What the black-box revealed..

Last-second moves tried in air crash, black boxes reveal
Planes hit at right angle over Germany:

Berlin – Black-box recordings reveal that the cockpit crews of two planes that collided over southern Germany, killing 71 people, saw each other coming and attempted last-second manoeuvres to avoid hitting at almost 10,670 metres, investigators said Friday.

A partial analysis of the flight data and voice recorders also showed that onboard collision warnings and a cargo plane pilot’s word to ground control that he was descending came significantly later than previously believed.

A Bashkirian Airlines Tu-154 and a DHL International Boeing 757-200 cargo jet slammed into each other July 1 after both planes descended – the Russian plane in response to an air traffic controller’s instruction, the cargo jet in response to its onboard collision-avoidance computer.

The Russian pilot, however, was warned by his onboard computer to climb just eight seconds before impact, investigators said.

The planes hit at a right angle in German airspace in a border region overseen by Swiss controllers.

“The recordings allow the conclusion that members of both planes’ crews saw the other aircraft a few seconds before the crash and attempted to avoid the collision with appropriate manoeuvres,” said Friday’s statement from the German air accident investigation agency.

Giving the most detailed timeline yet, the agency said both planes’ computers first warned the cockpit crews of a “possible conflict” 50 seconds before the crash without suggesting a course change.

Thirty-six seconds before the crash – nine seconds later than previously estimated – both planes’ computers told the pilots to take emergency evasive action, the statement said. The computers directed the DHL jet to descend and the Russian plane to climb.

The DHL plane immediately followed the command, but told ground control only 13 seconds before impact. Investigators previously believed the pilot advised the Zurich, Switzerland, controller 29 seconds before the crash, spokesman Frank Goeldner said.

But the Russian pilot started descending after a second request from Swiss air traffic control – putting his plane on a collision course.

Eight seconds before impact, the Russian plane’s computer told the pilot to “increase climb.” The DHL plane’s computer told it 22 seconds before the crash to “increase descent.”

Goeldner refused to elaborate on the final seconds, saying the inquiry was not yet complete.

The crash killed 69 people on the Russian plane, including 45 school students heading for a Spanish beach vacation, and the two DHL pilots, including Canadian Brant Campioni.

Investigators have focused on the role of Zurich controllers. Swiss prosecutors have launched a criminal investigation to see whether charges of negligent homicide are warranted.

A lone controller was on duty while a colleague took a break, a collision-warning system was down for maintenance and the phones were being serviced.

Switzerland has conceded that its air traffic controllers were at least partly to blame for the collision. The air traffic controller on duty at the time also offered his condolences.

Russian officials said the Bashkirian pilot correctly followed the controller’s order instead of his onboard warning system.
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Link: http://www.herald.ns.ca/stories/2002/07/20/f205.raw.html