IndiGo, India's largest airline, was forced to cancel 80 flights across its network on Monday, December 29, as dense fog severely impacted operations at several airports, particularly in the northern part of the country.
Major Disruptions Centered on Delhi
Half of the 80 cancelled flights were from Delhi's Indira Gandhi International Airport, which had been operating under challenging low visibility conditions. The airport operator, Delhi International Airport Ltd (DIAL), issued an advisory early Monday morning, warning passengers about continued disruptions. "Due to persistent dense fog, flight operations continue to remain under CAT III conditions, which may result in flight delays," DIAL stated, urging travelers to contact their airlines for the latest information.
The airline confirmed the widespread impact in a travel advisory posted at 11:20 am. "Foggy conditions remain in place across Delhi and several airports in northern India, with visibility yet to improve fully. As a result, the earlier impact on flight movements is likely to extend into the noon hours, and some delays may continue," IndiGo said. The carrier assured passengers that departures and arrivals were being carefully sequenced for orderly movement.
Nationwide Impact and Recurring Cancellations
The disruption was not confined to Delhi. Flights to and from other major hubs like Mumbai, Bengaluru, Cochin, Hyderabad, and Kolkata were also cancelled. The list of affected airports extended to Amritsar, Chandigarh, Jaipur, Dehradun, Indore, Patna, and Bhopal, among others.
This is not an isolated event for the airline during this winter season. IndiGo has been cancelling a significant number of flights since the official fog season began on December 10. Just a few days prior, on December 25, the airline cancelled 67 flights citing similar weather conditions. Another 57 flights were axed on Saturday due to bad weather. This follows massive disruptions earlier in the month when the airline cancelled thousands of flights, including 1,600 in a single day, due to new pilot duty time regulations mandated by the courts.
Understanding Fog Season and CAT-III Operations
The aviation regulator, the Directorate General of Civil Aviation (DGCA), has officially designated the period from December 10 to February 10 as the fog window for this winter. During this time, airlines must adhere to strict fog operation norms known as CAT-IIIB.
These regulations require airlines to roster only pilots specifically trained to operate in low-visibility conditions and to deploy aircraft equipped with advanced Category-III navigation systems. This technology is crucial for safe landings in dense fog. Category-III-A allows a plane to land with a runway visual range (RVR) of 200 metres, while the more advanced Category-III-B enables landing with an RVR of less than 50 metres.
Passengers traveling during the winter months are advised to stay updated on flight status through airline websites or apps, as weather-related delays and cancellations are likely to continue until the fog season subsides in February.
