Fog hits operations at Delhi airport, 27 flights cancelled; Indigo cancels 59 flights on domestic network

A pedestrian walks through dense fog on a cold winter morning, in New Delhi)

As many as 27 flights of various airlines were cancelled and many more delayed at Delhi Airport on Thursday due to dense fog and subsequent drop in visibility, an official source said.

Meanwhile, IndiGo cancelled 59 flights in its domestic network, as per the airline's website.

"As of now, 27 flights are cancelled -- 16 departures and 11 arrivals -- at Delhi Airport due to dense fog and low visibility," the source said.

In a passenger advisory on Thursday morning, DIAL said due to dense fog, "flight operations are currently under CAT-III conditions, which may lead to delays or disruptions.".

According to IndiGo website, the airline cancelled 59 flights on Thursday, and besides cancelling another 28 flights for Friday. IndiGo, however, did not specify any reason for these cancellations.

For conducting flight operations under low visibility, airlines have to mandatorily deploy CAT-III trained pilots as well as a CAT-compliant aircraft fleet.

CAT-III refers to a type of instrument landing system (ILS) approach that allows aircraft to land in conditions of very low visibility, such as fog, rain or snow, with a runway visual range (RVR) of 50-200 meters.