Flight safety situation assessment method

Abstract

The invention belongs to a flight safety assessment method, and particularly relates to a flight safety situation assessment method. The invention relates to a flight safety situation assessment method, which comprises the following steps of: 1, constructing a quantifiable flight safety situation assessment index system; 2, constructing a flight safety situation assessment model; and step 3, quantitatively evaluating the flight safety situation. Compared with the prior art, the method has the following beneficial effects: a flight safety situation evaluation index system and an evaluation model are constructed, so that quantitative mastering of the overall flight safety situation of a flight unit is realized, and scientific support is provided for flight safety supervision and management of the flight unit.

Description

Technical Field

[0001] The invention belongs to a flight safety assessment method, and in particular relates to a flight safety situation assessment method. Background Art

[0002] At present, in the field of flight safety management, risk assessment is a widely used technical method. Flight safety risk assessment refers to the identification of inherent and potential sources of danger in the flight safety system, making qualitative or quantitative safety evaluations, determining risk levels, and clarifying countermeasures for risk prevention and control. Flight safety situation assessment is a method of comprehensively evaluating the current global operating status of the assessment object through assessment indicators composed of various flight safety influencing factors. Carrying out flight safety situation assessment for flight units can quantitatively evaluate the flight safety situation of each flight unit, and on the basis of monitoring the peak and valley changes of the flight safety situation, determine the normal growth threshold of the flight safety situation, observe the turning point and development trend of the flight safety situation tending to malignant growth, and thus conduct control and treatment.

[0003] Patent CN201911148779.0 discloses an airspace safety situation assessment method based on category activation mapping technology for drone flights. This method uses historical drone airborne flight pictures as a data set, trains and constructs a perception network main body model combined with a residual network, and inputs photos of the drone's current flight status into the model to achieve real-time assessment of the current drone situation. Patent CN201610349299.0 discloses a low-altitude flight situation safety assessment index and its assessment method for the flight activities of dense aircraft groups in a specific low-altitude time and space. This method establishes a low-altitude flight situation safety evaluation key index by analyzing the low-altitude airspace operating environment characteristics and flight safety data, and realizes the quantitative assessment of low-altitude flight situation safety based on the comprehensive fuzzy clustering method, providing technical support for low-altitude flight activity monitoring, airspace demarcation and use. These methods are somewhat inspiring to the proposal of the present invention, but they are essentially different in the evaluation objects, indicators, models and other methods. Summary of the invention

[0004] The purpose of the present invention is to provide a flight safety situation assessment method in view of the defects of the prior art.

[0005] The specific technical solution adopted by the present invention is as follows: a flight safety situation assessment method, which includes the following steps:

[0006] Step 1: Construct a quantifiable flight safety situation assessment indicator system;

[0007] Step 2: Construct a flight safety situation assessment model;

[0008] Step 3: Quantitative assessment of flight safety situation.

[0009] In the flight safety situation assessment method as described above, step 1 includes the following contents:

[0010] The data that need to be input or calculated include: flight error or omission rate, flight interruption rate, flight time rate, aircraft defect rate, aircraft failure rate, aircraft failure air-to-ground ratio, flight accident rate per 10,000 hours, flight accident symptom rate per 1,000 hours and flight failure rate per 1,000 hours, a total of 9 dimensions of data.

[0011] A flight safety situation assessment method as described above, wherein the three standard flight error and omission rate, flight interruption rate and flight duration rate are indicators of personnel safety situation of the assessment unit; the aircraft incompleteness rate, aircraft failure rate and aircraft failure air-to-ground ratio are three indicators representing the equipment safety situation of the assessment unit; the dangerous weather rate and dangerous bird situation rate are two indicators representing the environmental safety situation of the assessment unit; and the flight accident rate per 10,000 hours, the flight accident symptom rate per 1,000 hours and the flight failure rate per 1,000 hours are three indicators representing the operational safety situation of the assessment unit.

