Monitoring for unstable approach of aircraft using specific energy

Abstract

To provide a method of monitoring an unstable approach of an aircraft during flight.SOLUTION: The method includes: determining, using values of a ground speed and a height of the aircraft derived from measurements acquired during the flight, a specific energy of the aircraft during an approach phase of the flight. The method further includes determining a reference specific energy of the aircraft, defining an energy range relative to the reference specific energy, and visually displaying, using a first flight instrument of the aircraft, an indicator of the specific energy relative to the energy range.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] Aspects of the present disclosure relate to aircraft systems, and more particularly to techniques for identifying unstable approaches of an aircraft in flight based on calculations of the specific energy of the aircraft. [Background technology]

[0002]

[0002] When landing an aircraft, over-energy or under-energy conditions can occur if the flight crew does not properly manage the aircraft's altitude and / or speed throughout the approach phase of flight. These factors can result in an unstable approach for the aircraft, increasing the risk of runway excursions, tailstrikes, hard landings, or runway undershoots. According to data from the International Air Transport Association (IATA), 26% of approach and landing accidents that occurred between 2016 and 2020 were due to unstable approaches.

[0003]

[0003] Most cases of unstable approaches result from excessive altitude and / or speed along the final approach segment of the approach phase (e.g., from the final approach fix to touchdown), even if the landing gear and landing flap configuration is technically correct. Generally, the pilot in command is responsible for ensuring that the aircraft does not meet one or more criteria for a stable approach, requiring a go-around or missed approach procedure. The Flight Safety Foundation (FSF) cites failure to verify stable approach conditions as one of the leading causes of runway excursions. Summary of the Invention

[0004] In one aspect, the present disclosure provides a method for monitoring an unstable approach of an aircraft in flight. The method includes identifying a specific energy of the aircraft during an approach phase of flight using values ​​of the aircraft's ground speed and altitude derived from measurements taken during the flight. The method further includes identifying a baseline specific energy of the aircraft, defining an energy range for the baseline specific energy, and visually displaying an indicator of the specific energy relative to the energy range using a first flight instrument on the aircraft.

[0005]

[0005] In one aspect, in combination with any exemplary method described above or below, the first flight instrument comprises a primary flight display (PFD), and the indicator of specific energy includes a graphical element superimposed on a vertical crossbar of a flight director (FD) of the PFD, and one or both of the position and color of the graphical element are based on the specific energy.

[0006]

[0006] In one aspect, in combination with any of the exemplary methods described above or below, the method further includes using a second flight instrument on the aircraft to visually display an indicator of the actual indicated airspeed relative to a reference speed based on the selected landing flap setting.

[0007]

[0007] In one aspect, in combination with any exemplary method described above or below, the second flight instrument includes a primary flight display (PFD), the indicator of actual indicated airspeed includes an airspeed readout of an airspeed indicator on the PFD, and the color of the airspeed readout is based on the actual indicated airspeed.

[0008]

[0008] In one aspect, in combination with any exemplary method described above or below, the method further includes visually displaying an indicator of vertical speed using a third flight instrument on the aircraft.

[0009]

[0009] In one aspect, in combination with any exemplary method described above or below, the third flight instrument comprises a primary flight display (PFD), and the vertical speed indicator includes one or both of a vertical speed readout and a vertical speed pointer on the PFD vertical speed indicator, and the color of the indicator is based on the vertical speed.

[0010]

[0010] In one aspect, in combination with any of the exemplary methods described above or below, the method further includes comparing the specific energy with one or more limits of an energy range, and presenting an audiovisual warning using a fourth flight instrument on the aircraft when the specific energy exceeds the limit of the energy range.

[0011] In one aspect, in combination with any exemplary method described above or below, the audiovisual warning includes a text warning displayed on the scratchpad of the fourth flight instrument.

[0012]

[0012] In one aspect, in combination with any exemplary method described above or below, the reference specific energy is the sum of a reference ground speed term and a reference altitude term based on the starting point elevation.

[0013] In one aspect, the present disclosure provides a method for identifying an unstable approach for an aircraft implemented using an aircraft flight management system (FMS). The method includes identifying a reference specific energy for the aircraft. Identifying the reference specific energy for the aircraft includes identifying a reference ground speed term including a reference speed according to a selected landing flap setting, and identifying a reference altitude term based in part on data retrieved from a navigation database of the FMS. The method further includes defining an energy range for the reference specific energy, and using the aircraft's actual altitude and actual ground speed to identify the aircraft's specific energy during the approach phase of flight. The method further includes generating a signal for visually displaying an indicator of the aircraft's specific energy relative to the energy range using the aircraft's flight instruments.

[0014]

[0014] In one aspect, in combination with any exemplary method described above or below, the reference specific energy includes the sum of a reference ground speed term and a reference altitude term.

[0015]

[0015] In one aspect, in combination with any of the exemplary methods described above or below, the reference ground speed term includes the sum of the reference speed, headwind term, and speed adjustment term due to the selected landing flap setting.

[0016] In one aspect, in combination with any exemplary method above or below, the reference altitude term includes one of the following: the product of the aircraft's distance to the start of the runway and the tangent of the approach phase path angle plus the altitude of the final approach fix (FAF) minus the start point elevation when the distance is between the FAF and a predetermined distance value, or the product of the distance and the tangent of the final approach path angle minus the start point elevation when the distance is between the FAF and a point at a predetermined altitude value above the start of the runway.

[0017]

[0017] In one aspect, in combination with any of the exemplary methods described above or below, defining the energy range includes specifying a minimum limit as the product of a first gain value and a reference ratio energy, and specifying a maximum limit as the product of a second gain value and a reference ratio energy.

