In March 2015 a Germanwings plane crashed, and all 150 people on board died. On 27 March the German aviation association BDL announced a provisional procedure. From then on, two authorized crew members always had to be in the cockpit. The airlines introduced the rule as a Sofortmaßnahme, an immediate measure. In April 2017 the association reported the result of its evaluation. The two-person rule had brought no gain in safety, and opening the cockpit door more often created additional risks. From June 2017 at the latest, a pilot could again be alone in the cockpit. Instead, the airlines pledged that doctors examining pilots would pay closer attention to psychological and psychiatric aspects.