A snag in the air traffic control system at Delhi airport on Friday delayed the take-offs of at least 600 domestic and international flights, causing chaos and leaving many passengers stranded.
Later in the evening, the Airports Authority of India (AAI) said the issue had been resolved, but normal operations might take some time.
According to flight-tracking website Flightradar24.com, 97 per cent of departing flights were delayed at the Indira Gandhi International Airport till 6pm, and the average delay was over an hour (62 minutes).
The website showed that 68 per cent of arrival flights were late, and the average delay was 46 minutes.
Air India, Air India Express, IndiGo, SpiceJet and Akasa Air issued travel advisories asking passengers to keep checking the latest updates on flights and contact the airlines in case of any difficulty.
Sources said Delhi airport handled around 1,300 flights on average daily.
The technical glitch at Delhi airport also affected flights at Mumbai, Lucknow and Jaipur airports.
The AAI, in a post on X at 10.08am, said flight operations at Delhi airport were facing delays because of 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. Technical teams are working to restore the system at the earliest. We appreciate the understanding and cooperation of all passengers and stakeholders,” the AAI posted.
What is AMSS?
The AMSS feeds data to the auto-track system, which helps it to display flight plans for air traffic controllers (ATC).
The ATCs give information and instructions to pilots to help them take off and land safely and on time. By managing the flow of critical operational messages between airports and airline units engaged in handling flight services, the AMSS helps in the smooth arrival and departure of flights.
The snag in AMSS disrupted data transmission to the screens of ATCs, forcing them to make flight plans manually and resulting in the delay.
Delhi International Airport Ltd issued an advisory asking passengers to follow updates on revised flight schedules.
Airlines expressed regret for the inconvenience caused by the unforeseen disruption and said their cabin crew and on-ground staff were extending immediate assistance to passengers.
“Due to an ongoing technical issue with the Automatic Message Switching System that supports Air Traffic Control data, flights across all airlines at Delhi Airport and some other airports in the northern region are currently experiencing delays,” IndiGo said in a post on X.
At Delhi airport, long queues were seen near boarding gates and hundreds of passengers had to wait inside the airport terminals for flight updates.
YouTuber Elvish Yadav, one of the affected passengers, took to X to vent his frustration. “Frustrating experience with Indigo Airlines! Flight 6E0615 was supposed to depart at 1 pm, but now it’s delayed again and departing at 3:35 pm! If you’re in a hurry, you’re out of luck! Such poor management and lack of respect for passengers’ time! #IndigoAirlines @IndiGo6E.”
A female passenger complained on social media about having to sit on the plane for three hours without any in-flight announcement, food, tea or coffee. A social media user complained that she missed an official meeting and a connecting flight and received no help or compensation.
Later in the evening, the AAI said the technical issue in the AMSS had been fixed.
“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,” the AAI said.
