NEW DELHI: An Air India Boeing 777 bound to Chicago from the capital returned to Delhi six hours after taking off from IGI airport on Monday after it suffered transponder failure just when it was about to cross Afghanistan . The flight, which took off from the capital about 2 in the morning with 313 passengers and 16 crew members on board, had flown for about three hours.

The aircraft had entered Afghanistan's air space but since it had to go through Europe which does not permit entry of such an aircraft in its airspace, it had to turn back. It returned to IGI at 5am.

"The flight took off at 2.15am but, when it entered the Afghan airspace, it developed a technical snag in its transponder whereby the signal transmitted by the ATC to the aircraft was not visible. The transponder assists the ATC in identifying aircraft on its radar and can give collision warning to the pilot if it gets dangerously close to another aircraft in air," said a senior airport official. TNNThe flight was scheduled to take off at 2 pm but since the duty hours of the crew had ended by that time, the passengers were asked to deboard and board another aircraft.

Later during the day another incident was reported from the IGI when an air-force aircraft faced some issues with its landing gear. The incident was described as minor in nature. "A Dornier aircraft was to land at the airport but the pilot reported some issues with the hydraulic landing gear. However the landing gear did open up in another attempt and the plane was guided down safely at runway 28," said a senior airport official.

