There are multiple ways, but first, you can set your spawn points the same way you do airspawns.
Insert a spawn point using the TE. Make it a vehicle spawn so that you can see it. Then rotate it to the direction you want, but you'll see that you can only have the 9 positions shown on the usual cbm. After you have it facing the direction you want, turn it into a fighter or bomber spawn using the set type the same way you would set a base as a Group Master.
See
this thread for more instructions.