>, displaying flight plan data to the pilots and accepting control input from the pilots via the MCDU <NUM>. For example, the FMS <NUM> may determine position information of the aircraft <NUM> based on data sensed by the GNSS receiver <NUM> and/or ADIRU <NUM>. The FMS <NUM> may maintain and consult navigation data, waypoint data associated with fixes and navigational aids, terrain data associated with conditions and obstacles along the flight plan, weather and atmospheric data, and other flight plan components, updating this data (as well as the flight plan) based on new information (e.g., as received from ATC ground stations <NUM> or as input by the pilots).

In embodiments, the CMU <NUM> and datalink radios <NUM> may manage and execute uplink and downlink communications between the aircraft <NUM> and ATC control stations <NUM>. For example, datalink radios may include, but are not limited to, VHF components 106a for communications in the VHF band (c. <NUM> - <NUM>); HF components 106b for communications in the HF band (c. <NUM> - <NUM>); and/or satellite communications (SATCOM) components 106c. In embodiments the CMU <NUM> may route any received messages (e.g., from ATC ground stations <NUM>, from proximate aircraft) to their intended destinations.

In embodiments, the GNSS receiver <NUM> may determine high integrity position data of the aircraft <NUM> (e.g., an absolute position relative to an earth or world frame) based on positioning signals received from navigational satellites (e.g., GPS, GLONASS, Beidou, Galileo, IRNSS, QZSS). In embodiments, the ADIRU <NUM> may provide the FMS <NUM> with inertial navigation data (e.g., a relative position and/or orientation of the aircraft <NUM> in multiple degrees of freedom) and air data (e.g., airspeed, barometric/pressure altitude, angle of attack).

Broadly speaking, embodiments of the inventive concepts disclosed herein are directed to a CMU <NUM> (and methods of operation thereof) capable of offloading FANS <NUM>/A functionality from the FMS <NUM> based on trajectory intent data outputs received therefrom. For example, the CMU <NUM> may "intercept" trajectory intent data outputs from the FMS <NUM> and, based on these trajectory intent data outputs, independently determine dynamic trajectory, routing, or intent information required by ADS-C contracts between the aircraft <NUM> and ATC ground stations <NUM>, transmitting to the ATC ground stations ADS-C reports including any position and trajectory information associated with the fulfillment of ADS-C contracts. Similarly, the CMU <NUM> may receive, and fulfill as described above, any new ADS-C contracts initiated by the ATC ground stations <NUM>. In embodiments, while position and trajectory data independently determined by the CMU <NUM> may not directly correspond to flight plan data housed in the FMS <NUM> (e.g., as the CMU <NUM> will not have direct access to this flight plan data), the CMU <NUM> may fulfill any ADS-C contracts with position and trajectory data in compliance with ADS-C accuracy standards. For example, any dynamic route data determined by the CMU <NUM> may be accurate within <NUM> (as required by ADS-C) and provided to the relevant ATC ground stations <NUM> in timely fashion.

Conventional FANS <NUM>/A solutions provide that the CMU <NUM> receive any inbound ADS-C messages transmitted by ARC ground stations <NUM> and route any received messages to the FMS <NUM>. The FMS <NUM> would generate responses to received ADS-C messages (e.g., requests for specific information) for transmission to the ground station/s <NUM> via the CMU <NUM>. Further, the FMS <NUM> would generate intent data outputs <NUM>, or ADS-C reports including current position and trajectory information of the aircraft <NUM>. Such intent data outputs <NUM> are intended for periodic transmission (e.g., every half second (<NUM>) or event-based transmission (e.g., in response to a flight plan event), as provided for by ARINC specification 702A-<NUM>) and would be received by the CMU <NUM> for transmission via trajectory bus <NUM>, along with any other ADS-C reports generated by the FMS <NUM> (e.g., in response to demands received via the CMU <NUM>).

