The two planes should have been at least a thousand feet apart. So why did they collide?
Hours after a Saudi jetliner and a Kazahk cargo plane slammed into each other, killing up to 351 people Tuesday, explanations ranged from equipment trouble to a breakdown in communications.
But all theories were speculation.
Flight data recorders and cockpit voice recorders had not yet been found. Mohammed Akhil, a police officer supervising the recovery of bodies late Tuesday said that would have to wait until daybreak.
Yogesh Chandra, the civil aviation secretary, promised at a news conference “to get to the bottom of the crash.” The Indian government opened a judicial inquiry.
While civil aviation officials urged against speculation, the Air Traffic Controllers Guild of India suggested in a statement that the pilots of the Kazahkstan Airlines Ilyushin-76, working with metric instruments, may have misunderstood the feet-denominated instructions from controllers.
H.S. Khola, the director general of civil aviation, said the Saudia Airlines craft bound for Saudi Arabia had been told to climb to 14,000 feet, and the Kazahk plane was instructed to descend to 15,000 feet for its landing approach. Moments after the orders were given, the two planes disappeared from controllers’ radar screens.
Experts say Russian-built planes like the Kazahk cargo jet often don’t have equipment that detects the altitudes of nearby aircraft. Such transponders are required for planes flying into Europe or the United States, according to commercial pilot and aviation writer John Nance, based in Tacoma.
Equipment at New Delhi’s Indira Gandhi International Airport is considered state of the art.
Recently, air traffic controllers at the airport reportedly have been considering a strike over the dismissal of several colleagues. But airport manager Ranjan Chatterjee said he did not believe employee discontent could have contributed to the accident. Details of the controllers’ grievances were not immediately available.
The Saudi Boeing 747-100’s crew was commanded by one of the airline’s most senior captains, the official Saudi Press Agency reported.