“Over 150 flights at Delhi’s IGI airport were delayed on Tuesday. However, only seven of them had to be cancelled,” the English daily reported citing an official having knowledge of the matter.

“The cancellations, however, were due to operational reasons,” the official added.

An Airports Authority of India (AAI) official noted that dense fog in Delhi and other parts of North India led to these delays.

“Delhi along with North India witnessed dense fog leading to delayed take offs from their origin airports,” the official said.

This aligns with the Sunday forecast from the India Meteorological Department (IMD), which predicted dense fog and severe cold conditions in North India conditions to continue next four days.

The airports in Delhi, Amritsar, Jaipur, Lucknow, Kolkata, and Bangalore are equipped with Category III (CAT III) technology, enabling landings in low visibility conditions such as fog or rain. However, many airports are only CAT I or CAT II compliant, which limits operations during poor visibility.

CAT I (or Category I) allows landing with a visibility of 500 mts and CAT II calibrations allow flights to land with a visibility of 300 mts on the runway.

The recent increase in flight disruptions at Delhi airport due to fog caused severe inconvenience to passengers, forcing the government to come up with SOPs to be strictly followed by the airlines.

“The recent delays and inconvenience caused by fog and adverse weather conditions have underscored the pressing need to improve Category III (CAT III) facilities in airports across India…The absence of CAT III capabilities not only hampers operational efficiency but also strains the entire aviation ecosystem, impacting airlines..there is a compelling case for a collaborative effort between the government and the aviation industry to expedite the implementation of CAT III facilities at airports nationwide” HT quoted Jaideep Mirchandani, Group Chairman of Sky One, a VIP charter service company, as saying.

Airport officials said that the number of flight delays also increased due to airspace curbs in Delhi from January 19 to 26. According to a statement issued by Delhi International Airport Ltd (DIAL) last week, no flights are permitted to land or take- off from Delhi on the Republic Day week from 10.20 am to 12.45 pm.

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“While a Notice to Airmen (NOTAM) was issued to all the airlines, the closure of airspace leads to congestion in the airspace as airlines seek landing permissions from the air traffic control, as soon as it reopens. On Tuesday, the flights that were already delayed from smaller airports due to fog, had to be further delayed as per the Delhi airspace restrictions,” an airport official said.

IndiGo posted a travel advisory on X and alerted passengers of possible flight disruptions due to “weather challenges” in Lucknow, Patna, Varanasi, Jammu and Agartala. “..our flight schedules may experience interruptions..” their post said.