[0012] A flight safety situation assessment method as described above, wherein the flight error rate includes the total error rate of all pilots of the assessment unit during the assessment period, which is used to characterize the error rate of pilots of the assessment unit. It is expressed as:

[0013]

[0014] In the formula, represents the calculated row error rate, To evaluate the number of mistakes and omissions of all pilots during the period t0-t1, is the flight time of the i-th pilot in the evaluation period t0-t1, and n is the total number of pilots; t0, t1, n are all external inputs.

[0015] The flight interruption rate is the sum of the number of pilots whose flight interruption time exceeds 50% of the prescribed time and the number of pilots whose flight interruption time exceeds 100% of the prescribed time to the total number of pilots in the assessment unit. It is expressed as:

[0016]

[0017] In the formula, represents the calculated flight interruption rate, The number of pilots in the assessment unit whose flight interruption time exceeds the prescribed time by 50%-100% during the assessment period t0-t1, The number of pilots in the assessment unit whose flight breaks during the assessment period t0-t1 exceed 100% of the prescribed time. is the total number of pilots in the evaluation unit during the evaluation period t0-t1, and 0.418 and 0.582 are the corresponding weights; All are input from outside.

[0018] The flight time rate is the weighted sum of the ratio of the number of pilots with less than 500 hours of flight time to the total number of pilots, the ratio of the number of pilots with more than 500 hours but less than 1,000 hours of flight time to the total number of pilots, and the ratio of the number of pilots with more than 1,500 hours of flight time to the total number of pilots. It is expressed as:

[0019]

[0020] In the formula, represents the calculated flight time rate, The number of pilots in the assessment unit whose flight hours are less than 500 hours during the assessment period t0-t1, The number of pilots in the assessment unit whose flight hours are greater than 500 hours and less than 1000 hours during the assessment period t0-t1, The number of pilots in the assessment unit whose flight hours are greater than 500 hours and greater than 1500 hours during the assessment period t0-t1, The total number of pilots in the evaluation unit during the evaluation period t0-t1, 0.533, 0.345 and 0.122 are the corresponding weights; From external input,

[0021] The aircraft unavailable rate reflects the unavailable status of the aircraft in the inventory. It is expressed as:

[0022]

[0023] In the formula, is the calculated aircraft non-perfect rate, To evaluate the number of incomplete aircraft in the fleet during the period t0-t1, is the total number of aircraft in the fleet during the evaluation period t0-t1; All are input from outside.

[0024] The aircraft failure rate reflects the reliability and maintenance quality of the aircraft of the assessment unit. The aircraft failure rate is expressed as:

[0025]

[0026] In the formula, is the total number of aircraft failures during the evaluation period t0-t1, is the flight time of the i-th aircraft in the evaluation period t0-t1, and m is the total number of evaluation periods; m are input from the outside,

[0027] The aircraft failure air-to-ground ratio reflects the situation of the assessment unit's aircraft failure in the air and on the ground. It is expressed as:

[0028]

[0029] In the formula, is the calculated aircraft failure air-to-ground ratio, To evaluate the number of aircraft failures in the air during the period t0-t1, is the number of aircraft failures on the ground during the evaluation period t0-t1; From external input,

[0030] The dangerous weather rate reflects the impact of dangerous weather on flight safety during the assessment period. It is expressed as:

[0031]

[0032] In the formula, is the calculated dangerous weather rate, is the number of dangerous weather events during the evaluation period t0-t1, is the total number of weather events during the evaluation period t0-t1; From external input,

[0033] The dangerous bird situation rate reflects the impact of dangerous bird situation on flight safety during the assessment period. It is expressed as:

[0034]

[0035] In the formula, is the number of dangerous bird situations during the evaluation period t0-t1, is the total number of bird sightings during the evaluation period t0-t1; All are input from outside.

