Goof-up sees Delhi airport radar screens go blank

Air traffic controllers at the Indira Gandhi International Airport in Delhi averted disaster on Friday afternoon after radar screens at the airport's air traffic control tower went blank for 10 minutes because electricians on routine maintenance duty had inadvertently switched off the main power button.

Some 22 flights were delayed as the screens of the ATC officers went blank at 12.21 pm. According to airport officers, standby power was restored within 10 minutes, though it took over 45 minutes to restore flight operations.

The ATC is equipped with three layers of power supply - one main and two auxiliaries. ''After the power failure occurred, the backup system was switched on. Power was restored by 12.31 pm,'' said Airport Authority of India spokesperson G S Bawa.

''There were no major problems with flight operations. The delays were because officers had to handle flight operations manually for at least 20 minutes,'' another airport official reportedly said.

The power shutdown caused both primary and back-up radar systems to go dead. These systems give the complete coordinates - such as altitude, speed and horizontal separation - of all aircraft over vast stretches of north India, and are essential guiding tools to avoid mid-air collisions. When the screens went blank, one aircraft was in its final descent over IGI.

Personnel of the ATC had to manually bring in arriving aircraft. All departing aircraft were asked to remain on the ground. An Air India and a Jet Airways aircraft were even given priority landing after the pilots reported fuel shortage. No plane was asked to go around the airport.