Patent Description:
CDTI (Cockpit Display of Traffic Information) may allow a flight crew to maintain ownship separation from a target aircraft that the ownship follows when visual contact is lost (e.g., due to hazy or night conditions) by using the information provided by the CDTI as a substitute for an out-the-window view. CDTI may be provided to the flight crew via a navigation display, which can provide a two-dimensional (2D) view. The flight crew may, however, have other displays, such as a primary flight display (PFD), which can provide a three-dimensional (3D) view, within the flight crew's field of view during procedures when following target aircraft. These other displays may not provide CDTI. A flight crew's situational awareness may be improved by a simultaneous display of 2D and 3D information related to a target aircraft that the ownship follows.

Hence, it is desirable to provide the CDTI on the PFD and/or head up display (HUD) to achieve simultaneous display of 2D and 3D information related to a target aircraft that the ownship follows. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

<CIT> discloses a vertical situation display (VSD), presenting visual approach; information, such as a vertical distance between the ownship and a Traffic-To-Follow (TTF) aircraft and descent rates of the ownship and the TTF aircraft. The provided system also receives and processes user selections of target aircraft from both a lateral display and the VSD.

<CIT> discloses displaying an enhanced longitudinal scale providing user interface and awareness for executing the Cockpit Display of Traffic Information (CDTI) application Enhanced Visual Separation on Approach (VSA) to provide a required spacing between aircraft based on distance and time. An own-ship and a reference (in-trail) aircraft are displayed in relation to a desired flight path. A symbol indicates the desired separation of the own-ship from the aircraft.

In one embodiment, a visualization assistance system for providing visual cues to flight crew on multiple displays while following a proceeding aircraft during an approach using visual separation rules is provided. The visualization assistance system includes one or more processors configured by programming instructions on non-transient computer readable media. The visualization assistance system is configured to: position, on an SVS (synthetic vision system) display section of a primary flight display (PFD) and/or head up display (HUD), one or more traffic icons, wherein each is representative of a lead aircraft ahead of an ownship and wherein the size of each traffic icon is scaled based on proximity to the ownship; designate a lead aircraft as traffic to follow (TTF) via selection of a first traffic icon representative of one lead aircraft displayed on a navigation display (ND) or via selection of a second traffic icon representative of the same lead aircraft displayed on the SVS (on the PFD and/or HUD), wherein selection of either the first traffic icon or the second traffic icon results in designation of the selected lead aircraft as TTF and results in both the first traffic icon and the second traffic icon in being made to more visually stand out; and position, on an HSI (horizontal situation indicator) section of the PFD, a third TTF icon representative of the lead aircraft when a TTF has been designated.

In another embodiment, a computer-implemented method in a trail aircraft for providing visual cues to flight crew on multiple displays while following a proceeding aircraft during an approach using visual separation rules is provided. The method includes: positioning, on an SVS (synthetic vision system) display section of a primary flight display (PFD) and/or HUD, one or more traffic icons wherein each is representative of a lead aircraft ahead of an ownship and wherein the size of each traffic icon is scaled based on proximity to the ownship; designating a lead aircraft as traffic to follow (TTF) via selection of a first traffic icon representative of one lead aircraft displayed on a navigation display (ND) or via selection of a second traffic icon representative of the same lead aircraft displayed on the SVS, wherein selection of either the first traffic icon or the second traffic icon results in designation of the selected lead aircraft as TTF and results in both the first traffic icon and the second traffic icon being made to more visually stand out; and positioning, on an HSI (horizontal situation indicator) section of the PFD, a third TTF icon representative of the lead aircraft when a TTF has been designated.

The subject matter described herein discloses apparatus, systems, techniques and articles for increasing the situational awareness of the flight crew when using information displayed in the cockpit such as CDTI to maintain ownship separation when visual contact is lost. The apparatus, systems, techniques and articles provided herein can provide a simultaneous 2D and 3D presentation of designated traffic and CDTI to enhance awareness of traffic to follow, separation criteria and differential groundspeed.