[0036] The flight accident rate per 10,000 hours takes into account the impact of the number of accidents and every 10,000 flight hours. The number of flight accidents is the total number of flight accidents of the evaluation unit during the evaluation period based on the statistics of accident reports, reflecting the overall accident status of the unit. It is expressed as:

[0037]

[0038] In the formula, is the calculated flight accident rate per 10,000 hours, To evaluate whether an accident occurs to aircraft i in the unit during the period t0-t1. If an accident occurs, otherwise q is the flight hours of the evaluation unit in the statistical time period, and q is input from the outside;

[0039] The flight accident incident thousand-hour rate takes into account the impact of both the number of accident incidents and every thousand flight hours. The number of flight accident incidents is the total number of flight accidents of the assessment unit during the assessment period based on the accident report statistics, reflecting the overall accident incident status of the unit. The flight accident incident thousand-hour rate It is expressed as:

[0040]

[0041] In the formula, is the calculated traffic incident rate per thousand hours, To evaluate whether an incident occurs to aircraft i in the unit during the period t0-t1. If an incident occurs, otherwise l is the thousand flight hours of the evaluation unit during the statistical period;

[0042] The flight failure rate per thousand hours takes into account both the number of major failures and the impact of every thousand flight hours. The number of major failures is the total number of major failures related to the flight safety of the unit in a certain period of time based on the statistics of failure reports, reflecting the overall flight safety failure status of the unit. The flight failure rate per thousand hours takes into account both the number of major failures and the impact of every thousand flight hours. It is expressed as:

[0043]

[0044] In the formula, is the calculated flight failure rate per thousand hours, To evaluate whether a major fault occurs to aircraft i in the unit during the period t0-t1. If a major fault occurs, otherwise l is the thousand flight hours of the evaluation unit during the statistical period.

[0045] A flight safety situation assessment method as described above, wherein the step two includes the following contents: constructing a flight safety situation assessment model in combination with the constructed flight safety situation assessment index system and the grey system theoretical method, and collecting quantitative data of corresponding indicators according to the index system.

[0046] In the above-mentioned flight safety situation assessment method, the step 2 specifically includes the following contents:

[0047] Step 2.1: Read data

[0048] The first step is to read these data and form the initial matrix form for u groups of data sequences of o indicators as follows

[0049]

[0050] Among them, o represents o indicators, and u represents the number of data groups.

[0051] Then determine the reference sequence. The reference sequence is the reference for calculating the correlation degree. The correlation degree is the correlation degree between the pre-calculated data and the reference sequence. The basis for selecting the reference sequence is to see what problem is to be solved. The reference sequence can be a sequence in the data or a sequence that does not exist in the data. The reference sequence is generally the optimal state sequence, that is, the maximum value of each indicator is used as the reference sequence. The reference sequence is recorded as:

[0052] X′0=(x′0(1),x′0(2),…,x′0(u)) T

[0053] Step 2.2: Dimensionless processing

[0054] Dimensionless preprocessing of data

[0055]

[0056] in, x ij are the maximum value, minimum value and actual value of the jth indicator respectively, and each component of each row vector in the matrix is ​​divided by the corresponding component of the first row vector. The data matrix after the dimensionless method is as follows:

[0057]

[0058] Step 2.3: Calculate the correlation coefficient between each comparison sequence and the corresponding element of the reference sequence

[0059] Calculate the absolute difference between the corresponding elements of each evaluated object indicator sequence (comparison sequence) and the reference sequence one by one:

[0060] |x′0(k)-x i (k)|(k=1,…,u; i=1,…,o)

[0061] k is the indicator index, o is the number of evaluated objects, and the smallest one is found after traversing:

[0062]

[0063] After traversing, find the largest one:

[0064]

[0065] Calculate the correlation coefficient of each comparison sequence and the corresponding element of the reference sequence separately:

[0066]

[0067] Where ρ is the resolution coefficient and takes the value as 0.5.

[0068] Step 2.4: Calculate the mean correlation coefficient

[0069] The mean of the correlation coefficient between each indicator and the corresponding element of the reference sequence is calculated to reflect the correlation between each evaluation indicator and the reference sequence, which is recorded as:

[0070]

[0071] Step 2.5: Calculate indicator weights

[0072] Normalizing the correlation of each indicator can get the weight of the corresponding indicator

[0073]

[0074] Step 2.6: Form an evaluation model

[0075] The flight safety situation assessment model is obtained by weighted summing up the weights of the flight safety situation assessment indicators.

