Remember when using acronyms, it's a good idea to define it. Although the UK has a CAA, the first aviation agency in the United States was the Civil Aeronautics Authority which became the Civil Aeronautics Administration and eventually became the Federal Aviation Agency and finally the Federal Aviation Administration. Since the poster is from "Winchester" I assume they're from the U.K., but then again they could be from Winchester, Virginia, Winchester, Kentucky or Winchester, Tennessee and probably any one of a number of other "Winchesters" in the USA.