<FIG> is a diagram depicting an example operating environment <NUM> in which visualization assistance queues may be provided for flight crew use. In poor visibility situations it may be difficult for flight crew to maintain a desired visual separation from a target aircraft. To support flight crew situation and traffic awareness, the apparatus, systems, techniques and articles described herein provide visualization assistance queues on multiple cockpit display screens that can help the flight crew maintain separation between a target aircraft and an ownship during an approach using visual separation rules.

In the example environment <NUM>, air traffic control (ATC) <NUM> provides clearance information to the flight crew on an ownship <NUM> indicating the identification designation for a target aircraft <NUM> to follow, for example, during a landing procedure. The flight crew of the ownship may report "Traffic in sight" to ATC <NUM>, designate the target aircraft <NUM> in its aircraft equipment, and select an alerting distance threshold (e.g., a pre-selected distance) as a minimum separation distance between the ownship <NUM> and the target aircraft <NUM> the flight crew would like to maintain. The flight crew of the ownship <NUM> may adjust the ownship aircraft speed based on an out the window view of the target aircraft <NUM> to maintain a desired ownship separation from the target aircraft <NUM>. If visual contact with the target aircraft <NUM> is lost (e.g., due to haze <NUM>), the flight crew may adjust the aircraft speed of the ownship <NUM> based on information provided by a visualization assistance system <NUM> to maintain ownship separation. Use of the visualization assistance system <NUM> can improve flight crew situational awareness. Use of the visualization assistance system <NUM> may end when the target aircraft <NUM> lands, e.g., at a runway <NUM>.

<FIG> is a block diagram of an example visualization assistance system <NUM>. The example visualization assistance system <NUM> is configured to provide visual cues <NUM> to flight crew on multiple displays - a navigation display (ND) <NUM>, a primary flight display (PFD) <NUM>, and/or a heads up display (HUD) <NUM> - while an ownship follows a lead (target) aircraft during an approach procedure that requires the use of visual separation rules. This can help make the flight crew more situational aware as the flight crew adjusts its view between the window to the outside, the ND <NUM>, the PFD <NUM>, and/or HUD <NUM>. For a PFD <NUM> that provides both a synthetic vision system (SVS) <NUM> and a horizontal situation indicator (HSI) <NUM>, the example visualization assistance system <NUM> is configured to provide visual cues to both the SVS <NUM> and the HSI <NUM>, to additionally improve the situational awareness of flight crew by providing four different sources of visual cues. The example visualization assistance system <NUM> is configured to retrieve traffic data from a traffic computer <NUM> onboard the ownship from a traffic source such as ADS-B, ADS-R, TIS-B or other data from the preceding aircraft, aircraft data from avionics systems <NUM> such as the FMS (flight management system), and flight crew input <NUM>.

The example visualization assistance system <NUM> is implemented using a controller. The controller includes at least one processor and a computer-readable storage device or media encoded with programming instructions for configuring the controller. The processor may be any custom-made or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), an auxiliary processor among several processors associated with the controller, a semiconductor-based microprocessor (in the form of a microchip or chip set), any combination thereof, or generally any device for executing instructions.

The computer readable storage device or media may include volatile and non-volatile storage in read-only memory (ROM), random-access memory (RAM), and keep-alive memory (KAM), for example. KAM is a persistent or non-volatile memory that may be used to store various operating variables while the processor is powered down. The computer-readable storage device or media may be implemented using any of a number of known memory devices such as PROMs (programmable read-only memory), EPROMs (electrically PROM), EEPROMs (electrically erasable PROM), flash memory, or any other electric, magnetic, optical, or combination memory devices capable of storing data, some of which represent executable programming instructions, used by the controller.

<FIG>, <FIG> are diagrams depicting example visualization assistance queues that the example visualization system <NUM> may cause to be displayed on a ND <NUM> for flight crew use during an approach using visual separation rules. <FIG>, <FIG>, <FIG>, <FIG> and <FIG> are diagrams depicting example visualization assistance queues that the example visualization system <NUM> may cause to be displayed on a PFD <NUM> for flight crew use during an approach using visual separation rules.