[0076] In the above-mentioned flight safety situation assessment method, the step three includes the following contents:

[0077] Based on the constructed flight safety situation assessment model, with the data corresponding to each indicator as input, the model comprehensively evaluates and outputs the overall flight safety situation quantitative assessment results, thereby realizing the quantitative assessment of the flight safety situation.

[0078] Compared with the prior art, the present invention has the following beneficial effects: the present invention constructs a flight safety situation assessment index system and assessment model to achieve quantitative grasp of the overall flight safety situation of the flight unit, and provide scientific support for the flight safety supervision and management of the flight unit. DETAILED DESCRIPTION

[0079] The present invention will be further described and illustrated below in conjunction with specific implementation modes.

[0080] A flight safety situation assessment method includes the following contents:

[0081] Step 1: Build a quantifiable flight safety situation assessment indicator system

[0082] The data that need to be input or calculated include: flight error or omission rate, flight interruption rate, flight time rate, aircraft defect rate, aircraft failure rate, aircraft failure air-to-ground ratio, flight accident rate per 10,000 hours, flight accident symptom rate per 1,000 hours and flight failure rate per 1,000 hours, a total of 9 dimensions of data.

[0083] Among them, the three standard indicators of flight error and omission rate, flight interruption rate and flight time rate are for evaluating the personnel safety status of the unit; the three indicators of aircraft incompleteness rate, aircraft failure rate and aircraft failure to air-to-ground ratio are for characterizing the equipment safety status of the unit; the two indicators of dangerous weather rate and dangerous bird situation rate are for characterizing the environmental safety status of the unit; the three indicators of flight accident rate per 10,000 hours, flight accident symptom rate per 1,000 hours and flight failure rate per 1,000 hours are for characterizing the operational safety status of the unit.

[0084] The flight error rate includes the total error rate of all pilots in the evaluation unit during the evaluation period, which is used to characterize the error rate of pilots in the evaluation unit. It is expressed as:

[0085]

[0086] In the formula, represents the calculated row error rate, To evaluate the number of mistakes and omissions of all pilots during the period t0-t1, is the flight time of the i-th pilot in the evaluation period t0-t1, and n is the total number of pilots; t0, t1, n are all external inputs.

[0087] The flight interruption rate is the sum of the number of pilots whose flight interruption time exceeds 50% of the prescribed time and the number of pilots whose flight interruption time exceeds 100% of the prescribed time to the total number of pilots in the assessment unit. It is expressed as:

[0088]

[0089] In the formula, represents the calculated flight interruption rate, The number of pilots in the assessment unit whose flight interruption time exceeds the prescribed time by 50%-100% during the assessment period t0-t1, The number of pilots in the assessment unit whose flight breaks during the assessment period t0-t1 exceed 100% of the prescribed time. is the total number of pilots in the evaluation unit during the evaluation period t0-t1, and 0.418 and 0.582 are the corresponding weights; All are input from the outside.

[0090] The flight time rate is the weighted sum of the ratio of the number of pilots with less than 500 hours of flight time to the total number of pilots, the ratio of the number of pilots with more than 500 hours but less than 1,000 hours of flight time to the total number of pilots, and the ratio of the number of pilots with more than 1,500 hours of flight time to the total number of pilots. It is expressed as:

[0091]

[0092] In the formula, represents the calculated flight time rate, The number of pilots in the assessment unit whose flight hours are less than 500 hours during the assessment period t0-t1, The number of pilots in the assessment unit whose flight hours are greater than 500 hours and less than 1000 hours during the assessment period t0-t1, The number of pilots in the assessment unit whose flight hours are greater than 500 hours and greater than 1500 hours during the assessment period t0-t1, The total number of pilots in the evaluation unit during the evaluation period t0-t1, 0.533, 0.345 and 0.122 are the corresponding weights; Input from outside.

