Passenger aircraft landing risk assessment method and implementation system thereof

Abstract

The application belongs to the field of flight performance calculation of an aerial vehicle, and particularly relates to a passenger airplane landing risk assessment method and an implementation system thereof, wherein the assessment method comprises the following steps: obtaining a landing reference distance without adverse factors; obtaining landing distance correction amounts caused by adverse factors and mutual influence factors; taking the landing distance as a target function, constructing a decision variable, constructing a constraint equation, and constructing a 01 programming model; solving the 01 programming model, comparing the landing distance result with an available field length of an airport, and obtaining an airport landing safety degree; repeating the above steps for the airport and a destination airport within a reserve radius, and providing a reference for dispatchers and controllers according to a landing safety degree ranking. The method uses scenarios including but not limited to an airline ground operation control center, and can effectively evaluate landing risks of the destination airport and the reserve airport, and assist dispatchers and controllers in dispatching and releasing a flight plan.

Description

Technical Field

[0001] The present application relates to the field of aircraft flight performance calculation, and in particular to a passenger aircraft landing risk assessment method and an implementation system thereof. Background Art

[0002] According to the "Compilation of Aircraft Accident Investigation Reports" published by the International Civil Aviation Transport Association in 2007, accidents are more likely to occur during takeoff, climb, approach, and landing, with landing accounting for a staggering 46%. Therefore, when preparing flight plans, dispatchers assess the aircraft's landing performance based on manufacturer-provided data and communicate with air traffic controllers to ensure that the requirements are met before clearing the flight. However, even if the landing distance is less than the available airport length, accidents can still occur due to failure to account for unexpected weather conditions at the landing airport, aircraft malfunctions, or crew errors (collectively referred to as adverse factors).

[0003] According to CCAR Part 25 and CCAR Part 121, the existing required landing distance (RLD) assessment is based on the certified landing distance (DLD) multiplied by a coefficient to ensure a safety margin. This only considers the landing performance of the aircraft under the current state and weather conditions when the flight plan is formulated. It does not consider the landing safety margin in the event of unexpected adverse factors during the landing phase (such as sudden weather conditions, sudden aircraft failures, and crew operational errors). At the same time, if there are multiple airports available for an aircraft to perform an alternate landing procedure, the nearest airport is generally selected. This does not consider whether the available runway length of the nearest airport is sufficient in the event of unexpected adverse factors. Therefore, it is necessary to study the safety assessment method during landing to provide a reference for the selection of alternate airports and assist dispatchers and air traffic controllers in dispatching and releasing flight plans. Summary of the Invention

[0004] In order to solve the above problems, the present application provides a passenger aircraft landing risk assessment method, which is characterized by comprising the following steps:

[0005] S1: Obtaining a landing reference distance for a passenger aircraft without adverse factors, wherein the adverse factors are factors that may affect the landing distance;

[0006] S2: Obtain the correction amount caused by each adverse factor relative to the landing reference distance;

[0007] S3: establishing an objective function for the longest landing distance based on multiple unfavorable factors, corrections caused by each unfavorable factor relative to the landing reference distance, influencing factors of coupling between unfavorable factors, and the landing reference distance;

[0008] S4: Calculate the objective function and compare the longest landing distance when the number of unfavorable factors is M with the available length of the destination or alternate airport. If the available length of the airport is greater than the longest landing distance, it means that M unfavorable factors can be tolerated when landing at the airport, and the landing safety degree at the airport can be considered to be M.

[0009] S5: Conduct safety assessment on the airports within the diversion radius and the destination airport according to steps S1-S4, sort them by landing safety level and provide reference for dispatchers and controllers.

[0010] Preferably, the adverse factors include: aircraft sideslip, failure of certain aircraft components, unfavorable landing airport conditions, and unfavorable weather factors.

[0011] Preferably, the failure of a certain component of the aircraft includes failure of multiple spoilers, failure of SEC computer, rudder jamming, and reverse thrust failure.

