Instructions for vertical takeoff: Slowly move the VTOL bar up until the plane ls off the ground, then slowly add power and at the same time slowly move the VTOL bar down. (similar to the way my helicopters work)
Instructions for vertical landings: basically the same process as before, slowly reduce power and at the same time slowly move the VTOL bar up.
(I hope those instructions make sense)

The Dornier Do 31 was a West German experimental VTOL jet transport built by Dornier. The Do 31 was designed to meet a NATO specification (NBMR-4) for a tactical support aircraft for the EWR VJ 101 VTOL strike aircraft designed under the NATO contract of BMR-3. The project was cancelled in 1970 owing to high costs, technical problems and a change of requirement.

And to my knowledge, this is the first Do 31 on this site.