[0093] The aircraft unavailable rate reflects the unavailable status of the aircraft in the inventory. It is expressed as:

[0094]

[0095] In the formula, is the calculated aircraft non-perfect rate, To evaluate the number of incomplete aircraft in the fleet during the period t0-t1, is the total number of aircraft in the fleet during the evaluation period t0-t1; All are input from the outside.

[0096] The aircraft failure rate reflects the reliability and maintenance quality of the aircraft of the assessment unit. The aircraft failure rate is expressed as:

[0097]

[0098] In the formula, is the total number of aircraft failures during the evaluation period t0-t1, is the flight time of the i-th aircraft in the evaluation period t0-t1, and m is the total number of evaluation periods; m are all input from the outside.

[0099] The aircraft failure air-to-ground ratio reflects the situation of the assessment unit's aircraft failure in the air and on the ground. It is expressed as:

[0100]

[0101] In the formula, is the calculated aircraft failure air-to-ground ratio, To evaluate the number of aircraft failures in the air during the period t0-t1, is the number of aircraft failures on the ground during the evaluation period t0-t1; Input from outside.

[0102] The dangerous weather rate reflects the impact of dangerous weather on flight safety during the assessment period. It is expressed as:

[0103]

[0104] In the formula, is the calculated dangerous weather rate, is the number of dangerous weather events during the evaluation period t0-t1, is the total number of weather events during the evaluation period t0-t1; Input from outside.

[0105] The dangerous weather is judged by meteorological professionals. This application only uses the conclusions given by personnel. For example, if the meteorological personnel's evaluation period is 30 days, the total number of weather days is 30, and the number of days with dangerous weather is the number of dangerous weather days.

[0106] The dangerous bird situation rate reflects the impact of dangerous bird situation on flight safety during the assessment period. It is expressed as:

[0107]

[0108] In the formula, is the number of dangerous bird situations during the evaluation period t0-t1, is the total number of bird sightings during the evaluation period t0-t1; All are input from the outside.

[0109] Dangerous bird conditions are determined by professional bird condition personnel. This application only uses the conclusion data given by professional bird condition personnel. For example, if the evaluation period is 30 days, the total number of weather days is 30, and the number of days with dangerous bird conditions is the number of dangerous bird conditions.

[0110] The flight accident rate per 10,000 hours takes into account the impact of the number of accidents and every 10,000 flight hours. The number of flight accidents is the total number of flight accidents of the evaluation unit during the evaluation period based on the statistics of accident reports, reflecting the overall accident status of the unit. It is expressed as:

[0111]

[0112] In the formula, is the calculated flight accident rate per 10,000 hours, To evaluate whether an accident occurs to aircraft i in the unit during the period t0-t1. If an accident occurs, otherwise q is the flight hours of the evaluation unit in the statistical time period, and q is input from the outside;

[0113] The flight accident incident thousand-hour rate takes into account the impact of both the number of accident incidents and every thousand flight hours. The number of flight accident incidents is the total number of flight accidents of the assessment unit during the assessment period based on the accident report statistics, reflecting the overall accident incident status of the unit. The flight accident incident thousand-hour rate It is expressed as:

[0114]

[0115] In the formula, is the calculated traffic incident rate per thousand hours, To evaluate whether an incident occurs to aircraft i in the unit during the period t0-t1. If an incident occurs, otherwise l is the thousand flight hours of the evaluation unit during the statistical period;

[0116] The flight failure rate per thousand hours takes into account both the number of major failures and the impact of every thousand flight hours. The number of major failures is the total number of major failures related to the flight safety of the unit in a certain period of time based on the statistics of failure reports, reflecting the overall flight safety failure status of the unit. The flight failure rate per thousand hours takes into account both the number of major failures and the impact of every thousand flight hours. It is expressed as:

[0117]

[0118] In the formula, is the calculated flight failure rate per thousand hours, To evaluate whether a major fault occurs to aircraft i in the unit during the period t0-t1. If a major fault occurs, otherwise l is the thousand flight hours of the evaluation unit during the statistical period;

[0119] The major faults are determined by professional maintenance personnel, and this application only uses the conclusion data given by professional maintenance personnel.

