NEW DELHI: Flight operations at Delhi’s Indira Gandhi International Airport were thrown into chaos on Friday after the Air Traffic Control’s (ATC) ageing software crashed, following a technical glitch first detected on Thursday evening. The disruption delayed more than 800 flights — both arrivals and departures — by up to two hours and led to the cancellation of around 100 services through the day.
The Airports Authority of India (AAI), which operates the ATC system, came under fire for delays in upgrading the critical software that manages flight plans for India’s busiest airport. Late on Friday, AAI said the Automatic Message Switching System (AMSS) had been restored to full functionality.
“Due to some backlogs, there may still be minor delays in automated operations, but the situation will return to normal soon,” AAI said in a statement.
The Directorate General of Civil Aviation (DGCA) has ordered a probe into the incident. Officials ruled out the possibility of a cyberattack, while airlines warned that residual delays could continue into the weekend.
Manual Operations Lead to Nationwide Delays
With the automated AMSS system down, ATC officials had to manually enter flight plan data — a time-consuming process that slowed down departures and arrivals across the country.
The AMSS allows airlines to file flight plans 24 hours in advance for both domestic and international routes operating in or over Delhi’s airspace. Its failure forced controllers to revert to manual coordination for hundreds of aircraft, significantly increasing workload and processing time.
Delhi airport handles around 1,550 flight movements daily, along with hundreds of overflying aircraft. Manual data handling, prone to human error, takes nearly four times longer than the automated system.
As a result, airports in other major cities — including Mumbai — also experienced cascading delays. Real-time tracker Flightradar24 showed Delhi as the world’s most disrupted airport for much of Friday.
AAI, Airlines Respond Amid Passenger Frustration
AAI said it had detected the issue on Thursday and immediately convened a review meeting.
“The original equipment manufacturer was engaged, and additional staff deployed to manually process flight plans for safe and uninterrupted air traffic operations. We regret the inconvenience caused to airlines and passengers,” the authority said in a post on X (formerly Twitter).
Amid widespread delays, IndiGo advised passengers traveling to or from Delhi to check updated flight schedules and arrive earlier than usual. Air India also issued a statement warning of “delays and longer wait times at the airport and onboard aircraft.”
Airline officials said the AMSS had a history of glitches and blamed the delay in implementing the new Air Traffic Services Message Handling System (ATSMHS), which is still being installed.
“The new system should have been in place five years ago,” one airline representative said. “Currently, flight plans must be filed separately with four different Flight Information Regions — Delhi, Mumbai, Kolkata, and Chennai. A centralized submission system would make operations far smoother.”
