Patent Description:
The subject matter disclosed herein is directed generally to aircraft display systems and more particularly to symbology for primary flight displays (PFD).

Runway overruns are a threat to aircraft landing on, or taking off from, an airport runway. For example, an aircraft on approach to a runway at a given airspeed and angle of attack (which in turn may be affected by winds over the runway and other external factors) will touch down at a particular point along the runway. If there is not enough runway remaining between this landing point and the end of the runway for the aircraft to decelerate after touchdown, overrun may result: the aircraft may exit the runway at its far end, resulting in damage to the aircraft, injury to passengers and crew, or worse. Conventional runway overrun prevention systems provide visual and/or aural warnings of a potential excursion, but these systems may integrate visual warnings into an already complex primary flight display (PFD) or navigational display. <CIT> describes a runway overrun monitor. <CIT> discloses a device for displaying a symbology for assisting the piloting of an aircraft during a phase of landing on a runway including a Runway Overrun Warning function.

An aircraft-based runway overrun awareness alerting system (ROAAS) is disclosed and defined in claim <NUM>.

In some embodiments, the dynamic graphic element is revised based on revisions to the trending overrun probability.

In some embodiments, the ROAAS determines trending position states of the aircraft based on information received from the aircraft flight management system (FMS), from onboard sensors, or from the engine indicator and crew alerting system (EICAS).

In some embodiments, the ROAAS determines trending energy states of the aircraft based on data received from the FMS, the onboard sensors, or the EICAS.

In some embodiments, the ROAAS receives runway data from the runway's ground control station or from some other source external to the aircraft.

In some embodiments, the aircraft display system includes synthetic vision system (SVS) or enhanced vision system (EVS) content displaying the environment in the vicinity of the runway (e.g., from the aircraft's perspective). The display system superimposes the PFD, other navigational instrumentation, and the dynamic graphic element over the SVS/EVS content.

In some embodiments, the dynamic graphic element includes dynamic shape and color components (e.g., the current predicted trend corresponding to the current color and/or shape).

In some embodiments, revisions in the predicted trend are indicated by a change in the shape, size, and/or color of the dynamic graphic element.

In some embodiments, the dynamic graphic element changes shape or size in unison with the color change.

In some embodiments, the dynamic graphic element is displayed within a region of the display surface not otherwise occupied by a displayed PFD component or navigational instrument.

Referring to <FIG>, a primary flight display (PFD) <NUM> is disclosed. The PFD <NUM> may include attitude indicator <NUM>, airspeed indicator <NUM>, altimeter <NUM>, vertical speed indicator <NUM>, turn coordinator <NUM>, horizontal situation indicator <NUM>, and artificial horizon <NUM>.

In embodiments, the PFD <NUM> may be embodied aboard an aircraft on approach to a runway <NUM>. For example, the PFD <NUM> may incorporate, or may be a display component of, an enhanced vision system (EVS) and/or a synthetic vision system (SVS), such that aircraft instruments and/or PFD components (e.g., the attitude indicator <NUM>, airspeed indicator <NUM>, altimeter <NUM>, vertical speed indicator <NUM>, turn coordinator <NUM>, horizontal situation indicator <NUM>, and artificial horizon <NUM>) are graphically superimposed over an enhanced-vision representation <NUM> of the environment surrounding the runway <NUM> (including, e.g., terrain, runway or airport facilities, and explanatory symbology noting natural or manmade features or proximate aircraft).

While the aircraft on approach to the runway <NUM>, the pilot monitors multiple indicators simultaneously while controlling the descent of the aircraft. The energy state of the aircraft may similarly be in constant flux from moment to moment, based on, e.g., the current airspeed, altitude, angle of attack, or factors external to the aircraft, such as shifting wind patterns over the runway <NUM>. Accordingly, the pilot may be aiming for a particular landing point or region of the runway <NUM> in order to allow sufficient runway to decelerate or stop after touching down, but the actual likelihood of achieving the intended landing point (e.g., as opposed to leaving insufficient runway and risking a runway excursion or overrun) may vary along with internal and external conditions.

