Andreas Lubitz tore up a sick note on the morning of the doomed flight . German prosecutors have found evidence questioning his mental health . The co-pilot was not wearing an oxygen mask when he took off from Barcelona to Berlin in March and crashed into the French Alps shortly after midnight local time, killing all 150 people aboard. Lubitz commanded the jet 's autopilot to fly into the Alps at 400mph .
Andreas Lubitz tore up a sick note on the morning of the doomed flight . German prosecutors have found evidence questioning his mental health . Relatives could sue Germanwings over their failure to spot Lubitz 's illness . Lubitz commanded the jet 's autopilot to fly into the Alps at 400mph .