The directorate General of Civil Aviation, which regulates civil flying in the country, recently gave permission to three private air carriers to operate in CAT III-A conditions and CAT II certification to three others.
However, when dense fog enveloped the Indira Gandhi International Airport on Wednesday, only few domestic flights operated in low-visibility conditions. CAT III-A and CAT II allow planes to land and take off safely in low visibility.
As visibility remained poor till 9.30 am on Wednesday, about 150 flights were delayed, 31 diverted to nearby airports and 20 cancelled.
Although 51 flights operated during low-visibility conditions, most were on international routes. Only four flights of Indian took off in CAT III-B conditions. A Kingfisher Airlines flight took off in CAT III-A conditions, and one each of Air Deccan and SpiceJet in CAT II conditions.
Last year, the Civil Aviation Ministry had warned all airlines to train pilots to operate flights in CAT III-B or go out of business in Delhi. "But apart from Indian, most private carriers do not have pilots trained in CAT III-B," said an airport official.
On Wednesday, Director-General of Civil Aviation Kanu Gohain said in a press conference it was the airline operator who had to approach DGCA for CAT III-A or B certificate. "If the airline does not come to us, what can we do?" he asked.
He said some airlines have CAT III-B-trained pilots but they prefer to use them on international sectors rather than on domestic routes.
Meanwhile, the DGCA has sought a reply from Air Deccan which cancelled its flight to Srinagar last week, leading to protests from passengers.