In order to assess the level of flight security threats as well as analyze and predict their developmental trend, an

assessment model of flight security threat posture based on set-pair analysis (SPA) and Markov chains was proposed. Firstly, evaluation index system of the flight security threat posture was constructed based on the occurrence posture of various types of in-flight cases (incidents), and the combined weights of the indicators were determined by integrating the calculation results of the gray correlation coefficient method and the entropy weighting method. Subsequently, by integrating the ternary connection number structure in the SPA theory and the civil

aviation risk classification standards, the level of flight security threat was classified into three levels. By calculating the connection degree, the flight security threat level and the development trend were determined, and by

combining it with the Markov state transition probability matrix, the future level of flight security threat was dynamically predicted. Finally, the proposed model was validated using 2021 in-flight cases (incidents) data. The

results indicated that the model can reflect the status of flight security threat.

flight security, posture assessment, set-pair analysis, Markov chain