Dense smog hampered visibility at the Delhi airport on Tuesday, affecting operations and leading to over 300 flights being delayed by up to two hours.
Poor visibility rendered one of the runways inoperable during the morning hours, leaving airport officials with just one airstrip of the total three to handle as many as 45 incoming and outgoing flights every hour.
Sources at the Indira Gandhi International (IGI) Airport said that due to low visibility on runway 9/27, they could only use runway 10/28 in the morning.
The third runway 11/29 is shut from today for three days for maintenance.
The sources said that the second runway was opened after visibility improved.
An airport official said that "most departures" were delayed through the day.
The sources said that many morning flights were rescheduled for non-peak hours in the evening, with travel plans for many passengers going for a toss.
The India Meteorological Department said that runway visibility between 7am and 8am was less than 200 metres and improved around 11am.
"Due to heavy air traffic congestion at #Delhi, departure delays up to 90 minutes are expected at Delhi airport till 1900 hours," Jet Airways informed passengers on Twitter.
"Flights to and from Delhi may get delayed by up to 2 hours due (to) runway closure for maintenance," Vistara tweeted.
Around 7 am, four flights of IndiGo, SpiceJet, Jet Airways and Finnair had to do a go-around or abort landing. These include a flight each of IndiGo, SpiceJet, Jet Airways and Finnair, according to the airport official.
At least one IndiGo flight was diverted to Jaipur because the pilots were not trained to operate the plane under poor visibility conditions.
The airport had already curtailed the total number of flights because of the maintenance work planned on Runway 11/29 and airlines had cancelled many flights between November 7 and November 9.
As a result, the airport will be handling only 70 per cent of the flights it witnesses everyday -- down from 1,100 to 800.
This means passengers will have fewer flight options to book and an increase in demand from travellers.
Delhi's air quality was at the season's worst today due to a combined effect of smoke from stubble burning and moisture. Visibility levels plunged as a thick blanket of haze hung low over the city.