Interesting bug while using this mod and Surfaces Reloaded together that allows planes to spawn in other... well levels without airports. I personaly wouldn't call it a bug but a feature cx. Nucking caves full of bitters.

Right, planes spawn on the surface where the player currently is. I'll change that to the surface on which the hangar is build in the next update...

But I'm afraid thats it regarding support for different surfaces. As long as you only use airports and targets and flares on the main surface you should be fine, but I can't let the targeting algorythm difference between several surfaces.

Tbh it is rather funny so... This bug doesn't need to be fixed cx. It allows for rather nice excavation of caves :D.