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.

A system is disclosed and defined in claim <NUM>.

In some embodiments, the display device revises the displayed symbology based on changes or revisions to the runway excursion probability.

In some embodiments, the position, heading, and energy state may be determined based on information received from the flight management system (FMS) and/or the engine indicator and crew alerting system (EICAS).

In some embodiments, the position, heading, and energy state may be determined based on runway data or other information received from ground control facilities or other sources external to the aircraft.

In some embodiments, the display device generates synthetic vision or enhanced vision (SVS, EVS) content of the runway environment and superimposes the ROAAS symbology over the SVS/EVS content.

In some embodiments, the ROAAS symbology includes a gauge and a color element for representing the severity of the runway excursion probability.

In some embodiments, the ROAAS represents a change in the runway excursion probability by a movement of an indicator relative to the gauge and/or a color change, e.g., from a less severe to a more severe likelihood.

In some embodiments, the gauge is divided into adjacent regions, each region corresponding to a severity level and a movement of the indicator into an adjacent region corresponding to a color change.

In some embodiments, the ROAAS symbology is displayed within unused areas of the PFD, e.g., not already occupied by PFD indicator or aircraft instrumentation displays.

In some embodiments, the ROAAS symbology is automatically displayed with aircraft conditions (or combinations of conditions) contributing to runway excursion reach or exceed a threshold level (e.g., a nonzero probability of excursion).

Broadly speaking, embodiments of the inventive concepts disclosed here in are directed to a runway overrun awareness alert system <NUM> (ROAAS) that assesses from the energy state of an aircraft on approach to land at a runway, predicting the likely touchdown point on the runway based on the current position and heading of the aircraft as well as the particulars of the runway itself (e.g., its length and orientation). Given this touchdown point and the current energy state (angle of attack, airspeed, acceleration/deceleration), the ROAAS continually determines a quantified variable projecting the likelihood (e.g., excursion probability) that the aircraft will overrun the runway, i.e., be unable to stop before exiting the far end of the runway. As the aircraft position and energy state change from moment to moment, the ROAAS reassesses the excursion probability and displays the quantified variable to the pilot in a graphic form digestible at a glance and segregated from other primary flight or instrument displays, so that the pilot can always peripherally assess the excursion probability at any time without interrupting any other flight information the pilot may be monitoring during the approach and landing segments.

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 may be monitoring 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.

In embodiments, the PFD <NUM> may incorporate a runway overrun awareness alert system <NUM> (ROAAS). For example, the ROAAS <NUM> may augment aircraft takeoff and landing awareness systems (e.g., TLAF) by monitoring multiple dimensions of aircraft data sources to continually evaluate whether conditions exist that warrant display of the ROAAS; when these conditions are determined to exist, and as long as these conditions persist, the ROAAS will be displayed. In embodiments, while on approach to the runway <NUM>, the ROAAS <NUM> may monitor 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, 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. By way of a non-limiting example, the aircraft state may indicate 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.

In embodiments, based on the current aircraft energy state, the ROAAS <NUM> may predict the likely landing point of the aircraft relative to the runway <NUM> based on the best information available. Based on this predicted landing point, and the aircraft energy state, the ROAAS <NUM> may further predict the likelihood of a runway excursion. The ROAAS <NUM> may send the predicted likelihood back to the EVS/SVS system for display to the pilot via the PFD <NUM>. For example, while the PFD <NUM> may incorporate runway excursion warnings, these warnings may only serve to warn the pilot of conditions consistent with a likely excursion when they exist (as opposed to, e.g., proactive prevention of excursion conditions). Further, runway excursion warnings may be incorporated into other display elements of the PFD (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 excursion probability 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.

In embodiments, the graphic representation displayed by the PFD <NUM> may represent a quantified variable determined by the ROAAS <NUM> and corresponding to an assessment of the most likely landing point relative to the runway and the aircraft energy state relative to the runway at a given moment. This quantified variable may be recalculated as the contributing factors (e.g., the aircraft airspeed, angle of attack, and position/heading relative to the runway) change, and the corresponding graphic representation refreshed by the PFD <NUM>.