In embodiments, the CMU <NUM> may "intercept" each intent data output <NUM> sent by the FMS <NUM> via the trajectory bus <NUM>. For example, the CMU <NUM> may receive intent data outputs <NUM> sent by the FMS via the trajectory bus <NUM>, whether periodic or event-driven. However, in embodiments the CMU <NUM> may "intercept" and process any ADS-C messages received from ATC ground stations <NUM>, e.g., rather than routing said ADS-C messages to the FMS <NUM> for processing. For example, each intent data output <NUM> received by the CMU <NUM> via the trajectory bus <NUM> may include a state of the aircraft <NUM> at a particular timestamp, e.g., a four-dimensional (4D) position and track of the aircraft comprising a latitude, longitude, and altitude of the aircraft and an estimated time of arrival (ETA) at the destination provided for by the flight plan (e.g., based on the current airspeed of the aircraft and according to the current flight plan). Further, each intent data output <NUM> may include intent path information comprising one or more trajectory points. For example, each trajectory point may correspond to a transition point or track change in the flight plan, e.g., a lateral path transition or a vertical path transition. Lateral path transitions may include: "fly by" and "fly over" (e.g., relative to a waypoint of fixed location ("fix")); "hold (pattern)", "proc(edure) hold", "proc(edure) turn" (e.g., special approach and landing procedures); "radius to fix (RF) leg" (e.g., an arcuate course relative to a fix and at a specified radius therefrom). Intent data outputs <NUM> including a lateral path transition may further include a turn direction and turn radius (e.g., indicative of the aircraft <NUM> flying clockwise or counterclockwise relative to, and at a fixed radius from, a waypoint or fix). Similarly, vertical path transitions may include "top climb" and "top desc(ent)" (e.g., indicative of the aircraft <NUM> either transitioning from a climb segment to level flight or from level flight to an initial descent); "start of level (flight)"; "crossover altitude" (e.g., an altitude at which airspeed corresponds to a specific Mach number), and "transition altitude" (e.g., an altitude above which aircraft altitude is expressed in terms of Flight Level (FL)).

In embodiments, the CMU <NUM> may generate a dynamic route (e.g., route representation) by correlating the set of intent data outputs <NUM> to approximate the route of the aircraft <NUM> (e.g., including trajectory points) without reference to the flight plan and without otherwise querying the FMS <NUM> or the pilot/s for information. For example, the CMU <NUM> may convert each latitude, longitude, and altitude of the aircraft <NUM> into a range, bearing, and altitude relative to a defined point or fix and corresponding to a state of the aircraft <NUM> at the time indicated by the timestamp of the intent data output <NUM>. In embodiments, by intercepting and correlating every intent data output <NUM> sent by the FMS <NUM> via the trajectory bus <NUM>, the CMU <NUM> may dynamically simulate the route of the aircraft <NUM> in real time or near real time with sufficient positional accuracy to generate and transmit ADS-C reports as required by any contracts extant between the aircraft <NUM> and the ATC ground stations <NUM>.

In embodiments, offloading of high demand ADS-C report processing to the CMU <NUM> may reduce demand on the FMS <NUM>, allowing FMS processing resources to be reallocated for navigation, flight optimization, or other purposes. Similarly, the CMU <NUM> may process rapid responses to ADS-C requests for information without the need to compete for FMS <NUM> processing time with system-critical flight control calculations. Further, overall flight control system architecture and interfaces may be simplified and made easier to maintain.

In embodiments, ADS-C contracts may be established by one or more ATC ground stations <NUM> and accepted by the aircraft <NUM>. In embodiments, every ADS-C report generated and transmitted by the CMU <NUM> may include a "basic group", or the minimum required information: a latitude, longitude, and altitude of the aircraft <NUM>, a timestamp, and a navigational accuracy status report (e.g., a figure of merit (FOM) assessing the current accuracy of all navigational and positioning systems aboard the aircraft on a scale of zero to seven (e.g., and based on the operating accuracy and/or redundancy of the GNSS receivers <NUM>, ADIRU <NUM>, and their respective backup systems). Accordingly, in embodiments the CMU <NUM> may be in communication with all GNSS receivers <NUM> and ADIRUs <NUM> aboard the aircraft <NUM> (e.g., and any other like navigational equipment, e.g., Traffic Collision Avoidance System (TCAS)) and may continually assess the accuracy and redundancy of aircraft navigation systems (e.g., that the main and backup GNSS receivers, and/or main and backup ADIRUs, and TCAS are operational and to what level of accuracy). For example, every ADS-C report generated by the CMU <NUM> (basic or otherwise) may include a navigational status accuracy report, e.g., an estimated position uncertainty of navigational solutions based on the availability of, and state information provided by, onboard GNSS receivers <NUM> and/or ADIRUs <NUM> (main and/or backup). In selected high-level airspaces, continual verification of navigational status accuracy may serve as continuing assurance by the aircraft <NUM> that its navigational systems are sufficiently accurate to remain within the high-level airspace through which the aircraft is navigating.

