 "By Friday morning, the tech issue had snowballed into widespread delays, particularly during Delhi airport’s peak rush hours, as airlines struggled to manage schedules and passengers flooded terminals in search of updates. File Image/PTI")
Hundreds of passengers were stranded at Delhi’s Indira Gandhi International Airport (IGIA) on Friday morning after a massive technical glitch disrupted operations, leading to over 100 flight delays and confusion across several northern airports.
The problem, which started late on Thursday, hit the airport’s central Air Traffic Control (ATC) system, a critical network that manages flight data and clearances. With the system down, air traffic controllers were forced to handle requests manually, slowing down departures and arrivals through the night.
By Friday morning, the issue had snowballed into widespread delays, particularly during the airport’s peak rush hours, as airlines struggled to manage schedules and passengers flooded terminals in search of updates.
Here’s what went wrong at India’s busiest airport.
What led to the tech glitch?
The Airports Authority of India (AAI) confirmed that the delays were triggered by a technical fault in the Automatic Message Switching System (AMSS), a crucial network that supports ATC by managing and transmitting flight data.
“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," they said in a statement.
With the automatic system down, controllers had to manually process and verify flight plans using limited data, a slow and tedious process that caused severe congestion in Delhi ’s airspace and cascading delays across multiple routes.
Sources told News18 that the agencies are probing if the failure may have been caused in the automation software, which was trying to handle conflict and potential malware attacks. “This is also targeting system interfaces or radar synchronisation modules," sources added.
The ATC said that technical teams were working around the clock to fix the issue and restore normal operations.
“Technical teams are working to restore the system at the earliest. We appreciate the understanding and cooperation of all passengers and stakeholders," it added.
While technicians continued efforts to restore full operations, officials warned that the backlog could take hours to clear, with ripple delays anticipated at airports in Lucknow, Jaipur, Chandigarh, and Amritsar.
Delhi’s Indira Gandhi International Airport, the busiest in India, handles more than 60 aircraft movements every hour, accounting for nearly 1,500 arrivals and departures daily and serving over 73 million passengers each year. Flight tracking website Flightradar24 showed departure delays averaging 45–50 minutes by 9 am.
Airlines release advisories
Several airlines issued travel advisories, urging passengers to check their flight status before leaving for the airport.
Air India said the disruptions had led to longer wait times both inside terminals and onboard aircraft. The airline assured that its cabin crew and ground staff were assisting passengers to minimise inconvenience.
“A technical issue with the ATC system in Delhi is impacting flight operations across all airlines, leading to delays and longer wait times at the airport and onboard aircraft. We regret the inconvenience caused by this unforeseen disruption, which is beyond our control, and appreciate your patience,” Air India said in a statement.
SpiceJet and IndiGo also confirmed that flights across Delhi and several northern regions were affected by the glitch.
SpiceJet said its crew and ground staff were working closely with airport authorities to reduce delays and restore normal operations as quickly as possible.
“We understand that extended wait times, both on the ground and onboard, may cause inconvenience, and we sincerely appreciate your patience,” IndiGo said in its advisory.
Frequent tech snags hit Delhi Airport
In recent weeks, operations at Delhi’s IGI airport have been hit by a series of technical issues.
Just days before Friday’s system failure, the airport faced major disruptions following suspected GPS spoofing incidents, which interfered with aircraft navigation systems.
GPS spoofing happens when fake satellite signals are sent to mislead navigation systems, making aircraft calculate false positions or altitude readings. Unlike GPS jamming, which blocks signals, spoofing feeds incorrect data, tricking systems into showing wrong routes or approach paths.
When spoofing occurs, pilots lose accurate navigational guidance, forcing air traffic controllers to manually maintain safe distances between planes. This increases radio communication and workload significantly, especially at a busy hub like Delhi.
Last month, a Delhi-bound flight from Vienna had to be diverted to Dubai after encountering spoofed signals mid-route.
According to FlightRadar data, Delhi’s IGI Airport ranked second globally for flight disruptions on Tuesday, just behind Kathmandu.
With input from agencies