The six slots -- two each of IndiGo, GoAir and Jet Airways --were withdrawn after an equal number of flights of these airlines were diverted due to fog since last evening till the wee hours today, DGCA sources told PTI, adding that the withdrawal of slots has been done with "immediate effect".
The Directorate General of Civil Aviation (DGCA) had earlier this month issued a stern warning to airlines to deploy pilots trained to fly under foggy conditions and aircraft fitted with devices to match CAT-III Instrument Landing System (ILS) in Delhi or face severe action.
DGCA's meeting with the airlines and airport operators was held on January 7, two days after 53 flights were diverted out of fog-hit Delhi to nearby destinations.
The largescale diversion was caused mainly due to the airlines operating planes with pilots not trained to land in foggy conditions or the aircraft not fitted with CAT-III ILS-matching devices.
Yesterday, visibility at the IGI Airport had started dropping after 1730 hours and the Runway Visual Range started reducing around 2030 hours, the sources said, adding that this trend was brought to the notice of all the airlines.
However, in spite of repeated efforts, two flights each of Jet Airways, Go Air and IndiGo were diverted from Delhi to Jaipur, they said, adding that by not adhering to DGCA directives, the airlines had violated several sections of the Civil Aviation Regulations (CARs) leading to the penal action.
DGCA sources said the Airports Authority of India's Operational Control had informed that crew or the aircraft of these three airlines were not CAT-III-compliant and therefore were diverted to Jaipur.
After the warnings, the diversions had come down from 53 on January 7 to only five the next day and not a single cancellation for a week thereafter. As many as 1,841 flights had operated in low visibility conditions during that period.
DGCA had warned the airlines that they would be stopped from operating in and out of Delhi during foggy season if they did not deploy CAT-III trained crew to operate flights in and out of the national capital in case CAT-III weather predictions were made by the Met department.
Among several steps decided at the meeting, the regulator had fixed the responsibility of the airlines to get the latest weather updates and ensure that CAT-III trained cockpit crew were deployed accordingly.
DGCA chief Prabhat Kumar also set up a committee headed by Joint Director General Lalit Gupta to examine and recommend steps to make Delhi airport "zero diversionary" by December.
The 10-member panel, which has been asked to submit its report by March 31, would also prepare a manual to deal with low visibility operations, containing dos and don'ts for all stakeholders.
It would take cognisance of global practices in such situations, including evacuation of passengers to the departure lounge in case a plane gets stranded due to low visibility conditions.
DGCA has also set up a special cell called SUGAM and a dedicated mail ID 'email@example.com' to enable harried air travellers lodge their complaint on any problem they face relating to flights or airport facilities due to delays caused by fog or other reasons, promising to take speedy action.
The committee has been tasked to first acknowledge the complaint electronically and direct the airline or airport operator concerned to address the issues expeditiously.