[0018]

[0018] In one aspect, in combination with any exemplary method described above or below, defining the energy range further includes receiving one or more user inputs for the first gain value and the second gain value, and determining whether the first gain value and the second gain value are within an acceptable range based on a margin value.

[0019] In one aspect, in combination with any exemplary method described above or below, defining the energy range further includes identifying a first intermediate limit between the reference specific energy and the minimum limit and identifying a second intermediate limit between the reference specific energy and the maximum limit, the method further including generating a first signal to cause a flight instrument of the aircraft to present a first audiovisual warning in response to the specific energy of the aircraft exceeding the first intermediate limit or the second intermediate limit, and generating a second signal to cause the flight instrument to present a second audiovisual warning in response to the specific energy of the aircraft exceeding the minimum limit or the maximum limit.

[0020] In one aspect, the present disclosure provides a system. The system includes one or more computer processors and a memory having a plurality of instructions stored thereon. When executed by the processor, the plurality of instructions enable performance of operations for identifying an unstable approach for an aircraft. The operations include identifying a reference specific energy for the aircraft. Identifying the reference specific energy for the aircraft includes identifying a reference ground speed term including a reference speed according to a selected landing flap setting, and identifying a reference altitude term based in part on data retrieved from a navigation database. The operations further include defining an energy range for the reference specific energy, and identifying the specific energy of the aircraft during the approach phase using the actual altitude and actual ground speed of the aircraft. The operations further include generating a signal for visually displaying, using a flight instrument on the aircraft, an indicator of the specific energy of the aircraft relative to the energy range.

[0021]

[0021] In one aspect, in combination with any of the exemplary systems described above or below, the reference specific energy includes the sum of a reference ground speed term and a reference altitude term.

[0022]

[0022] In one aspect, in combination with any of the exemplary systems described above or below, defining the energy range includes specifying a minimum limit as the product of a first gain value and a reference ratio energy, and specifying a maximum limit as the product of a second gain value and a reference ratio energy.

[0023]

[0023] In one aspect, in combination with any of the exemplary systems described above or below, the operation further includes comparing the specific energy with one or more limits of an energy range, and presenting an audiovisual warning using a second flight instrument on the aircraft when the specific energy exceeds the limit of the energy range.

[0024]

[0024] So that the above-described features of the present disclosure can be understood in detail, a more detailed description of the present disclosure than that briefly summarized above can be made by reference to several exemplary embodiments, some of which are illustrated in the accompanying drawings. [Brief explanation of the drawings]

[0025] [Figure 1] 1 illustrates an exemplary approach and landing of an aircraft, according to one or more aspects. [Figure 2]

[0026] FIG. 1 is a block diagram of an example system capable of identifying an unstable approach of an aircraft, according to one or more aspects. [Figure 3-1]

[0027] According to one or more aspects, a method for identifying an unstable approach for an aircraft. [Figure 3-2] According to one or more aspects, a method for identifying an unstable approach for an aircraft. [Figure 4]

[0028] 1 illustrates exemplary energy ranges defined relative to a reference specific energy, according to one or more embodiments. [Figure 5]

[0029] 1 illustrates an exemplary energy range with intermediate limits and a baseline specific energy based on landing flap setting, according to one or more embodiments. [Figure 6]

[0030] 1 illustrates an exemplary primary flight display (PFD) having an indicator of specific energy versus energy range, according to one or more embodiments. [Figure 7]

[0031] 1 illustrates an exemplary multipurpose control and display unit (MCDU) having textual alerts displayed on a scratchpad, according to one or more aspects. DETAILED DESCRIPTION OF THE INVENTION

[0026]

[0032] The present disclosure provides techniques for identifying an unstable approach of an aircraft in flight based on a calculation of the aircraft's specific energy during the approach segment of the flight. The specific energy is compared to a defined energy range against a baseline specific energy, and an indicator of the comparison is communicated using one or more flight instruments. In some aspects, the specific energy is compared to energy range limits. These limits may include intermediate limits. When the specific energy exceeds one of the limits, an audiovisual warning is presented.

[0027]

[0033] The techniques described herein can improve flight crew situational awareness and rapidly identify conditions that result in an unstable approach for the aircraft, particularly during the approach segment. In some aspects, indicators can be implemented that further provide recommendations to the pilot regarding thrust application and / or attitude changes, thereby maintaining and / or returning the aircraft to a stable approach (and balanced energy state). Improved situational awareness contributes to improved flight safety and reduces operating costs by reducing the number of go-around events.

[0028]

[0034] Conventional solutions for monitoring (and warning of) unstable approaches rely on sophisticated algorithms that evaluate several combinations of flight parameters and flight envelopes, but these conventional solutions do not consider the total specific energy of the aircraft during the approach. Furthermore, these conventional solutions require adaptation or custom configuration of various avionics systems, which increases costs. The techniques described herein provide a simple and cost-effective solution that can be implemented using standard avionics systems. For example, in some aspects, the specific energy calculation is performed by the flight management system (FMS) using existing parameters. An indicator is displayed using the primary flight display (PFD), and a warning message is visually displayed on the PFD and / or FMS (e.g., multipurpose control and display unit (MCDU)).

[0029]

[0035] In the present disclosure, reference is made to various embodiments. However, it should be understood that the disclosure is not limited to the particular described embodiments. Instead, any combination of the following features and elements, whether associated with various embodiments or not, is contemplated for implementing and practicing the teachings provided herein. Furthermore, when elements of an embodiment are described in the form of "at least one of A and B," it should be understood that embodiments including element A only, element B only, and elements A and B are each contemplated. Furthermore, while some embodiments may realize other potential solutions and / or advantages over the prior art, whether or not a particular advantage is realized by a given embodiment does not limit the disclosure. Accordingly, the embodiments, features, and advantages disclosed herein are merely exemplary and should not be considered elements of or limit the scope of the appended claim(s) unless expressly recited in the claim(s). Similarly, references to "the present invention" should not be construed as generalizing all inventive subject matter disclosed herein, and should not be considered an element of or limiting the scope of any accompanying claim(s) unless expressly recited in the claim(s).