[0120] Step 2: Build a flight safety situation assessment model

[0121] The flight safety situation assessment model is constructed by combining the constructed flight safety situation assessment index system and the grey system theoretical method. The quantitative data of the corresponding indicators are collected according to the index system.

[0122] Step 2.1: Read data

[0123] The first step is to read these data and form the initial matrix form for u groups of data sequences of o indicators as follows

[0124]

[0125] Among them, o represents o indicators, and u represents the number of data groups.

[0126] Then determine the reference sequence. The reference sequence is the reference for calculating the correlation degree. The correlation degree is the correlation degree between the pre-calculated data and the reference sequence. The basis for selecting the reference sequence is to see what problem is to be solved. The reference sequence can be a sequence in the data or a sequence that does not exist in the data. The reference sequence is generally the optimal state sequence, that is, the maximum value of each indicator is used as the reference sequence. The reference sequence is recorded as:

[0127] X′0=(x′0(1),x′0(2),…,x′0(u)) T

[0128] Step 2.2: Dimensionless processing

[0129] Dimensionless preprocessing of data

[0130]

[0131] in, x ij are the maximum value, minimum value and actual value of the jth indicator, respectively, and each component of each row vector in the matrix is ​​divided by the corresponding component of the first row vector. The data matrix after the dimensionless method is as follows:

[0132]

[0133] Step 2.3: Calculate the correlation coefficient between each comparison sequence and the corresponding element of the reference sequence

[0134] Calculate the absolute difference between the corresponding elements of each evaluated object indicator sequence (comparison sequence) and the reference sequence one by one:

[0135] |x′0(k)-x i (k)|(k=1,…,u; i=1,…,o)

[0136] k is the indicator index, o is the number of evaluated objects, and the smallest one is found after traversing:

[0137]

[0138] After traversing, find the largest one:

[0139]

[0140] Calculate the correlation coefficient of each comparison sequence and the corresponding element of the reference sequence separately:

[0141]

[0142] Where ρ is the resolution coefficient and its value is 0.5.

[0143] Step 2.4: Calculate the mean correlation coefficient

[0144] The mean of the correlation coefficient between each indicator and the corresponding element of the reference sequence is calculated to reflect the correlation between each evaluation indicator and the reference sequence, which is recorded as:

[0145]

[0146] Step 2.5: Calculate indicator weights

[0147] Normalizing the correlation of each indicator can obtain the weight of the corresponding indicator

[0148]

[0149] Step 2.6: Form an evaluation model

[0150] The flight safety situation assessment model is obtained by weighted summing up the weights of the flight safety situation assessment indicators.

[0151] Step 3: Quantitative assessment of flight safety situation

[0152] Based on the constructed flight safety situation assessment model, with the data corresponding to each indicator as input, the model comprehensively evaluates and outputs the overall flight safety situation quantitative assessment results, thereby realizing the quantitative assessment of the flight safety situation.

Claims

1. A flight safety situation assessment method, characterized in that: The steps include: Step 1: Construct a quantifiable flight safety situation assessment indicator system; Step 2: Construct a flight safety situation assessment model; Step 3: Quantitative assessment of flight safety situation.

2. A flight safety situation assessment method according to claim 1, characterized in that: The step 1 includes the following contents: The data that need to be input or calculated include: flight error or omission rate, flight interruption rate, flight time rate, aircraft defect rate, aircraft failure rate, aircraft failure air-to-ground ratio, flight accident rate per 10,000 hours, flight accident symptom rate per 1,000 hours and flight failure rate per 1,000 hours, a total of 9 dimensions of data.

3. A flight safety situation assessment method according to claim 2, characterized in that: The three standard flight error and omission rate, flight interruption rate and flight time rate are indicators of the personnel safety status of the assessment unit; the aircraft incompleteness rate, aircraft failure rate and aircraft failure air-to-ground ratio are three indicators that characterize the equipment safety status of the assessment unit; the dangerous weather rate and dangerous bird situation rate are two indicators that characterize the environmental safety status of the assessment unit; the flight accident rate per 10,000 hours, the flight accident symptom rate per 1,000 hours and the flight failure rate per 1,000 hours are three indicators that characterize the operational safety status of the assessment unit.

