CUSTOM BASES
1. Place an airbase & runway where you want.
2. You can specify the runway length & width in the runway properties tab.
3. Runways & splines are
independent of each other. So after you've positioned your runway, get a spline and place it along the runway length & specify the spline type.
SPLINES
You use splines to specify the direction of a "pathway". The pathway can be a dirt road, concrete highway, railway track, various types of runways (grass/concrete) or even an "invisible" spline.
1. Select the splines in the FMB & ctrl-LMClick where you want the spline to start, then ctrl-LMClick again where you want the next spline section to be. Splines can have many sections such as winding roadways with many bends. In the case of a runway, you probably want just a start & end point to the spline.
2. Now look between the start & first spline points and you will see two other flags. You can grab & drag these with LMClick, and you will see that they can be used to create curved & funny shaped splines. Position these so the runway is straight (or as straight as you want it to be).
3. Now, select the type of spline you want it to be in the FMB dialog box. Unfortunately, the spline does not show on the FMB screen until you save the mission, so save your mission & you will see your spline on screen.
4. You can reposition the spline as necessary, just remember to resave the mission to see how the repositioned spline looks
EXAMPLE
Here's an expample mission showing a highly modified Lympne airfield in England. Dirt runway has been changed to concrete; another dirt runway changed to grass; roadways positioned between hangars; new grass parking area; cars going along 'invisible road' next to runway; ambulance going along dirt road spline. Dowload
HERE
NB - I have notice a 'bug' where splines will sometimes not appear in multiplayer games, a bit like the army flags not showing in the map screen. I find if you back out & reenter the game a second time the splines will appear OK.