[0030]

[0036] Referring now to Figure 1, Figure 1 illustrates an exemplary approach and landing of an aircraft 105, according to one or more embodiments. In Figure 100, the aircraft 105 operates along a predetermined flight path 110 until it lands on a runway 115. The flight path 110 includes several phases, including a cruise phase 120, in which the aircraft 105 maintains a cruising altitude, a descent phase and an approach phase (illustrated as a single approach phase 125 for simplicity), in which the aircraft 105 gradually loses altitude, and a landing phase 130, in which the aircraft 105 touches down on the runway 115. The various phases are not shown to scale in Figure 100.

[0031]

[0037] One or more of the phases of flight path 110 may define multiple segments. For example, approach phase 125 may include an initial approach segment, an intermediate approach segment, a final approach segment, and a missed approach segment. The beginning and end of each phase (and each segment) is defined by specific operational criteria, which will be understood by those skilled in the art.

[0032]

[0038] In various aspects described herein, the specific energy of the aircraft 105 is calculated during the approach phase 125 and used to determine whether the aircraft 105 is on an unstable approach. The specific energy is compared to a defined energy range against a baseline specific energy, and an indicator of the comparison is communicated using one or more flight instruments. Communicating the indicator improves the flight crew's situational awareness during the approach phase 125.

[0033]

[0039] 2 is a block diagram of an example system 200 capable of identifying an unsafe approach of an aircraft, according to one or more aspects. Features of the system 200 may be used in conjunction with other aspects.

[0034]

[0040] In system 200, aircraft 105 includes FMS 205, multiple sensors 235, and multiple flight instruments 240. FMS 205 is an electronic device onboard aircraft 105 that provides navigation, performance, and piloting capabilities for aircraft 105. As used herein, "electronic device" generally refers to any device having electronic circuitry. The electronic circuitry provides processing or computing capabilities and implements logic and / or executes program code to perform various operations that collectively define the functionality of the electronic device. The functionality of an electronic device includes, for example, the ability to communicate with one or more other electronic devices when connected to the same network. Electronic devices may be implemented in any suitable form factor, whether relatively static (e.g., mainframe, computer terminal, server, kiosk, workstation) or mobile (e.g., laptop computer, tablet, handheld, smartphone, wearable device). The communication capability between electronic devices may be achieved using any suitable technique, such as conductive cables, wireless transmission, optical transmission, etc.

[0035]

[0041] As shown, FMS 205 is coupled to a plurality of sensors 235 and a plurality of flight instruments 240. In other embodiments, one or more of flight instruments 240 are integrated into FMS 205. FMS 205 may be coupled to one or more electronic devices external to aircraft 105 via network 255 (e.g., one or more local area networks (LANs) and / or wide area networks (WANs)).

[0036]

[0042] Although described as being performed by a single electronic device, in other aspects, the functions of FMS 205 may be performed by multiple electronic devices. In one non-limiting example, FMS 205 comprises a flight management computer (FMC) that allows a flight path to be pre-programmed, an automatic flight control system (AFCS) or automatic flight guidance system (AFGS) that receives information from one or more of sensors 235 and provides signals for the aircraft's 105 control surfaces and / or recommendations to the pilot, an aircraft navigation system that calculates the position of the aircraft 105 using an inertial reference system, a global positioning system (GPS), and / or ground-based aiding, and an electronic flight instrument system (EFIS) or electro-mechanical instruments.

[0037]

[0043] The FMS 205 includes one or more processors 210 and memory 215. The one or more processors 210 are any electronic circuitry including, but not limited to, one or a combination of a microprocessor, a microcontroller, an application specific integrated circuit (ASIC), an application specific instruction set processor (ASIP), and / or a state machine. The optional electronic circuitry is communicatively coupled to the memory 215 and controls the operation of the FMS 205. The one or more processors 210 are not limited to a single processing device, but may include multiple processing devices.

[0038]

[0044] The one or more processors 210 may include other hardware that runs software to control and process information. In some aspects, the one or more processors 210 execute software stored in memory 215 to perform any of the functions described herein. The one or more processors 210 control the operation and management of the FMS 205 by processing information (e.g., information received from input devices and / or communicatively coupled electronic devices).

[0039]

[0045] Memory 215 may store data, operable software, or other information for one or more processors 210, either permanently or temporarily. Memory 215 may include any one or combination of volatile or non-volatile local or remote devices suitable for storing information. For example, memory 215 may include random access memory (RAM), read-only memory (ROM), magnetic storage devices, optical storage devices, or any other suitable information storage device, or a combination of these devices. Software represents any suitable set of instructions, logic, or code embodied in a computer-readable storage medium. For example, software may be embodied in memory 215, a disk, a CD, or a flash drive. In certain embodiments, software may include applications executable by one or more processors 210 to perform one or more of the functions described herein.

[0040]

[0046] In this example, memory 215 stores approach monitoring service 220. Approach monitoring service 220 obtains measurements (or values ​​of one or more parameters derived from the measurements) from multiple sensors 235 and determines the specific energy 225 of aircraft 105 during the approach phase 125 of flight. The types of multiple sensors 235 used in aircraft 105 will be known to those skilled in the art. In some aspects, approach monitoring service 220 calculates the actual total specific energy of aircraft 105 throughout the approach phase 125 (e.g., at any ground location between the point at which the initial approach flap (also referred to herein as landing flap) setting is selected and 50 feet above the start of runway 115). In some aspects, approach monitoring service 220 compares the specific energy to an energy range and generates a signal to cause an indicator of the specific energy relative to the energy range to be visually displayed using flight instruments of aircraft 105. The energy range is defined relative to a baseline specific energy of aircraft 105. The energy range is also calculated by approach monitoring service 220 in some aspects. Further explanation of the calculation of the energy ranges is provided below with respect to FIGS.