The PFD <NUM> incorporates a runway overrun awareness alert system <NUM> (ROAAS). For example, while on approach to the runway <NUM>, the ROAAS <NUM> monitors the trending energy state of the aircraft along with its trending position and heading relative to the runway compared with the parameters of the runway itself (e.g., the length and orientation of the runway, environmental conditions that may affect the landing). In embodiments. While on approach to the runway <NUM>, the ROAAS <NUM> monitors the energy state of the aircraft along with its position and heading relative to the runway and the parameters of the runway itself (e.g., length, orientation, weather or environmental conditions). If, for example, one or more conditions or combinations of conditions meet or exceed predetermined threshold levels, the display of ROAAS symbology may be triggered. The aircraft state indicates an angle of attack consistent with approach and landing, but airspeed may be in
excess of a speed consistent with the current aircraft position relative to the runway, and a tailwind may be present. Based on these observations, the ROAAS <NUM> may conclude that the likelihood of a runway overrun is nonzero, and that the threshold for ROAAS symbology display has been crossed. Should the aircraft abort the attempted landing and go around for a subsequent attempt, the ROAAS <NUM> may conclude that display conditions no longer exist and cease display of ROAAS symbology.

Based on trends in the aircraft energy state, the ROAAS <NUM> predicts an evolving trend in the likely landing point of the aircraft relative to the runway <NUM>. Based on the trending landing point and aircraft energy state, the ROAAS <NUM> further predicts the likely trend toward, or away from, a runway excursion or overrun on the part of the aircraft. The ROAAS <NUM> sends the predicted likelihood back to the EVS/SVS system for display to the pilot via the PFD <NUM>. For example, while the PDF <NUM> may incorporate runway excursion warnings, these warnings may only serve to warn the pilot of conditions consistent with a likely excursion when these conditions already exist (as opposed to, e.g., proactive prevention of excursion conditions). Further, runway excursion warnings may be incorporated into other display elements of the PDF (e.g., the EVS-generated runway <NUM> corresponding to the runway <NUM>, which may flash red to warn of a potential excursion) and therefore may not be as quickly and easily digested by the pilot.

It is contemplated that the ROAAS <NUM> may provide a concise, discrete assessment of trending runway excursion likelihood that the pilot, in conjunction with other data provided by the PFD <NUM> (e.g., airspeed, angle of attack, altitude), may rapidly assimilate while managing the descent and landing phases. For example, the predictive ability of the ROAAS <NUM> may be enhanced by more robust runway data (e.g., runway conditions, weather conditions) or even performance data relevant to the aircraft or aircraft type, e.g., prior flight performance during approach and landing phases under similar conditions, braking performance and methods.

The ROAAS <NUM> is displayed separate from, and not integrated into, any other instruments, indicators, or SVS/EVS elements displayed by the PDF <NUM>. The graphic representation displayed by the PDF <NUM> represents a trend indicator determined by the ROAAS <NUM> and capable of displaying to the pilot at a glance (e.g., via the pilot's peripheral vision) whether the relationship between the aircraft and the runway <NUM> is improving (e.g., trending towards a safe landing) or declining (e.g., trending towards a runway overrun). The graphic representation dynamically changes in shape, and optionally also in size, and/or color as the contributing factors, including the aircraft airspeed, angle of attack, and position/heading relative to the runway, driving the trends in position state, energy state, predicted landing point, and overrun probability continuously change.

In embodiments, the ROAAS <NUM> may be displayed within the PFD <NUM> as a dynamic vertical bar <NUM> configured to change appearance in real time to reflect the evolving trend toward or away from runway excursion or overrun. For example, as the energy state of the aircraft trends upward or downward (along with any other external conditions accessible to the ROAAS <NUM>) the ROAAS may display the current excursion likelihood as it trends toward or away from increased certainty of overrun, e.g., by changing the height and/or color of the dynamic vertical bar <NUM> in real time. For example, the dynamic vertical bar <NUM> reaching the top of its allotted space <NUM> may indicate to the pilot conditions consistent with a near-certain runway overrun (and that the pilot's best remaining option may be to abort the landing and fly around for another approach). By displaying a dynamic trend indicator, the ROAAS <NUM> may present to the pilot at a glance visual feedback as to the effect of his/her actions toward, or away from, a safe landing on the intended runway.

Referring to <FIG>, the aircraft <NUM> is disclosed. The aircraft <NUM> may include a flight management system <NUM> (FMS), aircraft-based sensors <NUM>, and engine indicator/crew alerting system <NUM> (EICAS).

In embodiments, the ROAAS <NUM> may be embodied aboard the aircraft <NUM> and may communicate with other sources, both onboard and external to the aircraft, to receive updated aircraft data. As noted above, the ROAAS <NUM> may consider multiple data sources and their effect on each other to determine whether display conditions exist and, once display conditions are determined to exist, to continually evaluate whether conditions persist or, for example, have been resolved by pilot action.