[0012] Preferably, the objective function is:

[0013] max L=L0+x a ΔL a +x b ΔL b +...+x i ΔL i +x ab ΔL ab +...+x ij ΔL ij ;

[0014] The decision variables are expressed as:

[0015]

[0016]

[0017] Where maxL represents the longest landing distance, L0 represents the landing reference distance when the aircraft has no adverse factors, and x i It represents the control variable when the i-th adverse factor occurs, 1 means it occurs, 0 means it does not occur, ΔL i is the impact of the landing distance caused by the i-th unfavorable factor, x ij It represents the coupling influence factor between the i-th and j-th unfavorable factors, 1 is activated, 0 is not activated, ΔL ij is the correction caused by the coupling between the i-th and j-th unfavorable factors.

[0018] Preferably, the coupling of multiple adverse factors is characterized by a constraint equation.

[0019] Preferably, S4 specifically includes: adding 1 to the number of unfavorable factors of the objective function starting from 1, increasing to 2, 3, ..., M+1, until the result of the corresponding objective function is greater than the available length of the airport. At this time, the number of unfavorable factors that can be tolerated is M+1, and the airport landing safety is M.

[0020] Preferably, S5 specifically includes: when an aircraft needs to make an alternate landing, obtaining the position, pressure altitude, and speed of the passenger aircraft through the real-time aircraft position acquisition module, calculating the maximum radius that the aircraft can reach when executing the alternate landing procedure according to the data provided in the flight manual, and obtaining all alternate airports. The airports within the alternate landing range are traversed and implemented according to steps S1 to S4, and the safety levels of the destination airport and all alternate airports are calculated and displayed in order to provide a reference for dispatchers and air traffic controllers. In the event of an emergency alternate landing, airports with higher safety levels are given priority for the alternate landing.

[0021] Preferably, the decision variables specifically include:

[0022] First, second and third spoiler failure: x a 、x b 、x c ;

[0023] SEC1, SEC3 computer failure: x d 、x f ;

[0024] SEC2 computer failure: x e ;

[0025] Rudder jam: x g ;

[0026] Reverse thrust (single engine failure): x h ;

[0027] Plateau Airport: x i ;

[0028] The impact factor of any two spoiler failures: x aa ;

[0029] Impact factor of any three spoiler failures: x abc ;

[0030] The first spoiler failure and SEC1 computer failure impact factor: x ad ;

[0031] The second spoiler failure and SEC2 computer failure impact factor: x be ;

[0032] The third spoiler failure and SEC3 computer failure impact factor: x cf ;

[0033] SEC2 and SEC3 computer failure impact factor: x ef ;

[0034] SEC1 and SEC3 computer failure impact factor: x df ;

[0035] SEC1 and SEC2 computer failure impact factor: x de .

[0036] Preferably, the constraint equations for the occurrence of at most M items of the nine adverse conditions include:

[0037] x a +x b +x c +x d +x e +x f +x g +x h +x i ≤M;

[0038] The constraint equations for a spoiler failure and a SEC1 failure include:

[0039] 0≤x a +x d -x ad ≤1,x a +x ad -x d ≤1;x d +x ad -x a ≤1; Constraint equations of the two spoilers and SEC2:

[0040] 0≤x b +x e -x be ≤1,x b +x be -x e ≤1,x e +x be -x b ≤1; Constraint equations of the three spoilers and SEC3:

[0041] 0≤x c +x f -x cf ≤1,x c +x cf -x f ≤1,x f +x cf -x c ≤1; Constraint equations when one and two spoilers fail at the same time:

[0042] 0≤x a +x b -x aa ≤1,x a +x aa -x b ≤1,x b +x aa -x a ≤1; Constraint equations when one or three spoilers fail simultaneously:

[0043] 0≤x a +x c -x aa ≤1,x a +x aa -x c ≤1,x c +x aa -x a ≤1; Constraint equations when two or three bypass plates fail simultaneously:

[0044] 0≤x b +x c -x aa ≤1,x b +x aa -x c ≤1,x c +x aa -x b ≤1;

[0045] Constraint equations when three spoilers fail simultaneously:

[0046] x aa +x abc ≤1, 0≤x a +x b +x c -x aa ≤2,x a +x abc -x b -x c ≤1,

[0047] x b +x abc -x a -x c ≤1,x c +x abc -x a -x b ≤1;

