Delhi ATC failure disrupts air traffic nationwide; over 500 flights delayed at IGI

Guwahati: A technical fault in the Air Traffic Control (ATC) system at Delhi’s Indira Gandhi International Airport (IGI) on Friday (November 7, 2025) caused major delays for over 500 flights, disrupting air traffic nationwide, The Hindu reported.

From early morning at 5 a.m. until 8 p.m., more than 383 departures and 163 arrivals at IGI experienced delays exceeding 45 minutes, according to flightradar24.

The system had been sluggish over the previous two days, contributing to at least 23 earlier delays, which were further compounded by fog-related low visibility.

Handling an average of 63 aircraft movements per hour, IGI sees nearly 1,500 daily flights.

The Airports Authority of India (AAI), responsible for managing air traffic nationwide, said on X that the problem was caused by a “technical issue in the Automatic Message Switching System (AMSS), which supports Air Traffic Control data.” The AMSS, sourced from Spanish company Indra, contains flight plans and weather information.

Due to the malfunction, Air Traffic Controllers were forced to process flight plans manually, gathering details such as flight route, departure, destination, and call signs directly from pilots over radio.

By evening, the Ministry of Civil Aviation reported that the system had been restored, but clearing the backlog of delayed flights would require additional time.

While departures were hit hardest in the morning, arriving flights were also affected because departing aircraft still occupied parking spaces. This created a ripple effect at other airports, as delayed flights from Delhi reached destinations late, postponing subsequent departures.

A government official denied claims of a cyber attack, explaining that the glitch occurred during an AMSS update.

The Delhi-Mumbai route, the country’s busiest, recorded over 121 departures and arrivals delayed by more than 45 minutes at Mumbai airport until 8 p.m., according to flightradar24.

The AAI and the Ministry of Civil Aviation did not provide official data for other airports.

Airlines urged passengers to check flight statuses online.

“Our teams are actively assisting guests at the airport and working closely with the authorities to minimise delays,” an Air India Express spokesperson said.

Passengers were advised to verify their flight schedules before travelling.