[0041]

[0047] The indicators are displayed using one of a plurality of flight instruments 240. As shown, the flight instruments 240 include a PFD 245 and an MCDU 250, although other numbers and types of flight instruments 240 are contemplated. Flight instruments 240 used in the aircraft 105 will be known to those skilled in the art. In some aspects, the indicators are displayed using the PFD 245 of the aircraft 105. In some alternative aspects, the indicators may be displayed using another display of the aircraft 105, such as a multifunction display (MFD). Generally, the PFD 245 includes an electronic display implementing any suitable display technology (e.g., CRT, (O)LED, LCD). The PFD 245 displays various flight information, such as an airspeed indicator, a turn indicator, an attitude indicator, a heading indicator, an altimeter, and a vertical speed indicator. While the PFD 245 may display flight information in any suitable manner, in some aspects the PFD 245 displays a representation of mechanical flight instruments (e.g., a cluster of analog gauges). In one exemplary embodiment, the specific energy indicator comprises a graphical element superimposed on the vertical flight indicator (F / D) bar of the PFD 245. Further description of the display of indicators using the PFD 245 is provided below with respect to FIG. 6.

[0042]

[0048] In some aspects, the approach monitoring service 220 compares the specific energy to one or more limits of an energy range and, in response to the aircraft's specific energy exceeding the limit(s), generates a signal to cause the flight instruments 240 of the aircraft 105 to present audiovisual alert(s). In one exemplary embodiment, the audiovisual alert(s) comprise a text alert displayed on a scratchpad of the flight instruments 240, such as the PFD 245 or the MCDU 250. Further description of presenting audiovisual alert(s) is provided below with respect to FIG. 7.

[0043]

[0049] In some aspects, the memory 215 further stores a navigation database 230 that includes information used to construct a flight plan for the aircraft 105. For example, the navigation database 230 may include some or all of the following information: waypoints / intersections, airways, radio navigation aids, airports, runways, and / or standard procedures (SIDs, STARs, IAPs, holds). Information may be stored in the navigation database 230 in any suitable format.

[0044]

[0050] In some alternative aspects, approach monitoring service 220 may be implemented using one or more electronic devices other than FMS 205, such as an electronic device wirelessly coupled to FMS 205 via network 255. Such electronic devices may be onboard aircraft 105 (e.g., another electronic device on aircraft 105, a portable electronic device, etc.) or may be external to aircraft 105.

[0045]

[0051] 3 is a method 300 for identifying an unstable approach for an aircraft, according to one or more aspects. Method 300 may be used in conjunction with other aspects. For example, in some aspects, method 300 may be performed by approach monitoring service 220 and / or other components of FMS 205. In some aspects, method 300 may be performed partially or completely by electronic device(s) separate from FMS 205.

[0046]

[0052] The method 300 begins at block 305, where the FMS 205 acquires measurements during flight. In some aspects, the measurements include position information for the aircraft 105, such as samples of GPS signals, inertial navigation system signals, radio navigation signals, etc. Other measurements are also contemplated.

[0047]

[0053] In block 310, the FMS 205 determines the specific energy of the aircraft 105 during the approach phase 125 of flight using the ground speed and altitude values ​​of the aircraft 105. In some aspects, the specific energy of the aircraft 105 is determined according to equation (1), i.e., e_actual=GS 2 / 2+gH (1) where G represents the actual ground speed of the aircraft 105, H represents the actual altitude of the aircraft 105 above the starting elevation, and g represents the gravitational acceleration constant. In some aspects, G is calculated by the FMS 205 or by an Air Data Inertial Reference System (ADIRS) coupled to the FMS 205. In some aspects, H is calculated by the FMS 205.

[0048]

[0054] In some aspects, FMS 205 determines specific energy values ​​at multiple points along flight path 110, beginning at the point where approach flaps are first deployed and ending at a point 50 feet above (i.e., above ground level) the start of runway 115. FMS 205 may determine specific energy values ​​at any suitable sampling period, such as one (1) second.

[0049]

[0055] In block 315, the FMS 205 determines a reference specific energy for the aircraft 105. In some aspects, determining the reference specific energy for the aircraft 105 includes determining a reference ground speed term (block 320) and determining a reference altitude term (block 325), where the reference specific energy includes the sum of the reference ground speed term and the reference altitude term. In some aspects, the reference specific energy is determined according to equation (2), i.e., e_ref=GSref 2 / 2+gHref (2) where GSref 2 / 2 represents the reference ground speed term, and gHref represents the reference altitude term.

[0050]

[0056] In some aspects, the reference ground speed term GSref 2 / 2 includes a reference speed determined according to the selected landing flap setting. In some aspects, the reference ground speed term includes the sum of the reference speed, a headwind term, and a speed adjustment term. For example, when the landing flaps are extended, the reference ground speed term is determined according to equation (3): GSref=VREF+ΔV+HW (3) Then, when the approach flaps are deployed, the reference ground speed term is determined according to equation (4), i.e., GSref=VREF40+X+HW (4) where VREF represents the reference speed according to the selected landing flap setting as specified by FMS 205, ΔV represents the speed adjustment term entered into FMS 205 by the pilot for the approach (e.g., with a minimum value of 5 knots), and HW represents the headwind term calculated by FMS 205 based on the pilot's input (e.g., reported by air traffic control). VREF40 represents the reference speed for a flap setting of 40°, and X represents the pilot-selectable speed adjustment term (e.g., a default of five (5) knots). Thus, in calm conditions, the minimum selectable speed would be (VREF+5 knots).

