A 28-year-old co-pilot was able to deliberately crash Germanwings flight 4U9525 after using security locks, introduced after the September 11 terrorist attacks, to prevent the flight’s captain from re-entering the cockpit.
The information that the first officer, named as German national Andreas Lubitz, most likely slammed the plane into the Alpine hillsides deliberately was revealed today by French investigators who had analysed data from the cockpit voice recorder retrieved from the crash site.
According to French prosecutor Brice Robin, Lubitz changed the plane’s trajectory after the captain left the cockpit, presumably for the bathroom. Lubitz's actions could not have been done accidentally, the investigators said.
The information that one of the pilots was locked out of the cockpit when the tragedy unfolded was leaked earlier by the New York Times, citing insider sources.
The French investigators confirmed the speculation during a press conference today, specifying it was the 28-year-old co-pilot Lubitz who stayed at the controls.
In a harrowing account, the investigators described hearing the captain knocking on the door, trying to return to the cockpit, but receiving no response from the first officer who can be heard breathing normally up until the impact.
"He was not breathing like somebody struggling. He said nothing. There was total silence in the cockpit," Robin said.
The captain can be heard becoming increasingly frantic as he tried to force his way into the locked cockpit, aware of the impending tragedy.
Experts said it was not possible that the captain would have been locked out unless it was the intent of the first officer.
In the wake of the September 11 2001 terrorist attacks, the International Civil Aviation Organisation (ICAO) introduced new regulations requiring cockpits on commercial planes to be equipped with bulletproof doors with security locks.
Lufthansa said cockpit doors on its planes can be opened from outside with a code, in line with the ICAO regulations. Both pilots as well as all crew members always know the security code, but access from outside can be blocked from inside the cockpit. The measure was designed to prevent terrorists from forcing their way inside by threatening a crew member.
“Only the pilot in the cockpit can preclude another person from entering the cockpit,” an unnamed source told New Scientist. “If the pilot had a heart attack then there are procedures where the door will open after a request to open and a delay of a number of seconds. So if it is true that a pilot on the Germanwings flight was locked out, then the pilot in the cockpit must have flicked a switch to lock all others out of the cockpit."
According to New Scientist, Airbus cockpit doors use a triple lock mechanism that prevents the door from opening in flight. In case of an electricity outage, the doors are secured with a mechanical bolt that the pilots can activate to maintain security.
According to the French investigators, Lubitz had no ties with terrorist organisations. The passengers where reportedly unaware of what was happening until the final moments as the black box recordings revealed screams in the final moments of the flight. The impact was so severe that it killed everyone instantaneously, the investigators said.
Airbus cockpit security systems promotional video:
Germanwings Flight 4U 9525 infographic