Operations at the IGI airport in New Delhi were badly affected for the second consecutive day on Monday as dense fog once again created havoc on the schedule of over 120 flights besides forcing diversion of 18 others, including the one carrying a Russian delegation.
The dense fog enveloped the airport around 10.15 pm on Sunday night and by the morning, the general visibility dropped to zero. While the runway visibility was less than 25 m on third runway (29/11), it dipped to 150 m on the main runway (28/10).
No operations were going on the third runway as the visibility was far below the required minimum of 50 m for landing and 125 m and 150 m for small and large aircraft respectively to take off, an airport official said.
A total of 18 flights, three international and 15 domestic ones, were diverted to Jaipur, Kolkata, Ahmedabad, Mumbai, Lucknow, Bangalore, Hyderabad.
One of the planes, which was carrying a Russian delegation and coming from Sheremetyevo International Airport in Moscow, was diverted to Jaipur after the runway visibility dropped significantly, the official said.
Two other international flights, one of Jet Airways from Singapore and other of China Southern Airlines from Guangzhou, were also diverted Kolkata and Ahmedabad respectively.
Air traffic controllers had to return back two domestic flights -- a SpiceJet flight from Coimbatore to Delhi via Hyderabad (SG 236) to Hyderabad and a Jet Airways flight (9W 812) from Bangalore.
The operations at the third runway remained suspended for major part of the morning due to poor visibility, the airport official said.
Poor visibility and use of only one runway led to congestion at the IGI airport, leading to delay of over 120 flights.
As soon as fog started to engulf the airport, the airport authorities implemented low visibility procedures at around 7.38 pm on Sunday. It was lifted around 1.13 pm on Monday.
The airport is equipped with three CAT-III B instrument landing system (ILS) -- two on the main runway and one on the third runway.
A total of 232 domestic and international flights arrived assisted by various category of ILS. 107 flights with CAT-I (when visibility is upto 550 m), 40 flights with CAT-II (when visibility was between 550 and 300 me), 64 flights with CAT-IIIA (when visibility was between 300 and 200 m) and 21 flights with CAT-IIIB (visibility between 200 and 50 m).
According to the MeT office, the visibility today may reduce below 500 m in shallow fog after 8.30 pm and further reduce below 200 m in dense fog (CAT-III fog) from 1.30 am.
The MeT department had predicted CAT-III fog (dense fog when the runway visibility drops to below 50 m) till Christmas.
On Sunday, over 100 flights were badly affected due to dense fog.