Based on the data of quick access record(QAR),a mathematical model was formulated to find the high risk subspace',which has high probability for a special QAR exceedance in landing stage,in the space' consisted of the flight operation indexes,such as decline rate,aircraft pitch,etc.Focusing on this QAR exceedance,data of above mentioned indexes at 20 feet radio altitude and their change ratios from 20 feet to 0 feet were considered in the method.Preliminary analysis shows that the QAR exceedance samples and...