They aren't...Some have managed to model sloped and curved surface runways... Aerosoft have a couple in one of the German Airfield packages, one of FlyTampa's brand new release will have a sloped surface runway... check out the FT forum...Not many true, but it is possible...Though true enough they are not standard FSX surfaces...Andrew

:( This free add-on renders the approach to Courchevel more realistically .... although I still think the trees you see on approach are probably too close to the Threshold. It's especially apparent on take off.