Q. In some of my custom missions, aircraft do not take off from their airbase, but merely taxi across the ground. What causes this?
A. This problem is caused by the nationality alignment assignment of the runway and can affect AI flights and your wingmen.
Each FA map has default friendly and enemy national assignments. The problem is caused by changing these assignments. If one changes the friendly/enemy status of a runway that by default was enemy, and then place on that runway aircraft of a nationality that was by default friendly, the aircraft will not take off.
This also works in reverse.
For example, on the Baltics map, Estonia is by default friendly (blue). If Estonia
is changed to enemy, then Russian (default enemy, and still enemy in this scenario)
aircraft are placed on the runway, they will not take off. Estonian aircraft
(now enemy) may take off (I'm not sure), so that could be a potential work-around.