Patent Description:
Closely Spaced Parallel Runways (CSPR) have historically been defined as parallel runways spaced less than <NUM> ft. apart, but at least <NUM> ft. When visual approaches can be conducted, simultaneous arrivals to CSPR are permissible. In visual approaches, simultaneous arrivals to CPSR require that flight crews on both aircraft maintain a visual separation. Runways spaced less than <NUM> ft. apart have an additional requirement that flight crews must be aware of wakes produced by neighbor aircraft, and avoid wake encounters (typically by staying above or ahead of the wake of the neighbor aircraft).

When conditions do not permit CSPR visual approaches, instrument approach procedures (IAPs) may be utilized. However, the instruments may have surveillance uncertainties; for example, the angular nature of Instrument Landing System (ILS) localizer guidance may be between <NUM>° and <NUM>° degrees. The uncertainties may compound when used together, such that the two ILS localizers overlap somewhere on the extended final approach, degrading the resolution of the aircraft's position, and the accuracy as distance from the runway increases. As a result, increased separations may be required, which reduces the airport capacity.

To increase capacity during CSPR using the IAP, a flight deck-based solution called Paired Approach procedure (PA) is a standard regulatory solution. The PA procedure is a cooperative procedure enabling instrument dependent approaches to closely spaced parallel runways (CSPR) down to Category I minima (a Category <NUM> minima is one of several instrument landing system (ILS) categories for providing horizontal and vertical guidance for an aircraft during landing). The PA procedure leverages data from the Automatic Dependent Surveillance-Broadcast (ADS-B) out for the lead aircraft, received by the ADS-B in of the trail aircraft. When two aircraft on CSPR approaches are 'paired', Air Traffic Control (ATC) issues a required ASG (assigned spacing goal) to the "trail" aircraft, which is a position within a safe distance (free from turbulence) relative to the 'target' aircraft. The trail aircraft has to maintain this position, adding a new task to the pilot's already demanding approach duties. In addition to maintaining the ASG, from the start of the IAP until touchdown, the relative along-track position of the trail aircraft must remain within a forward and rear boundary that avoids an encounter with a wake vortex from the target aircraft.

Accordingly, improvements to paired approach (PA) systems are desirable. Specifically, technologically improved PA systems and methods that provide easily comprehensible, current, visual guidance distinguishing wake boundaries and speed boundaries are desirable. Furthermore, other desirable features and characteristics of the present disclosure will become apparent from the subsequent Detailed Description and the appended claims, taken in conjunction with the accompanying drawings and this Background.

Document "<NPL>, discloses the concept, controller and pilot tasks in addition to simulation results related to Paired Approach Operations.

The solution is provided by the features of the independent claims. Variations are as described by the features of the dependent claims.

Furthermore, other desirable features and characteristics of the system and method will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the preceding background.

The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and.

All of the embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention that is defined by the claims. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic, and/or processor device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. The provided system and method may take the form of a control module, and may be separate from, or integrated within, a preexisting mobile platform guidance system, avionics system, flight management system (FMS), or aircraft flight control system (FCS). <FIG> provides an example control module <NUM> for performing the herein described functionality.

Exemplary embodiments of the disclosed flight deck interval management paired approach (FIMPA) system <NUM> and control module (<FIG>, <NUM>) determine various speed boundaries and wake boundaries during paired approach (PA) procedures, and generate corresponding display commands to render and update a paired approach bar (PAB) (<FIG>, <NUM>) on a display system (<FIG>, <NUM>). The system <NUM> processes aircraft-specific parameters with current state data for both the target and trail aircraft to generate the features of the PAB <NUM>. With the herein described speed determinations, display features, and some of the additional features described below, the control module <NUM> delivers a technological improvement over many available paired approach guidance systems. These features and additional functionality are described in more detail below.

As illustrated in <FIG>, image <NUM> depicts two closely spaced parallel runways (CSPR): a first runway <NUM> and a second runway <NUM>. Target aircraft <NUM> is flying a target trajectory <NUM> that is a straight-in ILS approach to runway <NUM>. A trail aircraft <NUM> is on trail trajectory <NUM>, which is a <NUM> degree (<NUM>) offset approach from a straight-in approach <NUM> to runway <NUM>.

