On 28/08/2019 09:40, Mr Pounder Esquire wrote:



Brian Gaff wrote:
I believe over a certain size and or weight one has to have special
permission to fly them. They tend to have to be in managed areas for
public safety.

Sorry, not quoting mr pounder, but missed the OP of this thred.

Not only certification, but the CAA has to be involved at every
stage of the construction, including verifying that the
materials to be used in fabrication have been obtained
from certified sources, even before they are assembled.

(Experience from an acquaintance who made a 1/4 scale model
of a WWI biplane)