In embodiments, ADS-C contracts received and accepted by the CMU <NUM> may be characterized as periodic contracts, event contracts, or demand contracts. For example, a periodic contract may specify information to be provided (e.g., a "basic group" report and/or additional by-request data groups as specified by the ATC ground station <NUM>) and a reporting rate specifying the frequency at which the requested information is to be transmitted. Additional by-request data groups may include: flight identification (e.g., identifying a flight number or route segment); earth reference (e.g., true track, ground speed, vertical rate); air reference (e.g., true heading, airspeed/Mach number, vertical rate); airframe identification (e.g., <NUM>-bit ICAO address unique to the aircraft <NUM>); meteorological (e.g., wind speed, wind direction, air temperature); predicted route; and fixed or intermediate projected intent. In embodiments, with respect to the latter two groups the CMU <NUM> may, based on the dynamic route, predict a future position of the aircraft <NUM> as described in greater detail below.

In embodiments, event contracts may specify the generation and transmission of an ADS-C report by the CMU <NUM> whenever a predetermined event occurs. For example, the event contract may specify one or more parameters associated with performance of the aircraft <NUM> along its flight plan, with an event corresponding to the exceeding or deceeding by the aircraft of any specified parameter, e.g., vertical rate change (the rate of climb/descent of the aircraft exceeds the predetermined rate); lateral deviation (the actual position of the aircraft sufficiently deviates from its expected position according to the flight plan); altitude range change (the altitude of the aircraft exceeds a ceiling or floor relative to the cleared FL); or waypoint change (a change to an ATC or inserted waypoint, as described in greater detail below).

In embodiments, demand contracts may be associated with singular requests for specific information by the ATC ground station/s <NUM>. For example, the CMU <NUM> may receive the demand contract as a message from the ATC ground station/s <NUM> and may respond by generating and transmitting a "basic group" ADS-C report as described above.

In embodiments, the CMU <NUM> may include an Aircraft Communication Addressing and Reporting System (ACARS) compatible interface configured for transmission of datalink messages in text format between the aircraft <NUM> and the ATC ground station/s <NUM>. Accordingly, the CMU <NUM> may generate and transmit any ADS-C reports according to the ACARS protocol defined in ARINC specification <NUM>.

Referring to <FIG>, a dynamic route <NUM> is shown. In embodiments, the dynamic route <NUM> may be generated by the CMU (<NUM>, <FIG>) based on intent data outputs (<NUM>, <FIG>) received from the FMS (<NUM>, <FIG>) via the trajectory bus (<NUM>, <FIG>).

In embodiments, the dynamic route <NUM> may be constructed by the CMU <NUM> by arranging the received intent data outputs 116a-g in space and time, and projecting a route or path connecting each pair of consecutive intent data outputs, e.g., based on the path transition indicated by each intent data output. For example, each intent data output 116a-g may correspond to an aircraft state at a particular time (e.g., either the current state of the aircraft <NUM> according to the most recent timestamp, or a future state of the aircraft at a projected time according to the flight plan). The intent data output 116a, for example, may correspond to a current state of the aircraft <NUM>, e.g., its most recent latitude, longitude, and altitude as the aircraft climbs to cruising altitude. In embodiments, the dynamic route <NUM> may incorporate a projected lateral path <NUM> (associated with the trajectory of the aircraft <NUM> through xy-space) and/or a projected vertical path <NUM> (associated with the altitude and orientation of the aircraft through the various segments of the flight plan, e.g., takeoff, climb, cruise, descent, landing).

