Safety evaluation of aircraft pneumatic de-icing system and its improvement method

Abstract

The application belongs to the technical field of aircraft airbag deicing system design, and particularly relates to a safety evaluation and improvement method of an aircraft airbag deicing system, which comprises the following steps: step one, performing function hazard analysis on the failure state of the airbag deicing system to determine the hazard level; step two, formulating an emergency operation for the airbag deicing system failure state with an intermediate hazard level; step three, analyzing the hazard degree of the airbag deicing system failure state with an intermediate hazard level according to the formulated emergency operation, and re-determining the hazard level of the airbag deicing system failure state; and step four, performing safety evaluation on the airbag deicing system, and improving the airbag deicing system according to the evaluation result.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft airbag deicing system design, and specifically relates to a safety assessment and improvement method of an aircraft airbag deicing system. Background Art

[0002] When an aircraft flies in clouds containing supercooled water droplets, many parts will be frozen, which will deteriorate the aircraft's lift and drag characteristics and reduce the aircraft's flight safety. For this purpose, an airbag de-icing system is designed.

[0003] The aircraft airbag de-icing system is a mechanical de-icing system that arranges inflatable airbags in the anti-icing area of ​​the aircraft. When ice forms, the airbags are periodically inflated to break the ice layer, and the airflow is used to blow away the broken ice, thereby achieving de-icing of the anti-icing area.

[0004] Aircraft airbag de-icing systems need to consider various unsafe factors at the initial design stage, conduct safety assessments, and improve the design of the airbag de-icing system to ensure aircraft flight safety. However, currently, when conducting safety assessments on airbag de-icing systems, only the impact of failure of the airbag de-icing system itself is considered, and there is a lack of consideration of operational aspects when the airbag de-icing system fails. The results of the safety assessment are quite different from the actual degree of harm, and cannot effectively guide the improvement of the airbag de-icing system and obtain a reasonable and appropriate airbag de-icing system design plan.

[0005] This application is proposed in view of the above-mentioned technical defects. Summary of the Invention

[0006] The purpose of this application is to provide an aircraft airbag de-icing system safety assessment and improvement method thereof, so as to overcome or alleviate at least one of the known technical deficiencies.

[0007] The technical solution of this application is:

[0008] A safety assessment and improvement method for an aircraft airbag de-icing system, comprising:

[0009] Step 1: Conduct a functional hazard analysis of the airbag de-icing system failure state to determine the hazard level;

[0010] Step 2: Develop emergency response procedures for airbag de-icing system failures with an intermediate hazard level.

[0011] Step 3: Analyze the degree of harm caused by the airbag de-icing system failure state at an intermediate hazard level according to the established emergency operations, and redetermine the hazard level of the airbag de-icing system failure state;

[0012] Step 4: Conduct a safety assessment of the airbag de-icing system and improve the airbag de-icing system based on the assessment results.

[0013] According to at least one embodiment of the present application, in the above-mentioned aircraft airbag de-icing system safety assessment and improvement method, in step four, if the hazard level of the airbag de-icing system failure state does not reach the intermediate or higher hazard level, there is no need to improve the airbag de-icing system.

[0014] According to at least one embodiment of the present application, in the above-mentioned aircraft airbag de-icing system safety assessment and improvement method, in step four, if the hazard level of the airbag de-icing system failure state is intermediate or above, a Markov model is constructed to calculate the probability of occurrence of airbag de-icing system failure states of intermediate and above hazard levels. If the probability is less than the safety-allowed probability, there is no need to improve the airbag de-icing system. If the probability is greater than the safety-allowed probability, the airbag de-icing system needs to be improved, and steps one to four are repeated.

[0015] According to at least one embodiment of the present application, in the above-mentioned aircraft airbag de-icing system safety assessment and improvement method, step 4: if the hazard level of the airbag de-icing system failure state is intermediate or above, a Markov model is constructed to calculate the probability of occurrence of an airbag de-icing system failure state of intermediate or above hazard level, specifically:

[0016] Define the state before the occurrence of an intermediate or higher hazard level failure state of the airbag de-icing system;

[0017] Determine the state before the airbag de-icing system fails at an intermediate or higher hazard level, and the transition relationship between the state and the failure state of the airbag de-icing system at an intermediate or higher hazard level, and draw a state transition diagram;

[0018] Assign the state before the failure state of the airbag de-icing system with intermediate or higher hazard level occurs, the probability of transition to the failure state of the airbag de-icing system with intermediate or higher hazard level occurs, list the relevant differential equations, and calculate the probability of the failure state of the airbag de-icing system with intermediate or higher hazard level occurs.

[0019] According to at least one embodiment of the present application, in the above-mentioned aircraft airbag de-icing system safety assessment and improvement method, improving the airbag de-icing system specifically includes improving the logical architecture of the airbag de-icing system or adding a protective design.

