on time so the time of de-icing will be shortened and the departure time will not be in joepardy . After the de-icing the captain will report that the aircraft is fully ready within his TSAT window so he can get the start up approval to taxi to the runway .

The last couple of months Amsterdam Schiphol Airport has been confronted with high levels of mixed weather conditions . One of these conditions which is fog has a major influence on Airport operations . The fog we are talking about occurs when the temperature and dew point are equal or within a degree and the air becomes saturated . The dew point is the temperature at which the air becomes 100 % saturated . At that point the air condenses into water droplets which we see as fog . At the airport we have 4 visibility phases . A / B / C / D

AT PHASE ALPHA : The horizontal visibility is more than 550m and less then 1500m with a cloud base of 200 / 300 FT . AT PHASE BRAVO : The horizontal visibility is between the 350m and 550m . AT PHASE CHARLIE : The horizontal visibility is between the 200m / 350m . AT PHASE DELTA : The horizontal visibility is less than 200m and the cloud base is up less then 200ft . The lower the visibility the bigger the consequence for the runway uses .

Here you see a random weather message called METAR : Meteorological Aerodrome Report . This report contains information about actual weather circumstances which is routinely prepared by the meteorological service in an airport . For example :

METAR EHAM 230755Z 16003KT 0100 R18C / 0250N R27 / 0150N R18R / 0175N R06 / 0225N FZFG NSC M03 / M03 Q1027 NOSIG =

METAR shown of Amsterdam Schiphol Airport at the 23rd of the month , observed at 0755Z . The wind is blowing from 160 ° speed 3kts . The horizontal visibility is 100m . The RVR value of RWY 18C is 250m ( N ). The RVR value of RWY 27 is 150m ( N ). The RVR value of RWY 18R is 175m ( N ). The RVR value of RWY 06 is 225m ( N ). FZFG NSC . TEMP / DEWP are both M03 °/ 26.6 ° F . QNH1027 NOSIG =