article_snippet.sent: Authorities say the flight's co-pilot, Andreas Lubitz, locked the captain out of The cockpit voice recorder and engineered the plane's demise.
article_snippet.sent: Initial tests on the flight data recorder show that Lubitz purposely used the controls to speed up the plane's descent, according to the French air accident investigation agency, the BEA.
article_snippet.sent: the French air accident investigation agency, the BEA also has emerged that Lubitz had battled depression years before Lubitz took the controls of Flight 9525 and that Lubitz had concealed from Lubitz employer recent medical leave notes saying Lubitz was unfit for work.
highlights_snippet.sent: Authorities say co-pilot Andreas Lubitz deliberately crashed the plane, killing all 150 on board .