Therefore do those who fly for remuneration in the U.K. with only FAA licence and medical breach the rules when they do?
There is certainly one airframe in ‘God’s county’ on M reg with an FAA licence holder flying alternating with a PPL holder.
Also does a medical limitation or restriction limit what can be done? Many fly offshore multi crew with a multi crew only limitation for CAT but what about private NCO/NCC?