The example visualization assistance system <NUM> is configured to receive a selection of a target icon <NUM>, that represents a target aircraft ahead of the ownship. The ND may display one or more potential target aircraft via icons. The selection of an icon <NUM> may cause the opening of a dialog box <NUM> from which the selected icon and the aircraft represented by the icon <NUM> may be designated as traffic to follow (TTF) using the example visualization assistance system <NUM>.

Upon receiving a selection, the example system <NUM> is configured to make the selected target icon <NUM> become more visually pronounced, for example, by changing the color of the icon <NUM> (e.g. to green) and/or causing an area <NUM> surrounding the target icon to be displayed in a specific shape or color (e.g., green box). The example system <NUM> is configured to cause the display of a call sign (or flight ID) indicator <NUM> that provides the call sign/flight ID of the target aircraft, cause a display of a ground speed indicator <NUM> that provides the ground speed of the target aircraft, and relative numerical altitude <NUM> with a + sign for traffic above the ownship or - sign for traffic below the ownship. Traffic the same altitude is displayed with no preceding symbol. Also, the fixed size vertical sense arrow <NUM> is displayed as an upward arrow for ascending traffic and a downward arrow for descending traffics. The example system <NUM> is configured to provide a range ring symbol <NUM> that indicates a relative distance in front of an ownship symbol on the ND and a numeric value <NUM> for a flight crew selected minimum range value wherein the minimum range value (threshold value) is equal to a minimum flight crew selected desired separation distance between the target aircraft and the ownship. The example system <NUM> is configured to cause the distance between the selected target icon <NUM>, the range ring symbol <NUM> and an ownship symbol <NUM> on the ND to be proportional to the horizontal distance between the actual target aircraft, the threshold distance and the actual ownship. The visualization assistance system <NUM> is further configured to systematically adjust the position of the selected target icon <NUM> relative to the first range ring symbol <NUM> and the ownship symbol <NUM> on the ND.

The example system <NUM> is further configured to provide a differential ground speed widget <NUM> that provides an alpha numeric indication of the differential ground speed (DGS) between the target aircraft and the ownship, and a differential ground speed symbol <NUM> that provides a graphical indication of whether the ownship is slower or faster than preceding aircraft <NUM>. The differential ground speed symbol <NUM> is configured to provide a differential speed indicator symbol that indicates a range of differential speeds between the target and the ownship. In one example, a back chevron <NUM> below an ownship symbol <NUM> indicates a negative differential ground speed (e.g., the ownship speed is slower than preceding aircraft), a single chevron <NUM> above the ownship symbol <NUM> indicates a positive differential speed of <NUM> to <NUM> knots (e.g., the ownship is slightly faster that preceding aircraft), a directional triangle <NUM> above the ownship symbol <NUM> indicates a positive differential speed of <NUM> to <NUM> knots, and a directional triangle with a chevron <NUM> above the ownship symbol <NUM> indicates a positive differential speed of <NUM> or more knots. The example visualization assistance system <NUM> may also be configured to cause the display of the horizontal range between the target aircraft and the ownship in a location <NUM> on the ND adjacent to the differential ground speed magnitude. When the distance between the ownship and the target aircraft is less than the flight crew selected minimum range value <NUM> or the received traffic data (e.g., ADS-B data), which provides data from the target aircraft on its position, heading, and velocity, is of low quality, the example visualization assistance system <NUM> is configured to cause a caution alert to be presented, for example, by changing the color of the target symbol <NUM> and call sign/flight ID <NUM> (e.g., to an amber color), to cause the display of a label <NUM> (e.g., an UNABLE label) adjacent to the traffic icon <NUM>, and to cause the area surrounding the target icon (e.g., area <NUM>) to no longer be displayed in the specific shape or color in which it was displayed before the presentation of the caution alert.

