Not sure whether this is the right place however... I have put together a small airfield complete with AFCAD and AI. I have put parking spots and a taxiway with some hold shorts. For some reason and I just cannot figure it out, if 2 planes come out at the same time, in this case a cherokee and a cub, they crash into each other or get mighty close. I presume I am doing something dumb, any help would be really appreciatedThanksPaul

What you are describing sounds like a model.mdl radius problem and not a AFCAD problem.Some AI Plane designers set the radius to a unrealistic small value. This is the value that keeps planes from hitting each other when on the ground.Using the AFCAD program in the Tools menu open the Aircraft editor. Here you will see the model.mdl radius of each plane in you Aircraft folder.Select and look at each of your aircraft that have the problem and see what the radius value is. You can compare a AI type plane to what FS9 uses for their default Plane radius. Change the radius and save if needed.

At the moment I am using the planes that came with FS9, some, like the Cherokee are the AI, others like the Cub are not, would this still apply?

Yes if the model.mdl radius has been changed.I also have the FS9 default Cub and Cherokee. The default radius for these 2 type planes is 10MLook at the radius value with the AFCAD program and see if both type aircraft still show 10M for your models. If so then the problem will probably be something else. If a smaller radius of 4 or 5 is being used I would recommend increasing it upward until the planes don't make contact.