[0048] Constraint equations when SEC1 and SEC2 computers fail simultaneously:

[0049] 0≤xd +x e -x de ≤1,x d +x de -x e ≤1,x e +x de -x d ≤1;

[0050] Constraint equations when SEC1 and SEC3 computers fail simultaneously:

[0051] 0≤x d +x f -x df ≤1,x d +x df -x f ≤1,x f +x df -x d ≤1,

[0052] Constraint equations when SEC2 and SEC3 computers fail simultaneously:

[0053] 0≤x e +x f -x ef ≤1,x e +x ef -x f ≤1,x f +x ef -x e ≤1;

[0054] At most two of the three SEC computers will have faulty constraint equations:

[0055] x d +x e +x f ≤2,

[0056] x de +x df +x ef ≤1 is the constraint that only one of the three influencing factors can be effective at the same time.

[0057] A system for implementing a passenger aircraft landing risk assessment method, and an aircraft landing performance database, including the landing reference distance without adverse factors and the impact of adverse factors on the landing distance;

[0058] Weather server, which obtains real-time weather data of all airports within the diversion range and the destination airport;

[0059] Airport information database, including real-time public airport elevation and runway length information;

[0060] Aircraft position real-time acquisition module, used to obtain aircraft position and provide available airports within the diversion range;

[0061] A model and calculation module, comprising a landing distance assessment 01 planning model constructed by the passenger aircraft landing risk assessment method according to any one of claims 1 to 6, and a solver for solving the landing distance assessment 01 planning model.

[0062] The output end is used to output the landing safety of the alternate airport and the destination airport in the form of a list for reference by dispatchers and controllers.

[0063] The real-time meteorological data includes airport wind speed and direction, temperature, and runway water and snow conditions; the meteorological server transmits the data to the landing performance database to obtain the braking effect under the corresponding weather conditions and the corresponding landing distance impact.

[0064] The application scenarios of this application include but are not limited to the airline ground operation control center, which can effectively assess the landing risks of the destination airport and alternate airport, and assist dispatchers and controllers in issuing and releasing flight plans. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is a flow chart of a passenger aircraft landing risk assessment method according to a preferred embodiment of the present application;

[0066] Figure 2 This is a schematic diagram of the control relationship between the flight control computer and the control surface in a preferred embodiment of the present application.

[0067] Figure 3 This is a schematic diagram of the system structure of a preferred embodiment of the present application. DETAILED DESCRIPTION

[0068] To make the technical solution and its advantages of the present application clearer, the technical solution of the present application will be described in further detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of the present application and are only used to explain the present application, not to limit the present application. It should be noted that, for ease of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0069] Example 1: The present invention discloses a passenger aircraft landing risk assessment method. This risk assessment method is primarily based on performance data provided in the manufacturer's flight manual. For a specific aircraft model, the impact of adverse factors on landing distance is converted into an 0.1 planning mathematical model. Constraint equations are adjusted based on the coupling between adverse factors to calculate the landing distance. The safety factor is then compared with the available airport length to determine the landing distance. The specific implementation steps of the method are as follows:

[0070] S1: Obtain the landing reference distance for a non-skid landing without any failure or adverse conditions from the passenger aircraft flight manual. Taking a passenger aircraft manual as an example, the landing reference distance for a non-skid landing without any failure or adverse conditions with good braking effect is L0 = 1410m.

[0071] S2: As shown in Table 1, these are the adverse factors that can affect landing distance as listed in the flight manual for a certain passenger aircraft. These factors include weather, landing airport conditions, and failure of the aircraft's spoilers or spoiler-elevator computer (SEC computer). The bold numbers in the figure represent the landing distance when a specific failure occurs. For example, if a spoiler failure occurs as an adverse factor, the landing distance is 1560 meters. The impact of this adverse factor on the landing distance is ΔL = 1560 - 1410 = 150 meters.

[0072] It should be noted that when all three spoilers fail simultaneously, the impact on landing distance is ΔL = 177 - 0.14 = 10, which is 90m less than the simple superposition of three single spoiler failures, indicating that the impact of coupling needs to be considered. Similarly, the failure of a spoiler and the failure of the SEC computer that controls it will also affect each other, such as Figure 2 The control relationship between the three SEC computers and the three spoilers is relatively complex, which needs to be reflected when setting the mathematical model.