To provide visual cues to the flight crew on multiple displays (e.g., ND <NUM> and PFD <NUM>), the example visualization assistance system <NUM> is configured to provide icon, widgets and symbols on the PFD <NUM> that are similar to those provided by the visualization assistance system <NUM> on the ND <NUM>.

As illustrated in <FIG>, the example visualization assistance system <NUM> is configured to position, on an SVS (a three dimensional (3D) synthetic vision system) display section of a primary flight display (PFD), one or more traffic icons <NUM>, <NUM> each representative of an aircraft ahead of the ownship, wherein the size of each traffic icon <NUM>, <NUM> is scaled based on proximity to the ownship, and wherein a traffic icon <NUM> for a first traffic aircraft is smaller than a traffic icon <NUM> for a second traffic aircraft when the first traffic aircraft is further away from the ownship than the second traffic aircraft.

The example visualization assistance system <NUM> is configured to receive the selection of one traffic icon <NUM> of the traffic icons <NUM>, <NUM> on the SVS and designate an aircraft represented by the selected icon <NUM> as traffic to follow (TTF) via the selection of the traffic icon <NUM>. The example visualization assistance system <NUM> is therefore configured such that the selection of either a traffic icon <NUM> on the ND or a traffic icon <NUM> on the SVS results in designation of the selected aircraft as TTF and results in both the traffic icon <NUM> on the ND and the traffic icon <NUM> on the SVS being made to more visually stand out (e.g., pixels <NUM> surrounding the icon <NUM> may be made to be displayed in a different color or intensity or shading the pixels representing the icon <NUM> in a different color or intensity). Similar visual presentations could be provided on a head-up display (HUD).

As illustrated in <FIG>, the example visualization assistance system <NUM> is also configured to position, on an HSI (horizontal situation indicator) section of the PFD, a TTF icon <NUM> representative of the lead aircraft when a TTF has been designated. Similar to the traffic icon <NUM> on the ND, the TTF icon <NUM> may include a designation of the call sign/flight ID <NUM> for the TTF, the ground speed <NUM> of the TTF, and a numerical representation of an altitude difference <NUM> between the TTF and the ownship.

The example visualization assistance system <NUM> is configured to cause a range ring symbol <NUM> that indicates a relative distance in front of an ownship and a numeric representation <NUM> of the flight crew selected threshold distance (similar to range ring symbol <NUM>) to be displayed on the HSI section of the PFD. The distance between the TTF icon <NUM>, the range ring symbol <NUM> and an ownship symbol <NUM> on the HSI is proportional to the horizontal distance between the actual TTF, the threshold distance and the actual ownship. Selection of either the traffic icon <NUM> on the ND, the traffic icon <NUM> on the SVS, or the TTF icon <NUM> allows for entry of the threshold distance from the ND, the SVS or the HSI. The example visualization assistance system <NUM> is further configured to systematically adjust (e.g., periodically) the position of the TTF icon <NUM> relative to the range ring symbol <NUM> and the ownship symbol <NUM> on the HSI.

The example visualization assistance system <NUM> is configured to cause to be displayed, on the PFD, a numerical representation <NUM> of the differential ground speed between the TTF and the ownship and a differential ground speed symbol <NUM> representative of a range of differential ground speeds. In one example, the example visualization assistance system <NUM> is configured to cause to be displayed, adjacent to the ownship symbol <NUM> on the HSI, the numerical representation <NUM> of the differential ground speed difference between the TTF and the ownship, and the differential ground speed symbol <NUM> representative of a range of differential ground speeds as illustrated in <FIG> and <FIG>. In another example, the visualization assistance system <NUM> is configured to cause the numerical representation <NUM> of the differential ground speed and the differential ground speed symbol <NUM> to be displayed adjacent to an existing groundspeed display on the PFD as illustrated in <FIG>.

