Flight operations at Delhi’s Indira Gandhi International Airport (IGIA) were disrupted following a technical fault in the Automatic Message Switching System (AMSS), which facilitates data exchange for Air Traffic Control (ATC).
All airline operations at the airport have been affected, and authorities are working to resolve the issue. As many as 1,000 domestic and international flights have been delayed so far. At least 20 flights have been cancelled. The Mumbai airport also issued a statement announcing that its air traffic was impacted due to the malfunction. The slowdown began showing network-wide effects from Thursday afternoon. According to the flight-tracking website Flightradar24 , 513 flights were delayed on Thursday alone, and over 500 flights have faced delays since Friday morning.
IGI Airport, India’s busiest, handles over 1,500 flight movements daily. “The issue began on Thursday afternoon at around 3 pm. It has prevented air traffic controllers (ATCOs) from receiving flight plans automatically on their screens,” said one official familiar with the matter.
Following the disruption, the Airports Authority of India (AAI) in the evening said the technical issue in the air traffic control’s Automatic Message Switching System (AMSS) that had caused flight delays at the Delhi airport has been addressed and that the system is “up and functional now”. AAI also said that due to some backlogs, there may be some delays in the normal functioning of automated operations, but the situation will be normal soon. The State-owned AAI said the issue was detected in the IP-based AMSS system on November 6. AAI said it has addressed the “technical issue in the Automatic Message Switching System (AMSS), which caused delays in processing flight plan messages”.
“The OEM (Original Equipment Manufacturer) was engaged, and additional staff were deployed to manually process Flight Plans for the Air Traffic Control system to ensure uninterrupted and safe air traffic operations immediately.” A team of ECIL officials and AAI personnel is still on site. 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,” AAI said in a post on X at 8:56 pm.
The issue was detected on November 6, and immediately, a review meeting was conducted by the Civil Aviation Secretary, along with the AAI Chairman, AAI Member ANS, and other officials, and necessary directions were given to address the issue, as per the post.
“All airline operations at Delhi Airport are currently delayed. Concerned authorities are working to resolve the issue at the earliest,” Delhi International Airport Ltd (DIAL), the airport’s operator, said in a post on X at 1:42 pm.
DIAL added that flight operations have been affected due to an ongoing technical issue with the AMSS, which supports the air traffic control flight planning process.
The disruptions have led to long delays and extended waiting times both at the airport and onboard aircraft, Air India said in a morning post. The airline added that its cabin crew and ground staff are providing prompt assistance to minimise inconvenience to passengers. “A technical issue with the ATC system in Delhi is impacting flight operations across all airlines, resulting in 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,” the airline’s travel advisory read.
Budget carriers SpiceJet and IndiGo also confirmed that flights at Delhi Airport and across several northern regions have been affected by the disruption. SpiceJet said its crew and ground teams are working closely with airport authorities to minimise the impact and resume normal operations as soon as possible. IndiGo posted on X that “due to an ongoing technical issue with the Automatic Message Switching System (AMSS) that supports Air Traffic Control data, flights across all airlines at #DelhiAirport and other airports in the northern region are currently experiencing delays.”
Sources reported long queues near boarding gates, with hundreds of passengers waiting inside terminal buildings for flight updates. Air traffic controllers have been unable to receive flight plans automatically since Thursday evening due to a technical fault. One source added that the AMSS, which provides data to the Auto Track System (ATS) for generating flight plans, has been experiencing issues. With the system malfunction ongoing, controllers are manually preparing flight plans using available data - a time-consuming process - resulting in widespread delays.
The sources also noted that the problem is causing air traffic congestion at the airport, and technical teams continue efforts to fix the fault as soon as possible. The airport had been facing major disruptions over the past week after suspected GPS spoofing incidents that interfered with the aircraft navigation systems and forced many flights to divert. This led to unexpected air traffic congestion.
