-open the editor
-go to the runway at the airfield (or anywhere else)
-create a playable unit (Offroad, Hunter, Ifrit...)
-create six concrete ramps (Side:"Empty", Class: "Objects" (Training), Unit: "Concrete ramp")
-name them from "a" to "f"
-place ramp "a" on the runway (or anywhere else)
-doubleclick on ramp "b" and write into the init-field: "this attachto [a, [0,-8.9,2]]; this setvectorup [0,0.1,1]" (with this command line, you attach ramp "b" at the end of ramp "a" and change its tilt angle)
-go to ramp "c" and write into the init-field: "this attachto [b, [0,-8.9,2]]; this setvectorup [0,0.1,1]" (the only difference is the letter b after "attachto".
-go on with the other three ramps, fill the init-fields with the same lines you see above and just change the letters (b attach to a, c attach to b, [...], f attach to e)
-now click on preview and you'll see a great "skateboard like" ramp
-drive on the ramp -----> fall through the second segment