Over 100 flights a day to be cancelled at Delhi airport for three-month runway upgrade; operator DIAL expects minimal disruption

Runway 10/28, one of the four runways at Delhi’s Indira Gandhi International Airport (IGIA), is to be upgraded to the CAT 3B-compliant status, along with upgradation of its instrument landing system (ILS). After the upgradation works, the runway will be fully equipped to handle low-visibility operations from both its ends, instead of just one end at present. After the upgrade, the airport will have three runways capable of low visibility operations, equipping it to better manage operations during the winter fog spells. Being in North India, the Delhi airport is prone to dense fog during winter, which can lead to major disruptions at the country’s largest airport.

DIAL had initially attempted the runway upgradation work in April-May, and closed the runway in April. However, lack of visible coordination between DIAL and the airlines—who did not rationalise flights to the extent needed—led to substantial delays and cancellations across the network for days as sudden changes in wind patterns added to the complications. IGIA is the country’s largest and busiest airport and any major disruption there has a cascading impact on flight operations all over the country. Amid public outcry at the time, the Ministry of Civil Aviation (MoCA) intervened and asked DIAL to operationalise the runway and put off the upgradation works by a few weeks to let the peak summer travel season pass. Airlines were also directed to work on slot adjustments to accommodate the revised aircraft arrival capacity and ensure minimum passenger inconvenience.

DIAL wants the upgradation to be completed before the October-December festival season kicks off as it is immediately followed by winters, when fog-related disruptions are a regular affair at the Delhi airport. To that extent, the three-month window ending September 15 is likely to work well for the airport and the airlines. According to Jaipuriar, every one-hour of fog-related disruption takes about three hours to clear out during westerly runway operations. However, during easterly runway operations, it takes up to six hours for the operations to normalise. With low-visibility operations from both ends of Runway 10/28, westerly and easterly operations will be at par in terms of time taken to operations to normalise.

In simple terms, westerly and easterly runway operations refer to the direction in which aircraft land and take off based on the wind direction, as planes generally take off and land against the wind. Westerly operations are when the wind is blowing from west to east, and aircraft usually land from the east and take off towards the west. On the other hand, in easterly operations, wind is blowing from east to west, and aircraft land from the west and take off towards the east.

According to data provided by DIAL, during low visibility conditions at IGIA, the capacity to handle flight arrivals during westerly operations stands at 30 flights an hour, while during easterly operations, it halves to just 15 flights an hour. Once Runway 10/28 is upgraded, the arrival capacity in low visibility conditions during easterly operations will be similar to westerly operations.