4. A flight safety situation assessment method according to claim 3, characterized in that: The flight error rate includes the total error rate of all pilots in the evaluation unit during the evaluation period, which is used to characterize the error rate of pilots in the evaluation unit. It is expressed as: In the formula, represents the calculated row error rate, To evaluate the number of mistakes and omissions of all pilots during the period t0-t1, is the flight time of the i-th pilot in the evaluation period t0-t1, and n is the total number of pilots; t0, t1, n are all external inputs. The flight interruption rate is the sum of the number of pilots whose flight interruption time exceeds 50% of the prescribed time and the number of pilots whose flight interruption time exceeds 100% of the prescribed time to the total number of pilots in the assessment unit. It is expressed as: In the formula, represents the calculated flight interruption rate, The number of pilots in the assessment unit whose flight interruption time exceeds the prescribed time by 50%-100% during the assessment period t0-t1, The number of pilots in the assessment unit whose flight breaks during the assessment period t0-t1 exceed 100% of the prescribed time. is the total number of pilots in the evaluation unit during the evaluation period t0-t1, and 0.418 and 0.582 are the corresponding weights; All are input from outside. The flight time rate is the weighted sum of the ratio of the number of pilots with less than 500 hours of flight time to the total number of pilots, the ratio of the number of pilots with more than 500 hours but less than 1,000 hours of flight time to the total number of pilots, and the ratio of the number of pilots with more than 1,500 hours of flight time to the total number of pilots. It is expressed as: In the formula, represents the calculated flight time rate, The number of pilots in the assessment unit whose flight hours are less than 500 hours during the assessment period t0-t1, The number of pilots in the assessment unit whose flight hours are greater than 500 hours and less than 1000 hours during the assessment period t0-t1, The number of pilots in the assessment unit whose flight hours are greater than 500 hours and greater than 1500 hours during the assessment period t0-t1, The total number of pilots in the evaluation unit during the evaluation period t0-t1, 0.533, 0.345 and 0.122 are the corresponding weights; From external input, The aircraft unavailable rate reflects the unavailable status of the aircraft in the inventory. It is expressed as: In the formula, is the calculated aircraft non-perfect rate, To evaluate the number of incomplete aircraft in the fleet during the period t0-t1, is the total number of aircraft in the fleet during the evaluation period t0-t1; All are input from outside. The aircraft failure rate reflects the reliability and maintenance quality of the aircraft of the assessment unit. The aircraft failure rate is expressed as: In the formula, is the total number of aircraft failures during the evaluation period t0-t1, is the flight time of the i-th aircraft in the evaluation period t0-t1, and m is the total number of evaluation periods; m are input from the outside, The aircraft failure air-to-ground ratio reflects the situation of the assessment unit's aircraft failure in the air and on the ground. It is expressed as: In the formula, is the calculated aircraft failure air-to-ground ratio, To evaluate the number of aircraft failures in the air during the period t0-t1, is the number of aircraft failures on the ground during the evaluation period t0-t1; From external input, The dangerous weather rate reflects the impact of dangerous weather on flight safety during the assessment period. It is expressed as: In the formula, is the calculated dangerous weather rate, is the number of dangerous weather events during the evaluation period t0-t1, is the total number of weather events during the evaluation period t0-t1; From external input, The dangerous bird situation rate reflects the impact of dangerous bird situation on flight safety during the assessment period. It is expressed as: In the formula, is the number of dangerous bird situations during the evaluation period t0-t1, is the total number of bird sightings during the evaluation period t0-t1; All are input from outside. The flight accident rate per 10,000 hours takes into account the impact of the number of accidents and every 10,000 flight hours. The number of flight accidents is the total number of flight accidents of the evaluation unit during the evaluation period based on the statistics of accident reports, reflecting the overall accident status of the unit. It is expressed as: In the formula, is the calculated flight accident rate per 10,000 hours, To evaluate whether an accident occurs to aircraft i in the unit during the period t0-t1. If an accident occurs, otherwise q is the flight hours of the evaluation unit in the statistical time period, and q is input from the outside; The flight accident incident thousand-hour rate takes into account the impact of both the number of accident incidents and every thousand flight hours. The number of flight accident incidents is the total number of flight accidents of the assessment unit during the assessment period based on the accident report statistics, reflecting the overall accident incident status of the unit. The flight accident incident thousand-hour rate It is expressed as: In the formula, is the calculated traffic incident rate per thousand hours, To evaluate whether an incident occurs to aircraft i in the unit during the period t0-t1. If an incident occurs, otherwise l is the thousand flight hours of the evaluation unit during the statistical period; The flight failure rate per thousand hours takes into account both the number of major failures and the impact of every thousand flight hours. The number of major failures is the total number of major failures related to the flight safety of the unit in a certain period of time based on the statistics of failure reports, reflecting the overall flight safety failure status of the unit. The flight failure rate per thousand hours takes into account both the number of major failures and the impact of every thousand flight hours. It is expressed as: In the formula, is the calculated flight failure rate per thousand hours, To evaluate whether a major fault occurs to aircraft i in the unit during the period t0-t1. If a major fault occurs, otherwise l is the thousand flight hours of the evaluation unit during the statistical period.

