Fog creates chaos at IGI, over 200 flights delayed
NEW DELHI: After a long break, fog returned to haunt Delhi early Wednesday morning, hitting air and rail traffic, even as icy northerly winds continued to keep the city in the chill zone during the day.
Visibility plunged below 50m at IGI Airport around 1.30am on Wednesday, when international departures were in full swing. The new runway had to be shut, leaving the main runway to handle night operations. More than 200 flights were delayed by 1-6 hours, four flights diverted and 11 cancelled.
Low visibility procedures were implemented at the new runway 29/11 at 1.46am and on the main runway 28/10 at 3.45am. During this period only 172 flights managed to operate, most of which were arrivals as visibility was too low for departures.
"For CAT-III compliant aircraft, the minimum landing visibility is 50m though various airlines have their own minima set. For landing, the minima ranges from 125m for smaller aircraft to 150m for bigger aircraft, normally used in international operations. The RVR on runway 29/11 (the new runway) fluctuated between 75m and 125m till morning and while runway 28/10 was operational, departures on that were also getting held up intermittently. From 4.30am to 8.30am, the RVR on this runway was also 100m to 125m, too low for most departures," said airport sources.
Between 3am and 4am, visibility fluctuated to such an extent that some aircraft waited for a few hours at the holding point on the taxiways and had to return to the parking bays. "International flights were asked to taxi to the holding point in 125m visibility with the expectation that it would improve. However, nothing happened for a few hours by which time domestic flights with the capability of operating in 125m had also lined up behind these. At this point, international flights had to be taken onto the runway and made to exit from the other end so that the domestic aircraft could operate," added sources.
Delays in the later part of the day were due to the massive congestion due to the closure of runway 29/11. "The runway usage is at least 35-40% less than the main runway in dense fog conditions. On Wednesday, it could not be used for a long time with all flights arriving at and taking off from the main runway. Two Jet Airways flights and two SpiceJet flights had to be diverted as their landing minima was 175m and the RVR then was around 125-150m," said an official.
Air India's flight to Chicago, scheduled to depart in the early hours of Wednesday, was delayed by more than 12 hours as the flight duty hours of its first crew expired after the flight was unable to take off on time due to the dense fog.
With many areas in north India also coming under dense fog, trains were badly hit. More than 75 trains were delayed, including Rajdhanis to Mumbai and Kolkata, and five cancelled. The blanket of fog remained for a good 8-9 hours, clearing only after 10am.