The airport's IT system, installed and maintained by the airport operator -- Delhi International Airport Limited, developed snag at around 8.20 AM which was rectified by around 9.40 am.
Due to this, 20 domestic, including nine of Air India, and one international flights departing from the airport were delayed by up to one-and-a-half hours, sources said.
The glitch in the computer system led to malfunctioning of CUTE (Common User Terminal Equipment) systems, which helps streamline reservation system at the airport and facilitates check-in of passengers of individual airlines from a common terminal, forcing the airlines to do the check-in manually.
The airlines and passengers faced problems in boarding aircraft. The boarding gates and baggage belts were not functioning properly due to which everything had to be done manually, a senior airline official said.
The official said the Visual Docking Guidance System, which gives information to a pilot about park a plane, was also not working functioning properly, airport sources said, adding the aircraft had to guided to their stands by the marshals.
A DIAL spokesperson said, "A technical glitch was observed at T3 at 8.20 am which was fully restored at 9.40 am. This led to some interruption in passenger processing and information display services. All systems are fully functional now."
However, airline officials claimed though it was restored, it had functioned "erratically".
IGI airport witnesses a great departure rush between 5 am to 9 am. As most of the flights had left, only a few departures were affected, they said.
Also, Terminal 3 has less number of domestic departures compared to Terminal 1 D from where all the low-cost carriers -- IndiGo, GoAir and SpiceJet -- fly. Air India and Jet Airways operate flights from Terminal 3.
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