New Delhi: Dense fog hit operations at the Indira Gandhi International Airport here affecting over 160 flights, including that of External Affairs Minister Salman Khurshid.
Khurshid`s flight, which was to take-off from Palam Technical area for Bhutan around 9.30 AM, was delayed by two hours due to fog.
Flight operations at the airport came to a standstill for around one-and-half hours, between 5 AM and 6.30 AM, as the runway visibility was less than 50 metres on both the runways, main (28/10) and third (29/11), airport sources said.
Around 130 domestic and international flights were delayed by over three to four hours after dense fog enveloped the airport and visibility become poor while 11 were cancelled.
Also 21 domestic and international flights to Delhi were diverted to Jaipur, Mumbai, Ahmedabad, Amritsar, Nagpur and Lucknow. Of these 11 were diverted to Jaipur, three each to Ahmedabad and Mumbai two to Amritsar and one each to Nagpur and Lucknow.
The flights were diverted as the visibility was less than 50 metres, which is the minimum required visibility for a flight to land using the most advanced Category III B (CAT-IIIB) of the instrument landing system.
According to sources, these flights were diverted as either their crew was not trained to operate in CAT-IIIB conditions or their aircraft were not CAT-IIIB compliant.
"This is in violation of clear cut instructions by the Director General of Civil Aviation to deploy CAT-IIIB compliant aircraft and pilots during the fog season," they said.
Smaller aircraft like turbo prop ATR, Canadian Regional Jets (CRJs) and Bombardier`s Q400 turbo prop are not CAT-IIIB complaint, hence not fit to operate in dense fog conditions.
Eight flights coming to Delhi were diverted to Jaipur, Nagpur and Mumbai between 4 AM and 6 AM, when the runway visibility was less than 50 metres. Also no flights took-off between 3.30 AM and 6 AM due to which there was a huge backlog of flights, airport officials said.
An Air India flight, coming from Frankfurt - a Dreamliner - was diverted to Mumbai as the aircraft and crew is not CAT-IIIB rated by the DGCA.
The fog started to descend at the airport around 8 PM last night but it become dense from 11.30 PM. The general visibility and the runway visibility worsened after 2.30 AM when it reduced to less than 50 metres.
As the visibility dropped, the airport authorities implemented low visibility procedures at 9.30 PM last night on third runway and at 2.29 AM on main runway. It was finally lifted around 1 PM today.
During this period, 74 flights operated under CAT-I conditions, 27 in CAT-II and 40 in CAT-IIIA and CAT-IIIB.
A Royal Dutch Airline flight (KLM 872) to Amsterdam was delayed by over 20 hours due to fog and subsequent completion of flight duty time limitations (FDTL) of the crew.
The flight was cleared for take off at 2.30 AM but it had to return from taxiway due to some technical reasons. In the meantime fog enveloped the airport and the visibility dropped to less than 100 metres, and the flight was held up.
When visibility rose above the permissible limit, the FDTL of the crew ended and the flight was rescheduled for departure at 11.45 PM, sources said, adding passengers have been accommodated in hotels.
Airport MeT incharge, RK Jenamani said that very dense fog had formed over IGI between 2:30 AM to 9:30 AM with runway visual range dropping to less than 50 metres on third runway and it was less than 175 metres on main runway which affected the flights badly.
He said the airport is likely to witness the same situation overnight. The visibility is likely to reduce due to fog from 9.30 PM and would be enveloped in very dense fog from 1.30 AM tomorrow morning.