Separation determining method of closely spaced parallel runways

By using wake vortex movement characteristics under the most adverse environment, the effects of the slant range and approach glide angles of paired aircrafts and aircraft type combination on runway separation under the dependent parallel approach mode of closely spaced parallel runways were researched, the minimum wake vortex separation standard and crosswind statistical data of NASA were used, and the determination methods of runway centerline distance and threshold offset were put out based on aircraft type parameters. Analysis result shows that when the slant separation standard of paired leading and trailing aircrafts is a certain value, threshold offset decreases with the increases of runway centerline distance and the glide angle of paired trailing aircraft. When the glide angles of paired leading and trailing aircrafts are same, threshold offset decreases with the increases of runway centerline distance and slant separation standard. When runway centerline distance is 380 m, the glide angles of paired leading and trailing aircrafts are both 3°, and slant separation standard is 2 780 m, the threshold offset of Changsha Huanghua International Airport should be more than 1 483 m, which is accord with the runway parameter of foreign authorized airports.