Major Technical Glitch at Delhi Airport: How AMSS Failure Disrupted Nearly 800 Flights and Stranded Thousands

Thousands of passengers were stranded inside Delhi's terminals due to the flight delays.

New Delhi:

Nearly 800 flights experienced delays at Delhi airport, India's busiest aviation hub, following a significant technical malfunction in the Air Traffic Control (ATC) system on Thursday evening. This disruption affected flight planning procedures and created a domino effect across multiple airports nationwide.

The problem originated in the Automatic Message Switching System (AMSS), a critical component supporting the ATC's data network, which forced controllers to resort to manual processing of flight plans.

Officials characterized the situation as "unprecedented," noting that such a severe technical failure "has not happened earlier."

The Airports Authority of India (AAI) has announced that flight operations at Delhi's Indira Gandhi International Airport have now stabilized following the technical fault in the AMSS that disrupted services on Thursday.

In their official statement, the AAI explained that the glitch, detected on November 6 in the IP-based AMSS system, had caused significant delays in processing flight plan messages for Air Traffic Control. The system has since been restored and is "up and functional now," according to the authority.

"Immediately after the fault was identified, a review meeting was conducted by the Secretary, Ministry of Civil Aviation, along with the Chairman of AAI, Member (ANS), and other senior officials. Necessary directions were issued to address the issue," stated the AAI.

The organization further explained that they engaged the Original Equipment Manufacturer (OEM) to assist with repairs, while additional personnel were deployed to manually process flight plans, ensuring uninterrupted and safe air traffic operations during the system downtime.

A specialized team comprising officials from Electronics Corporation of India Limited (ECIL) and AAI remains on-site to monitor the system's performance continuously.

"The AMSS systems are up and functional now. Due to some backlog, there may still be minor delays in the normal functioning of automated operations, but the situation will return to normal soon. We regret the inconvenience caused to airlines and passengers," the AAI acknowledged.

What Is AMSS?

The Automatic Message Switching System (AMSS) serves as a vital component of India's air traffic management infrastructure. It automatically receives, processes, and distributes flight plan data—detailed information submitted by airlines prior to each departure—to controllers throughout the country.

At Delhi's Indira Gandhi International Airport (IGIA), which handles over 1,500 flight movements daily and approximately 70 per hour, the AMSS supplies real-time data to the Auto Track System (ATS), enabling controllers to monitor aircraft routes, altitudes, and schedules with precision.

When the system failed on Thursday evening, controllers lost access to automated flight plan data. Every flight plan, containing routing information, fuel requirements, altitude specifications, and weather parameters, needed manual generation—a process requiring several minutes per flight. With hundreds of aircraft scheduled hourly, operations slowed dramatically.

How Did The Glitch Happen?

Sources informed NDTV that the issue was first detected Thursday evening when ATC officers reported missing flight plan data on their terminals. Within minutes, controllers realized that the AMSS had malfunctioned, interrupting automatic message transmission.

NDTV learned that since controllers weren't receiving flight plans automatically on their screens, airlines resorted to preparing them manually. The system stopped transmitting data to the auto track system.

The Airports Authority of India (AAI) stated, "Technical teams are working to restore the system at the earliest. Such a glitch is uncommon and has not happened earlier."

Widespread Impact On Flights

Delhi's IGI Airport, ranked among the world's top 10 busiest airports, experienced hundreds of delayed flights throughout Thursday night and into Friday. According to flight-tracking service Flightradar24, 513 flights were delayed on Thursday, and by Friday, the number had increased to nearly 800 delayed flights.

Average departure delays ranged between 45 minutes to an hour, while arrivals also faced delays due to limited parking bays and airspace congestion. Officials indicated that the cascading effect could "take several hours to normalise even after full restoration."

Chaos At Delhi Airport

With each pre-departure task now being performed manually, the airport experienced massive disruption. Thousands of passengers were stranded in Delhi's terminals by Friday evening. Many waited for hours as departure boards displayed repeated delays. Long queues formed at check-in counters and boarding gates, with passengers seeking updates from airline personnel.

Numerous travelers reported on social media that they were kept on board aircraft for extended periods before takeoff. Airport staff distributed refreshments and provided updates through announcements.

Airlines Issue Statements To Alert Passengers

All major airlines, including IndiGo, Air India, SpiceJet, Akasa Air and Air India Express, were affected by the outage. Some deployed additional staff to coordinate directly with ATC.

An Air India Express spokesperson said, "A technical issue with Air Traffic Control in Delhi has impacted flight operations across all airlines, including Air India Express. Our teams are actively assisting guests at the airport and working closely with the authorities to minimise delays."

Air India Express, which operates approximately 60 domestic flights and four international services daily from Delhi, advised passengers to verify their flight status on the airline's website or mobile app before heading to the airport.

IndiGo, in an advisory on X, stated: "Flight operations at Delhi Airport are currently experiencing delays due to a technical issue with the Air Traffic Control system. As a result, flight operations at Delhi and several northern regions are impacted. We understand the inconvenience and appreciate your patience."

Air India also acknowledged the disruption, saying: "We regret the inconvenience caused by this unforeseen disruption, which is beyond our control. Our cabin crew and on-ground staff are assisting passengers. Please check your flight status before heading to the airport."

The effects of the glitch extended to several airports, including Hyderabad, where multiple flights were delayed as ATC operations slowed.

In Hyderabad, flight-tracking data revealed that at least 21 flights between Delhi and Hyderabad—11 arrivals and 10 departures—were delayed between 8 am and 8 pm on Friday. Most affected flights were operated by IndiGo, followed by Air India and Akasa Air.

What Officials Are Saying

AAI officials emphasized that while such technical issues are uncommon, flight safety was never compromised. "There was no impact on aircraft already in the air. The disruption was purely related to the pre-departure message flow and flight plan processing," an official explained.

They confirmed that the root cause appears to be a malfunction in the central AMSS software, which manages message routing between airports.