As illustrated in <FIG>, the example visualization assistance system <NUM> is configured to estimate an airspeed target <NUM> at which to fly to maintain a desired distance between the ownship and the TTF and cause the estimated airspeed target <NUM> to be displayed on the SVS. The estimated airspeed target <NUM> may be displayed (e.g., green line and diamond) in an airspeed indicator section <NUM> on the SVS or HUD. The example visualization assistance system <NUM> is configured to estimate the airspeed target <NUM> using a current ownship airspeed, wind speed and direction, current ownship groundspeed, and differential groundspeed between the TTF and the ownship. This information may be determined from information from the traffic computer <NUM>, sensors, and avionics systems <NUM> on the ownship. The example visualization assistance system <NUM> is further configured to cause a vertical line <NUM> from the TTF icon <NUM> displayed on the SVS to provide an indication of the distance between the TTF and the ownship. Also, the visualization assistance system <NUM> could be configured to provide some or all of the features depicting in <FIG> based on the target platform or the personal preference of the flight crew.

As illustrated in <FIG>, the example visualization assistance system <NUM> is configured to cause the state of the TTF icon <NUM> displayed on the SVS and the TTF icon <NUM> displayed on HSI to change (e.g., different color and/or shape) when the TTF transitions to a TCAS Traffic Advisory (TA) state due to inadequate separation. The example visualization assistance system <NUM> is configured to cause an alert to be displayed on both the ND and the PFD when traffic that becomes a potential hazard is detected. The TFF <NUM> may also no longer meets minimum specified criteria, such as the threshold distance is violated or the ADS-B has dropped out. The example visualization assistance system <NUM> is configured to cause similar types of range advisory alerts to be displayed on both the ND and the PFD.

<FIG> is a process flow chart depicting an example process <NUM> in a trail aircraft for providing visual and aural cues to flight crew on multiple displays (e.g., ND, PFD, and HUD) while following a proceeding aircraft during an approach using visual separation rules. The order of operation within the process <NUM> is not limited to the sequential execution as illustrated in the figure, but may be performed in one or more varying orders as applicable and in accordance with the present disclosure.

The example process <NUM> includes positioning on an SVS (and/or HUD) one or more traffic icons, each representative of a lead aircraft ahead of the ownship (operation <NUM>). The size of each traffic icon is scaled based on proximity to ownship. For example, a traffic icon may be smaller when the lead aircraft is further away from the ownship.

The example process <NUM> includes designating an aircraft as traffic to follow (TTF) via selection of a traffic icon representative of the aircraft displayed on either a navigation display (ND) or on the SVS/HUD (operation <NUM>). Selection of either a traffic icon on the ND or SVS/HUD results in designation of the lead aircraft represented by the traffic icon as TTF and results in both traffic icons on the ND and SVS/HUD being made to more visually stand out (e.g., pixels surrounding the icon to be displayed in a different color or intensity or shading of the pixels representing the icon to be displayed in a different color or intensity);.

The example process <NUM> includes positioning, on an HSI (horizontal situation indicator) section of the PFD, a TTF icon representative of the selected aircraft when a TTF has been designated (operation <NUM>). The TTF icon on the HSI may include a designation of the call sign/flight ID for the TTF, the ground speed of the TTF, and a numerical representation of an altitude difference between the TTF and the ownship.

The example process <NUM> includes causing a first range ring symbol along with a numerical representation of a flight crew selected threshold distance to be displayed on the ND adjacent the first range ring symbol (operation <NUM>). The threshold distance is flight crew selected as a minimum separation distance between the TTF and the ownship. The distance between the traffic icon, the first range ring and an ownship symbol on the ND is proportional to the horizontal distance between the actual TTF, the threshold distance and the actual ownship.

The example process <NUM> includes causing a second range ring symbol along with a numerical representation of the flight crew selected threshold distance to be displayed on the HSI section of the PFD (operation <NUM>). The distance between the traffic icon, the second range ring and an ownship symbol on the HSI is proportional to the horizontal distance between the actual TTF, the threshold distance and the actual ownship. Also, selection of either the traffic icon on the ND, the traffic icon on the SVS, or the TTF icon on the HSI allows for entry of the threshold distance from the ND, the SVS or the HSI.