For example, the ROAAS <NUM> may receive continual updates from the flight management system <NUM> (FMS) with respect to the position of the aircraft and its progress relative to the flight plan of the aircraft (or, e.g., relative to the current flight segment or phase). Further, the FMS <NUM> may provide runway, instrument approach, beacon or waypoint data, and other navigational database data to the ROAAS <NUM>.

In embodiments, the ROAAS <NUM> may receive additional aircraft performance data from aircraft-based sensors <NUM> (e.g., airspeed indicators, altimeters, angle of attack sensors, barometers) and engine indicator/crew alerting systems <NUM> (EICAS). For example, the EICAS <NUM> may provide updates as to the current and evolving states of aircraft engines, fuel systems, hydraulic and pneumatic systems, and aircraft components not in direct communication with navigation systems but whose performance regardless may affect the energy state of the aircraft.

In embodiments, the ROAAS <NUM> may receive some information from external sources <NUM> not onboard the aircraft. For example, the ROAAS <NUM> may receive position, runway, or weather data from ground-based facilities (e.g., wind pattern data measured by ground facilities proximate to the runway <NUM>).

In embodiments, based on a continual evaluation of these diverse data sources, the ROAAS <NUM> may determine that conditions exist that warrant display of the ROAAS symbology within the PFD <NUM>. For example, the ROAAS <NUM> may be displayed as long as these conditions continue to exist (e.g., until the aircraft has touched down or remedial action on the part of the pilot or crew sufficiently changes the observed conditions).

Referring to <FIG>, the ROAAS 120a-f, similarly to the ROAAS <NUM> of <FIG>, may incorporate dynamic shape and color changes to indicate trending toward or away from a certain runway excursion or overrun on the part of the aircraft (<NUM>, <FIG>).

In embodiments, the dynamic vertical bars 124b-f of the respective ROAAS 120a-f may be situated within their allotted spaces <NUM> (e.g., as drawn or otherwise displayed by the EVS/SVS system onto the PFD (<NUM>, <FIG>). For example, the ROAAS 120a may be displayed when the likelihood of runway excursion is nominally zero, e.g., when the aircraft <NUM> is not on approach. In embodiments, the ROAAS 120a may be displayed as an allotted space <NUM> without a visible dynamic vertical bar <NUM>.

In embodiments, the ROAAS 120b may be displayed within the PFD <NUM> to indicate a trend toward a possible runway excursion, e.g., predicted landing points of the aircraft <NUM> where the actual likelihood of excursion or overrun may be slight but no longer nonzero. For example, the dynamic vertical bar may rise (124b) but to a relatively low height (e.g., relative to the full height of the allotted space <NUM>) and may be rendered in a green or greenish color to indicate to the pilot a change of state relative to the ROAAS 120a, e.g., predicted landing points within acceptable distance of the end of the runway and thus a likelihood of runway excursion that remains relatively low (and may not yet indicate remedial action), but wherein the likelihood of excursion may continue to trend upward if corrective action is not taken.

In embodiments, the ROAAS 120c-d may represent further changes in state from the ROAAS 120b, e.g., if the predicted landing points continue to trend into a part of the runway where the likelihood of overrun is more probable. For example, the ROAAS 120c may include a dynamic vertical bar 124c increasing in height and gradually shading in color from green to yellow (e.g., yellow-green, green-yellow) to indicate an upward trending likelihood of excursion. Similarly, the ROAAS 120d may include a still higher dynamic vertical bar 124d of a substantially yellow color.

In embodiments, the ROAAS 120e-f may indicate continued upward trends in the likelihood of excursion. For example, the dynamic vertical bar 124e of the ROAAS 120e may further increase in height and shade from yellow to red (e.g., red-orange, orangered), indicating the gradually increasing likelihood of runway excursion. When the ROAAS 120f is displayed, the dynamic vertical bar 124f may be at or near its maximum height relative to its allotted space <NUM>, and may be colored fully red to indicate a likelihood of runway excursion nearing certainty, and that may warrant either a runway excursion alert or immediate corrective action on the part of the pilot.

Referring now to <FIG>, the ROAAS <NUM> may be implemented and may function similarly to the ROAAS <NUM>, 120a-f of <FIG>, except that the ROAAS <NUM> and/or its component symbologies may be condensed or otherwise altered for some configurations of PFD (<NUM>, <FIG>), e.g., condensed PFD with less available free space than the PFD <NUM>. In embodiments, the ROAAS <NUM>, <NUM> may be represented by any other appropriate graphic combinations of real-time dynamic shape and color changes not explicitly disclosed herein.

