Over 100 flights delayed, 25 cancelled so far as dense fog drapes Delhi airport on Jan 16

The National Capital Delhi has been engulfed in dense fog for the past few days.

Dense fog and low visibility have once again affected flight operations at New Delhi’s Indira Gandhi International (IGI) airport on January 16, with around 100 flights being delayed and 25 cancelled till 10.30am, multiple sources aware of the situation told Moneycontrol.

According to flight tracker website Flightradar24, over 100 flights have been affected or delayed due to adverse weather conditions.

The situation has prompted authorities to implement low visibility procedures at Delhi Airport. "Low visibility procedures are in progress at the Delhi Airport. All flight operations are presently normal. Passengers are requested to contact the airline concerned for updated flight information," the Delhi airport said in a statement at 6.50am.

Due to the prevailing conditions, the Delhi airport said, passengers are advised that flights not equipped for low-visibility landings (Category III compliant) may experience delays or diversions.

"While landing and takeoffs continue at the Delhi airport, flights that are not CAT-III compliant may get affected. Passengers are requested to contact the airline concerned for updated flight information. Any inconvenience caused is deeply regretted," it said.

The minimum temperature in the national capital was recorded at 4.8 degrees Celsius. According to the India Meteorological Department (IMD), dense to very dense fog conditions are likely to continue over North India during the next 4-5 days.

Delhi Palam (VIDP) and Safdarjung airports are reporting 500 metre visibility at 5.30am on January 16, IMD said.

Airport officials said pilots trained in CAT-III procedures can land an aircraft with a minimum visibility of 50 metres. An aircraft can take off with a visibility of 125 metres.

Indian aviation regulator the Directorate General of Civil Aviation on January 15, asked airlines to cancel flights “sufficiently in advance” if they are expected to be delayed by more than three hours, as part of new standard operating procedures (SOPs) released for airlines.

“In view of the prevalent fog season and adverse weather conditions, airlines may cancel, sufficiently in advance, such flights that are anticipated to be delayed or consequentially delayed on account of such conditions beyond a period of three hours with a view to obviate congestion at the airport and mitigate passenger inconvenience,” the DGCA said.

The DGCA also asked airlines to publish real-time information regarding flight delays on their websites, inform affected passengers through WhatsApp messages and email, and sensitise their staff at airports to communicate with passengers.

The SOP also states that airlines are required to display updated information on delays at airports.

It also said carriers must sensitise staff at airports to communicate with and “continuously guide and inform the passengers about flight delays”.

According to Flightradar24, the adverse weather conditions led to delays in 310 arriving flights and 72 cancellations on January 15; 460 flights were delayed and 87 cancelled in departures.

On January 14, 414 flights were delayed in arrivals and 508 in departures. The airport also saw 42 cancelled flights in arrivals and 87 cancelled departures.

In addition to the fog, the fact that one of the runways equipped to handle aircraft movements in low visibility is currently inoperative worsened matters.

The Delhi airport has four runways in all, of which two are Instrument Landing System (ILS) CAT IIIB-compliant, which means they are equipped to handle aircraft in extremely low visibility.

However, one of the two such runways is under maintenance for recarpeting, and therefore, has not been in operation for weeks.

The problem was further complicated as the only operational CAT-IIIB-compliant runway was reportedly recently downgraded in category from one end due to construction activity close to the runway. This meant that CAT-IIIB landings could only operate from one side of that runway.

It is worth noting that having CAT IIIB-compliant runways is not enough in low visibility. Airlines are also required to deploy aircraft equipped for ILS CAT IIIB and pilots trained to handle low-visibility operations. These requirements could also have added to the woes.