The example process <NUM> further includes systematically adjusting the position of the traffic icon on the ND relative to the first range ring and the ownship symbol on the ND, and the position of the TTF icon on the HSI relative to the second range ring and the ownship symbol on the HSI (operation <NUM>).

Described herein are apparatus, systems, techniques and articles for increasing the situational awareness of the flight crew by providing a simultaneous two-dimensional (2D) and three-dimensional (3D) presentation of visual cues on multiple displays to enhance awareness of traffic to follow, separation criteria and/or differential ground speed. The visualization assistance may be configured to cause the numerical representation of the differential ground speed and the differential ground speed symbol to be displayed either adjacent to an ownship symbol on the SVS or adjacent to an existing groundspeed display on the SVS. The visualization assistance system may be further configured to: estimate an airspeed target at which to fly to maintain a desired distance between the ownship and the TTF; and cause the estimated airspeed target to be displayed on the SVS. The visualization assistance system may be configured to cause the estimated airspeed target to be displayed in an airspeed indicator section on the SVS. The visualization assistance system may be configured to estimate the airspeed target using a current ownship airspeed, wind speed and direction, current ownship groundspeed, and differential groundspeed between the TTF and the ownship. The visualization assistance system may be further configured to cause the state of the TFF symbol on SVS and the TTF symbol on the HSI to change when the TTF no longer meets minimum CAVS criteria.

These aspects and other embodiments may include one or more of the following features. The third TTF icon may include a designation of the call sign/flight ID for the TTF, the ground speed of the TTF, and a numerical representation of an altitude difference between the TTF and the ownship. method may further comprise: causing to be displayed, adjacent to an ownship symbol on the ND, a numerical representation of the differential ground speed between the TTF and ownship and a differential ground speed symbol representative of a range of differential ground speeds; and causing to be displayed, on the SVS, a numerical representation of the differential ground speed between the TTF and the ownship and a differential ground speed symbol representative of a range of differential ground speeds. The method may comprise causing the numerical representation of the differential ground speed and the differential ground speed symbol to be displayed either adjacent to an ownship symbol on the SVS or adjacent to an existing groundspeed display on the SVS/HUD. The method may further comprise: estimating an airspeed target at which to fly to maintain a desired distance between the ownship and the TTF; and causing the estimated airspeed target to be displayed on the SVS/HUD. The method may comprise causing the estimated airspeed target to be displayed in an airspeed indicator section on the SVS/HUD. The method may comprise estimating the airspeed target using a current ownship airspeed, wind speed and direction, current ownship groundspeed, and differential groundspeed between the TTF and the ownship. The method may further comprise causing a vertical line from TTF symbol displayed on SVS to TTF symbol displayed on PFD to provide indication of how close the TTF is from ownship. The method may further comprise causing the state of the TFF symbol on SVS and the TTF symbol on the HSI to change when the TTF no longer meets minimum CAVS criteria.

In another embodiment not forming part of the invention, a non-transient computer readable media encoded with programming instructions that when executed by one or more processors in a trail aircraft causes the one or more processors to perform a method of providing visual cues to flight crew on multiple displays while the trail aircraft follows a proceeding aircraft during an approach using visual separation rules is provided. The method comprises: positioning, on an SVS (synthetic vision system) display section of a primary flight display (PFD) or HUD, one or more traffic icons wherein each is representative of a lead aircraft ahead of an ownship and wherein the size of each traffic icon is scaled based on proximity to the ownship; designating a lead aircraft as traffic to follow (TTF) via selection of a first traffic icon representative of one lead aircraft displayed on a navigation display (ND) or via selection of a second traffic icon representative of the same lead aircraft displayed on the SVS, wherein selection of either the first traffic icon or the second traffic icon results in designation of the selected lead aircraft as TTF and results in both the first traffic icon and the second traffic icon being made to more visually stand out; and positioning, on an HSI (horizontal situation indicator) section of the PFD, a third TTF icon representative of the lead aircraft when a TTF has been designated.

