Probe to focus on 8-minute drop without a mayday
TRAGIC: A screen grab showing debris of the Germanwings A320 at the crash site in the French Alps. The plane, which had taken off from Barcelona, Spain, and was headed for Dusseldorf, Germany, crashed with 150 people onboard. - PHOTO: AFP
Investigators probing the crash of Germanwings Airbus A320 will focus on its mysterious drop which spanned eight minutes without a single mayday call.
It was French air traffic controllers, not the A320's two pilots, who declared an emergency after the plane spent just 60 seconds cruising at 38,000 feet before plunging to 5,000 feet, Bloomberg reported.
Declaring an emergency even in difficult circumstances is a bedrock principle of pilot training, compounding the mystery over the crew's silence as the tragedy unfolded in broad daylight and benign weather conditions.
"Something triggered a descent," said Mr Paul Hayes, director of safety at London-based Ascend, an aviation data provider.
"They'll want to know whether that's to do with the aircraft, with some external event, with the crew, or with a combination of all of those. And they'll want to know why the descent wasn't stopped and the aircraft recovered," he said.
Attempts were made to contact the crew during the descent, without success, according to the SNCTA union, which represents air traffic management workers.
"There were a lot of consecutive calls," SNCTA national secretary Roger Rousseau said. "The controller sees the altitude of the aircraft on his radar, and if he sees the altitude dropping he immediately calls the pilot."
Mr Bill Waldock at the Embry Riddle Aeronautical University in Prescott, Arizona, said that the Germanwings A320's eight-minute descent was "fast, but not outside the limits", and that the silence of its pilots may suggest they were too preoccupied with getting the plane to a lower altitude to talk.
"No communication would argue something was going on which caused the pilots to not really try to communicate," Bloomberg quoted him as saying.
"If they had an emergency of some sort and were trying to control the airplane, that's the number one priority."