The families of victims killed last year when a suicidal pilot flew an airliner into the French Alps are suing US flight school where the pilot was trained, alleging the school failed to properly screen his medical background.
The suit was filed in US District Court in Phoenix against the Airline Training Center of Arizona.
The centre is owned by Lufthansa, which is also the parent company of Germanwings, a regional Europe carrier that employed pilot Andreas Lubitz.
On March 24, 2015, Lubitz locked Germanwings Flight 9525's captain out of the cockpit and deliberately set the plane on a collision course with the mountainside.
All 150 people aboard, including Lubitz, were killed.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
While training in Europe with Lufthansa, Lubitz was suspended from his academic course work for nearly 10 months while he sought treatment for depression.
In 2010, after returning to Lufthansa with letters from his doctors saying he was no longer depressed or taking medication, he was sent to the US for flight training.
German authorities had twice turned down applications from Lubitz for a pilot medical certificate because of his history of depression before issuing him a medical certificate in July 2009 that included a restriction stating it would become invalid if he had a relapse, the suit said.
Had the Arizona school screened Lubitz, the restriction on his German medical certificate would have tipped officials that he'd been previously hospitalised for severe depression and treated with medications that would have prohibited him from flying, according to the suit, which was filed on behalf of more than 80 families.
Lubitz's behaviour while at the flight school should also have caused officials to inquire further, the suit said, without providing details of that behaviour.
