Officials pinned the chaos on Sunday on a combination of poor planning and months-long miscommunication, with one of the airport’s 4 runways shut for upgrades.
— Omar Abdullah (@OmarAbdullah) April 19, 2025
Runway 28/10 was closed on April 8 to enhance its Instrument Landing System (ILS) to CAT III B standards – an upgrade that would help it better cope with fog in winter. The timelines were set out to ensure work was completed before winter this year.
In mid-December, key aviation stakeholders were in discussions to devise a plan to minimize weather-related disruptions, said officials aware of the matter. DIAL anticipated a reduction in runway capacity — and possible flight cancellations — because of the upgrade.
By January, DIAL formally informed stakeholders and stated that the runway work would not impact flight operations.
Further complicating the situation, the Directorate General of Civil Aviation (DGCA) experienced a leadership change at the same time. DIAL first sought approvals from the civil aviation ministry in December 2024 and later from both the DGCA and the Airports Authority of India (AAI) on January 15. These approvals were granted in February, said the people cited above.
A meeting on March 4 involving DIAL, AAI, the civil aviation ministry and airline representatives discussed DIAL’s mitigation plan to handle passenger operations during the closure and ILS upgrade. According to the meeting minutes reviewed by HT, all stakeholders were made aware of the shift in wind patterns and were advised to plan their operations accordingly.
In the meeting led by the AAI chairman Vipin Kumar, it was noted that when the airport operates with easterly winds in mind, the flight paths for runways 09 and 11R cross each other about 7.6 nautical miles west of the airport at a 12 degree angle. Because of this, the number of arriving flights are forced to be reduced to 32 per hour.
A former AAI official explained, “When Runway 11L is used for departures and 11R for arrivals, and runway 09 is also used only for departures, the flight paths are not fully separate. So, there must be a gap of 100 to 110 seconds between each arriving flight on Runway 11R, which limits the number of arrivals to about 32 per hour.”
Officials from AAI confirmed that airlines were informed about IMD’s forecast, which predicted an increase in easterly wind conditions. In March and April, around 30% of flights were expected to operate in easterly Mode, increasing to 50% by May and June. This seasonal shift, driven by pre-monsoon changes, was expected to further reduce runway capacity.
During westerly winds — when Runway 27 operates in mixed mode, Runway 29 is used for departures, and Runway 29L for arrivals — the combined capacity is 74 flights per hour. Under Easterly winds, with Runway 09 and 11L handling departures and Runway 11R managing arrivals, capacity is around 72. But with only one runway available for arrivals, the effective arrival capacity drops significantly.
Runway 28/10 had been reopened in February 2024 after being shut for re-carpeting in September 2023. It was closed again in April, right when summer flight traffic started increasing.
Relief may be on the way. A senior IMD official said the wind direction is expected to shift back to westerly in two days.
“Every time a western disturbance hits the western Himalayas, wind direction temporarily shifts to easterly. This is normal. As for how operations are affected, that’s for the airport authorities to determine,” the official said.
Some officials suggested that the upgrade work could have been phased. However, industry experts disagreed, saying the nature of the work—milling the runway surface and installing inset lights—required it to be completed in one go. They added that the March to June window was optimal, as it avoids fog in winter and heavy rains during the monsoon.
Airlines were also advised that delays and diversions during easterly mode were inevitable. They were encouraged to review and adjust their schedules every two weeks based on actual operating conditions and unscheduled flight movements to minimise cancellations.
“The airport operator shares its plans with stakeholders as per standard procedures. It’s the airlines who should have trimmed their operations to avoid disruption,” said Mohan Ranganathan, an aviation safety expert.
“A four-month closure of a major runway is a long time for a hub like Delhi. DGCA, as the regulator, should have revisited the summer schedule and possibly issued a revised one.”
However, a former airline official said that no airline would want to lose business. “Advance planning should have included the cancellation of some flights by the airlines, but no airline wants its revenue to be severely impacted.”
“However, such massive delays might also be causing them significant losses,” the official concluded.
The article originally appeared on Hindustan Times