In embodiments, each intent data output 116a-g may correspond to a path transition, to a waypoint, or both. For example, waypoints may include ATC waypoints, inserted waypoints, and dynamic or pseudo-waypoints. In embodiments, ATC waypoints (e.g., "fixes") may correspond to a fixed geographic location, may be defined by absolute coordinates (e.g., latitude/longitude) and/or relative coordinates (e.g., distance and bearing from a radio navigation (RNAV) beacon), and may be informally referred to in voice communications by pilots by distinct five-letter terms (e.g., CANIO, AANDY, GEEZR). For example, ATC waypoints may be used for navigation via Instrument Flight Rules (IFR) or other RNAV procedures and may define approach patterns to airports and runways. "Fly-over" ATC waypoints must be vertically crossed by the aircraft <NUM>, and "fly-by" ATC waypoints generally mark a path transition, e.g., from a first lateral track to a second lateral track, such that the aircraft "flies by" the waypoint in turning from the first track to the second. For example, the intent data outputs 116d, 116e, and <NUM> may correspond to ATC waypoints which the aircraft <NUM> is projected to fly-by or fly-over at future times projected by the flight plan.

Similarly, inserted waypoints may be inserted into the flight plan (e.g., by the pilot, via the MCDU <NUM>) to trigger a report by the FMS <NUM> (and therefore an intent data output <NUM>). Dynamic waypoints, or pseudo-waypoints, may be inserted into the flight plan by the FMS <NUM> and may be updated by the FMS based on the actual path of the aircraft <NUM> (e.g., as opposed to the expected path of the aircraft per the flight plan). For example, dynamic waypoints may correspond to state transitions according to flight parameters, e.g., a top of climb (TOC) or top of descent (TOD). For example, the trajectory intent data output 116b may correspond to a dynamic TOC point wherein the aircraft <NUM> levels off from its climb segment to cruise at altitude, and the intent data outputs 116c, 116f may correspond to other inserted waypoints.

Accordingly, in embodiments the CMU <NUM> may infer a waypoint based on an intent data output based on a variety of factors, e.g., a geographical location or altitude not already achieved by the aircraft <NUM> along the flight plan (implying a future location or altitude) or a path transition as described above. For example, the projected lateral and vertical paths <NUM>, <NUM> may connect a set of waypoints based on the intent data output 116b corresponding to a TOC point (e.g., implying a transition between climb and cruise segments with respect to the projected vertical path). In embodiments, the projected vertical and lateral paths <NUM>, <NUM> may not correspond exactly to the flight plan, but may represent the construction by the CMU <NUM> of a reasonable approximation or representation of the active route of the aircraft <NUM> (e.g., sufficiently accurate to fulfill ADS-C reporting requirements) based on received intent data outputs 116a-g without querying the FMS <NUM> or the pilot for additional information.

In embodiments, each intent data output 116b-g may correspond to a projected time subsequent to a current time associated with the current state of the aircraft <NUM> (e.g., intent data output 116a). For example, each intent data output 116b-g may be timestamped by the FMS <NUM>, e.g., based on the current airspeed or according to the flight plan, and some intent data outputs (e.g., corresponding to dynamic waypoints) may be updated with more accurate timestamps as the aircraft <NUM> approaches the said dynamic waypoints, or as the FMS <NUM> is updated to changing atmospheric or traffic conditions.

In embodiments, the intent data outputs 116b, 116c, 116d, 116e, 116f, <NUM> may each correspond to projected times T(+<NUM>), T(+<NUM>), T(+<NUM>), T(+<NUM>), T(+<NUM>), and T(+<NUM>) respectively, where X (T+X) is a relative number of minutes ahead of the current time T(<NUM>) corresponding to the intent data output 116a. Similarly, the CMU <NUM> may convert the absolute coordinates (e.g., latitude, longitude, altitude) of each intent data output 116a-<NUM> to relative coordinates (distance, bearing, altitude) relative to a defined point. For example, based on relative time and distance information for each intent data output 116a-<NUM>, the CMU <NUM> may infer an average speed between each consecutive pair of waypoints.

