Robin a while ago you responded to a post concerning disappearing runways attributed to the RealNZ Wellington Airport addon.
unfortunately I can't recall which forum I posted it on.
I am in the process of Installing FS9 and addons on a new computer and wonder if you could provide me with the fix.
I am aware that this effects the flattening of a part of the Wellington scenery but I prefer the compromise to be able to land at airports such as Wanganui and Palmerston North etc without the runways disappearing.
Regards Richard

I've moved this here as a 'quick fix', and I'll pin it for a while.

This was covered in this thread.
The relevant info is:
In the folder Scenery\Ocen\scenery --
Rename FL994460.GVF to FL994460.bgl
Rename GVF994460.bgl to GVF994460.bak.

Many thanks Robin, that will do the trick.

Hi there Robin

I am getting this in FSX. Is the fix the same?

No, this issue only happens to other airports when NZWN is installed, and is FS2004 only.
I'm not too sure why you would see this in FSX -- I'll have a look through some past posts and see if anyone else has come across this.
-Robin

I remember a few times if I had reinstalled FSX and tried to just copy my Real NZ TG folders without properly installing it off the discs, sometimes the runway would dissapear to grass as I approached it, dunno if this is similar to what your experiencing :S

Yes, you'd get this with any airport where the elevation had changed, as the elevation is partly controlled by a separate file in Scenery\World\Scenery. Unless you back this up as well, just copying the scenery folder won't work properly.