The paired approach (PA) separation standard has two components measured from the target aircraft <NUM>: the collision safety limit (CSL <NUM>) and the wake safety limit (WSL <NUM>). Both of these limits represent along-path projections of the required separation measured relative to the target aircraft <NUM>. These limits bound a safe zone <NUM>. The trail aircraft <NUM> is deemed safely separated if it remains in the safe zone <NUM>. Air Traffic Control (ATC) will generally issue commands sufficient to vector target aircraft <NUM> and trail aircraft <NUM> to their respective initial approach fixes (IAF) of their respective initial approach procedures (IAP) within an interval management (IM) initiation time/distance tolerance. One component of IM is the required ASG <NUM>. As can be seen, the ASG <NUM> is within the safe zone <NUM>.

The FIMPA system <NUM> further decomposes the safe zone <NUM> into a normal operating zone <NUM> and two non-transgression zones (NTZ): collision NTZ <NUM> and wake NTZ <NUM>. The FIMPA system <NUM> processes current state data and aircraft-specific parameters and generates therefrom FIMPA speed guidance comprising a PA speed profile, with speed advisories marking the collision NTZ <NUM> and the wake NTZ <NUM>. The generated FIMPA speed guidance demark a wake free zone (the safe zone <NUM>), and speeds at which the trail aircraft <NUM> may impede on either of the collision NTZ <NUM> and wake NTZ <NUM>. The FIMPA system <NUM> commands the display system <NUM> to render the FIMPA speed guidance in a visually distinguishable manner, as is described in connection with <FIG>.

At the planned termination point <NUM> (expected to be the final approach fix (FAF) for most situations), the PA procedure and associated FIMPA speed guidance are terminated for the remainder of the approach. This segment is referred to as the "open-loop segment" <NUM> of a paired approach (PA) procedure. At the planned termination point <NUM>, the trail aircraft <NUM> slows to final approach speed and follows normal instrument approach procedures (IAP) for the remainder of the approach.

<FIG> and <FIG> depict a functional block diagram for implementing an exemplary enhanced FIMPA system <NUM> and control module <NUM>. In the described embodiments, the platform <NUM> is an aircraft (referred to as aircraft <NUM>), and the control module <NUM> and the system <NUM> are within the aircraft <NUM>; however, the concepts presented herein can be deployed in a variety of mobile platforms, spacecraft, and the like. Accordingly, in various embodiments, the control module <NUM> may reside elsewhere and/or enhance part of larger avionics management system, or platform management system. Further, it will be appreciated that the system <NUM> may differ from the embodiment depicted in <FIG>.

The control module <NUM> performs the functions of: paired approach speed calculations <NUM>, FIM-PA processing <NUM>, and display processing <NUM>. In order to perform these functions, the control module <NUM> may be operationally coupled to: a Navigation System <NUM>, a user interface <NUM>, a transponder for communicating with neighbor traffic, such as, an automatic dependent surveillance broadcast (ADS-B) system <NUM>, and a transponder for communicating with ground and/or air traffic control (ATC), such as, a datalink system <NUM>. The operation of these functional blocks is described in more detail below.

The navigation system <NUM> processes input from its components to (i) determine an aircraft instantaneous position with respect to a flight plan, and to (ii) provide vertical and lateral guidance for the aircraft <NUM> along the flight plan. The navigation system <NUM> may also process the flight plan and position determining data to determine a current phase of flight. To provide this data and information, the navigation system <NUM> generally comprises a processing system called a flight management system (FMS) <NUM>, operationally coupled to a navigation database <NUM>, a flight plan database <NUM>, and a sensor system <NUM>. As used herein, "navigation data" from the navigation system <NUM> may comprise data and information from the navigation system <NUM> and/or any of its components, such as, but not limited to, (trail) aircraft instantaneous, current state data and (trail aircraft) current phase of flight information.

The navigation database <NUM> may comprise waypoint information, airport features information, runway position and location data, holding patterns, flight procedures, approach procedures, and various flight planning and distance measuring rules and parameters. The flight plan database <NUM> is a database that contains flight plans and flight plan information, for example, a series of waypoints and associated constraints such as altitudes, airspeeds etc. Generally, before flight, the aircraft <NUM> is assigned a flight plan (FP); it may be programmed or uploaded into the flight plan database <NUM>.