In embodiments, the ATC ground station (<NUM>, <FIG>) may request via ADS-C contract a predicted route including absolute position data corresponding to the next two ATS or inserted waypoints from the flight plan. For example, the CMU <NUM> may respond to this request with an ADS-C report including, according to a timestamp, the latitude, longitude, and altitude the inserted waypoint and ATC waypoint corresponding to intent data outputs 116c, 116d.

In embodiments, the CMU <NUM> may further project a state or position of the aircraft <NUM> at other points along the dynamic route <NUM>, e.g., in fulfillment of an ADS-C contract requesting a projected intent of the aircraft <NUM>. For example, an ATC ground station (<NUM>, <FIG>) may request via ADS-C contract a fixed projected intent, or a projected position of the aircraft <NUM> at a projected subsequent time T(+X) which may or may not correspond to any identified waypoint of the dynamic route <NUM>. In embodiments, if the fixed projected intent request corresponds to a time T(+<NUM>), or <NUM> minutes into the future, the CMU <NUM> may interpolate, based on the straight track and average speed between the waypoints corresponding to intent data outputs 116f, <NUM> at T(+<NUM>) and T(+<NUM>) respectively, a fixed projected intent (e.g., projected point) <NUM> at T(+<NUM>).

Similarly, in embodiments the CMU <NUM> may receive a request via ADS-C contract for an intermediate projected intent of the aircraft <NUM>. For example, the CMU <NUM> may generate and transmit an ADS-C report identifying not only the fixed projected intent/projected point <NUM> at T(+<NUM>), but a series of eligible waypoints between the current position/state (intent data output 116a) of the aircraft <NUM> and the fixed projected intent, e.g., any of all of the ATC, dynamic, or inserted waypoints corresponding to the intent data outputs 116b-116f.

In embodiments, the CMU <NUM> may detect one or more events associated with the fulfillment of an event contract, generating and transmitting an ADS-C report indicative of the detected event. For example, based on changes in position or altitude between intent data outputs 116a-<NUM> (e.g., either between consecutive intent data outputs or cumulative changes over a series of intent data outputs), the CMU <NUM> may detect vertical rate changes, lateral deviations, or altitude range changes in excess of parameters provided for by the received ADS-C event contract, and may generate and transmit ADS-C reports documents any such detected events. Similarly, based on trajectory intent data (e.g., trajectory points) provided by the received intent data outputs 116a-<NUM>, the CMU <NUM> may detect waypoint sequencing changes by the FMS <NUM> (e.g., changes to next or next-plus-one waypoints indicative of a waypoint change event).

Referring to <FIG>, the dynamic route 200a may be implemented and may function similarly to the dynamic route <NUM> of <FIG>, except that the dynamic route 200a may incorporate a lateral track change <NUM> between the waypoints corresponding to intent data outputs 116c and 116d.

In embodiments, similarly to the dynamic route <NUM> of <FIG>, the CMU <NUM> may determine a projected point (e.g., fixed projected intent <NUM>) between the "fly-over" waypoint corresponding to intent data output 116c and the "fly-by" waypoint corresponding to intent data output 116d (e.g., a projected point corresponding to a subsequent projected time T(+X) wherein the intent data outputs 116c, 116d respectively correspond to projected times T(+[X-m]) and T(+[X+n])), based on nominal performance associated with the aircraft <NUM>. For example, if the aircraft <NUM> is established by the CMU <NUM> to be cruising at altitude, the projected point <NUM> at projected time T(+X) may be determined in terms of linear progression based on nominal turn rates at cruising altitude (e.g., assuming the aircraft has been established by the CMU to be cruising at altitude).

