Flight operations were severely affected at Delhi's Indira Gandhi International Airport on Friday morning due to a major snag affecting the air traffic control (ATC) system. The problem occurred with the Automatic Message Switching System, which relays the flight plans to the Auto Track System used by controllers.
As per a report by the Hindustan Times, due to the failure, air traffic controllers had to process flight plans manually, slowing operations down and creating massive delays. Officials characterised the situation as "chaotic," amid round-the-clock work by technical teams to restore normalcy.
AAI confirms ongoing technical issue
In a statement, the Airports Authority of India confirmed the disruption and assured passengers that restoration work was underway. "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,” AAI said.
Hundreds of flights affected
According to Flightradar24, a global flight tracking platform, Delhi airport - India's busiest with more than 1,500 flight movements in a day - recorded 513 delays on Thursday and 171 more by Friday morning. Delays to departures during the early hours stretched up to 53 minutes, and the number is still rising.
As per the report by the Hindustan Times, an official aware of the development said the problem started at around 3 pm on Thursday, wherein ATCOs were not getting the flight plans on their screens automatically. “As a result, controllers are now preparing flight plans manually using available data, a process that is slowing down operations and contributing to congestion at the airport,” the official explained.
Another official added, “Such a glitch is uncommon and has not happened earlier. Since each task before a flight departure is being done manually. There is chaos at Delhi ATC currently.”
Airlines issue travel advisories
Leading carriers like IndiGo and Air India issued public advisories on X (formerly Twitter), informing passengers about the situation and asking for patience.
IndiGo wrote,“#6ETravelAdvisory 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. Thank you for your continued understanding.”
Similarly, Air India said, "#TravelAdvisory 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. We request you to check your flight status at https://airindia.com/in/en/manage/flight-status.html before heading to the airport.”
Both carriers encouraged passengers to check the status of their flights online before coming to the airport.
Delays likely to continue until full restoration
As per the report, the officials said that efforts to fix the glitch are underway, but flight delays are expected to continue until the AMSS resumes normal functioning. With controllers depending on manual entry of data, the process is still slow, particularly during the busy morning hours when most flights see departures. Delhi airport authorities have requested passengers to stay updated through airline websites and cooperate with the staff as technical teams work to restore the system fully.