[0073] Table 1 Impact of a single spoiler failure on a passenger aircraft

[0074]

[0075] S3: According to S2, the coupling between multiple adverse factors needs to be considered when setting up the mathematical model. This embodiment considers multiple adverse conditions such as failure of multiple spoilers, failure of the SEC computer, rudder jamming, and reverse thrust failure. The objective function is:

[0076] max L=1410+x a 150+x b 150+x c 150-x aa 40-x abc 90-x ad 150-x be100-x cf 150+x d 170+x e 100+x f 170-x ef 60-x df 70-x de 30+x g 270+x h 60+x i 120

[0077] In the above formula, maxL is the maximum landing distance, x i Single superscript and x ij The multi-superscripts are all decision variables. The coefficient multiplied by each decision variable is the impact of the corresponding landing distance, in meters.

[0078]

[0079] The meaning of decision variables is shown in Table 2, x i Indicates whether a certain adverse condition occurs, x ij It represents the influence factor between the adverse conditions. That is, when two adverse conditions occur at the same time, their impact on the landing distance cannot be simply added together, and an additional value needs to be added or subtracted. In this case, the influence factor x ij activation.

[0080] Table 2 Comparison table of decision variables

[0081]

[0082]

[0083] In the constraint equation, we also need to consider the influence of adverse conditions on each other, so we have the constraint equation:

[0084] S301, x a +x b +x c +x d +x e +x f +x g +x h +x i ≤M, this formula means that there are only M items of the 9 adverse conditions. The number on the right side of the inequality is only used to control the number of adverse conditions that may occur, and is used to determine the safety level in step S4. In this embodiment, 4 is taken, x a +x b +x c +x d +x e +x f +xg +x h +x i ≤4, that is, if the available length of the airport in step S4 is greater than the objective function maxL, it means that the airport safety level is at least 4. In actual use, it needs to start from 1 and increase by 1 each time.

[0085] S302, 0≤x a +x d -x ad ≤1, indicating that a spoiler failure and SEC1 failure can occur simultaneously, and the impact of the two on the landing distance only retains the maximum value; x a +x ad -x d ≤1,x d +x ad -x a ≤1 The two formulas ensure that there will be no spoiler and SEC1. Only one failure occurs, affecting the factor x ad But it is activated; Similarly, the constraint equations of the two spoilers and SEC2 are established, 0≤x b +x e -x be ≤1,x b +x be -x e ≤1,x e +x be -x b ≤1; constraint equations of the three spoilers and SEC3, 0≤x c +x f -x cf ≤1,x c +x cf -x f ≤1,x f +x cf -x c ≤1.

[0086] S303, 0≤x a +x b -x aa ≤1,x a +x aa -x b ≤1,x b +x aa -x a ≤1 is the constraint equation when one and two spoilers fail at the same time. In this case, to ensure the influence factor x aa Only in x a with x b At the same time, it is activated when it is 1, so the constraint equation is established in this way. Similarly, there are one or three spoilers 0≤x a +x c -x aa≤1,x a +x aa -x c ≤1,x c +x aa -x a ≤1, second and third spoilers 0≤x b +x c -x aa ≤1,x b +x aa -x c ≤1,x c +x aa -x b ≤1.

[0087] S304, x aa +x abc ≤1, 0≤x a +x b +x c -x aa ≤2,x a +x abc -x b -x c ≤1,x b +x abc -x a -x c ≤1,x c +x abc -x a -x b ≤1 is the constraint equation when the three spoilers fail at the same time. At this time, it is necessary to ensure that the influence factor x of the three spoilers abc Only in x a x b x c Activated when both are 1, and the two spoilers affect the factor x aa Cannot be activated;

[0088] S305, 0≤x d +x e -x de ≤1,x d +x de -x e ≤1,x e +x de -x d ≤1 is the constraint equation when SEC1 and SEC2 computers fail at the same time. In this case, to ensure the impact factor x de Only in x d with x e At the same time, it is activated when it is 1, so the constraint equation is established in this way. Similarly, there are SEC1,3 computers 0≤x d +x f -xdf ≤1,x d +x df -x f ≤1,x f +x df -x d ≤1,SEC2,3Computer 0≤x e +x f -x ef ≤1,x e +x ef -x f ≤1,x f +x ef -x e ≤1.

