Statistical Analysis on the Low Level Windshear and Its Impacts on the Flight Safety at Nyingchi Airport

To better understand the Low level vertical windshear’s impacts on the civil aviation safety，a statistical analysis is applied on the Low level windshearanditsimpacts on the flight safety at Nyingchi airport，based on the wind observation．Highly frequentwindshearis recognized as a significant fact threatening the flight safety at this airport．The annualfrequency is 1.1% ，for the strong intensitytailwindshear，0.3% for the severe intensity tail windshear，and the maximum tailwindshear10.1m/s/30m; the annual frequency is 2.2%for thestrongintensitycrosswind shear，0.6%for the severe crosswind shear，and the maximum crosswind shear 22.2 ms^－1．The high frequency and intensity of strong windshear mainly occur in the afternoon of all season，and relatively low frequency and intensity occur in August．