This is what I see doing both the RNAV Y and Z for 25L:Simon, your ND is completely filled with green at this same location. What I'll bet is happening is that you somehow have scenery installed and enabled that has effectively lowered the whole Phoenix area to sit below its real altitude. That's the only way you'd get the ND showing terrain that isn't shown on mine like that. The elevations in our terrain database are accurate and don't change - if your Phoenix area was lower, this is exactly what it would look like - the plane thinks it's closer to the ground (because it's using our terrain data as the basis for determining that) than it actually is in the lowered FS world.I really don't think this is an NGX problem - if it was I'd see it too. I'd try disabling all your addon scenery or maybe even try uninstalling that Megascenery stuff - I don't know what it does with mesh, it may put it in the global scenery folders for the sim, which means you can't really disabled it without getting rid of the bgl that's doing it. If all else fails, reinstall FSX clean and I'll bet the problem isn't there.

Hi Ryan,I think I've found the problem - following the train of thought from your earlier comments. I installed an earlier Navigraph data set (1109) and had no problem. I then reinstalled 1111, which was the one I had been using and still no problem in 2 approaches..... I can only assume the original navigraph install was corrupt.I'll run a few more tests to see if the issue reappears - thanks for pointing me in the right direction.Simon.

Hi folks,Happy New Year to all of you, first of all, and this combined with the message that I obviously was able to solve this problem with a little help of our friend Ryan - thanks to him. After running a Ticket regarding this issue, he advised me to make a clean install with SP1b and the first tests are promising, everything worked fine and as expected.