they dont show up in the game. im saving them into Addon Scenery/Scenery and i get the airport in the GPS, airport list and the Map but i cant see them. I spawn at a runway and i end up in a patch of grass. I really need your help. Im making an extention for my Virtual Airline and i need to get it finished soon !!! Please Help!

I'm assuming here and you know what happens when you assume....These are new airports or are they modifications to existing airports? The AFCADs are probably there, but buried in the ground where you can't see them.All but a very rare, highly modified and coded airport requires a flattening of the terrain so that the runway, taxiways, etc can rest and display properly. Any small variance between the elevation within the AFCAD and the flatten can cause them to disappear, covered by whatever texture was there first. And small means small, as I had a problem with a differential of 1/100th of a meter.So if they are new airports, realize you need to flatten the area where the airports will go. Existing airports I'd look for some type of elevation discrepancy.