Flight operations normal at Delhi airport; govt to carry out root cause analysis of ATC glitch

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.

In a statement, the civil aviation ministry said the system was fully restored to automatic mode by Saturday afternoon and that there were no flight cancellations on Saturday owing to the issue.

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

Civil Aviation Minister K Rammohan Naidu has directed officials to carry out a detailed root-cause analysis of the technical glitch and also have more system advancements, including additional or fallback servers to strengthen ATC operations.

''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 that 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.

''We are happy to share that operations are stabilizing, and flights will soon be running as scheduled,'' the country's largest airline IndiGo said in a post on X on Saturday evening.

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.

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.