In another embodiment not forming part of the invention, a visualization assistance system for providing visual cues to flight crew on multiple displays (e.g., ND and PFD) while following a proceeding aircraft during an approach using visual separation rules is provided. The visualization assistance system comprises one or more processors configured by programming instructions on non-transient computer readable media.

The visualization assistance system is configured, with respect to the ND, to: receive the selection of an icon displayed on a navigation display (ND) that represents an aircraft ahead of the ownship aircraft, designate the selected aircraft as traffic to follow (TTF), and cause the selected icon to be highlighted; cause a range ring symbol along with a designation of a flight crew selected threshold distance to be displayed on the ND, the threshold distance equal to minimum flight crew selected separation distance between the TTF and ownship; and cause the display of a numerical representation of the differential ground speed between the TTF and ownship and a differential ground speed symbol representative of a range of differential ground speeds to be displayed adjacent to an ownship symbol on the ND;.

The visualization assistance system is configured, with respect to the PFD, to: position, on HSI, widget representative of TTF and range ring symbol, the TTF widget including icon representative of TTF, call sign/flight ID for TTF, ground speed of TTF, numerical representation of altitude difference between TTF and ownship, numerical representation of the differential ground speed between the TTF and ownship and a differential ground speed symbol representative of a range of differential ground speeds to be displayed adjacent to an ownship symbol on the HSI; position, on the SVS, a selectable traffic symbol representative of traffic ahead of the ownship wherein the size of the traffic symbol is scaled based on proximity to ownship; highlight a traffic symbol on SVS that is representative of an aircraft that has been designated as a TTF; designate an aircraft as a TTF responsive to selection of a traffic symbol on SVS representative of the aircraft, wherein TTF is selectable from ND, SVS and HSI and threshold distance can be entered from ND, SVS or HSI; cause the display of a numerical representation of the differential ground speed between the TTF and ownship and a differential ground speed symbol representative of a range of differential ground speeds to be displayed either adjacent to an ownship symbol on the SVS or adjacent to existing groundspeed display on the SVS; estimate airspeed target using current airspeed, wind speed and direction, and current and differential groundspeed for achieving a suitable target speed to maintain the desired distance from TTF and cause estimated airspeed target to be displayed on SVS; cause estimated airspeed target to be displayed in airspeed indicator section on SVS; cause a vertical line from TTF symbol displayed on SVS to TTF symbol displayed on PFD to provide indication of the TTF range; and cause the state of the TFF symbol on SVS and the TTF symbol on the HSI to change when TTF no longer meets minimum CAVS criteria.

Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention, as defined in the appended claims.

Claim 1:
A visualization assistance system (<NUM>) for providing visual cues to flight crew on multiple displays operably connectable to the visualisation assistance system (<NUM>) while following a proceeding aircraft during an approach using visual separation rules, the visualization assistance system comprising one or more processors configured by programming instructions on non-transient computer readable media, the visualization assistance system configured to:
position on a synthetic vision system, SVS, display (<NUM>) section of a primary flight display, PFD, (<NUM>) or on a head-up display, HUD, one or more traffic icons wherein each is representative of a lead aircraft ahead of an ownship and wherein the size of each traffic icon is scaled based on proximity to the ownship;
provide one or more traffic icons on a navigation display, ND; designate a lead aircraft as traffic to follow, TTF, via selection , by the flight crew, of a first traffic icon (<NUM>) representative of one lead aircraft displayed on the ND or via selection, by the flight crew, of a second traffic icon representative of the same lead aircraft displayed on the SVS (<NUM>), wherein selection of either the first traffic icon or the second traffic icon results in designation of the selected lead aircraft as TTF and results in both the first traffic icon and the second traffic icon being made to more visually stand out; and
position, on a horizontal situation indicator, HSI, section of the PFD, a third TTF icon representative of the lead aircraft when a TTF has been designated.