[0089] S306, x de +x df +x ef ≤1 means only one of the three influencing factors can be effective at the same time, x d +x e +x f ≤2 means that at most two of the three SEC computers will fail. This embodiment does not consider the simultaneous failure of the three SEC computers.

[0090] S307. All the above constraint equations have been established. Using the integer programming solver, it can be calculated that when a maximum of four adverse conditions occur, the longest landing distance is 2220m. The most dangerous adverse condition combination is failure of the first or third spoiler, SEC1 computer or SEC3 computer failure, rudder jam, and high-altitude airport.

[0091] S4: The above step S3 has calculated that the longest landing distance for the combination of four adverse conditions is 2220m. If the runway length of the alternate airport or the destination airport is greater than 2220m, the safety factor is at least 4. At this time, the number of possible adverse conditions on the right side of the inequality S301 can be increased by 1, and step S3 can be repeated until the calculated longest landing distance exceeds the available length of the alternate airport. At this time, if the number of possible adverse conditions is M+1, the airport landing safety factor is M.

[0092] S5: Conduct safety assessment on the airports within the diversion radius and the destination airport according to steps S1-S4, sort them by landing safety level and provide reference for dispatchers and controllers.

[0093] Example 2: This example provides a system for implementing the above-mentioned landing risk assessment method. The application scenarios include but are not limited to airline ground operations control centers. The implementation system includes:

[0094] Aircraft landing performance database, including the landing reference distance without sideslip landing, any failure or adverse conditions, and the impact of adverse factors on landing distance under various braking effects;

[0095] Weather servers and airport information databases that provide access to aviation intelligence services (including domestic static intelligence MAIP and dynamic intelligence NOTAM), including:

[0096] The weather server can obtain real-time weather data for all airports within the diversion range and the destination airport;

[0097] Airport information database, including the latest airport information published by the Civil Aviation Administration of China, such as airport elevation, runway length, etc.

[0098] The real-time aircraft position acquisition module can obtain the aircraft position and provide available airports within the diversion range;

[0099] The model and calculation module includes the landing risk assessment model described in claim 1 and contains a commercial solver that can perform fast solutions for 01 planning and has basic calculation functions.

[0100] At the output end, the landing safety of the alternate airport and the destination airport can be output in the form of a list for reference by dispatchers and controllers.

[0101] The specific implementation method of the system is to establish a landing performance database based on the flight manual provided by the passenger aircraft manufacturer, which includes the landing reference distance when the aircraft lands without sideslip and without any failure or adverse conditions, as well as the impact of adverse factors on the landing distance under various braking effects.

[0102] A program can be written based on the mathematical model established in step S3 of Example 1. To determine the impact of weather factors on landing distance, a specific implementation method for the system is to provide a data interface and establish a dedicated meteorological network or server to obtain real-time meteorological data for all airports within the diversion range and the destination airport, primarily including airport wind speed and direction, temperature, and braking action conditions corresponding to runway water and snow accumulation. The program then automatically reads the airport weather conditions and, using an interpolation algorithm based on the landing performance database, derives the impact of adverse factors on landing distance under the corresponding weather conditions.

[0103] Mathematical models can be solved using mature commercial solvers. Currently, commercial solvers employ heuristic intelligent algorithms, enabling them to solve 01 planning problems in a short period of time. The system also includes a pre-defined control interface, allowing for the selection and exclusion of unfavorable conditions, resulting in more accurate results.

[0104] According to step S4 in Example 1, the system is specifically implemented by establishing an airport information database and providing the available lengths of the destination and alternate airports based on aviation intelligence. The calculated objective function is compared with the available length of the airport. The number of unfavorable factors is incremented by 1, starting from 1, to 2, 3, ..., M+1, until the corresponding objective function exceeds the available length of the airport. At this point, the tolerable number of unfavorable factors is M+1, and the airport landing safety is M.