Referring also to <FIG>, the dynamic routes 200b-200d, waypoints corresponding to intent data outputs 116c and 116e, and the "fly-by" waypoint corresponding to intent data output 116d are respectively shown. In embodiments, the dynamic route 200b may be associated with a projected lateral path <NUM> indicative of a track change <NUM> of up to <NUM> degrees between the waypoints corresponding to intent data outputs 116b and 116c. For example, any projected point <NUM> between the waypoints corresponding to intent data outputs 116c, 116d or between the waypoints <NUM> corresponding to intent data outputs 16d, 116e may be interpolated by the CMU <NUM> according to an arcuate track change <NUM> (e.g., associated with a turn radius <NUM>) tangent to straight lateral track segments 310a, 310b (and, e.g., based on nominal turn rate at cruising altitude or the appropriate flight segment).

In embodiments, referring in particular to <FIG>, the dynamic route 200c may be associated with a projected lateral path <NUM> indicative of a track change <NUM> of c. <NUM> to <NUM> degrees between the waypoints corresponding to intent data outputs 116c and 116e, and the projected point <NUM> may be interpolated similarly to the dynamic route 200b.

In embodiments, referring in particular to <FIG>, the dynamic route 200d may be associated with a projected lateral path <NUM> indicative of a track change <NUM> of c. <NUM> degrees or greater between the waypoints corresponding to intent data outputs 116c and 116e, and the projected point <NUM> may be interpolated based on multiple arcuate track changes 306a, 306b and straight lateral track segments 310a, 310b, 310c (along which the CMU <NUM> may apply straight linear progression, as described above with reference to the dynamic route 200a of <FIG>).

Referring also to <FIG>, the dynamic routes 200e, 200f, <NUM>, and <NUM> are shown. In embodiments, more complex dynamic routes and projected points <NUM> may be interpreted by the CMU <NUM> as sequences or sets of component lateral straight and arcuate path segments <NUM>, <NUM> as described above with respect to <FIG>.

Referring in particular to <FIG>, in embodiments the dynamic route 200e may be associated with a holding pattern (e.g., type "hold", "hold at", "hold pattern") defined by entry/exit waypoint <NUM>, "fly-over" waypoint <NUM>, and subsequent waypoint <NUM> associated with a projected time after the aircraft <NUM> has left the holding pattern. For example, the projected point <NUM> may be interpolated based on substantially semicircular arcuate track changes <NUM> connected by substantially straight linear track segments <NUM>, and, e.g., whether the projected point is between the entry point <NUM> and waypoint <NUM>, between the waypoint <NUM> and exit point <NUM>, or between the exit point <NUM> and subsequent waypoint <NUM>.

Referring in particular to <FIG>, in embodiments the dynamic route 200f may be associated with a procedure hold (e.g., type "proc hold") defined by entry/exit waypoint <NUM>, "fly-over" waypoint <NUM>, and subsequent waypoint <NUM> associated with a projected time after the aircraft (<NUM>, <FIG>) has left the procedure hold. For example, projected points <NUM> may be projected based on arcuate track changes <NUM> and straight segments <NUM> based on, e.g., whether the projected point is between entry point <NUM> and waypoint <NUM>, between waypoint <NUM> and exit point <NUM>, or between exit point <NUM> and subsequent waypoint <NUM>.

Referring in particular to <FIG>, in embodiments the dynamic route <NUM> may be associated with a procedure turn (e.g., type "proc turn") defined by entry point <NUM>, "fly-by" waypoints 314a, 314b having track changes substantially not more than <NUM> degrees and subsequent waypoint <NUM>. For example, projected points <NUM> may be projected based on arcuate track changes <NUM> and straight segments <NUM> based on, e.g., whether the projected point is between entry point <NUM> and waypoint 314a, between waypoints 314a and 314b, or between waypoint 314b and subsequent waypoint <NUM>.

Referring in particular to <FIG>, in embodiments the dynamic route <NUM> may be associated with a radius-to-fix leg (e.g., type "RF leg") defined by fixed point <NUM> (e.g., "fix"), turn radius <NUM>, entry and exit waypoints 312a, 312b (the latter transitioning between arcuate track change <NUM> and straight track segment <NUM>) and subsequent waypoint <NUM>.

Referring now to <FIG>, the method <NUM> may be implemented by the aircraft-based communications management unit <NUM> (CMU) and may include the following steps.