The sensor system <NUM> comprises sensors for determining instantaneous current position for the aircraft <NUM>. The instantaneous current position of a platform or aircraft <NUM> may be referred to as aircraft state data, and/or position determining data, and comprises the current latitude, longitude, heading, and the current altitude (or above ground level) for the aircraft <NUM>. Aircraft state data may also include airspeed. The means for ascertaining current or instantaneous aircraft state data for the aircraft <NUM> may be realized, in various embodiments, as a global positioning system (GPS), inertial reference system (IRS), or a radio-based navigation system (e.g., VHF Omni-directional radio range (VOR) or long range aid to navigation (LORAN)), and may include one or more navigational radios or other sensors suitably configured to support operation of the navigation system <NUM>, as will be appreciated in the art.

A user interface <NUM> comprises one or more user input/output devices <NUM> and one or more display systems <NUM>, described below. The user interface <NUM> is cooperatively configured to allow a user (e.g., a pilot, co-pilot, or crew member) to interact with the display system <NUM>, the navigation system <NUM>, and/or other elements of the system <NUM> in a conventional manner. In various embodiments, the user interface <NUM> additionally comprises an audio system for receiving voice commands and/or emitting audible alerts.

In general, the display system <NUM> may include any device or apparatus, and associated software, suitable for displaying (also referred to as rendering) flight information or other data associated with operation of the aircraft <NUM> in a format viewable by a user. The renderings of the display system <NUM> are often called "cockpit displays" or "images. " Employed display devices may provide three dimensional or two-dimensional map images, and may further provide synthetic vision imaging. Accordingly, a display device responds to a respective communication protocol that is either two- or three-dimensional, and may support the overlay of text, alphanumeric information, or visual symbology on a given map image. Non-limiting examples of such display devices include cathode ray tube (CRT) displays, and flat panel displays such as LCD (liquid crystal displays) and TFT (thin film transistor) displays. In practice, the display system <NUM> may be part of, or include, a primary flight display (PFD) system, a multi-function display (MFD), a panel-mounted head down display (HDD), a head up display (HUD), or a head mounted display system, such as a "near to eye display" system.

The renderings of the display system <NUM> may be processed by a graphics system, components of which may be integrated into the display system <NUM> and/or be integrated within the control module <NUM>. Display methods include various types of computer generated symbols, text, and graphic information representing, for example, pitch, heading, flight path, airspeed, altitude, runway information, waypoints, targets, obstacles, terrain, and required navigation performance (RNP) data in an integrated, multi-color or monochrome form. Responsive to receiving display commands from the control module <NUM>, the display system <NUM> displays, renders, or otherwise visually conveys, one or more graphical representations or images associated with operation of the aircraft <NUM>, and specifically, the PAB <NUM> described in greater detail below. In various embodiments, images displayed on the display system <NUM> may also be responsive to processed user input that was received via a user input/output device <NUM>.

The user input/output device <NUM> may include any one, or combination, of various known user input device devices including, but not limited to: a touch sensitive screen; a cursor control device (CCD) (not shown), such as a mouse, a trackball, or joystick; a keyboard; one or more buttons, switches, or knobs; a voice input system; and a gesture recognition system. Non-limiting examples of uses for the user input/output device <NUM> include: entering values for stored variables (<FIG>, <NUM>), loading or updating instructions and applications (<FIG>, <NUM>), loading and updating a novel program (<FIG>, <NUM>), and loading and updating the contents of a database (<FIG>, <NUM>), each described in more detail below. In addition, pilots or crew may enter flight plans, Standard Operating Procedures (SOP), and the like, via the user input/output device <NUM>. In embodiments using a touch sensitive screen, the user input/output device <NUM> may be integrated with a display device in display system <NUM>.

External source(s) <NUM> may comprise air traffic control (ATC), neighboring aircraft, sources of weather information, and other suitable command centers and ground locations. Non-limiting examples of data received from the external source(s) <NUM> include, for example, instantaneous (i.e., real time or current) air traffic control (ATC) communications, traffic collision and avoidance system (TCAS) data from other aircraft, automatic dependent surveillance broadcast (ADS-B) data, and weather communications. In addition, an external data source <NUM> may be used to load or program a flight plan into the system <NUM> (generally, into the flight plan database <NUM>).

