Fog started to descend at the airport around 3.30 AM, when visibility dropped suddenly from 1200 metres to 400 metres at third runway, while it was above 1200 metres for main runway.
But within half an hour, dense fog also the enveloped main runway and visibility decreased to 150 to 225 metres while at the third runway it dropped to 50 to 100 metres.
The situation remained the same till 9.30 AM but slowly the visibility started to improve.
The flights were delayed from half an hour to four hours.
