Warning System Switched Off in Midair Collision over Germany

Midair Collision Over Southern Germany
Air traffic controllers in Switzerland said on Wednesday an automatic warning system was switched off and one staff member was on a break when a Russian airliner and a cargo jet collided over southern Germany.

Skyguide, the Swiss air traffic control company responsible for planes at the time of the crash, said the system, which should have warned ground control that the two planes were on a collision course, was out of action for routine maintenance.

German aviation officials said the Russian plane was given just50 seconds to drop its altitude. Swiss controllers previously said the pilots had two minutes of warning and the Russian pilots were too slow to react.

By the time the Russian plane responded to ground control's warnings and changed its altitude, a safety device on board the cargo jet meant it too was plunging downwards and - instead of avoiding each other - the two planes collided, bursting into a fireball.

Nikolai Odegov, director of Bashkirian Airlines (BAL), has denied that its Tupolev pilot could have been responsible for the crash by failing to heed the first warning, saying he was extremely experienced.

The midair collision over the Constance Lake at German-Swill border on late Monday killed 71 people including 45 children.

Initially, Skyguide said that under its regulations, two members of staff should be on duty when the early warning system is off line.

Later, it said in a statement it said controllers could take breaks at night if the skies were quiet.

Investigators are trying to establish why Swiss air traffic controllers allowed the two aircraft to fly so close to each other on Monday night that a disaster could not be avoided.

They will especially want to know why the Swiss agency was forced to change its story about how many warnings it gave the Russian pilot and how long they were issued before the impact.

The inquiry is also attempting to find out how two planes equipped with automatic avoidance systems dived into each other.

Initially the Swiss said the pilot of the Bashkirian Airlines Tupolev 154 was given "two or three warnings" about the impending danger up to two minutes before the crash.

A later statement, however, said there had been two warnings, the first of which was transmitted 50 seconds before the collision. When the Russian pilot responded on the second occasion it was too late.

Just as baffling is the fact that both the Russian aircraft and the Boeing 757 freight plane seemed to have been equipped with the ACAS collision-avoidance system, which should have advised the captains on evasive action. Both aircraft dived from a height of about 36,000 feet.

People's Daily Online --- http://english.peopledaily.com.cn/