NZFF

It appears there is a problem with the file "OmakaAirportFsx.bgl" (patched for SP2). On take off (runways 01 and 30) the aircraft crashes (into nothing visible) 1 to 2 hundred meters into the take off roll. If I replace this file with the OmakaAirport.bgl file from fs9 and rename it to "OmakaAirportFsx.bgl" then all is ok (well not the trees). Has anyone else experienced this problem and/ or know of a proper fix? I have already done the obvious and reinstalled the scenery but the problem persists.

Sorry about the wait, I have 2 children with birthdays on Jan 2, so that's definitely a day off in our household:)

Although it seems like a facetious answer, the problem isn't with OmakaAirportFsx.bgl, but with the way in which crash detection is handled in FSX (and most previous versions.) Basically, crash detection doesn't work well enough to rely on at all in close proximity to just about anything. MS get around this with default scenery by spreading things out, and keeping parking etc away from objects. NZWN is a good example of this -- the default Wellington is spread out all over the place, just to give everything plenty of room, but in reality it's a lot tighter. Most addon scenery is this way -- it doesn't make sense to base spacing of objects on the sloppy crash detection, if you are going for realistic placement.

I admit that although crash detection is a part of beta testing, most of my testers do not have crash detection turned on. This is because they've probably got too annoyed with the fact that it doesn't always work as expected. In reality, the sim doesn't detect crashes based on the actual objects, it builds a crash model algorithmically, based on its best-guess of the actual shape of the object. This guess has a large latitude for error, normally in proportion to the size of the object. So you can get quite close to a small object without triggering a crash, but not very close at all to a large object.

To fix this, I normally recommend that you fly without crash detection enabled. I know a lot of people want to use it because it makes the sim 'more realistic', but that would only be the case if it worked properly. I'd love to see the ability to turn off object collision detection but leave in the hitting-the-ground-too-hard bit. Unfortunately there's just one switch, so if you want the one, you're stuck with the other.

However there is another fix, which is to simply turn off crash detection on an object/placement basis. Some designers use this on everything, but in a way it doesn't make sense when 90% of users don't use crash detection at all. It does, though, do a good job of what I was talking about earlier, turning off object collision and still knowing that you have to land gently enough to survive.

The offending objects in this case are the vine fields, simply because they are huge, and therefore suffer from sloppy crash detection. Try the attached BGL file with the vine field crash detection turned off, and let me know if it helps.

[attachment=90:OmakaAirportFSX.zip]

Thanks for that. The replacement bgl works a treat.
And thanks for the detailed explanation. It all makes so much sense that now I'm kicking myself for not realising the obvious. I guess I need to try a bit of scenery design to gain a better understanding. I now know that Omaka is not the only airport where I have experienced this problem so the alternate solution seems a wise choice.
I have often flown into Omaka and probably used 30 or 01 on most visits so being able to relive those experiences again is great. There were no vines on the airfield when I was flying though.