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.
Flight operations at Delhi’s Indira Gandhi International Airport remained hobbled on Sunday, with roughly 68% of all arrivals and departures delayed, as the airport operator said airlines failed to heed warnings about disruptions issued four months ago and neglected to adjust their flight schedules.
Officials pinned the chaos on a combination of poor planning and months-long miscommunication, with one of the airport’s four runways shut for upgrades during the busy summer travel season, coupled with an untimely change in wind direction – a perfect storm of factors that slashed capacity and left passengers blind-sided.
Delhi International Airport Ltd (DIAL), the airport operator, said airlines were informed about the planned runway upgrade and potential wind disruption four months ago, but made “minimal or no changes”.
“The closure of Runway 10/28 since 8th April for essential Instrument Landing System (ILS) upgradation, was planned well in advance in consultation with all relevant stakeholders and based on historical wind patterns over 4 months ago…it was agreed amongst all stakeholders, including Airlines and ATC [air traffic control] that will be temporary capacity constraints for arrivals…,” DIAL said in a statement on X.
“During such moments the Airlines are to reschedule or cancel flights at short notice in interest of passenger safety and convenience… However, there were minimal to no changes made. Unfortunately this limited action/non action has led to significant operational challenges for all the stakeholders including Delhi airport and ATC and in the end impacted the passengers significantly,” it added.
DIAL said the airport, in coordination with stakeholders, had decided to temporarily suspend the upgrade work.
“Runway 10/28 will be brought back into operation in the first week of May, with the remaining upgrade activities deferred for a month or so,” it said.
Thousands of passengers were affected on Sunday as 501 departures and 384 arrivals were delayed, as of 11.30pm, according to flight-tracking service Flightradar24. This is just over 68% of the 1,300-odd flights the airport handles a day.
The service also said departures were, on average, delayed by an hour and arrivals by 75 minutes.
The airport operates four runways; 27/09, 28/10 (both these runways are old), 29L/11R, and 29R/11L, with the newest runway becoming operational in 2023. On a typical day, the airport handles up to 46 arrivals per hour.
Meanwhile, Terminal 2 was closed on April 15 2025 with the 46,000 passengers and 270,280 flights it handled being shifted to expanded Terminal 1, which was completely operational on the same day, April 15.
These concurrent factors snowballed into a harrowing time for passengers, and the mayhem was thrown under the spotlight again when Jammu & Kashmir chief minister Omar Abdullah early on Sunday morning criticised the airport for a lengthy delay.
“Delhi airport is a bloody shit show (excuse my French but I’m in no mood to be polite). 3 hours in the air after we left Jammu we get diverted to Jaipur & so here I am at 1 in the morning on the steps of the plane getting some fresh air. I’ve no idea what time we will leave from here,” he said on X.
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.”