Air traffic controllers in Mumbai are operating with heightened vigilance as flights through the city’s airspace have surged by over 60% following escalating tensions between India and Pakistan, multiple officials said, even as scores of more flights were scrapped on Thursday.
Twenty-four airports across northern India remain closed for civil aviation until at least Saturday morning, with Delhi and Dehradun now serving as the only operational northernmost airports in the country. The closures, which have led to widespread flight cancellations, came after India’s targeted strikes on Pakistan and Pakistan-occupied Kashmir early on Wednesday, which was followed by attempts by Pakistani forces to strike India, which Indian officials said were thwarted by air defences.
The closure has forced airlines to cancel over 250 flights. IndiGo alone has cancelled more than 165 flights, while Air India has scrapped approximately 65 services since Wednesday.
The Mumbai Flight Information Region (FIR), which typically handles about 750 international overflights daily, is now managing approximately 1,200, pushing the total daily traffic in Mumbai’s airspace beyond 3,000 flights when combined with the airport’s 900+ movements and domestic overflights.
“The entire northern international traffic of the country is funnelling through Mumbai’s airspace,” said a pilot who recently operated in the region. “Despite ten planes keying in together, the communication on the frequency is smooth. It is chaotic flying on the route as it is new to the pilots, however the ATCOs have been calm and composed.”
This dramatic rerouting follows India’s decision on Wednesday to shut down 25 international flight routes that would allow aircraft to enter Pakistani airspace via India, part of broader restrictions affecting airports across five states including major facilities such as Srinagar, Amritsar, Jammu, Leh, and Chandigarh.
Mumbai’s L301, the northernmost international overflight route over the Arabian Sea, now bears the brunt of the diverted traffic, while the N571 route has seen a 40% increase in flights. Route L639, which runs close to Karachi’s airspace, was among those closed on Wednesday.
“Senior officials have been working extra hours to ensure the increased traffic is managed smoothly. Staffing levels have also been increased for every duty shift,” said an official familiar with the situation.
Controllers are also likely to be employing “over-the-shoulder monitoring”—a supervisory technique where experienced controllers observe their colleagues in real time to ensure safety during the high-traffic period, a former AAI official said, sharing insights on what typically happens during such periods.
Indian authorities have requested officials in Oman to reroute flights away from the congested L301 route while proactively redirecting departures from Pune, Nagpur, Kolkata, and Hyderabad to prevent further overcrowding, a third person said, asking not to be named.
The flight disruptions have dramatically extended journey times for both international and regional carriers.
Pakistani carriers face similar challenges. Pakistan International Airlines’ Islamabad-Kuala Lumpur service (PK894) has increased from 5 hours 39 minutes to 8 hours 19 minutes, while its Lahore-Kuala Lumpur flight (PK898) now requires nearly 9 hours compared to the previous 5-hour journey.
Long-haul operations have been particularly affected. Air India has rerouted most of its transatlantic services, adding both distance and complexity to operations. Routes to North America, which previously passed efficiently over Pakistan and into Central Asia, now divert south and west before looping north, necessitating fuel stops en route. The airline has designated Vienna and Copenhagen as primary refuelling points for these flights.