Flight operations at Delhi airport are normal: DIAL

Airline operations at the Delhi airport, the country's busiest airport, are normal now, airport operator DIAL said on Saturday, a day after a glitch with the air traffic control system delayed more than 800 flights.

The technical problem with the Automatic Message Switching System (AMSS), which supports the air traffic control's flight planning process, continued for over 15 hours from around 5:45 am on Friday before the Airports Authority of India (AAI) said at around 9 pm that the issue had been addressed.

The Indira Gandhi International Airport (IGIA) in the national capital, which has four runways, handles more than 1,500 flight movements daily.

All flight operations are normal, an official said.

''All flight operations are normal at Delhi Airport... passengers are advised to stay in touch with their respective airlines for the latest flight updates,'' DIAL said in a post on X.

Earlier in the day, Delhi International Airport Ltd (DIAL) had said the technical issue that affected the AMSS is gradually improving.

Apart from over 800 flights that faced delays, some services were also cancelled on Friday, impacting hundreds of passengers.

The country's largest airline, IndiGo, on Saturday morning said the airport operator and Air Traffic Control (ATC) teams are working on a priority basis to fully restore systems and stabilise operations.

''The situation is expected to be normalised over the next few hours. During this period, some departure and arrival timings may continue to be adjusted,'' it said in a post on X in the morning.

Information available on the flight tracking website Flightradar24.com showed that over 500 flights were delayed at the airport, including arrivals and departures, on Saturday.

Specific reasons for the delays could not be immediately ascertained, while the official said it was also due to the backlog from Friday.

While the AMSS started facing the technical issue on Thursday late afternoon, the outage with the system happened at around 5:45 am on Friday, following which air traffic controllers had to prepare flight plans manually, according to sources.

The Airports Authority of India (AAI), which provides navigation and other services, had also deployed additional manpower to prepare the flight plans manually, which is a time-consuming process.

On Friday evening, the AAI said it had addressed the ''technical issue in the AMSS, which caused delays in processing flight plan messages''.

The issue was detected in the IP-based AMSS system on November 6.

''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,'' the AAI had said.