[0105] According to step S5 in Example 1, the specific implementation method of the system is as follows: when an aircraft needs to make an alternate landing, the real-time aircraft position acquisition module is used to obtain the passenger aircraft's position, pressure altitude, speed, and other flight data. The maximum radius that the aircraft can reach when executing the alternate landing procedure is calculated according to the data provided in the flight manual to obtain all alternate airports. The airports within the alternate landing range are traversed, and the implementation is carried out in accordance with claims 3 to 6. The safety levels of the destination airport and all alternate airports are calculated and displayed in order to provide a reference for dispatchers and air traffic controllers. In particular, in the event of an emergency diversion, airports with high safety levels can be given priority for diversion.

[0106] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A passenger aircraft landing risk assessment method, characterized in that: The following steps are involved: S1: Obtaining a landing reference distance for a passenger aircraft without adverse factors, wherein the adverse factors are factors that may affect the landing distance; S2: Obtain the correction amount caused by each adverse factor relative to the landing reference distance; S3: establishing an objective function for the longest landing distance based on multiple unfavorable factors, corrections caused by each unfavorable factor relative to the landing reference distance, influencing factors of coupling between unfavorable factors, and the landing reference distance; S4: Calculate the objective function and compare the longest landing distance when the number of unfavorable factors is M with the available length of the destination or alternate airport. If the available length of the airport is greater than the longest landing distance, it means that M unfavorable factors can be tolerated when landing at the airport, and the landing safety degree at the airport can be considered to be M. S5: Conduct safety assessment on the airports within the diversion radius and the destination airport according to steps S1-S4, sort them by landing safety level and provide reference for dispatchers and controllers.

2. The passenger aircraft landing risk assessment method according to claim 1, wherein: The adverse factors include: aircraft sideslip, failure of certain aircraft components, unfavorable landing airport conditions, and unfavorable weather factors.

3. The passenger aircraft landing risk assessment method according to claim 1, wherein: The failure of certain aircraft components includes failure of multiple spoilers, failure of SEC computer, rudder jamming, and reverse thrust failure.

4. The passenger aircraft landing risk assessment method according to claim 1, wherein: The objective function is: max L=L0+x a ·ΔL a +x b ·ΔL b +...+x i ·ΔL i +x ab ·ΔL ab +...+x ij ·ΔL ij ; The decision variables are expressed as: Where maxL represents the longest landing distance, L0 represents the landing reference distance when the aircraft has no adverse factors, and x i It represents the control variable when the i-th adverse factor occurs, 1 means it occurs, 0 means it does not occur, ΔL i is the impact of the landing distance caused by the i-th unfavorable factor, x ij It represents the coupling influence factor between the i-th and j-th unfavorable factors, 1 is activated, 0 is not activated, ΔL ij is the correction caused by the coupling between the i-th and j-th unfavorable factors.

5. The passenger aircraft landing risk assessment method according to claim 4, characterized in that: The coupling of various adverse factors is characterized by constraint equations.

6. The passenger aircraft landing risk assessment method according to claim 4, wherein: S4 specifically includes: starting from 1, the number of unfavorable factors in the objective function is increased by 1, increasing to 2, 3, ..., M+1, until the result of the corresponding objective function is greater than the available length of the airport. At this time, the number of unfavorable factors that can be tolerated is M+1, and the airport landing safety is M.

7. The passenger aircraft landing risk assessment method according to claim 1, wherein: S5 specifically includes: When an aircraft needs to make an alternate landing, the real-time aircraft position acquisition module obtains the passenger aircraft's position, pressure altitude, and speed. Based on the data provided in the flight manual, the maximum radius the aircraft can reach when executing the alternate landing procedure is calculated to obtain all alternate airports. The airports within the alternate landing range are traversed, following steps S1 through S4. The safety levels of the destination airport and all alternate airports are calculated and displayed in order to provide a reference for dispatchers and air traffic controllers. In the event of an emergency diversion, airports with higher safety levels are prioritized for diversion.

