Operations at Delhi’s Indira Gandhi International Airport (IGIA) were severely disrupted on Friday after a technical failure in the Air Traffic Control (ATC) system caused delays to more than 100 flights. The airport authorities, along with the Airports Authority of India (AAI), confirmed that the issue stemmed from a malfunction in the Automatic Message Switching System (AMSS), a crucial component that supports the transmission and processing of ATC data. The disruption led to significant congestion, confusion, and frustration among passengers who found themselves stranded without clear updates from airlines or the airport.

In a statement issued on social media platform X, the Delhi International Airport Limited (DIAL), which operates IGIA, said that the matter was being treated with the highest urgency. The airport noted that close coordination was underway among Air Traffic Control, DIAL, and other aviation stakeholders to resolve the glitch and restore normal operations as quickly as possible. “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,” the airport’s post read. It also urged passengers to follow updates from their respective airlines regarding revised schedules.

The technical problem, described by officials as “unexpected and critical,” forced ATC controllers to revert to manual processing of flight plans—an arduous and time-consuming procedure that slows down overall traffic flow. ATC normally relies on automated systems to transmit, classify, and distribute flight-related messages to controllers, pilots, and ground personnel. The AMSS system plays a central role in ensuring flight plans, weather updates, route clearances, and other essential communications are delivered swiftly and accurately. When this system malfunctioned, controllers had to enter data manually, significantly reducing operational efficiency and leading to a cascading effect of delays across arrivals and departures.

Passengers at the airport experienced a mix of confusion and growing anxiety as flight schedules became increasingly uncertain. One passenger, Yogesh, who had flown in from Jaipur and was headed to Switzerland, described the situation as chaotic. Speaking to ANI, he said he had received calls from acquaintances asking about the delays but had not received a single official communication from his airline. “I am going to Switzerland. I am getting phone calls but I have not received any message from the air agency. We have not received any official intimation. There is no display on board. I will know better once I go in,” he said. His experience echoed that of many other travellers who waited at terminals with little information available on display boards or through customer service desks.

As delays mounted, the AAI released a separate advisory informing passengers that technical teams were working around the clock to restore the AMSS. The authority explained that the issue had forced ATC personnel to carry out time-sensitive tasks manually, inevitably slowing down flight clearance procedures. “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 in its post.

Given that IGIA is India’s busiest airport, handling hundreds of domestic and international flights daily, even a brief disruption can quickly magnify across the aviation network. On Friday, as more than 100 flights were delayed, airline schedules were thrown into disarray. Several carriers, including Air India, IndiGo, and SpiceJet, issued public advisories alerting passengers to anticipate delays and urging them to check the latest updates before heading to the airport. Some airlines activated contingency measures, such as manned kiosks, additional customer service personnel, and mobile notifications, but many travellers still reported receiving insufficient communication.

Air traffic control, a highly specialised service, involves guiding aircraft on the ground, during takeoff, in transit through controlled airspace, and during landing. Controllers depend on a suite of interconnected systems to ensure safety, efficiency, and real-time communication. The AMSS is one such system responsible for handling automated electronic messages related to flight movements. Any interruption to this system poses immediate operational challenges. Aviation experts noted that while manual processing is a necessary fallback method, it cannot match the speed and precision of automated systems, especially in high-traffic air hubs such as Delhi.

In addition to causing delays at IGIA, the ATC glitch had a ripple effect on operations at other airports. Flights headed to Delhi were placed in holding patterns, diverted, or delayed at their points of origin to prevent runway congestion. Some airlines temporarily suspended check-in procedures for certain Delhi-bound flights to avoid overwhelming the passengers already waiting at the terminals. Aviation analysts said that such technical disruptions highlight the importance of redundancy in critical communication systems, including robust backup mechanisms, updated software infrastructure, and real-time monitoring tools.

Amid the growing disruption, airport authorities urged travellers to remain patient and assured them that all efforts were underway to restore the system. Staff on the ground attempted to manage large crowds by regulating queues, providing water and seating where possible, and directing passengers toward airline help counters. However, the volume of travellers and the uncertainty surrounding revised schedules stretched resources thin. Airport lounges also saw a surge in demand as passengers sought comfortable spaces to wait out the delays.

By late afternoon, technical teams were still working to identify the exact cause of the system failure and perform necessary fixes. Although officials did not specify a timeline for full restoration, sources indicated that progress was being made and that partial functionality of the AMSS could be restored before the end of the day. In the meantime, manual operations continued, ensuring that flights could still be cleared, albeit at a slower pace.

Situations like these underline the pivotal role that airport communication systems play in modern aviation. Whether managing routine operations or handling unexpected glitches, ATC systems must operate with precision, speed, and resilience. The incident at Delhi airport serves as a reminder of how dependent aviation networks are on seamless technological integration, and how vulnerable they can be when systems fail.

As passengers waited for the situation to stabilise, airlines and airport authorities maintained that safety remained their top priority. “Delays are inconvenient, but ensuring safe operations is our foremost responsibility,” an airline official said. “We appreciate passengers’ patience as we work with ATC and the airport to restore normalcy.”

With flights disrupted throughout the day, the recovery process is expected to take several hours, even after the system is fully restored. Travellers have been urged to continue monitoring airline channels for real-time updates. For many, the day’s events have highlighted the unpredictability of air travel, particularly when it hinges on complex technical systems that must function flawlessly to keep aviation moving without interruption.