New Delhi: Flight operations at Delhi’s Indira Gandhi International Airport (IGIA) were severely disrupted on Friday morning due to a technical malfunction in the Air Traffic Control (ATC) system, leading to widespread delays.

According to the Airports Authority of India (AAI), the issue lies with the Aeronautical Message Switching System (AMSS) — a critical software that processes flight plans — which has reportedly been malfunctioning for at least the past two days.

By 9 a.m. Friday, more than 150 flights had been delayed, with departures running over an hour behind schedule. As aircraft failed to take off on time, the airport began running short of parking space for arriving flights, further adding to the congestion.

In a statement posted on X, Delhi Airport said, “Flight operations at Delhi Airport are experiencing delays due to a technical issue in the Automatic Message Switching System (AMSS), which supports Air Traffic Control data. Controllers are processing flight plans manually, leading to some delays. Technical teams are working to restore the system at the earliest. We appreciate the understanding and cooperation of all passengers and stakeholders.”

The AMSS, which processes flight plans for arriving, departing, and overflying aircraft, reportedly became overloaded. With the automated system down, controllers are now entering flight details manually, significantly increasing workload and the potential for errors.

Amid the disruption, all major airlines issued advisories to passengers:

Air India on X said, “A technical issue with the ATC system in Delhi is impacting flight operations across all airlines, leading to delays and longer wait times at the airport and onboard aircraft. We regret the inconvenience caused by this unforeseen disruption, which is beyond our control, and appreciate your patience. Our cabin crew and on-ground staff at the airport are extending immediate assistance to reduce passenger inconvenience.”

Meanwhile, IndiGo said, “Flight operations at #Delhi Airport are currently experiencing delays due to a technical issue with the Air Traffic Control (ATC) system. As a result, flight operations at Delhi and several northern regions are impacted. We understand that extended wait times, both on the ground and onboard, may cause inconvenience, and we sincerely appreciate your patience. Please be assured that our crew and ground teams are actively assisting and doing their best to make your wait as smooth as possible. For the latest updates on your flight, we encourage you to check our website.”

“#TravelUpdate: Flight operations at Delhi Airport are currently affected due to a technical issue with the Air Traffic Control (ATC) system. This disruption is impacting flights across Delhi and several northern regions. We sincerely regret the inconvenience this may cause. Our crew and ground teams are assisting passengers and working closely with the authorities to minimize the impact and resume normal operations as soon as possible,” stated Spice Jet in a tweet.