呂維峰

Abstract：Complex weather conditions is meaning thunderstorm freezing turbulence wind-shear low visibility weather affect the flight safety. When confronted with complex weather conditions，the controllers should know the weather condition and trend weather，and notify the aircraft under your control zone.The controllers provide the required services to the pilots，help the pilots to avoid the complex weather.In this paper， through different complex weathers under different control command，get the different methods of control.

Keyword：complex weather；low visibility；air traffic control

1 Introduction of Suining airport

Suining airport is located in the southern suburbs of Suining City， the runway 1200 meters long and 30 meters wide，conclude one parallel taxiway and four contact channels， it belongs to the general training 2C runway. Two aprons lie in sides of the tower，they can park close to 30 planes. The airport can accomplish about 400 flights everyday when the weather is CAVOK.There are multiple complex weathers in this area，such as low temperature、low clouds、low visibility and so on.The obstacles are some small factories， a few hills and farmlands.The clearance of airport is good.The navigation equipment of airport contain out marker、inner marker and VOR/DME beacon. The surveillance system is ADS-B which common in the European and American countries.Because of the length of airport，there is no any aviation flights.All activities are training flight.

2 Several common complex weather conditions in Suining airport

As we all know，multiple factors will affect the weather.At Suining airport，the dangerous seasons are summer and winter. Low level wind-shear is the most terrible weather during summer.It is very dangerous and may cause accident or incident in this season.The obvious weather features is low visibility、low temperature、low clouds and foggy day in winter.Since there is no ILS system in Suining airport，the standard qualification of takeoff and landing is very high.Minimum standards require visibility is not less than 1600m during departure and takeoff.In this season，the area will suffer low temperature and low clouds，the plane will be wrapped in ice owing to there is no anti-icing system.Low clouds over the airport also makes it more difficult to fly.

3 Traffic control measures

To some extent， the controller is the eye of pilots，when the planes encounter wind-shear during flight，the controllers need to do the following guidelines.First controllers should record the position、degree and other relevant information when the plane encounter wind-shear.Second the controllers should be informed of the aircraft may be affected the information of wind-shear.Third the best way to forecast wind-shear is install the automatic terminal information system，by the way of broadcasting every plane will receive the wind-shear information，it is useful to help the pilot make decision to wait or alternate.To some extent the alternate is one of the most effective way to protect flight safety. Because of the large temperature difference，low-level wind-shear is very common in Suining airport.Therefore， when the controllers encounter such a situation， we must attract enough attention.

The most obvious feature weather of Suining airport in winter is“Three lows over one”.It means low temperature、low clouds、low visibility and always fog day.Because of the complex weather，it is difficult to control.We should execute flight actives not less than the standard procedure.The Cessna 172R and PA44 have no anti-icing system，this reduces the safety and security of the winter flight.For example，when we get the information of icing from pilots，the most important aim is to help the pilot out of the current predicament.We should provide all the useful navigation equipment， lighting equipment at this time.After the pilot out of the predicament，as controllers we need to know the area、intensity and other useful information of icing to ensure that other aircraft no longer suffer the same deep end.

4 Conclusion

With increasing of air traffic flow，more and more flight activities will be executed under the edge of the complex weather.As a controller of training airport，should give the student pilot to provide all needed services to make sure of safe flight .No matter summer or winter the most important thing is that we should strict be performed under the standards.