I have never heard of anybody getting done for enroute stuff of this sort.
Yes, the French, and apparently increasingly the Germans, like to harrass N-reg aircraft and check their VAT status, and the pilot's IR if he arrived on an IFR flight plan.
How many people got done 20k euros for busting the nuclear TRAs? The "pilot forum figure" for the fine varies between 10k and 30k euros, with confiscation often included
But nobody I know has actually got this treatment for a nuclear RA bust. I did such a bust in 2003 and the French went after me 6 months later but it went nowhere after I proved I was under a radar service, with a discrete squawk, the whole time, with their ATC saying nothing at the time. They probably didn't know about the RA, as back then they were not notamed
I'm not disagreeing and it would make sense as the N reg aircraft is limited to UK airspace anyway as it is being flown on a UK issued license - but if that came from John Lynch then take it with a very large caveat. He was not part of FAA Legal Counsel so unless he reprinted a FAA Legal Counsel formal response then it counts for little and is simply his opinion. His infamous FAQ carries that large caveat. I think you will not find that FAQ on any FAA website.
Not really. There is the concept of "apparent authority". It is absolutely not necessary to get a Chief Counsel reply for it to be legally binding on the FAA, in the same way it is not necessary to have some reply from the UK CAA signed by the Secretary of State. Such replies (if legally inaccurate) do not create new law but they remain valid for that individual recipient. And if they become publicly known, the public becomes entitled to a correction from the authority. I got this from a barrister.
What this means is that if e.g. the CAA told you that you can fly a plane under the Tower Bridge, but unknown to you the letter was written by somebody there not authorised to reply or not understanding the legal position (which has happened many times, with both the CAA and the FAA) then you cannot be prosecuted for doing it.
If this was not so, every reply from every corporate or got body to any question whatsoever would be completely worthless!
John Lynch wrote most of the FAR/AIM and he also wrote the FAQ, which was taken off the FAA website c. 2004 because the FAA did not want it to be regarded as law and usurping the authority of the FARs. The bit about the IMCR for an N-reg I got from the FAA personally; it is not in the FAQ.