In the illustrated embodiment, components within the system <NUM> communicate with external data source(s) <NUM> via communications link <NUM>. Communications link <NUM> may be wireless, utilizing one or more industry-standard wireless communication protocols. Specifically utilizing the communications link <NUM> are the automatic dependent surveillance broadcast (ADS-B) system <NUM>, and the datalink system <NUM>. The automatic dependent surveillance broadcast (ADS-B) system <NUM> includes the hardware and software required to transmit and receive digital data communication between the aircraft <NUM> and other neighboring aircraft. Incoming ADS-B data includes pressure altitude, geometric altitude, horizontal speed, and vertical speed (speeds measured with respect to earth). In various embodiments, the ADS-B system <NUM> provides information via one or more components of the user interface <NUM>. The datalink system <NUM> includes the hardware and software required to transmit and receive digital data communications between the aircraft <NUM> and the external sources <NUM>. Accordingly, it may perform multiple communication protocols. In various embodiments, the datalink system <NUM> provides controller-pilot communications, i.e., between air traffic control (ATC) and a pilot onboard the aircraft <NUM> (generally, via one or more components of the user interface <NUM>). The system <NUM> receives ATC PA commands from the datalink system <NUM>.

As mentioned, the control module <NUM> performs the functions of: paired approach speed calculations <NUM>, FIMPA processing <NUM>, and display processing <NUM>. The control module <NUM> performs these functions upon receiving ATC paired approach commands, which include the ASG. In an embodiment of the control module <NUM>, which is depicted in <FIG>, a processor <NUM> and a memory <NUM> (having therein the program <NUM>) form a novel processing engine or unit that performs the processing activities of the system <NUM>, and generates commands for the display system <NUM>, in accordance with the program <NUM>, as is described herein.

The processor <NUM> may comprise any type of processor or multiple processors, single integrated circuits such as a microprocessor, or any suitable number of integrated circuit devices and/or circuit boards working in cooperation to 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 <NUM> maintains data bits and may be utilized by the processor <NUM> as storage and/or a scratch pad. 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. The memory <NUM> can be any type of suitable computer readable storage medium, such as, various types of: dynamic random access memory (DRAM), SDRAM, static RAM (SRAM), and non-volatile memory (PROM, EPROM, and flash). In certain examples, the memory <NUM> is located on and/or co-located on the same computer chip as the processor <NUM>. In the depicted embodiment, the memory <NUM> stores the above-referenced instructions and applications <NUM> along with one or more configurable variables in stored variables <NUM>. In various embodiments, a database <NUM> may be part of the memory <NUM>. The database <NUM> is computer readable storage media in the form of any suitable type of storage apparatus, including direct access storage devices such as hard disk drives, flash systems, floppy disk drives and optical disk drives. The database <NUM> may include an aircraft-specific parameters database (comprising aircraft-specific parameters for a variety of aircrafts), an airport database (comprising airport features) and a terrain database (comprising terrain features), parameters and instructions for runway detection and selection, and parameters and instructions for determining speeds and rendering the PAB <NUM>, as described herein. Information in the database <NUM> may be organized and/or imported from an external data source <NUM> during an initialization step of a process; it may also be programmed via a user input device <NUM>.

In various embodiments, the processor/memory unit of the control module <NUM> is additionally communicatively coupled (via a bus <NUM>) to an input/output (I/O) interface <NUM>, and a database <NUM>. The bus <NUM> serves to transmit programs, data, status and other information or signals between the various components of the control module <NUM>. The bus <NUM> can be any suitable physical or logical means of connecting computer systems and components. This includes, but is not limited to, direct hard-wired connections, fiber optics, infrared and wireless bus technologies. The I/O interface <NUM> enables communications between the control module <NUM> and other system <NUM> components, as well as with other external devices <NUM> not already addressed herein, and as well as within the control module <NUM>, can include one or more network interfaces to communicate with other systems or components. The I/O interface <NUM> can be implemented using any suitable method and apparatus. For example, the I/O interface <NUM> supports communication from a system driver and/or another computer system. In one embodiment, the I/O interface <NUM> obtains data from external data source(s) <NUM> directly. The I/O interface <NUM> may also include one or more network interfaces to communicate with technicians, and/or one or more storage interfaces for direct connection to storage apparatuses, such as the database <NUM>.

During operation, the processor <NUM> loads and executes one or more programs, algorithms and rules embodied as instructions and applications <NUM> contained within the memory <NUM> and, as such, controls the general operation of the control module <NUM> as well as the system <NUM>. In executing the process described herein, the processor <NUM> specifically loads and executes the instructions embodied in the novel program <NUM>. Additionally, the processor <NUM> is configured to, in accordance with the program <NUM>: process received inputs (selectively, any combination of input from the set including: external data sources <NUM>, the navigation system <NUM>, the user interface <NUM>, the ADS-B system <NUM>, and the datalink system <NUM>; reference any of the databases (such as, the navigation database <NUM>, and the database <NUM> for aircraft-specific parameters); determine various speed guidance; and, generate display commands that command and control the display system <NUM>.

