Mike,
Are these codes a secret or is there an AIC, a NOTAM or even a note on the AIS website where the average person will find out that they exist?
As for your idea for making a local plan - sorry but the idea of having to find some point 10 nm away is not required. Furthermore, it will not create a circle of the aerodrome!
To create a local radius from an airfield lucky enough to have an ICAO designator, simply note the airfields lat/long (if you don't know then look it up on the AIS website!). In the route, specify dct to a lat/long that is 1 minute North, South, East or West of the airfield lat/long and then dct back to the same airfield. Produces a nice circle (or very close to) of the desired radius.
However, the point is that we should not have to come up with ways of cheating the system. The system should be able to produce a report based on a radius from an aerodrome with height and time filters specified. The software can do it but it has not been enabled.
Shame because that is the most common type of briefing required by clubs and schools.
Perhaps we can get AIS to look at other countries that use the same software properly and produce better reports for local UK flying than UK AIS!
Regards,
DFC