Over 800 flights delayed at Delhi Airport as ATC system glitch cripples operations

A major technical failure crippled flight operations at Delhi’s Indira Gandhi International Airport (IGIA) on Friday, causing delays to more than 800 flights and leaving hundreds of passengers stranded. The disruption, which began late Thursday, stemmed from a breakdown in the Automatic Message Switching System (AMSS), a key Air Traffic Control (ATC) network responsible for feeding data into the Auto Track System (ATS) that generates flight plans. The Airports Authority of India (AAI) confirmed that the AMSS was restored by late Friday evening, allowing operations to gradually return to normal.

In an official statement, Delhi airport authorities said, “Flight operations at Delhi Airport have been disrupted due to an ongoing technical issue with the Automatic Message Switching System (AMSS) that supports Air Traffic Control flight planning process. All airline operations at Delhi Airport are currently impacted. Concerned authorities are working on resolving the issue at the earliest.”
The advisory further urged passengers to “follow updates from their airlines regarding revised schedules.”

The system glitch had hit the processing of flight plan messages, forcing controllers to revert to manual operations to maintain air traffic safety. The AAI, along with engineers from Electronics Corporation of India Limited (ECIL) and support from the Original Equipment Manufacturer (OEM), worked through the day to restore the system. “Though minor delays may persist due to backlogs, automated operations are resuming, and normalcy is expected shortly,” the AAI said.

The outage triggered widespread disruptions at India’s busiest airport, which handles more than 1,500 flights daily. By 9 am, flight-tracking platform Flightradar24 showed average departure delays of 45 to 50 minutes, with ripple effects at other major airports including Mumbai, Lucknow, Jaipur, Chandigarh, and Amritsar.

A senior airport official confirmed, “Controllers are preparing flight plans manually, which is taking significant time.”
Aviation expert Captain Sharath Panicker explained the impact: “The system failure meant flight plans had to be entered manually instead of being automatically interpreted by the software. This manual process takes much longer and naturally leads to delays.”

He further noted that the disruption extended to the Automatic Terminal Information System (ATIS), which integrates real-time meteorological data. “Even the weather updates that pilots and controllers rely on now have to be fed in manually,” he said. “Once the aircraft is in the air, there’s not much impact, but getting the aircraft airborne takes significantly longer under such conditions.”

At the terminals, passengers reported long queues, repeated rescheduling, and confusion over departure times. Airlines including IndiGo, SpiceJet, and Air India issued advisories alerting passengers to possible delays. IndiGo posted on X that its operations were affected due to the technical issue, while SpiceJet warned of “possible delays in departures and arrivals due to ATC congestion.” Air India apologised for the “unforeseen disruption,” assuring that crew and ground staff were assisting passengers.

Technicians worked throughout the day to restore full functionality. By evening, AAI confirmed that the AMSS system was back online, and automated flight data processing had resumed. While some residual delays continued into the night, authorities said flight operations were steadily returning to normal.