Ghengis wrote :
I then took a similar aircraft out myself and put a force gauge on the door, at the bottom catch, at 50 kn (compared to Vd around 95) I got a 6daN force to hold the door in position with it just very slightly open.
I don't know what your numbers mean there, but I had the right door unlatch on a 172RG in flight. At ~100 knots, I could not even move it against the airflow !