Research on safety assessment methods based on tasks for aircraft takeoff pitch attitude

During the aircraft's takeoff process, the pitch attitude is the key factor determining takeoff safety. It is crucial to objectively and accurately evaluate the safety level of the aircraft's takeoff pitch attitude. This study quantitatively evaluates the safety level associated with aircraft takeoff pitch attitude. Firstly, based on the task-oriented system safety assessment theory, a safety assessment mathematical model for aircraft takeoff pitch attitude is constructed using key parameters such as the pitch angle and its changing rate in Quick Access Recorder (QAR) data. Secondly, the model was quantified using Flight Operational Quality Assurance (FOQA) and industry-wide attitude data of the A319 fleet in 2023. Then, the model's effectiveness was verified by comparing the evaluation results with actual flight exceedance situations, using QAR data from a Chinese airline's A319 fleet. Finally, an in-depth analysis was conducted on the correlation between the pitch attitude at the moment of the main wheels off the ground and the process of lifting the nose wheel, identifying the key moments in the formation of the takeoff pitch attitude. By conducting sensitivity analysis on the safety level of takeoff pitch attitude and the rate at which the nose wheel is lifted, the study proposes suggestions for the optimal range of nose wheel lifting rates for the aircraft. The research has ultimately developed a quantitative evaluation method and formation law for aircraft takeoff pitch attitude, offering new insights and ideas for QAR data-driven flight safety risk management.