This was what I initialy though was a bug. Whenever I started "exploring" LB2 map and approached edge of the map the copter flight was reset to 0 pitch and speed. Has anyone experience that?
Now I am thinking that it must be perhaps done on purpose and is just hitting the "invisible fence" sorrounding LB2 world or map.
Yes, it exists in every mission. I just tried it on one of the Lasing missions that takes you to the city (Stepanakert? pardon my spelling) to see if it is constant. I flew all the ay to the NW limits and took some screen shots. I want to establish whether or not this distance is a constant or if it possibly varies by mission/map. Here's what I came up with from that little exercise: Link
It appears to be 5km S and 6.5km W of the map edge. Many Iranians died to obtain the information.