[0020] According to at least one embodiment of the present application, in the above-mentioned aircraft airbag de-icing system safety assessment and improvement method, the hazard level of the airbag de-icing system failure state is divided with reference to SAE 4761, and is divided into I, II, III, IV, and V from high to low.

[0021] This application has at least the following beneficial technical effects:

[0022] Provided is a safety assessment method for an aircraft airbag de-icing system and an improvement method thereof. When conducting a safety assessment of an aircraft airbag de-icing system, consideration is given to mitigating the hazard level of an airbag de-icing system failure state of an intermediate hazard level according to established emergency operations, and the hazard level of the airbag de-icing system failure state is re-determined. The result of the safety assessment differs significantly from the actual hazard level, and can effectively guide improvements to the airbag de-icing system, thereby obtaining a reasonable and appropriate airbag de-icing system design scheme. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the safety assessment and improvement method of the aircraft airbag de-icing system provided in the embodiment of the present application. DETAILED DESCRIPTION

[0024] To make the technical solution and its advantages of this application more clear, the technical solution of this application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described here are only some of the embodiments of this application and are only used to explain this application, not to limit this application. It should be noted that for ease of description, only the parts relevant to this application are shown in the accompanying drawings, and other relevant parts can refer to the general design.

[0025] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application should have the common meanings understood by those skilled in the art in the art to which this application belongs.

[0026] A safety assessment and improvement method for aircraft airbag de-icing system, such as Figure 1 As shown, the following steps are included.

[0027] Step 1: Conduct a functional hazard analysis of the airbag de-icing system failure state to determine the hazard level.

[0028] Through the analysis of mission scenarios, the impact of the airbag de-icing system failure state on the crew, personnel and mission is analyzed, and the hazard level of the airbag de-icing system failure state is determined.

[0029] The hazard level of the airbag de-icing system failure state can be divided with reference to SAE 4761, and can be divided into I, II, III, IV, and V from high to low. Among them, hazard level I is that the aircraft is seriously damaged, the aircraft is destroyed, and it cannot continue to perform the mission, and the safety of the crew and personnel is seriously threatened; hazard level II is that the aircraft is seriously damaged, greatly reducing the aircraft's functions and safety margins, but being able to continue to perform the mission, and the safety of the crew and personnel is threatened to a large extent; hazard level III is that the aircraft is damaged, significantly reducing the aircraft's functions and safety margins, but being able to continue to perform the mission, and the safety of the crew and personnel is threatened to a certain extent; hazard level IV is that the aircraft is damaged, slightly reducing the aircraft's functions and safety margins, being able to continue to perform the mission, and the crew and personnel are slightly threatened; hazard level V is that the aircraft malfunctions, with almost no impact on the aircraft's operation and safety, being able to continue to perform the mission, and the safety of the crew and personnel is not threatened.

[0030] In the event of an airbag de-icing system failure at hazard level I, the aircraft is severely damaged and no operational mitigation is possible. In the event of an airbag de-icing system failure at hazard levels II, III, and IV, the degree of damage can be mitigated or even eliminated through operation. In the event of an airbag de-icing system failure at hazard level V, the aircraft operation and safety are hardly affected and the mission can continue to be performed. The safety of the crew and personnel is not threatened and no operational mitigation is required.

[0031] Step 2: Develop emergency response procedures for airbag de-icing system failure conditions with an intermediate hazard level.

[0032] Emergency operations can be formulated for air bag de-icing system failure states with hazard levels II, III, and IV, that is, air bag de-icing system failure states with intermediate hazard levels. When the air bag de-icing system fails in states with hazard levels II, III, and IV, the formulated emergency operations shall be followed to alleviate the degree of hazard, reduce the hazard level, or eliminate the hazard.

[0033] Step 3: Analyze the hazard level of the airbag de-icing system failure state at the intermediate hazard level according to the established emergency operations, and redetermine the hazard level of the airbag de-icing system failure state.

[0034] When an airbag de-icing system failure state with an intermediate hazard level occurs, operations shall be performed in accordance with the established emergency operations. In the mission scenario, operational errors such as insufficient operational level, operational errors, incorrect operations and omissions may occur. When analyzing the hazard level, it is necessary to consider the impact of operational errors on the crew, personnel and mission, and redetermine the hazard level of this type of airbag de-icing system failure state.

[0035] Step 4: Conduct a safety assessment of the airbag de-icing system and improve the airbag de-icing system based on the assessment results.

[0036] If the hazard level of the airbag de-icing system failure state does not reach the intermediate or higher hazard levels (I, II, III, IV), there is no need to improve the airbag de-icing system.

