Season’s worst fog played havoc at the Indira Gandhi International Airport (IGIA) as over 200 flights into and out of Delhi were delayed, diverted or cancelled. The density of the fog could be judged by the fact that runway visual range (RVR) decreased to 50 metres at the IGIA on the New Year’s eve.

Take-offs from the airport required a minimum visibility range of 125 metres. With around 1,100 flight movements per day, the IGIA is the busiest airport in the country.

Over 150 flights were delayed, nearly 50 diverted and an estimated 20 were cancelled. No flights could take-off from Delhi for nearly four hours between 7.30 am and 11.05 am, according to an airport official.

However, as the IGIA has advanced technology for low-visibility landings, called the CAT-IIIB system, aircraft qualified to land in visibility of 25-50 metres could arrive here.

There were, however, nearly 50 diversions to nearby airports as many pilots deployed by airlines were not CAT-IIIB compliant, the source said.

“Runway visibility since 5.30 am has been between 50 metres and metres. This is so far the worst fog we have experienced this year,” RK Jenamani, Director, Indian Meteorological Department (IMD), Delhi area and IGI Airport said.

An official from the Meteorological department termed it the “worst” fog of the season. According to them, little over 140 flights were delayed and out of them 94 were due to weather conditions that resulted in poor runway visibility in the morning hours. As many as 47 were delayed on account of “other reasons”.

At least two international flights were diverted in the morning. One Air India flight from Paris was diverted to Mumbai while an Oman Air flight from Muscat was diverted to Jaipur, as per the officials.

A senior official said over 100 flights were delayed on Saturday as well due to dense fog in the morning apart from 16 cancellations for “other reasons”.

While visibility improved to 2,000 metres later in the day and operations were restored to normal, there were consequential delays throughout the day and a waiting time of up to six hours was common.

Harried passengers took to social media to share pictures of the overcrowded domestic terminal where passengers could be seen sitting on floors and occupying staircases.