# Causation Correlation Analysis of Aviation Accidents: A Knowledge Graph-Based Approach
## 4 Discussion  
### Identifying Key Risks  
Based on the correlation analysis between the direct and indirect severity of accident consequences caused by causal factors shown in Figure 9, it is possible to identify the causal factors that have a greater impact on the severity of accident consequences and their corresponding numerical values. By systematically controlling factors that have a significant influence during different flight phases, it is possible to effectively reduce the severity and impact of accident consequences, thereby enhancing the safety of the aircraft and onboard personnel. According to Equations (16) and (17), the causal factors are ranked in descending order based on their impact on the severity of accident consequences, and causative elimination is carried out. The resulting curves illustrating the impact of mitigating causal factors on the severity of accident consequences at different phases are shown in Figure 10.  
We eliminate causal factors in descending order of the severity of their impact on the consequences of the accident. If two causal factors are of equal severity, the causal factors are eliminated first in the order of types H, A, E, and M and then in increasing order of number. In Figure 10, the successive elimination of 31 causal factors significantly reduces the severity of indirect accident consequences. The most notable effects in reducing the harm caused by aviation accidents are observed by eliminating causal factors during the take-off/landing and level flight phases. When four main causal factors (H7, A5, E1, and M1) are eliminated, the severity index of direct accident consequences is reduced to 76.5% in the ground phase, and the severity index of direct accident consequences is reduced to 81.9% in the take-off/landing and level flight phases. When three main causal factors (H7, E1, and M1) are eliminated, the severity index of direct accident consequences is reduced to 79.2% in the maneuvering phase. When four causal factors (H10-H12 and A2) are eliminated, the severity index of indirect accident consequences is reduced to 60.4% in the ground phase. When four causal factors (H1 and H4-H6) are eliminated, the severity index of indirect accident consequences is reduced to 59.9% in the take-off/landing and level flight phases. When four causal factors (H8, H12, A3, and A4) are eliminated, the severity index of indirect accident consequences is reduced to 69% in the maneuvering phase. During the ground phase, when 15 causal factors (H1, H2, H4-H9, H13, A1, A2-A4, E1, and M1) are eliminated, the severity index of direct accident consequences is reduced by 80%; when 10 causal factors (H1, H4-H6, H8, H10-H13, and A2) are eliminated, the severity index of indirect accident consequences is reduced by 80%. During the take-off/landing and level flight phases, when 20 causal factors (H1, H2, H4-H11, H13, A1-A5, and E1-E4) are eliminated, the severity index of direct accident consequences is reduced by 80%; when 10 causal factors (H1, H4-H6, H8, H10-H13, and A1) are eliminated, the severity index of indirect accident consequences is reduced by 80%. In the maneuvering phase, when 16 causal factors (H1, H2, H4-H7, H9-H11, H13, A1-A2, E1, E3, and M1-M2) are eliminated, the severity index of direct accident consequences is reduced by 80%;  
Figure 10: The impact curves of mitigating causal factors at different phases on the severity of accident consequences. (**a**) Direct impact. (**b**) Indirect impact. when 10 causal factors (H1, H4-H6, H8, H10-H12, and A3-A4) are eliminated, the indirect severity index of accident consequences is reduced by 80%. Overall, eliminating the indirect causal factors that affect accident consequences, as opposed to direct causal factors, is more effective in reducing the probability of accidents and their severity. Focusing on the key identified factors is beneficial for efficiently reducing the likelihood of accidents.