Are you familiar with the soaring turnpoint exchange? Do you have Seeyou? Assuming you don't have seeyou, you can download the google earth format for the database in the area of interest from the soaring turnpoint exchange (try internet explorer if Google doesn't link) and view it in google earth.. And you could also convert any database you have into google earth using gpsvisualizer. Then display both in GE and toggle them on and off to try and find any discrepancies so you could edit the file in the oudie to your liking. Also, you can filter waypoints in a variety of ways in the oudie, "landable" for example, and that would limit the database to airports and airstrips (for the most part, it's not perfect) . It's a bit of work without seeyou but it can be done. Google earth is nice anyway because you can look at landouts against the latest aerial imagery and get a feel for the landouts. Hope that points you in a direction.