pps it's also worth noting that the NFD, as the FAA/NACO's designated
source for in-flight digital airspace navigation data, is updated
every 28 days. These updates are not just routine changes to airspace
definitions -- they include the addition of things like corridors
through restricted areas, special case airspaces (e.g. the Grand
Canyon no-fly zone, which is only in the NFD), and (coming soon)
contact frequencies.

This off-season the justsoar.com site will also add a few optional
features, including country boundary data and a subscriber-populated
database of landout locations. Stay tuned ...