[0051]

[0057] In some aspects, the reference altitude term gHref is based in part on data received from the navigation database 230 of the FMS 205. In some aspects, Href is a reference altitude above the starting point elevation and is determined according to equations (5) and (6), i.e., Href=Dtan(GPA)-Elev_thr (5) That is, when the distance to the starting point, D, is between the final approach fix (FAF) and a point that is a predetermined altitude value (e.g., 50 feet) above the starting point; and Href=Dtan(Path_angle)+ALT FAF -Elev_thr (6) That is, when the distance D to the starting point is between a predetermined distance value (for example, 15 nautical miles) and the FAF. Different values ​​of the predetermined altitude value and the predetermined distance value are also considered.

[0052]

[0058] Therefore, according to equation (5), the FMS 205 determines the reference altitude Href as the product of the distance D and the tangent of the final flight path angle GPA minus the start point elevation Elev_thr. According to equation (6), the FMS 205 determines the reference altitude Href as the product of the distance D and the tangent of the approach segment flight path angle minus the FAF altitude ALT FAF and subtract the starting point elevation Elev_thr. In some aspects, the FMS 205 calculates the distance D and the approach segment path angle Path_angle, and obtains the final approach path angle GPA and the landing starting point elevation Elev_thr from the navigation database 230.

[0053]

[0059] In block 330, the FMS 205 defines an energy range for the reference ratio energy. In some aspects, defining the energy range includes receiving one or more user inputs for a first gain value Kmin and a second gain value Kmax (block 335). For example, the first gain value Kmin and the second gain value Kmax may be configurable in the FMS 205 via a dedicated page (e.g., an extension of the performance factors page).

[0054]

[0060] In block 340, the FMS 205 determines whether the first gain value Kmin and the second gain value Kmax are within a tolerance range based on a margin value. In some aspects, the tolerance range is defined according to equations (7) and (8), i.e., 1-Margin <Kmin<0.99 (7) 1.01 <Kmax<1+マージン (8) In some embodiments, the default value for the margin is 0.2, however, other margin values ​​and other parameters of the tolerance are also contemplated.

[0055]

[0061] Assuming that the first gain value Kmin and the second gain value Kmax are within the acceptable range, the method 300 proceeds to block 345. In that case, the FMS 205 identifies a minimum limit for the energy range as the product of the first gain value Kmin and the reference ratio energy e_ref, as expressed in equation (9): e_min=Kmin*e_ref (9) In block 350, the FMS 205 identifies the maximum limit of the energy range as the product of the second gain value Kmax and the reference specific energy e_ref, as expressed in equation (10): e_max=Kmax*e_ref (10)

[0056]

[0062] 4, an example energy range 420 defined for reference specific energy e_ref is shown, in accordance with one or more embodiments. In graph 400, plot 405 represents reference specific energy e_ref for the approach phase. Plot 410 represents the minimum limit e_min, and plot 415 represents the maximum limit e_max. Each of plots 405, 410, and 415 decreases in proportion to the decrease in the aircraft 105's distance to touchdown. For example, the reference ground speed term GSref of the aircraft 105 decreases as the aircraft 105 approaches the runway (i.e., as the distance to touchdown decreases). As shown in equations (2), (9), and (10), the reference specific energy e_ref, minimum limit e_min, and maximum limit e_max each decrease in accordance with the square of the decrease in the reference ground speed term GSref.

[0057]

[0063] Point 425 represents a single measurement of the specific energy e_actual of aircraft 105, for example, as calculated by FMS 205. Point 425 falls within energy range 420, indicating that the specific energy of aircraft 105 does not result in an unstable approach. As will be described in more detail below, in some aspects, no audiovisual warning (or other alert) is generated by FMS 205 about this condition.

[0058]

[0064] In some aspects, one or more intermediate limits may be defined within the energy range 420 between the minimum and maximum limits. Such intermediate limit(s) may be used to trigger different alerts and / or warnings to improve the pilot's situational awareness. Referring to FIG. 3 , in block 355, the FMS 205 identifies a first intermediate limit between the reference specific energy and the minimum limit, and in block 360, identifies a second intermediate limit between the reference specific energy and the maximum limit.

[0059]

[0065] FIG. 5 illustrates an example energy range with intermediate limits and a reference specific energy based on landing flap settings, according to one or more embodiments. In graph 500, plot 405 represents the reference specific energy e_ref for the approach phase. However, instead of a single linear plot as in graph 400, plot 405 includes multiple segments corresponding to multiple landing flap settings 505, 510, 515, 520 according to a flap extension schedule for the approach phase. In one non-limiting example, landing flap setting 505 is “Flap 1,” landing flap setting 510 is “Flap 5,” landing flap setting 515 is “Flap 15,” and landing flap setting 520 is “Flap 40,” although other values ​​and sequences of landing flap settings are also contemplated. As shown, plot 405 includes relatively steep segments where the landing flaps transition from one setting to the next and flatter segments between the transitions.

[0060]

[0066] Plots 410, 415 define minimum and maximum limits of energy range 420. Like plot 405, plots 410, 415 each include different segments corresponding to landing flap settings 505, 510, 515, and 520. Graph 500 further includes plot 525, which represents a first intermediate limit between the reference specific energy (plot 405) and the minimum limit (plot 410), and plot 530, which represents a second intermediate limit between the reference specific energy (plot 405) and the maximum limit (plot 415). Plots 525, 530 each include different segments corresponding to landing flap settings 505, 510, 515, and 520. The first and second intermediate limits may have any suitable values. The values ​​may correspond to a particular value of specific energy or may be relative to the reference specific energy, the minimum limit, and / or the maximum limit (e.g., the midpoint between the reference specific energy and the maximum limit).

