여수공항의 윈드시어 발생 특성 연구

Abstract

Lately, the air traffic of Korea has been steadily increasing. Especially improving the level of the national economy with aviation and tourism, leisure activities and population, light aircraft flying at a low altitude demand has been noticeably increasing, accordingly importance about safe operation of aircraft is required urgently. According statistics from the U.S. Federal Aviation Administration, aviation accident investigation, ratio of approximately 21% of aircraft accidents is weather, specifically the ratio of approximately 60% of cross wind, tailwind, wind shear, turbulence, etc is wind(a large proportion). And aircraft accident is very high ratio about landing(31%), take-off(19%), landing approach(11%). Similarly in the case of the Yeosu Airport, according to statistics over the past five years, ratio of 31% of aircraft operated abnormal factors is weather and specifically, the ratio of 37%, 34.2%, 10.4%, 9.8% is strong wind, low visibility, snowfall, sea breeze. Through the above statistics, we know that ratio of cancellations about wind is very high. Especially, Yeosu Airport is located in the boundaries of the land and the sea, as a result wind is strong, nature of geographical conditions caused by wind shear, because around the runway is formed by mountains, foothills about 1,000ft altitude but wind shear has difficult to define to occurrence mechanism because it occurs very locally and has very short duration of occurrence. Thus, the aircraft has constraints take-off & landing and potential risk of an aircraft accident is higher. So, Yeosu Airport had installed wind profiler in runway for take-off and landing ground near in August 2007 and has been providing wind shear information less than the hight of 2,000ft. We were analyzed typical types of wind shear occurrence & cause and characteristics of wind shear through wind shear data from wind profiler observations, various numerical weather chart, analysis weather chart. And we were analyzed statistical probability about wind shear mechanism of occurrence, wind shear observations each season, pressure patterns and presence of strong winds in Yeosu Airport. Also, not only characteristics of wind shear occurrence at both ends of runway but also frequency of occurrence of wind shear difference about Ulsan airport, Gimhae Airport which has been operating same equipment(wind profiler) had been analyzed. The results of the study are as follows. (1) Frequency of occurrence of wind shear each airport is 2.54times(Ulsan Airport) and 1.08times(Gimhae Airport). (2) Frequency of occurrence of wind shear each season, month is concentrated in the winter and spring. Especially, the distribution of occurrence of wind shear is high(March, January). (3) Frequency of occurrence of wind shear each pressure patterns is most frequent in Anticyclone Border(256days/37.7%) but, occurrence of probability is the highest in cP expansion(85.7%) except the typhoon(100%). (4) Frequency of occurrence of wind shear each runway is 2.1times more R35 than R17. R35 occurs more frequently than R17 all of pressure patterns. (5) Representative types of occurrence of wind shear is cP expansion, cyclone(Rain) (6) In Yeosu Airprot the main factors causing wind shear is strong wind, terrain effects and in order to forecast wind shear, we should consider formation & enforcement of 850hPa trough, blocking of anticyclone in East-sea, penetration of see breeze, frontogenesis(whether precipitation), north-south oscillation of stationary front, cold-advection and so on. (7) When strong wind occurs(10 minute average wind speed is more than 20 kts), probability of occurrence of wind shear is 93%. when wind speed is observed more than standard of strong wind warning(10 minute average wind speed is more than 25 kts), probability of occurrence of wind shear is 100%. But, just wind shear occurrence doesn't reach standard of strong wind warning. As a result, first we analysis pressure patterns and then consider probability of statics. In sequence weatherman discern comprehensive occurrence of wind shear or not by applying each pressure patterns about major weather forecasting factors in Yeosu Airport. If weatherman progress above procedure, wind shear probability of occurrence may be more efficient. I hope this study helps safe operation of aircraft in Yeosu Airport.