5. A flight safety situation assessment method according to claim 4, characterized in that: The step 2 includes the following contents: constructing a flight safety situation assessment model in combination with the constructed flight safety situation assessment index system and the grey system theoretical method, and collecting quantitative data of corresponding indicators according to the index system.

6. A flight safety situation assessment method according to claim 5, characterized in that: The step 2 specifically includes the following contents: Step 2.1: Read data The first step is to read these data and form the initial matrix form for u groups of data sequences of o indicators as follows Among them, o represents o indicators, and u represents the number of data groups. Then determine the reference sequence. The reference sequence is the reference for calculating the correlation degree. The correlation degree is the correlation degree between the pre-calculated data and the reference sequence. The basis for selecting the reference sequence is to see what problem is to be solved. The reference sequence can be a sequence in the data or a sequence that does not exist in the data. The reference sequence is generally the optimal state sequence, that is, the maximum value of each indicator is used as the reference sequence. The reference sequence is recorded as: X′0=(x′0(1),x′0(2),…,x′0(u)) T Step 2.2: Dimensionless processing Dimensionless preprocessing of data in, x ij are the maximum value, minimum value and i-th actual value of the j-th indicator respectively, and each component of each row vector in the matrix is ​​divided by the corresponding component of the first row vector. The data matrix after the dimensionless method is as follows: Step 2.3: Calculate the correlation coefficient between each comparison sequence and the corresponding element of the reference sequence Calculate the absolute difference between the corresponding elements of each evaluated object indicator sequence (comparison sequence) and the reference sequence one by one: |x′0(k)-x i (k)|(k=1,…,u;i=1,…,o) k is the indicator index, o is the number of evaluated objects, and the smallest one is found after traversing: After traversing, find the largest one: Calculate the correlation coefficient of each comparison sequence and the corresponding element of the reference sequence separately: Where ρ is the resolution coefficient and takes the value as 0.

5. Step 2.4: Calculate the mean correlation coefficient The mean of the correlation coefficient between each indicator and the corresponding element of the reference sequence is calculated to reflect the correlation between each evaluation indicator and the reference sequence, which is recorded as: Step 2.5: Calculate indicator weights Normalizing the correlation of each indicator can get the weight of the corresponding indicator Step 2.6: Form an evaluation model The flight safety situation assessment model is obtained by weighted summing up the weights of the flight safety situation assessment indicators.

7. A flight safety situation assessment method according to claim 6, characterized in that: The step three includes the following contents: Based on the constructed flight safety situation assessment model, with the data corresponding to each indicator as input, the model comprehensively evaluates and outputs the overall flight safety situation quantitative assessment results, thereby realizing the quantitative assessment of the flight safety situation.

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