NEW DELHI: The mercury dropped on Sunday in Delhi and other parts of northern India turning it quite chilly as the winter season advanced. With the Meteorology Department forecasting a rainy week
ahead, the airlines heaved a sigh of relief as showers can clear out the fog, making flights at Delhi airport less difficult. Air passengers had to face delays and cancellations of flights over the week.
The first fog of the winter season last Monday delayed 25 domestic and international flights at the Indira Gandhi International Airport (IGI) in Delhi. The dense fog had enveloped the whole of the National
Capital Region in the morning, visibility at airport runway dropping below 50 metres, leading to cancellation of flights and diversion of incoming flights. It almost cleared up as the day progressed. The
minimum visibility range needed for a CAT-III B-enabled aircraft is 50 metres for landing. For takeoff, the minimum visibility requirement for such aircraft is 125 metres. There are two runways at the IGI
airport where instrumental landing is possible.
Dense fog severely disrupts flight operations when aircrafts and/or crew are not CAT-IIIA/B compliant. However, Instrumental Landing System (ILS) facilities at the IGI Airport enable those
aircrafts which are CAT-IIIA/B compliant to land till Runway Visibility Range (RVR) drops below 50 metres. No aircraft can operate when RVR is below 50 metres.
On Wednesday, the adverse weather conditions delayed over 40 flights although overnight the sky was clear and the operations were smooth. Fog descended after 6 am. Runway visibility dropped to less
than 125 metres, the requirement for Low Visibility Take-Offs. Landing was possible till 7:30 am with the CAT-III B instrument landing system (ILS). Eight flights were not operating as destinations in the
north had the same problems. Several flights had also to be diverted.
On Friday, the situation changed to a great extent, the fog had no real impact on the flights at Delhi airport. The haze was disturbing for airlines for a while in the morning but the sky cleared up shortly as the day progressed. Airport officials said there were no major delays in departures or landing. But trains continued to be delayed and detained in Delhi and other northern areas due to the fog.
It was getting colder in the north as the winter season advanced. The maximum and minimum temperatures were around 15 and 11 degrees C, respectively, in Delhi on Saturday. The Met office has
predicted showers for Delhi which is expected to clear out the morning fog and make flights smoother.
