Doody,
thanks, just trying that out now, seems quite interesting. I have to admit im not conversant with the various classes, so a bit of research needed on my part.
A bit of background - the main problem I have is with our structures that are not high enough to be considered en-route obstructions, but are close to or within ATZ boundaries etc. These are a bit of a nightmare as to whether or not they are lit, and if they are, who is responsible for the maintenance of the lamps. This is why im trying to get such information onto my mapping, so I can superimpose my structure locations on the map with the various airspace regions, and see where any may come into conflict.
Cheers
Martin