As mentioned above, the proposed embodiments generate and command a display system <NUM> to render a paired approach bar (PAB <NUM>) on a cockpit display, and use symbolic indicators to visually communicate trail aircraft <NUM> speed information and associated key informational items, as related to the target aircraft <NUM>. The indicators are rendered such that they are separate and visually distinguishable from each other. Turning now to <FIG> and with continued reference to <FIG>, a cockpit display <NUM> is shown having the PAB <NUM> rendered in an area called the Paired Approach Home <NUM>. Using flight identifying text (UAL2345), a current location of the target aircraft <NUM> (with respect to the trail aircraft <NUM>) is indicated at the top of the PAB <NUM>. Instantaneous current state data of the trail aircraft <NUM> is received through the navigation system <NUM>, as described above. A minimum speed <NUM> (<NUM>) associated with a stall of the trail aircraft <NUM> is determined based in part on aircraft-specific parameters, and is rendered as bounding the bottom of the PAB <NUM>. Target aircraft <NUM> current state data, which may comprise a four dimensional (4D) trajectory, is continually received by the system <NUM> and is indicated via an ascending/descending/level-off indicator <NUM>. Target aircraft <NUM> instantaneous current state data is processed with respective aircraft-specific data to determine a related turbulence/wake and collision risk area. The turbulence/wake and collision risk area (referred to herein as "wake risk" area for simplification purposes) caused by the target aircraft <NUM> is rendered as the dots from dot <NUM> down to the minimum speed <NUM> (<NUM>).

Processing the determined wake risk area with aircraft-specific parameters for the trail aircraft <NUM>, various speed guidance are generated, such as, the minimum safe speed <NUM> (<NUM>), which is a minimum speed that the trail aircraft <NUM> can fly to avoid entering into the wake risk area while aligning for a paired approach (PA). It is to be understood that the minimum safe speed <NUM> changes responsive to real-time changes in aircraft state data (of the target aircraft <NUM>). On the PAB <NUM>, a PAB safe speed range is rendered as extending from above the minimum safe speed <NUM> (<NUM>) to an aircraft maximum speed <NUM> (<NUM>). Further, the system <NUM> determines and renders a region <NUM>, which is a target safe speed zone.

A symbol indicating the current speed <NUM> (of the trail aircraft <NUM>) depicts the current speed <NUM>. In <FIG>, the current speed <NUM> is within the PAB safe speed range. When the system <NUM> determines the current speed <NUM> should be adjusted, it generates and renders speed guidance, which is a recommended speed <NUM> (<NUM>) displayed as a separate symbol on the PAB <NUM>. The current speed <NUM> and the recommended speed <NUM> are overlaid on the PAB <NUM> on the cockpit display <NUM> in a visually distinguishable manner to enhance crew awareness about the wake/turbulence area. In an exemplary embodiment, the symbol for the current speed <NUM> is rendered on the left, and the symbol for the recommended speed <NUM> is rendered on the right of the PAB <NUM>.

Since current speed <NUM> (<NUM>) is well above the minimum safe speed <NUM> (<NUM>), in various embodiments, the current speed <NUM> may be indicated in a familiar, universally affirmative color, such as green. Using familiar colors for the indicators helps a crew to visualize the safe zone and reduces his work load during paired approach (PA) procedure execution. The target aircraft identifier and associated ascending/descending/level off information at indicator <NUM> also enhances pilot awareness and reduces his work load.

<FIG> are provided to illustrate the proposed PAB <NUM> in various other speed scenarios. In cockpit display <NUM>, the trail aircraft <NUM> is again trailing the target aircraft <NUM> (UAL2345), but the trail aircraft <NUM> current speed <NUM> (<NUM>) is below the recommended speed <NUM> (<NUM>). In practice, such slowing down (of the trail aircraft <NUM>) may be, for example, because of a strong head wind. The current speed <NUM> is displayed on the PAB <NUM> in a visually distinguishable manner to alert a pilot that the trail aircraft <NUM> is about to enter into the wake risk area (turbulence zone). In an embodiment, the current speed <NUM> may be displayed in a familiar, universal alert color, such as red, to draw the pilot's attention. The speed guidance, recommended speed <NUM> (<NUM>), is also provided to aid the pilot in successfully completing the paired approach.

