The automover routine just picks a random available move for every automoving plane. After that, all the game is handled normally (e.g. planes will open fire on enemies, perform restricted maneuvers, extinguish fires, try to unjam guns etc).
All the settings remain the same (burst lenght remains medium if the player didn't change it before going into automove, else it will remain as changed, as the automoving engine should not bother about adjusting burst lenght...).
Many cases have been reported in which active planes have been shot down by automoving planes, so... don't take it too easy!