A rare technical glitch in the Delhi Air Traffic Control system threw flight schedules into chaos this morning,
disrupting one of the busiest airports in the world and leaving thousands of passengers stranded or delayed for hours.
More than 150 flights were hit due to a sudden malfunction of the Automatic Message Switching System, a critical digital network that routes flight plan data to the Auto Track System at the Indira Gandhi International Airport. In simple terms, the advanced computer system that usually helped air traffic controllers track and manage flights stopped functioning, forcing them to go manual — an almost unthinkable scenario in an airport which handles over 1,500 flights every single day.
“Flight operations at Delhi Airport are facing delays due to a technical glitch in the Automatic Message Switching System (AMSS) that supports Air Traffic Control data. Controllers are manually processing flight plans, causing delays,” the AAI said in a statement.
“Technical teams are working for the restoration of the system at the earliest. We appreciate the understanding and cooperation of all passengers and stakeholders.”
According to real-time data from flight tracking site Flightradar24, more than 500 flights were delayed on Thursday and 171 had already been affected by Friday morning. Average departure delays stretched to about 53 minutes, numbers that continued to climb through the busy morning hours — the peak time for departures.
“The problem started on Thursday afternoon at 3 pm. It prevented automatic flight plans from coming to the screens of the air traffic controllers,” an official said on condition of anonymity.
“Now, the controllers are preparing flight plans manually and then cross-checking all plans. Everything from coordination with airlines to clearance is taking longer, leading to a cumulative delay effect.”
Another official termed the mood at the Delhi ATC as “tense and chaotic”. “Such a glitch is extremely rare. Almost every part of the departure process is being handled manually now. It’s slow and stressful because safety checks cannot be rushed,” said the official.While engineers worked around the clock to fix the technical breakdown, airlines scrambled to manage passenger frustration.
IndiGo, India’s largest carrier, posted a travel advisory on X, acknowledging the system failure and its impact on flight schedules across northern India.
“Travel Advisory Due to a technical glitch in the Delhi ATC system, flight operations are currently running behind schedule at Delhi Airport. This is causing flights to be held up not only at DEL but also in the northern part of the country. We realize this will cause inconvenience due to lengthy wait times on the ground and in the air, and we truly appreciate your patience,” IndiGo stated.
Air India, too, released a statement of regret over the disruption. “We regret the inconvenience this unforeseen technical issue, beyond our control, has caused and appreciate your patience. Our cabin crew and on-ground staff are assisting passengers to reduce discomfort,” the airline said, urging travellers to check flight status before heading to the airport.
As engineers continued to troubleshoot the problem, long queues formed at check-in counters, and departure boards blinked with rescheduled timings. Passengers waited anxiously, many unaware of the highly technical nature of the glitch that had brought India’s busiest airport to a crawl.
By Friday afternoon, limited automation had been restored. For now, Delhi’s airspace – normally a symphony of precision – was learning to hum along the old-fashioned way: with humans, not machines, guiding the skies.
