Both in MDL format conversion and trying to do it with SCASM API conversion, I can't seem to get a helipad landing platform to work...the aircraft just falls through. The SCASM source was correct and it worked that way, but seeing as I have a bunch of these to place, any thoughts on how to make it work as an MDL model? ---EDIT--- Ended up just editing the model in GMAX using the landing box cheat underlay, but the question remains...is it an FS limitation? Difference between FS2004 and FSX? What makes the surface landable in FSX but not FS9?