[0061]

[0067] As described above, the intermediate limits represented by plots 525, 530 may be used to provide finer resolution alerts and / or warnings to the pilot of the aircraft 105. If the value of the specific energy of the aircraft 105 falls between plots 525, 530, the specific energy of the aircraft 105 does not cause (or is particularly likely to cause) an unstable approach. In some aspects, no audiovisual warning (or other alert) is generated by the FMS 205 for this condition.

[0062]

[0068] In some aspects, for values ​​of specific energy between the minimum limit (plot 410) and the first intermediate limit (plot 525), the FMS 205 generates a first audiovisual warning 540 ("Low Energy"). In some aspects, for values ​​of specific energy below the minimum limit, the FMS 205 generates a second audiovisual warning 535 ("Low Energy / Go-Around"), which instructs the pilot to perform a go-around.

[0063]

[0069] In some aspects, for values ​​of specific energy between the second intermediate limit (plot 530) and the maximum limit (plot 415), the FMS 205 generates a third audiovisual warning 545 ("High Energy"). As shown, point 425 falls between the second intermediate limit and the maximum limit. In some aspects, for values ​​of specific energy greater than the maximum limit, the FMS 205 generates a fourth audiovisual warning 550 ("High Energy / Go-Around"), which instructs the pilot to perform a go-around.

[0064]

[0070] The text of the various audiovisual warnings 535, 540, 545, 550 is provided as one non-limiting example. Other text, visual, and / or auditory elements are also contemplated. Additionally, while a first intermediate limit and a second intermediate limit are described, other aspects may include a different number of intermediate limits that provide different levels of granularity to the pilot.

[0065]

[0071] Although described with respect to the FMS 205 defining the energy range 420, in some aspects, multiple characteristics of the energy range 420 may be displayed within the aircraft 105 (e.g., on a vertical situation display (VSD)) to enhance the pilot's situational awareness.

[0066]

[0072] 3 , in block 365, the FMS 205 visually displays an indicator of the specific energy versus energy range using the flight instruments 240 of the aircraft 105. In some aspects, the FMS 205 generates a signal that causes the indicator to be visually displayed. In some aspects, the flight instruments 240 comprise the PFD 245 of the aircraft 105.

[0067]

[0073] 6 illustrates an example PFD 245 with indicators, according to one or more embodiments. In diagram 600, the PFD 245 displays (from left to right) an airspeed indicator 605, an attitude indicator 610, an altimeter 615, and a vertical speed indicator 620. A flight director (FD) 640, which includes dual crossbars, is superimposed on the attitude indicator 610. An indicator 630-1 of specific energy versus energy range includes a graphical element superimposed on the vertical crossbar 645 of the FD 640.

[0068]

[0074] As shown, indicator 630-1 is a green circle superimposed on the center of vertical crossbar 645. In some aspects, one or more characteristics of indicator 630-1, such as the position, color, shape, and size of indicator 630-1, are controlled based on the specific energy.

[0069]

[0075] In some aspects, the specific energy controls one or both of the position and color of indicator 630-1. In some aspects, the range of indicator 630-1 along vertical crossbar 645 is determined according to equation (11): L=K(e_actual-e_ref) / e_ref (11) where K represents a scale factor to fit the range over the length of the vertical crossbar 645.

[0070]

[0076] In some embodiments where the specific energy is between the first intermediate limit and the second intermediate limit, indicator 630-1 is green (or white) and is located at the center of vertical crossbar 645. When the specific energy is between the second intermediate limit and the maximum limit, the indicator is amber and is located above the center of vertical crossbar 645 (illustrated as outline 630-2). When the specific energy exceeds the maximum limit, the indicator is red and is located above vertical crossbar 645 (illustrated as outline 630-3).

[0071]

[0077] Continuing with an example where the specific energy is between the first intermediate limit and the minimum limit, the indicator is amber and located below the center of vertical crossbar 645 (illustrated as outline 630-4). If the specific energy exceeds the minimum limit, the indicator is red and located below vertical crossbar 645 (illustrated as outline 630-5).

[0072]

[0078] In block 370, the FMS 205 compares the specific energy to one or more limits of an energy range. In some embodiments, the one or more limits include a minimum limit, a maximum limit, a first intermediate limit, and a second intermediate limit.

[0073]

[0079] In block 375, the FMS 205 uses the flight instruments 240 of the aircraft 105 to present an audiovisual warning when the specific energy exceeds the energy range limit. As used herein, an "audiovisual warning" may be presented audibly, visually, or both. In some aspects, the audiovisual warning is a text warning displayed on a scratchpad of the FMS 205 or MCDU 250.

[0074]

[0080] In some aspects, the audiovisual warning may further include an audio warning corresponding to the text warning. The audio warning may be presented each time a breach condition is met. In some aspects, the audio warning may be latched at a defined interval, for example, depending on the radar altitude. For example, between FAF altitude and 1000 ft AGL, the audio warning may be triggered every five (5) seconds. Between 1000 ft and 500 ft AGL, the audio warning may be triggered every three (3) seconds, indicating a greater degree of urgency. In some aspects, the audio warning may be suppressed by the operator below a certain radar altitude (e.g., 500 ft AGL).

[0075]

[0081] If the specific energy exceeds the second intermediate limit (but is less than the maximum limit), the FMS 205 generates a third audiovisual warning 545 ("High Energy"). If the specific energy exceeds the maximum limit, the FMS 205 generates a fourth audiovisual warning 550 ("High Energy / Go-Around"). If the specific energy exceeds the first intermediate limit (but is greater than the minimum limit), the FMS 205 generates the first audiovisual warning 540 ("Low Energy"). If the specific energy exceeds the minimum limit, the FMS 205 generates a second audiovisual warning 535 ("Low Energy / Go-Around").

