A layer of very dense fog over the national capital has hit flight operations. It delayed 364 flights, led to 20 cancellations and 6 diversions at Indira Gandhi International Airport.
Nearly 213 departing flights and 159 incoming flights were delayed between 5.30 a.m. to 7 p.m. on Wednesday, according to flight tracking website flightradar24. The maximum impact on flights was felt between 6 a.m. to 10 a.m. when the runway visual range was at its worst though there were delays through the day.
Zero visibility
“General visibility was zero between 6 a.m. to 10 a.m. The runway visual range (RVR) was between 100 metres to 150 metres in this period. Later in the morning, visibility improved but there was still shallow to moderate fog, which along with rain and drizzle continued to hamper visibility,” said R.K. Jenamani, senior scientist at the IMD.
An RVR of 125 metres is required for departures. Landings can take place with RVR of upto 50 metres if an aircraft’s navigation system is CAT IIIB compliant.
Mr Jenamani likened the fog seen on Wednesday at IGI to the last spell of severe fog seen on January 14 when at least 600 flights were delayed. The impact on flights was far more severe last time as the runway visual range remained below 50 metres for five hours bringing departures to a complete halt between 6 a.m. to 11 a.m., said airline sources.
An IndiGo official said with hindsight, this time it has taken steps to proactively cancel flights and the airline has also put together a team of senior leaders including the CEO to take pre-emptive steps after assessing weather forecast and manage the flight schedule better.
The fog witnessed in Delhi and over several parts of northern India is due to low-level clouds from ‘western disturbances,’ which are rain-bearing storms. Usually, 5-6 WDs pass over northern India from December-February but this year, there have been none during December and most of January.
The first significant WD in Delhi was reported on Wednesday. “One more such western disturbance is expected over the next week. This will result in persistent cloudiness over this period (and continued fog) but will increase night time temperatures,” M Mohapatra, Director General, India Meteorological Department (IMD), said at a briefing on Wednesday.
