There is a problem i noticed while build new models. It seems there is a problem when the position of a passenger is to close to models 0/0/0.
It looks like the zero point is colliding with the passengers spot and stopping the plane, just for few moments before increasing speed again. Cause this happens every few seconds the plane starts "jumping" (not sure how to describe it) the flying is not smooth, is notchy.
Close means about 30 units away from 0/0/0 no passenger can be placed or this problem is showing.