[0076]

[0082] 7 illustrates an exemplary MCDU 250 having a textual warning displayed on a scratchpad, according to one or more aspects. In diagram 700, the MCDU 250 includes a display area 705 disposed between a first row of virtual buttons 710-1 and a second row of virtual buttons 710-2. A scratchpad is displayed on the display area 705, and a third audiovisual warning 545 is shown at the scratchpad location 715.

[0077]

[0083] In block 380, the FMS 205 uses the flight instruments 240 of the aircraft 105 to visually display an indicator of the actual indicated airspeed relative to a reference speed according to the selected landing flap setting. In some aspects, the flight instruments 240 include a PFD 245, and the indicator of the actual indicated airspeed includes the airspeed readout 625 of the PFD airspeed indicator 605. In some aspects, the color of the airspeed readout 625 is based on the actual indicated airspeed.

[0078]

[0084] In some aspects, when the actual indicated airspeed is between Vref and Vref+5 knots indicated airspeed (KIAS), the color of the airspeed readout 625 is white (or green). When the actual indicated airspeed is between Vref+5 and Vref+X KIAS or between Vref and Vref-X KIAS, the color of the airspeed readout 625 is amber. When the actual indicated airspeed is greater than Vref+X KIAS or less than Vref-X KIAS, the color of the airspeed readout 625 is red, where X represents operator-defined limits for stable approach criteria (e.g., those loaded by the operator into the FMS configuration DB).

[0079]

[0085] In block 385, the FMS 205 visually displays an indicator of vertical speed using the flight instruments 240 of the aircraft 105. In some aspects, the flight instruments 240 include a PFD 245, and the vertical speed indicator includes one or both of a vertical speed readout of the vertical speed indicator 620 and a vertical speed pointer 635-1. The color of the indicator is based on the vertical speed.

[0080]

[0086] In some aspects, when the vertical velocity is between a first threshold and a second threshold (e.g., ±500 FT / min), the vertical velocity pointer 635-1 and / or vertical velocity readout is white (or green). When the vertical velocity is between the first threshold (e.g., +500 FT / min) and a third threshold (e.g., +1000 FT / min) (as illustrated by outline 635-4) or between the second threshold (e.g., −500 FT / min) and a fourth threshold (e.g., −1000 FT / min) (as illustrated by outline 635-2), the vertical velocity pointer 635-1 and / or vertical velocity readout is amber. If the vertical velocity is greater than a third threshold (e.g., +1000 FT / min) (as illustrated by outline 635-5) or less than a fourth threshold (e.g., -1000 FT / min) (as illustrated by outline 635-3), the vertical velocity pointer 635-1 and / or vertical velocity readout is red. Method 300 ends after completing block 385.

[0081]

[0087] As will be appreciated by one of ordinary skill in the art, aspects described herein may be embodied as a system, method, and / or computer program product. Accordingly, aspects may take the form of entirely hardware aspects, entirely software aspects (including firmware, resident software, microcode, etc.), or aspects combining software and hardware aspects, all of which may be broadly referred to herein as "circuits," "modules," or "systems." Furthermore, aspects described herein may take the form of a computer program product embodied in one or more computer-readable storage medium(s) having computer-readable program code embodied therein.

[0082]

[0088] The program code embodied in the computer readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, fiber optic cable, RF, etc., or any suitable combination thereof.

[0083]

[0089] Computer program code for carrying out operations of aspects of the present disclosure may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" programming language or similar programming languages. The program code may run entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet Service Provider).

[0084]

[0090] Aspects of the present disclosure are described herein with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to aspects of the present disclosure. It will be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general-purpose or special-purpose computer or other programmable data processing device to produce a machine. These instructions, executed via the processor of the computer or other programmable data processing device, thereby create means for performing the function(s) / acts identified in the block(s) of the flowcharts and / or block diagrams.

[0085]

[0091] These computer program instructions may also be stored on a computer-readable medium that may direct a computer, other programmable data processing apparatus, or other device to function in a particular manner. The instructions stored in the computer-readable medium thereby produce an article of manufacture. The instructions include instructions that implement the functions / acts identified in the flowchart and / or block diagram block(s).

[0086]

[0092] Computer program instructions may also be loaded into a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be executed on the computer, other programmable data processing apparatus, or other device to generate a computer-implemented process, whereby the instructions executing on the computer, other programmable data processing apparatus, or other device provide a process for implementing the function(s) / act(s) identified in the flowchart and / or block diagram block(s).

[0087]

[0093] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various aspects of the present disclosure. As such, each block in the flowcharts and block diagrams may represent a module, segment, or portion of code, including one or more executable instructions for implementing specific logical function(s). In some alternative implementations, the functions shown in the blocks need not occur in the order depicted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially simultaneously, or the blocks may be executed in reverse or out of order, depending on the functionality involved. It should also be noted that each block of the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a special-purpose hardware-based system that performs particular functions or functions, or by a combination of special-purpose hardware and computer instructions.

[0088]

[0094] While the foregoing is directed to aspects of the disclosure, other and further aspects of the disclosure may be devised without departing from the basic scope thereof, the scope of which is defined by the following claims.

Claims

1. A method (300) for monitoring an unstable approach of an aircraft (105) in flight, comprising: determining (310) a specific energy (425) of the aircraft during an approach phase (125) of the flight using aircraft ground speed and altitude values ​​derived from measurements taken during the flight; determining (315) a baseline specific energy (405) for the aircraft; defining (330) an energy range (420) for the reference specific energy; and visually displaying (365) an indicator of the specific energy relative to the energy range using a first flight instrument (240) of the aircraft.

