Hello, I'm trying to build my own airfield outside of Bozeman, but I'm having a heck of a time trying to get the runway flush with the terrain. I tried finding a flat space to place the runway, but still, the runway floats about 3 or so feet off the ground. Is there anyway to make it sit flush? Am I missing something? Thanks. Ty89m

Hi...'Not sure but I assume AFCAD will apply the terrain elevation 'sensed' at the Lat/Lon location of your work area that you specify? If that area is not perfectly flat, other placed objects might indeed 'float' in places.In most cases, for a new airport where there is no MS default airport, the designer would normally apply such a Flatten Area command to make the entire airport area flat, including where you might add runways, taxiways, aprons, buildings, etc. If you're using SCASM code that truly builds a MSFS type runway, the area's terrain would normally be "sucked-up" to fit the runway in the runway area only.If you're building the runway by using a ground polygon, the ground poly will sit-on-top-of the highest point in the area and there would be gaps underneath it where the terrain was lower than that highest point. In the later case, again, the The solution would be to simply apply a Flatten Area command to the entire area before AFCAD senses it.Hopefully, some AFCAD experts will pop in here and set you straight. There may be other "AFCAD tricks" to use?J.R

Hey thanks, sorry I thought I put in that I was using AFCAD 2 "New airport" option. Are there other freeware programs that use the code you spoke of? To suck the terrain to the runway? Thanks, Ty89m

LOL, we crossed paths while I was editing the original reply to recognize you mentioned you're using AFCAD.Yes, there are such freeware programs. I use Airport for windows 3.0 which applies SCASM code to build MSFS type runways. I'd guess the other freeware airport design programs also use the same code but since I don't use them I can't say for sure.I've seen posts that say AFCAD 2.11 can build it's own taxiways & Aprons, etc, however I don't know if it actually places runway objects? Regardless, I would think you'd need your entire airport area to be made flat with a "Flatten Area Command". AFW 3.0 can quickly install such Flatten Areas or any other scenery objects.J.R

This offset makes me wonder, which altitude did you enter for the runway?If you have measured the altitude with shift-z in FS you should remember that that is the altitude of the refpoint and not of the ground. For a Cessna that ussually gives an offset of about 1 meter (3 ft).

If you use FSSC, it forces the runway to be on a flat space. Depending on the elevation you set, the runway can be above the terrain or under the terrain. It won't create a sloping runway.