What with rebasing aircraft?

Why it is possible to rebasing aircraft from one city(airport, carrier) to another regardless to distance. So i can rebase helicopter with op. range 6 to base in any place on map, even on the opposite place of earth. This is allowed in all version of civ3(vanilla, ptw and conquest) and i think it should be changed as fast as possible.

In C3C, planes can rebase only at 6 times their operational range, so they did add it, I guess you just missed it.

yes i missed it, but i think it is still much too much, especially with standard or even large map.