CNN Legal View With Ashleigh Banfield May 6, 2015 16:33:00
Andreas lubitz practiced the move he would use hours later to bring down the next plane he was going to fly out. he practiced it on the outbound flight from dusseldorf to barcelona. look at this from the flight data recorder. the blue line on your screen is the altitude that flight actually maintained. but the red line is shocking. it's how many times lubitz changed the autopilot altitude controller on that earlier flight. he didn't actually take that earlier plane down. he just fidsled with the controls, checking things out. on the next flight he made the same adjustment and carried the thing...
Source: archive.org