I've noticed that when a pilot exits any plane while moving, after a few seconds, the propellers disappear. Helicopters seem to be unaffected. However, when you break the plane and replace it, the propeller is there again. The only time the prop wont disappear is if you exit after you've come to a complete stop.

Just found it kind of odd.

Thats our new feature! That's very strange lel, I would guess the position goes to null or NaN somehow. I'll look into it.

Fixed in 5bd0def