Research on the influence of airspace key fix point adjusting on air traffic flow in terminal area

In order to optimize airspace structure and improve its operational efficiency, a motion model for aircrafts departure and arrival and an airspace structure network model are presented based on the generalized following theory and basic operation rules in terminal area. The airspace structure is changed by adjusting the coordinate of Holding Fix point and the influence of airspace structure adjusting on air traffic flow is analyzed by simulation. The simulation results show that the traffic flow is quite sensitive to coordinate adjusting of Holding Fix point. There is an obvious quadratic non-linear relationship between the airplane delay and length of Holding Fix point and downstream convergent point. With this length increased, it is found that the air traffic flows more slowly and the air traffic density increases more rapidly. In addition, the increase of the length would turn the air traffic into congested status more rapidly and make the congestion dissipate more tardily.