[0037] If the hazard level of the airbag de-icing system failure state is intermediate or above, a Markov model is constructed to calculate the probability of an airbag de-icing system failure state of intermediate or above hazard level. If the probability is less than the safety-allowed probability, there is no need to improve the airbag de-icing system. If the probability is greater than the safety-allowed probability, the airbag de-icing system needs to be improved, and steps 1 to 4 are repeated.

[0038] A Markov model was constructed to calculate the probability of airbag de-icing system failure at intermediate and higher hazard levels, specifically:

[0039] Define the state before the occurrence of an intermediate or higher hazard level failure state of the airbag de-icing system;

[0040] Determine the state before the airbag de-icing system fails at an intermediate or higher hazard level, and the transition relationship between the state and the failure state of the airbag de-icing system at an intermediate or higher hazard level, and draw a state transition diagram;

[0041] Assign the state before the failure state of the airbag de-icing system with intermediate or higher hazard level occurs, the probability of transition to the failure state of the airbag de-icing system with intermediate or higher hazard level occurs, list the relevant differential equations, and calculate the probability of the failure state of the airbag de-icing system with intermediate or higher hazard level occurs.

[0042] Improvements to the airbag de-icing system may specifically include improving the logical architecture of the airbag de-icing system or adding protective designs.

[0043] In the aircraft airbag de-icing system safety assessment and improvement method disclosed in the above-mentioned embodiment, when conducting a safety assessment of the aircraft airbag de-icing system, consideration is given to mitigating the hazard level of an airbag de-icing system failure state of an intermediate hazard level according to established emergency operations, and the hazard level of the airbag de-icing system failure state is re-determined. The result of the safety assessment differs significantly from the actual hazard level, which can effectively guide the improvement of the airbag de-icing system and obtain a reasonable and appropriate airbag de-icing system design scheme.

[0044] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or replacements to the relevant technical features, and the technical solutions after these changes or replacements will fall within the scope of protection of the present application.

Claims

1. A safety assessment and improvement method for an aircraft airbag de-icing system, characterized in that: include: Step 1: Conduct a functional hazard analysis of the airbag de-icing system failure state to determine the hazard level; Step 2: Develop emergency response procedures for airbag de-icing system failures with an intermediate hazard level. Step 3: Analyze the degree of harm caused by the airbag de-icing system failure state at an intermediate hazard level according to the established emergency operations, and redetermine the hazard level of the airbag de-icing system failure state; Step 4: Conduct a safety assessment of the airbag de-icing system and improve the airbag de-icing system based on the assessment results; In step 4, if the hazard level of the airbag de-icing system failure state does not reach the intermediate or higher hazard level, then there is no need to improve the airbag de-icing system; In step 4, if the hazard level of the airbag de-icing system failure state is intermediate or higher, a Markov model is constructed to calculate the probability of the airbag de-icing system failure state of intermediate or higher hazard levels occurring, specifically: Define the state before the occurrence of an intermediate or higher hazard level failure state of the airbag de-icing system; Determine the state before the airbag de-icing system fails at an intermediate or higher hazard level, and the transition relationship between the state and the failure state of the airbag de-icing system at an intermediate or higher hazard level, and draw a state transition diagram; Assign the state before the occurrence of the intermediate and higher hazard level airbag de-icing system failure state, the probability of transition to the intermediate and higher hazard level airbag de-icing system failure state, list the relevant differential equations, and calculate the probability of the occurrence of the intermediate and higher hazard level airbag de-icing system failure state; In step 4, if the calculated probability of the airbag de-icing system failure state of intermediate or higher hazard levels is less than the safety-allowed probability, then there is no need to improve the airbag de-icing system; In step 4, if the calculated probability of an airbag de-icing system failure state of intermediate or higher hazard levels is greater than the safety-allowed probability, the airbag de-icing system needs to be improved and steps 1 to 4 must be repeated.

2. The aircraft airbag de-icing system safety assessment and improvement method according to claim 1, characterized in that: In step 4, after determining the state before the failure state of the airbag de-icing system with intermediate or higher hazard levels occurs and the transition relationship between the state and the failure state of the airbag de-icing system with intermediate or higher hazard levels, a state transition diagram is drawn.

3. The aircraft airbag de-icing system safety assessment and improvement method according to claim 1, characterized in that: Improving the airbag deicing system specifically involves improving the logical architecture of the airbag deicing system.

4. The aircraft airbag de-icing system safety assessment and improvement method according to claim 1, characterized in that: The improvement of the airbag de-icing system is specifically designed to increase protection.

5. The aircraft airbag de-icing system safety assessment and improvement method according to claim 1, characterized in that: The hazard level of the airbag de-icing system failure state is divided according to SAE 4761, from high to low into Ⅰ, Ⅱ, Ⅲ, Ⅳ, and Ⅴ.

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