At a step <NUM>, the CMU receives (e.g., intercepts, blocks further transmission of) intent data outputs sent by the flight management system (FMS), each intent data output including an aircraft state (e.g., a four-dimensional position of the aircraft: latitude, longitude, altitude, ETA at destination) and one or more trajectory points (intent path information, e.g., lateral or vertical path transition and (e.g., for lateral path transitions) a turn direction and turn radius (e.g., a radius relative to a fix around which the aircraft turns)). For example, each intent data output may correspond to a waypoint within the flight plan, e.g., an ATC waypoint associated with a fixed location (a "fly-by" or "fly-over" waypoint), an inserted waypoint added to a flight plan of the aircraft via the FMS (e.g., by the pilot), and/or a dynamic or pseudo-waypoint associated with a programmed change to one or more flight parameters.

At a step <NUM>, the CMU maintains a dynamic route (e.g., route representation, route approximation) based on the received intent data outputs, wherein each dynamic route describes a trajectory connecting the sequence of aircraft states included in the intent data outputs. For example, the CMU may convert absolute position information (e.g., latitude, longitude, altitude, ETA) associated with each intent data output into relative position information, where each intent data output includes an aircraft state relative to a baseline aircraft state or position.

At a step <NUM>, the CMU generates ADS-C reports based on the dynamic route, e.g., based on ADS-C contracts initiated with the aircraft by ATC ground station/s. Each ADS-C report corresponds to a current and/or future state of the aircraft as indicated by (or as projected based on) the dynamic route. For example, the CMU may generate periodic ADS-C reports based on periodic contracts established with ATC ground station/s. Additionally or alternatively, the CMU may receive demand contracts from the ATC ground station/s and generate ADS-C reports responsive thereto. ADS-C reports may include basic information, e.g., latitude, longitude, altitude, timestamp, or additional specific information groups as requested by an ADS-C contract. In some embodiments, the CMU determines a projected position of the aircraft at a requested subsequent time and/or a projected route, e.g., a sequence of waypoints between the current state or position of the aircraft and the projected position at the requested time.

At a step <NUM>, the CMU transmits the generated ADS-C report/s to the requesting ATC ground station/s.

Referring also to <FIG>, the method <NUM> may include an additional step <NUM>. At the step <NUM>, the CMU queries absolute positioning systems (e.g., main and backup GNSS receivers) and inertial reference systems (IRS, e.g., main and backup air data inertial reference units (ADIRU)) to verify the availability and/or accuracy of aircraft navigational systems, such that each generated ADS-C report includes a navigational status accuracy assessment (e.g., estimated position uncertainty).

Referring also to <FIG>, the method <NUM> may include an additional step <NUM>. At the step <NUM>, the CMU detects, based on the dynamic route, a contract event associated with an event-based ADS-C contract. For example, the event-based contract provides that when a particular flight parameter is met or exceeded (ordeceeded), an ADS-C report will be generated documenting the exceeded parameter and transmitted to the initiating ground station/s. Accordingly, the CMU identifies any such event from within the dynamic trajectory set, generating and transmitting the appropriate report.

Claim 1:
An aircraft-based communications management unit (<NUM>), CMU, configured for control of communications between an aircraft (<NUM>) and at least one ground station (<NUM>), the CMU comprising:
an input in communication with a flight management system (<NUM>), FMS, of the aircraft via a trajectory bus (<NUM>), the input configured to receive one or more intent data outputs (<NUM>) from the FMS (<NUM>) via the trajectory bus (<NUM>), each intent data output (<NUM>) including at least one of an aircraft state and a trajectory point;
at least one processor in communication with the input and configured to:
based on the one or more intent data outputs (<NUM>), independently determine at least one dynamic route (<NUM>) corresponding to a trajectory connecting two or more aircraft states associated with the one or more intent data outputs;
generate, based on the at least one dynamic route, at least one ADS-C report associated with an ADS-C contract between the aircraft (<NUM>) and the at least one ground station (<NUM>), the ADS-C report comprising at least one aircraft state associated with the one or more intent data outputs;
and
at least one Aircraft Communications Addressing and Reporting System, ACARS,-compatible communications interface, the communications interface configured for transmitting the at least one ADS-C report.