8. The passenger aircraft landing risk assessment method according to claim 6, wherein: The decision variables include: First, second and third spoiler failure: x a 、x b 、x c ; SEC1, SEC3 computer failure: x d 、x f ; SEC2 computer failure: x e ; Rudder jam: x g ; Reverse thrust (single engine failure): x h ; Plateau Airport: x i ; The impact factor of any two spoiler failures: x aa ; Impact factor of any three spoiler failures: x abc ; The first spoiler failure and SEC1 computer failure impact factor: x ad ; The second spoiler failure and SEC2 computer failure impact factor: x be ; The third spoiler failure and SEC3 computer failure impact factor: x cf ; SEC2 and SEC3 computer failure impact factor: x ef ; SEC1 and SEC3 computer failure impact factor: x df ; SEC1 and SEC2 computer failure impact factor: x de .

9. The passenger aircraft landing risk assessment method according to claim 8, characterized in that: The landing safety factor M, that is, only M items of the nine adverse conditions occur at most, is expressed as the constraint equation: x a +x b +x c +x d +x e +x f +x g +x h +x i ≤M; The constraint equations for a spoiler failure and a SEC1 failure include: 0≤x a +x d -x ad ≤1,x a +x ad -x d ≤1;x d +x ad -x a ≤1; Constraint equations for the two-part spoiler and SEC2: 0≤x b +x e -x be ≤1,x b +x be -x e ≤1,x e +x be -x b ≤1; Constraint equations for the three spoilers and SEC3: 0≤x c +x f -x cf ≤1,x c +x cf -x f ≤1,x f +x cf -x c ≤1; Constraint equations when one and two spoilers fail simultaneously: 0≤x a +x b -x aa ≤1,x a +x aa -x b ≤1,x b +x aa -x a ≤1; 1. Constraint equations when three spoilers fail simultaneously: 0≤x a +x c -x aa ≤1,x a +x aa -x c ≤1,x c +x aa -x a ≤1; Constraint equations when two or three bypass plates fail simultaneously: 0≤x b +x c -x aa ≤1,x b +x aa -x c ≤1,x c +x aa -x b ≤1; Constraint equations when three spoilers fail simultaneously: x aa +x abc ≤1,0≤x a +x b +x c -x aa ≤2,x a +x abc -x b -x c ≤1, x b +x abc -x a -x c ≤1,x c +x abc -x a -x b ≤1; Constraint equations when SEC1 and SEC2 computers fail simultaneously: 0≤x d +x e -x de ≤1,x d +x de -x e ≤1,x e +x de -x d ≤1; Constraint equations when SEC1 and SEC3 computers fail simultaneously: 0≤x d +x f -x df ≤1,x d +x df -x f ≤1,x f +x df -x d ≤1, Constraint equations when SEC2 and SEC3 computers fail simultaneously: 0≤x e +x f -x ef ≤1,x e +x ef -x f ≤1,x f +x ef -x e ≤1; At most two of the three SEC computers will have faulty constraint equations: x d +x e +x f ≤2, x de +x df +x ef ≤1 is the constraint that only one of the three influencing factors can be effective at the same time.

10. A system for implementing a passenger aircraft landing risk assessment method, characterized in that: Aircraft landing performance database, including the landing reference distance without adverse factors and the impact of adverse factors on landing distance; Weather server, which obtains real-time weather data of all airports within the diversion range and the destination airport; Airport information database, including real-time public airport elevation and runway length information; Aircraft position real-time acquisition module, used to obtain aircraft position and provide available airports within the diversion range; A model and calculation module, comprising a landing distance assessment 01 planning model constructed by the passenger aircraft landing risk assessment method according to any one of claims 1 to 6, and a solver for solving the landing distance assessment 01 planning model. The output end is used to output the landing safety of the alternate airport and the destination airport in the form of a list for reference by dispatchers and controllers.

11. The system for implementing the passenger aircraft landing risk assessment method according to claim 10, characterized in that: The real-time meteorological data includes airport wind speed and direction, temperature, and runway water and snow conditions; the meteorological server transmits the data to the landing performance database to obtain the braking effect under the corresponding weather conditions and the corresponding landing distance impact.

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