I am trying to create an island in FSX which is fairly small (about a mile across) and consists of steep cliffs about 60 meters high. I tried both putting together an altitude specification and using resample and also using AB Flattens via SBuider. In the former case TMFViewer shows the altitudes correct in the BGL but FSX ignores them (but does pay attention to other altitudes on a larger island nearby). In the latter case FSX starts the slope up to the flatten over water which results in some strange looking water. It appears FSX is not allowing me to have cliffs with more than a modest slope and is rejecting what I am trying to do in the former case since it cannot get where I want to go in the limited land terrain I am giving it, and when I force the issue in the latter case that results in the strange water. Is there some way around this short of having to do this as a 3D object via GMax?