Found this link:
http://www.csgnetwork.com/aircraftturninfocalc.html
(Some other interesting calculators there also)

I think the turing radius calculator is borked......

Try 80MPH at 89 degree bank angle....

Impressive piece of engineering if possible. Found this link:

--
Mike Flyin'8
PP-ASEL
Temecula, CA
http://flying.4alexanders.com