Thank you, tgibson. As I said I am new to Sketchup. I have some experience modeling for fs9/fsx/p3d and my intention in learn Sketchup is to have a unique 3D modeling tool and export the modeled 3d objetcs from that to others 3d formats.
If you allow me I have a one more question. Which tool I use to position a simple 3D objetc like a house in a specific coordinates into scenery? To position a 3D objetc into an airport I can use the WED but what I want is to put the 3D object anywhere like a landmark in the scenery. I read about georeferencing but I did not understand how to work with it. Do you have experience with the exporter of SketchUp2Xplane?