Delhi airport’s air traffic control systems to be upgraded by Jan 2026

The rebuilt configuration ensures that the backup can function independently in case the primary system faces another fault.

New Delhi: Days after a major system “glitch” left over 900 flights delayed at the Indira Gandhi International airport, the Airports Authority of India (AAI) is set to upgrade its computer systems at Delhi’s Air Traffic Control (ATC) by January next year, a project that was originally slated for completion by mid-2026.

Passengers wait outside the departure terminal at Indira Gandhi International (IGI) Airport on November 7 when the glitch took place (Sanjeev Verma/HT Photo)

An official privy to the development said the Aeronautical Message Handling System (AMHS) had already been installed at the ATC, and was currently in the process of being commissioned. It will be ready to use in two months.

“The AMHS requires air traffic controllers to be trained, which is currently ongoing. It will operate parallelly with the existing system for the initial few days before fully taking over operations,” the official added.

In the interim, however, AAI has rushed in emergency hardware changes, including installation of new primary and secondary servers along with an entirely new switch, after both the main and backup server units collapsed due to a single point of failure on November 6.

Another official said: “Though the impact on flights was controlled within hours, our systems were fully recovered and secured last week by the Electronics Corporation of India Limited (ECIL),” adding that what and why the glitch occurred was being ascertained.

“The existing Automatic Message Switching System (AMSS — which was commissioned in 2017 — has both the primary and backup server units dependent on a common switch for data flow. The switch distributes real-time information to both the servers. If the primary unitfails, the backup takes over, but both rely on the same switch.,” the official explained.

“When the issue occurred, we initially didn’t know whether the problem was with the switch or the servers. When the main server failed, operations shifted to the backup server, but full control could not be established,” the official added, adding that standalone controls had to be reinstalled on the spot to restore the system.

Officials informed that temporary safeguards were capable of preventing the kind of disruption triggered on November 6. The rebuilt configuration ensures that the backup can function independently in case the primary system faces another fault.

Notably, glitches are not uncommon in computer systems, even in ATC infrastructure, but this was the first incident that took more than 24 hours to be resolved, raising questions on the nature of the failure.

Union civil aviation minister Ram Mohan Naidu took stock of the Delhi ATC on November 7, and directed that a detailed root-cause analysis be undertaken to prevent recurrence of such glitches.