The qualifying mechanisms in 14 CFR 61.56 clearly exclude, in the absence of a specific exemption, proficiency checks conducted under a foreign authority. The "examiner" referred to in 14 CFR 61.56(d)(1) for instance is well defined and has been held by the Office of the Chief Counsel as excluding foreign examiners. A relevant opinion was given to John D Collins on 4 Apr 2013 by Mark W Bury, Acting Assistant Chief Counsel for International Law, Legislation and Regulations Division (PDF). Besides, non-US personnel have not been found competent to deliver ground training on the relevant rules in 14 CFR 91.

Any reference to "flight training" in part 61 is a reference to training carried out by an "authorized instructor" which, in the absence of a specific exemption, may include foreign flight instructors pursuant to the conditions in 14 CFR 61.41. The conditions for the latter are that the training shall only be credited towards the training requirements of a pilot certificate or rating issued under part 61 and the training has been received outside the US. There is a further condition limiting the purview of the foreign instructor to giving endorsements to show training given which falls short of the requirement in 14 CFR 61.56(c)(2) for an endorsement "from an authorized instructor who gave the review certifying that the person has satisfactorily completed the review."

Instructor conducting flight reviews in the United States may not be remunerated, which includes logging flight time, when foreign (non-leased) aircraft are used. See 14 CFR 375.

Sure I have, why do you aks? This great thread finally has produced indications that a "missing EASA TR" is not a "limitation" in the FAA's sense of the word.

Reely - you say: "The final question is what happens when after acquiring a piggy back lic and maintaining a recent enough BFR all my EASA TRs have expired, from FAA's point of view?"

I think that's covered above in response to Claudia's similar question: "As per the legal opinion issued by the Office of Chief Counsel for FAA quoted above, "...the FAA has not considered the absence of a rating as a restriction on a person's pilot certificate." So the revalidation of the type ratings in the 'parent' license, via a proficiency check, is irrelevant to the validity of the 61.75 'piggy back' license. The requirement is only that the license itself remains valid (which, being not time limited is not hard to achieve) and that a valid medical supports the license. So an EASA type rating that has expired (i.e. not been revalidated) does not constitute a limitation on the EASA license such that it limits the validity of the 61.75 certificate based upon it."

So, in short, nothing happens (to your ability to fly an N reg aircraft on your 61.75 certificate) if your EASA type ratings expire, so long as you retain your FAA BFR, logbook endorsement and appropriate medical. Indeed, I suppose nothing would happen either if your EASA type ratings expired before acquiring a 'piggy back' certificate, because, as we know, a "missing EASA TR" is not a "limitation" in the FAA's sense of the word.

As ever, I am no authority, I've just read the legal opinions and talked to some instructors and examiners. Am happy to be proved wrong by any one of the many people that told me and apparently continue to believe that: "...the 61.75 certificate covers only the type’s on your UK license."