In embodiments, the ROAAS <NUM> may display the trending likelihood of runway excursion as a dynamic arc <NUM> that, similarly to the dynamic vertical bar (<NUM>, 124b-f) of the ROAAS <NUM>, 120a-f, changes color and shape in real time within its allotted space <NUM> to reflect upward and downward trends of the likelihood of runway excursion by the aircraft (<NUM>, <FIG>) (e.g., toward or away from a certain runway excursion or overrun). For example, the ROAAS <NUM> may represent relatively low excursion probabilities as a green arc of relatively small size (e.g., proximate to the center of the arc).

In embodiments, the ROAAS 300a-b may be implemented and may function similarly to the ROAAS <NUM>, but may respectively reflect landing points trending toward an increasingly more probable runway excursion. For example, the dynamic arc <NUM> of the ROAAS <NUM> may grow into a larger arc 302a shading toward yellow, as the ROAAS 300a indicates a growing likelihood of excursion, and a still larger arc 302b shading toward red as the ROAAS 300b indicates likely landing points trending toward near certain excursion. In some embodiments, the ROAAS 300a may shift back toward the smaller, greener dynamic arc <NUM> of the ROAAS <NUM>, e.g., if corrective action is taken causing the predicted landing points to trend away from runway excursion.

Referring to <FIG>, the PFD <NUM> is disclosed.

In embodiments, the ROAAS <NUM>, <NUM> of <FIG> may be displayed in an area of the PFD <NUM> not otherwise dedicated to aircraft instruments or to PFD components. For example, the placement of the ROAAS <NUM>, <NUM> may be based on observed pilot scan patterns of the PFD <NUM>. It is contemplated that the pilot may construct a multidimensional model of the aircraft energy state in real time, based on multiple discrete and easily assimilated data points. Based on this evolving real time model, the pilot may make more informed decisions regarding, e.g., whether to continue or abort a landing or descent in progress (and if to abort, at what point to do so). For example, the pilot's scanning pattern with respect to the PFD may include starting at the attitude indicator <NUM> to check pitch and roll information, scanning left (<NUM>) to check the airspeed indicator <NUM>, scanning center (<NUM>) and then right (<NUM>) to monitor the altimeter <NUM>, returning to center (<NUM>) and then scanning down (<NUM>) to the turn coordinator <NUM> and horizontal situation indicator <NUM>. In embodiments, the ROAAS <NUM>, <NUM> may be positioned relative to the PFD <NUM> such that the ROAAS appears at the periphery of the pilot's scan pattern where its information may be easily captured in the pilot's peripheral vision.

Referring also to <FIG>, the PFD 100a may be implemented and may function similarly to the PFD <NUM> of <FIG>, except that the ROAAS <NUM>, <NUM> may be displayed in other otherwise undedicated areas (<NUM>, <NUM>, <NUM>) of the PFD. In embodiments, the ROAAS <NUM>, <NUM> may be positioned in other parts within the PFD 100a that may fall within the periphery of the pilot's scan pattern.

Claim 1:
An aircraft-based runway overrun awareness alerting system (<NUM>), comprising:
one or more processors installable aboard an aircraft and configured for:
determining a plurality of sequential position states corresponding to the aircraft, each position state associated with an inflight position of the aircraft and a direction of the aircraft;
determining one or more runway attributes corresponding to a runway proximate to the aircraft;
determining a plurality of sequential energy states of the aircraft, wherein each energy state includes an angle of attack and an airspeed;
predicting, based on the plurality of position states, the plurality of energy states, and the one or more runway attributes, a plurality of sequential landing points on the proximate runway, and whether, given the plurality of energy states and the plurality of position states, the predicted landing point is trending forward or backward relative the runway;
predicting, based on at least the plurality of landing points and the plurality of energy states, at least one trend corresponding to a runway overrun probability;
and
revising at least one of the plurality of landing points and the predicted trend based on one or more of a change in the plurality of position states and a change in the plurality of energy states,
and
at least one display device in communication with the one or more processors, the display device configured to:
display, within a display surface, one or more of a primary flight display "PFD" component and a navigational instrument corresponding to the aircraft;
and
display at least one dynamic graphic representation corresponding to the predicted trend, the dynamic graphic representation not integrated with the one or more of the PFD component and the navigational instrument and wherein the dynamic graphic representation is configured to change in shape to reflect trending away towards a safe landing or toward a runway overrun.