The Airports Authority of India said that the air traffic control messaging system (AMSS) at Delhi airport was “up and functional”, after a technical glitch disrupted over 800 flights. However, it said that due to “some backlogs, there may be some delays in the normal functioning of automated operations”.“The AMSS systems are up and functional now. Due to some backlogs, there may be some delays in the normal functioning of automated operations, but the situation will be normal soon,” it said in a post on X.Chaos erupted at Delhi’s Indira Gandhi International Airport on Friday after a glitch in the AMSS system caused over 800 flight delays, PTI reported citing sources. At least 20 flights have been cancelled, according to the report. The Mumbai airport also issued a statement announcing that its air traffic was impacted due to the malfunction.The glitch occurred in the AMSS system that prompted the ATC to abandon automation and switch to manual procedures. The slowdown began showing network-wide effects from Thursday afternoon.
As India’s busiest hub, IGIA typically manages about 1,500 aircraft movements a day with peak rates near 60–70 per hour in normal conditions, leaving little slack when automation falters.What failed: AMSS breakdown and impact on flight-plan distributionThe problem started at the Automatic Message Switching System, a system responsible for transferring the flight plan data to the air traffic controllers’ screens, which crashed. This caused the controllers to process each data manually, significantly delaying the arrival and departure process. The disruption that began to impact the operations since Thursday 3pm, had been occurring since Wednesday evening.Scale of disruption: Number of flights delayed and average wait timesThe technical failure has affected more than 100 flight operations as per PTI. The glitch has largely increased the wait times for all the passengers at the airport. The airport officials have assured the passengers that resolution efforts are under way.From automated to manualAir traffic control oversees aircraft movements in the sky and on the ground, keeping safe separation and efficient air traffic flow. The system that ingests flight plans, tracks positions, and streams real-time data to controllers’ consoles is automated. The Auto Track System presents this live picture to controllers for sequencing departures, arrivals, and taxi movements, while the Automatic Message Switching System (AMSS) relays high-volume flight plans, weather, and operational notices between ATC and airlines each day.Since these automated layers went down with technical failures, controllers were forced to shift to manual methods—noting flight details by hand, calculating separation standards, and coordinating via voice circuits—which preserves safety but greatly reduces throughput and creates operational choke points compared with normal automated rates.Restoration efforts and status updatesAnnouncing the expected delays due to manual processing, Airport Authority of India shared a post on their X on Friday stating, “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.“Delhi Airport also shared the announcement on its Instagram. It assured the passengers of addressing the matter on a priority basis and asked them to stay in touch with their respective airlines for further advisories. “We regret the disruption being experienced at IGIA due to a technical issue at ATC that is affecting flight operations. This matter is being addressed on priority with close coordination among ATC, DIAL, and other stakeholders. Passengers are requested to follow updates from their airlines regarding revised schedules. Thank you for your cooperation,” it wrote.Airlines update passenger advisoriesFollowing the disruptions, various airlines issued advisories for their respective flyers. IndiGo announced that the AMSS system is being resolved and shared a link for the passengers to check the latest flight status before flying. “Customers with upcoming departures are advised to check the latest flight status before starting their journey and to arrive at the airport a little earlier than usual to allow additional time for travel formalities,” IndiGo wrote.SpiceJet assured its flyers that, amidst the delay chaos, its ground staff is present at the airport to assist the passengers. “Our crew and ground teams are assisting passengers and working closely with the authorities to minimise the impact and resume normal operations as soon as possible,” they wrote further, asking the passengers to keep checking the flight status.Air India, while regretting for the delay, also asked the passengers to keep in touch with the updates about their flights so that they could efficiently manage their travel time. “Our cabin crew and on-ground staff at the airport are extending immediate assistance to reduce passenger inconvenience,” they wrote, “We request you to check your flight status before heading to the airport.”Akasa Air announced the longer wait times at the airport for the passengers as the situation was beyond their control. “This may lead to longer wait times at the airport and delays for some of our flights. While this situation is beyond our control, we sincerely regret the inconvenience to your travel plans and seek your understanding during these times,” read its post on X.Air India Express also shared a notice asking for patience and advising passengers to check the flight status before heading to the airport. “Our Cabin Crew and Airport Services teams are doing their best to assist you,” the notice read, “Before heading to the airport, please check your flight status.”The delays for departing flights, as reflected on Flightradar24.com, showed around 50 minutes from the Delhi airport.
