Copilot practiced putting plane into controlled descent prior to crash of Germanwings Flight 9525, French authorities say

May 9, 2015

A report from  released on Wednesday said the co-pilot, Andreas Lubitz, practiced putting a plane into a controlled descent earlier in the day of the March 24 crash of, which officials allege the co-pilot caused by a controlled descent. The report was based on data from the plane's.

According to the report, the indicated the captain left the cockpit for a few minutes. During these few minutes, told the  to decend from 37,000 to 35,000 feet. But the co-pilot has set the altitude to a much lower than that before going back to 35,000 feet.

The co-pilot then set the altitude close to the ground again after air traffic control instructed descent to 21,000 feet. The plane remained on its flight path throughout, so there was no deviation from flight path for air traffic controllers to notice. The report does not say whether the pilot on the "test" flight also piloted the accident flight.