The ROAAS <NUM> is displayed separate from (e.g., not integrated into) any other instruments, indicators, or EVS elements displayed by the PFD <NUM>. The ROAAS <NUM> is displayed within the PFD <NUM> as a three-segment gauge <NUM> and indicator <NUM>. For example, as the energy state of the aircraft changes (along with any other external conditions accessible to the ROAAS <NUM>) the ROAAS may display the current excursion likelihood on a continuum of increasing severity (e.g., as represented by the current position of the indicator <NUM> within the gauge <NUM>) and within a broad level of increasing severity (e.g., as represented by the current segment 124a of the gauge <NUM> occupied by the indicator <NUM>). If, for example, the indicator <NUM> reaches the top of the gauge <NUM> with no remedial action taken on the part of the pilot, a visual and/or aural excursion warning may be displayed by the PFD <NUM>.

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.

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 some embodiments, the FMS <NUM> and/or EICAS <NUM> may provide historical performance data associated with prior approaches and landings of the aircraft <NUM> at the runway (<NUM>, <FIG>).

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 a ground station 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 may be implemented and may function similarly to the ROAAS <NUM> of <FIG>, except that the ROAAS 120a may incorporate color changes to indicate changes in severity.

In embodiments, the gauge <NUM> may be split into three (or, e.g., four, five, or any other appropriate number of) regions 124a-c corresponding to increasing levels of severity. While the transition of the indicator <NUM> between regions 124a-c may indicate to the pilot an increasing severity (e.g., an increasing likelihood of runway excursion). the ROAAS 120a may also indicate increasing severity (e.g., via a full color PFD <NUM>) via real-time color changes to the indicator <NUM>. For example, the ROAAS 120a of <FIG> may correspond to a nominal state of the aircraft (<NUM>, <FIG>) on approach to the runway (<NUM>, <FIG>) wherein the predicted landing point of the aircraft is within acceptable distance of the end of the runway and the likelihood of incursion is therefore slim to none. Accordingly, the indicator <NUM> may remain within the lowermost region 124a and may maintain a green color.

Referring now to <FIG>, the ROAAS 120b-c may be implemented and may function similarly to the ROAAS 120a of <FIG>, except that the ROAAS 120b may indicate an increased likelihood of runway excursion (based on, e.g., changes in the energy state of the aircraft and/or to the predicted landing point). For example, the indicator <NUM> may rise into the middle region 124b and change color from green to yellow. Similarly, the ROAAS 120c of <FIG> may indicate a further increase in severity, e.g., associated with a predicted landing point in an area of the runway <NUM> where runway overrun is highly likely (and where immediate corrective action by the pilot may be indicated). For example, the indicator <NUM> may rise into the topmost region 124c of the gauge <NUM> and change color to red. In embodiments, the gauge <NUM>, regions 124a-c and indicator <NUM> may incorporate any other appropriately visible shapes and colors in order to indicate the appropriate likelihood of runway incursion.

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

In embodiments, the ROAAS <NUM> may be displayed in an area of the PFD <NUM> not otherwise dedicated to aircraft instruments or PFD components. For example, the placement of the ROAAS <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>. The ROAAS <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> may be displayed in other otherwise undedicated areas (<NUM>, <NUM>, <NUM>) of the PFD. For example, the ROAAS <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:
A system (<NUM>) comprising:
one or more processors installable aboard an aircraft and configured for:
determining navigational information corresponding to the aircraft;
determining an energy state of the aircraft, wherein the energy state includes angle of attack, airspeed, acceleration, and deceleration;
determining one or more runway attributes corresponding to a proximate runway;
predicting, based on the determined navigational information, energy state, and runway attributes, a landing point on the proximate runway;
predicting, based on at least the predicted landing point and the energy state, a runway excursion probability;
and
revising at least one of the predicted landing point or the predicted runway excursion probability based on one or more of a change in the navigational information or a change in the energy state;
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 primary flight display (PFD) components and navigational instruments corresponding to the aircraft;
and
display at least one dynamic graphic representation corresponding to the predicted runway excursion probability, wherein the dynamic graphic representation is not integrated with the one or more PFD components and the navigational instruments,
wherein the dynamic graphic representation comprises a three-segment gauge and an indicator, and
wherein a location of the indicator within the three-segment gauge directly indicates the predicted runway excursion probability, and a change in the location of the indicator within the three-segment gauge directly indicates a change in the predicted runway excursion probability.