As stated, a real-time change in the aircraft state data (of the target aircraft <NUM>), results in a real-time change in speed guidance, as shown in <FIG>. On cockpit display <NUM>, the control module <NUM> determines that the target aircraft <NUM> is speeding up or accelerating, and updates the PAB <NUM> on the Paired Approach Home <NUM> responsive thereto. The increasing target aircraft <NUM> speed is visually presented with the upward-pointing arrow and the text "<NUM> FT/MIN" used for the ascending/descending/level-off indicator <NUM>. In practice, the target aircraft <NUM> may be accelerating or speeding up due to a tail wind. Responsive thereto, the control module <NUM> determines a new recommended speed <NUM> for the trail aircraft <NUM> to successfully complete the paired approach. In this scenario, the symbol for current speed <NUM> may be rendered in green or in red, depending on whether the current speed <NUM> is within the safe speed zone <NUM> when the new recommended speed <NUM> (<NUM>) is determined.

The example shown in cockpit display <NUM> (<FIG>) depicts another variation in speed guidance. The control module <NUM> determines that the trail aircraft <NUM> has reduced speed too much with respect to the target aircraft <NUM>, and has entered the wake risk area. The PAB <NUM> on the Paired Approach Home <NUM> has been updated responsive thereto. In practice, the trail aircraft <NUM> may have reduced speed responsive to encountering environmental conditions. In this case, the control module <NUM> renders the symbol for the current speed <NUM> in the wake risk area of the PAB <NUM>, and may additionally utilize a visual distinguishability technique such as the universal alert color red. As with the previous examples, the recommended speed <NUM> (<NUM>) is based on a combination of the current state data of the trail aircraft <NUM>, the aircraft-specific parameters of the target aircraft <NUM>, and the current state data of the target aircraft <NUM>. In this example, the target aircraft <NUM> may also have slowed down, as the recommended FIM-PA speed <NUM> (<NUM>) is a slightly lower speed goal than what is rendered in <FIG> and <FIG> (<NUM> instead of <NUM>).

Accordingly, the exemplary embodiments discussed above provide a technologically improved FIMPA system <NUM>. The FIMPA system <NUM> provides easily comprehensible, current, visual speed guidance for a trail aircraft <NUM>. The speed guidance distinguishes speeds associated with wake boundaries and aircraft-specific speed boundaries. The FIMPA system <NUM> determines a recommended speed to achieve the AG <NUM> based on aircraft-specific parameters and current state data for each of the target aircraft <NUM> and the trail aircraft <NUM>. The FIMPA system <NUM> changes the visual presentation of the speed marker symbols to intuitively communicate safe speeds and alert speeds responsive to determining that a recommended speed is different than a current speed.

Claim 1:
A method for a paired approach (PA) procedure in a trail aircraft (<NUM>), the method comprising:
receiving instantaneous target aircraft state data from an automatic dependent surveillance-broadcast (<NUM>);
receiving instantaneous state data of the trail aircraft from a navigation system (<NUM>);
obtaining aircraft-specific parameters for the trail and target aircraft from a database;
processing the state data of the trail aircraft and target aircraft state data and aircraft specific parameters for both the target and trail aircraft to determine a target safe speed zone (<NUM>) for the trail aircraft to perform a paired approach with a target aircraft (<NUM>), and a recommended speed (<NUM>) for the trail aircraft;
rendering, on a display system (<NUM>), a paired approach bar (PAB) (<NUM>) comprising:
flight identifying text for the target aircraft;
a PAB safe trail aircraft speed range extending from above a trail aircraft minimum safe speed (<NUM>) to a trail aircraft maximum speed (<NUM>);
a current trail aircraft speed (<NUM>);
a target safe speed zone (<NUM>), the target safe speed zone having a maximum speed which is less than the trail aircraft maximum speed (<NUM>) and a minimum speed which is greater than a trail minimum safe speed (<NUM>);
the recommended speed for the trail aircraft (<NUM>); and
a wake risk area caused by the target aircraft, the wake risk area being a range of trail aircraft speeds below the safe speed range and above a trail aircraft minimum speed (<NUM>).