2. the first flight instrument comprises a Primary Flight Display (PFD) (245); the indicators (630-1, ..., 630-5) of the specific energy include graphical elements superimposed on a vertical crossbar (645) of a flight director (FD) (640) of the PFD; The method of claim 1 , wherein one or both of the position and color of the graphical element is based on the specific energy.

3. 2. The method of claim 1, further comprising visually displaying an indicator of actual indicated airspeed relative to a reference speed according to a selected landing flap setting (505, 510, 515, 520) using a second flight instrument on the aircraft.

4. the second flight instrument comprises a Primary Flight Display (PFD) (245); the indicator of the actual indicated airspeed includes an airspeed readout (625) of the PFD airspeed indicator (605); The method of claim 3 , wherein the color of the airspeed readout is based on the actual indicated airspeed.

5. The method of claim 1 , further comprising visually displaying an indicator of vertical speed using a third flight instrument of the aircraft.

6. the third flight instrument comprises a Primary Flight Display (PFD) (245); the indicator of the vertical velocity includes one or both of a vertical velocity readout of a vertical velocity indicator (620) of the PFD and vertical velocity pointers (635-1, ..., 635-5); The method of claim 5 , wherein the color of the indicator is based on the vertical speed.

7. comparing (370) the specific energy to one or more limits (410, 415, 525, 530) of the energy range; and 2. The method of claim 1, further comprising: presenting an audiovisual warning using a fourth flight instrument of the aircraft when the specific energy exceeds a limit of the energy range (375).

8. 8. The method of claim 7, wherein the audiovisual warning comprises a text warning (715) displayed on a scratchpad (705) of the fourth flight instrument.

9. The method of claim 1 , wherein the reference specific energy is the sum of a reference ground speed term and a reference altitude term based on a starting point elevation.

10. 1. A method for identifying an unstable approach of an aircraft (105), performed using a Flight Management System (FMS) (205) of the aircraft, comprising: determining (315) a baseline specific energy (405) for the aircraft; Identifying (320) a reference ground speed term that includes a reference speed due to a selected landing flap setting (505, 510, 515, 520); and determining (315) a reference specific energy (405), including determining (325) a reference altitude term based in part on data retrieved from a navigation database (230) of the FMS; defining (330) an energy range (420) for said reference ratio energy; determining (310) the specific energy (425) of the aircraft during the approach phase (125) of flight using the actual altitude and actual ground speed of the aircraft; and generating a signal to cause (365) a visual display using a flight instrument of the aircraft of an indicator of the specific energy of the aircraft relative to the energy range.

11. The method of claim 10 , wherein the reference specific energy comprises the sum of the reference ground speed term and the reference altitude term.

12. The method of claim 11 , wherein the reference ground speed term comprises the sum of a reference speed, a headwind term, and a speed adjustment term due to a selected landing flap setting.

13. The reference altitude term is When the distance of the aircraft to the start of the runway is between a predetermined distance value and a final approach fix (FAF), the product of the distance and the tangent of the approach phase path angle plus the altitude of the FAF minus the start elevation; the product of the distance and the tangent of the final approach path angle, minus the start point elevation, when the distance is between the FAF and a point at a predetermined altitude value above the start of the runway.

14. Defining the energy range includes: specifying (345) a minimum limit (410) as the product of a first gain value and the reference ratio energy; and 11. The method of claim 10, comprising specifying (350) a maximum limit (415) as a product of a second gain value and the reference ratio energy.

15. Defining the energy range includes: receiving one or more user inputs for the first gain value and the second gain value (335); and 15. The method of claim 14, further comprising determining (340) whether the first gain value and the second gain value are within an acceptable range based on a margin value.

16. Defining the energy range includes: Identifying (355) a first intermediate limit (525) between the reference specific energy and the minimum limit; and identifying (360) a second intermediate limit (530) between the reference specific energy and the maximum limit; The method comprises: generating (375) a first signal to cause a flight instrument of the aircraft to present a first audiovisual warning in response to the specific energy of the aircraft exceeding the first intermediate limit or the second intermediate limit; and 15. The method of claim 14, further comprising: generating (375) a second signal to cause the flight instrument to present a second audiovisual warning in response to the specific energy of the aircraft exceeding the minimum limit or the maximum limit.

17. one or more computer processors (210); and A system (200) comprising a memory (215) storing a plurality of instructions, The instructions, when executed by the processor, enable performance of an operation (300) of identifying an unstable approach for an aircraft (105), the operation comprising: determining (315) a baseline specific energy (405) for the aircraft; Identifying (320) a reference ground speed term that includes a reference speed due to a selected landing flap setting (505, 510, 515, 520); and determining (315) a reference specific energy (405), including determining (325) a reference altitude term based in part on data retrieved from a navigation database (230); defining (330) an energy range (420) for said reference ratio energy; determining (310) the specific energy (425) of the aircraft during the approach phase (125) using the actual altitude and actual ground speed of the aircraft; and generating a signal to cause a visual display (365) of an indicator of the specific energy of the aircraft relative to the energy range using a flight instrument of the aircraft.

18. The system of claim 17 , wherein the reference specific energy comprises the sum of the reference ground speed term and the reference altitude term.

19. Defining the energy range includes: specifying (345) a minimum limit (410) as the product of a first gain value and the reference ratio energy; and 20. The system of claim 17, further comprising specifying (350) a maximum limit (415) as a product of a second gain value and the reference ratio energy.

20. The operation is comparing (370) the specific energy to one or more limits (410, 415, 525, 530) of the energy range; and 20. The system of claim 17, further comprising: presenting an audiovisual warning using a second flight instrument of the aircraft when the specific energy exceeds a limit of the energy range (375).

Images