Errr...
Have you thought of phoning or e-mailing the CAA and asking them?
Contrary to some opinion here, the folk there are not shape-shifting death lizards from the planet Zarg, but, rather, professional not-quite-civil-servants who will be able to answer your question, especially if you demonstrate a legitimate interest in the answer...
(Apologies to any shape-shifting death lizards from the planet Zarg, who may be reading this and feel put out by the comparison).
