<<Print>>The co-pilot of the doomed Germanwings Airbus A320 locked his captain out of the cockpit before deliberately crashing into a mountain to 'destroy the plane', it was sensationally revealed today.
French prosecutor Brice Robin gave further chilling details of the final ten minutes in the cockpit before the Airbus A320 plunged into the French Alps killing 150 people.
Revealing data extracted from the black box voice recorder, he said the co-pilot - named as 28-year-old German Andreas Lubitz - locked his captain out after the senior officer left the cockpit. At that point, Lubitz uses the flight monitoring system to put the plane into a descent, something that can only be done manually.
He said: 'The intention was to destroy the plane. Death was instant. The plane hit the mountain at 700km per hour.
'I don't think that the passengers realised what was happening until the last moments because on the recording you only hear the screams in the final seconds'.
Earlier in the flight, Mr Brice said Lubitz's responses, initially courteous, became 'curt' when the captain began the mid-flight briefing on the planned landing of the plane.
The captain - named by local media as German father-of-two Patrick S - then leaves the cockpit but finds he is locked out when he tries to re-enter.
Mr Robin said: 'We hear the pilot asking the co-pilot to take over and we hear the sound of a chair being pushed back and a door closing so we assume that the captain went to the toilet or something.
'So the co-pilot is on his own, and it is while he’s on his own that the co-pilot is in charge of the plane and uses the flight monitoring system to start the descent of the plane.
'At this altitude, this can only be done voluntarily. We hear several shouts from the captain asking to get in, speaking through the intercom system, but there’s no answer from the cockpit.’
Mr Robin said Lubitz 'voluntarily' refused to open the door and his breathing was normal throughout the final minutes of the flight.
He said: 'His breath was not of somebody who was struggling. He never said a single word. It was total silence in the cockpit for the ten past minutes. Nothing.'
Mr Robin said he had no known links with terrorism, adding: 'There is no reason to suspect a terrorist attack.'
And asked whether he believed the crash that killed 150 people was the result of suicide, he said: 'People who commit suicide usually do so alone... I don't call it a suicide.'
The revelations came after audio files taken from the black box recorder suggested that one of the pilots was forced to try and smash down the door after being unable to enter the flight deck, according to the New York Times.
Experienced pilots today told MailOnline that under normal conditions crew have an emergency access code to enter the cockpit through the locked door.
They can only be stopped from using it if whoever is inside the cockpit manually – and intentionally – disables it.
The revelation will heighten fears that suicide or a terror attack was the cause of the disaster.
Locks on cockpit doors were introduced throughout the world's airlines in the aftermath of 9/11 to keep terrorists from taking the controls in a hijacking.