Assessment On The Collision Risk Of Closely Spaced Parallel Runways Paired Approach

With the continuous growth of Chinese aviation passenger traffic volume,the flow of airports is increasing,and the capacity of airports is becoming saturated.In the current situation of limited land resources,the airport achieves the purpose of increasing airport capacity by building closed spaced parallel runways.However,the current operation mode of closely spaced parallel runways in China can’t effectively increase the airport capacity.The implementation of closed spaced parallel runways paired approach can further improve the airport landing capacity.Compared with the traditional approach,the distance between the front and rear aircrafts of the new approach way is very small,and the possibility of the rear aircraft encountering the tail flow of the front aircraft is also increased.In order to study the collision risk of the closely spaced parallel runways paired approach,firstly,based on the QAR(Quick Access Recorder)data,the movement mode of the aircrafts in the last stage of the traditional approach is analyzed,and based on this,the paired approach procedure of the closely spaced parallel runways is established,thus the kinematic model and theoretical interval model of the pairing aircraft are established.Through the analysis of QAR data,the appropriate initial velocity,acceleration,approach time and other parameters are selected to calculate the trend of the theoretical interval over time.Then,in order to analyze the position error of the front and rear aircrafts in the paired approach and get the actual spacing distribution of the front and rear aircrafts,the course error,glide path error and acceleration error of the aircraft in the approach stage are analyzed based on the QAR data,and the probability distribution is obtained.Secondly,compared with the traditional concept of paired approach in which the rear aircraft completely avoids the wake of the front aircraft,this paper considers that the rear aircraft can bear a certain strength of the wake of the front aircraft.The response mechanism of aircraft after encountering wake in different driving modes is analyzed.The attenuation model of wake intensity is simulated by large eddy simulation,and the induced velocity calculation model and vortex core motion model are established based on the classic Hallock Burnham vortex model.Based on the maximum roll angle is equal to the critical roll angle when the rear engine encounters the wake,thelongitudinal,lateral and vertical wake safety interval calculation models under different driving modes are established.The influence of crosswind,initial longitudinal interval,runway interval and other factors on wake safety interval and the influence of different driving modes on wake safety interval are analyzed.Finally,based on the probability theory,combined with the wake safety interval calculation model and the actual interval distribution of paired aircraft pairs,the longitudinal,lateral and vertical collision risk calculation models under different driving modes are established,and the effects of crosswind,initial longitudinal distance,runway distance and other factors on the collision risk of pairing approach are analyzed,as well as the changes of collision risk with time and the effects of different driving modes on collision risk.