Mike, EASA regulations are UK law and override the ANO. The ANO is a worthless law for flight crew licencing, unless you have a CAA national licence, so there's no point referring to it or quoting it. If you have a JAR or EASA licence then Part-FCL and Part-MED are the regs to know and comply with.
Nobody is saying that an offence is committed under UK law, so I'm not sure why you mention that. FAA 61.75 says that you must have a valid foreign licence, so the key point is whether a foreign licence is valid or not when using an FAA piggyback licence. EASA regs (remember, they are UK law), and the CAA's interpretation of them, say that a PPL licence holder must have a minimum Class 2 medical certificate for a licence to be valid. Which bit of that is ambiguous?
If an incident occurs, the FAA won't be the ones to determine if a foreign licence is valid or not. It could have been revoked or suspended since they initially verified it, so they'll go back to the issuing authority for confirmation. And what will the CAA's response be? If it's a no, then what happens to the FAA piggyback licence? How can you be certain that the CAA will say your licence is valid and, if not, that the FAA will still confirm your piggyback licence is valid? Prosecution or not, I am pretty sure the FAA will make sure you never fly in the US again if you get caught flying "illegally".
If someone at an FSDO tells you it would be legal to fly with an FAA medical instead of an EASA medical and then you should get that in writing. Because it won't be that FSDO that makes a decision on how to proceed if someone else says it's not legal.
Last edited by wb9999; 25th Aug 2013 at 08:41.