The dotted line is just a “point A to point B line” on FlightRadar24...that flight usually swings out “to the right” on the map plot...you can see prior days flight plots for that flight # here: http://flightaware.com/live/flight/GWI9525/history/20150324/0835Z/LEBL/EDDL
Usually about a 1 hour 40 minute flight.
Thank you for the explanation and info.