On March 24, 2015, Germanwings Flight 9525 crashed in the French Alps. All 150 passengers and crew members died. After just 48 hours, the French public prosecutor's office was certain that co-pilot Andreas Lubitz deliberately caused the plane to crash.

Germanwings - Was geschah an Bord von Flug 9525? takes a meticulous look at the event and makes it clear that ten years after the crash, many questions remain unanswered - for example, relatives and aviation accident experts have identified inconsistencies that make them doubt the narrative of the French authorities. In three episodes, relatives of the victims and their lawyer Elmar Giemulla as well as journalists and other experts have their say. Aviation safety expert Simon Hradecky is also accompanied in a detailed reconstruction of the last minutes of the flight.