Patna: Dense fog threw flight schedules at Patna airport haywire on Thursday, delaying all of them and causing immense hardship for hundreds of passengers who had to wait outside the low-capacity terminal building in bone-chilling weather in one of Patna's coldest days of the season.

The first flight could land only at 1.20pm when the visibility improved.

The only saving grace was none of the 26 flights scheduled on Thursday was cancelled or diverted. They took off with all bonafide passengers.

"The first one to land was a GoAir flight from Bangalore at 1.20pm. On a normal winter day when fog is less dense, landing and take-offs start around 11.30am," Patna airport director Rajender Singh Lahauria told The Telegraph.

Lahauria added that visibility in the morning was 200 metres, which went up slowly to 700, 900 and finally 1,100 metres. Aircraft need a visibility of 1,200 metres for safe landing operations. The delay in landings had an impact on take-offs too.

Seeing the dense fog and gauging the poor visibility, the airport director had issued an advisory to all airlines in the morning not to release any aircraft for Patna until cleared by the air traffic controller. This ensured that none of the flights to Patna was diverted to other airports because of the poor visibility.

About the crowd, Lahauria said delay in flight departures led to the congestion.

Passengers had to wait outside the terminal building because of lack of space inside, where only 600 people can be accommodated at one time. The terminal building could cater to passengers of only four flights at one go.

Airport officials are expecting the fog cover to thin in a day or two, which would bring normalcy to flight operations.

Blanket distribution

The Patna unit of the Airports Authority of India Women's Welfare Association, also known as Kalyanmayee, distributed blankets to the poor on Thursday at Boring Road in Patna.

The drive was spearheaded by Patna unit secretary Sukanya Singh Lahauria, who said more such activities were being planned for the welfare of the poor in Patna.