The dense blanket of fog over the Delhi skies on Friday delayed several flights on the Bangalore-Delhi sector.
It is for the first time this winter, that flights and train services were disrupted in the capital causing great discomfort to the passengers.
Airport sources said that around seven to eight flights scheduled for departure to the national capital on Friday morning was held up for a few hours. Later they were re-scheduled as visibility range at the Delhi airport was very low, making the flights take-offs and landing difficult.
According to airport operator DIAL (Delhi International Airport Limited), the low  visibility procedures were initiated at 2.40 am as the visibility range fell lower than 1100 metre. By 3.30 am, the runway visibility dropped to 75 m. This prompted the airport authorities to switch to Category IIIB instrument landing system where flights can make touchdown even at 100 m visibility.
The Runway Visual Range (RVR) gradually improved to 400 m at around 9 am and after over eight hours, the safeguard procedures were terminated at 11 am leading to simultaneous use of the two runways.
During these eight hours, arrival and departure of only 72 flights — 41 domestic and 31 international — could take place. Seven international flights were diverted to neighbouring cities but no flight was cancelled, DIAL added. Kingfisher Airlines, Simplyfly Deccan, Jet Airways and other airlines reported delay in departures to Delhi and vice versa.
Simplyfly Deccan, Kingfisher and Jet Airways flights scheduled to depart from Bangalore at 5.30 am, 6.40 am and 7.10 am, departed at 9.40 am, 7.11 am and 7.30 am respectively.
Similarly, flights from Delhi were also affected as they were delayed for a few hours. Kingfisher reported all its flights to be delayed for a couple of hours and a Jet airways flight which was to depart at 6.35 am, took off at 1.25 pm and arrived in the City at 4.20 pm.
The delay in the flights on the Delhi sector also had a cascading effect on the flight routes as well. This was due to the backlog as some flights departed a few minutes later than its actual schedule.
However, airlines operating on CAT III landing systems reported no delays on the Bangalore-Delhi sector.
Harrowing time
Passengers, however, had a harrowing time. With information not coming by, those who reached airport early, learnt that the flights have been delayed. One passenger, who was to take the 9.30 am flight to Kolkata from Delhi, was told that his flight had been delayed for take off by three hours.
Though they were asked to board at 1 pm, they were made to sit in the aircraft till 4 pm when it took off. The passengers landed in Kolkata at 6 pm.
Fog did not spare even train passengers. Several trains were reported running late because of dense fog across northern India.