A Free Source for US Airspace Data

I don't want to discourage anyone from using Lynn's airspace files,
but I do want to encourage pilots to understand the data they're
using, and in this case the TINSTAFL rule applies (along with its
corollary, YGWYPF).

I took a quick peak at the current version of Lynn's NASR translation
at the turnpoint exchange, and looking at just the Phoenix area, I
could find differences from the current (justsoar.com) NFD version.
For example, the Luke AFB Class D in Lynn's file is the old 4.4 mile
radius (it was changed to 5.6 miles in May of 2007, along with a
couple of other tweaks). Now, if you were a contest manager and had to
designate a particular data set for your contest, which would you
choose?

(Speaking of contests, I've arranged with the Contest Committee to
provide current airspace files for all sanctioned contests, for free
distribution among the pilots for use at that contest.)

A general difference, which may or may not be significant depending on
how picky you are about the different flavors of SUA, is that all of
the MOA and ALERT areas in Lynn’s version are categorized as “DANGER”..
Danger is a valid SUA type, but has a different definition than MOA or
ALERT.

Something Lynn’s data does have that I wish the NFD had is effective
times for the MOAs. But the NACO has told me it’s on the list of
things they’re adding to the NFD, along with contact frequencies. If
NACO hasn't added these by 2009, I plan on adding them myself by cross-
referencing other available data.

A significant item missing from both data sets are USA boundary data
-- pilots flying close to Mexico or Canada need to rely on something
besides their airspace data to stay legal. (Yes, that's coming soon as
a justsoar.com add-on too

~ted
ASG28.7 "2NO"

ps I cannot find anything anywhere in the faa.gov or naco.faa.gov web
sites that discusses publishing SUA in GIS format. I'm not saying it's
not there -- I just can't find it.

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 ...