Technically for the SEP rating you can do that hour with an instructor at any time during the validity of the rating. If you do it too early you will just get a new and earlier expiry day.
Part-FCL says that you shall do “at least” one hour with an instructor which must mean that you can do more than one and you can use up to 6 hours to use for that revalidation.
I think it is safe to say that a holder can log dual and an instructor can log PIC and FI any time during the validity.
As an instructor you can only log PIC and instruction, otherwise you can’t log anything at all. That is my view of it.
As you say („my view“), I think most of these are just interpretations. We don‘t know any much better because there is no specific guidance in the regs on this. And that‘s because Part-FCL obviously concerns itself with the training and experience requirements for obtaining and maintaining licenses/ratings and not with training which is NOT towards ANY of these licenses/ratings.
I stand by my initial statement: if nothing happens, nobody will ever take interest in what people write into their logbooks. And when something does happen, and a court case ensues, then all bets are off anyway,
my view on flights “not towards specified rating per approved syllabus”:
LHS pilot can log this as PIC time – as long as FI/CRI is not touching the controls and he/she is happy how LHS is performing . FI/CRI is of course logging instructing hours – even he is sitting with hands folded and silent whole time. I believe this is covered by FCL 050 – (b) (1) (ii).
when FI/CRI is not 100% happy – LHS logs this as dual no matter this is not per approved syllabus
That’s a really good Q.
Obviously it is physically possible to train somebody (it can be called “mentoring”). Obviously the hours will not be loggable by the “student”. I did that with a couple of people, years ago.
Whether the FI can log it, I don’t know. It is not legal to freelance-instruct towards these things, so probably not.
Can a freelance FI teach the syllabus of “ATO subjects” (PPL, IR, ME) outside an ATO assuming the training and hours do not count toward the issue of the rating?
Say an FI take a fresh student and do all his PPL exercises (except solo circuit/nav 
?) before sending him to the ATO to log his 45h? Same for an IRI doing all CBIR training?
On the other hand, the other question is that can you give any instruction as freelance , not connected to an ATO?
Yes, legal.
On the other hand, the other question is that can you give any instruction as freelance , not connected to an ATO? It is not legal in Turkey, the most of our civil aviation rules are derived from EASA rules, for better coordination.
Under EASA all instruction for the issue or renewal of a licence or rating must be given at either an ATO or a DTO. Some instruction in instrument flying may be given outside an ATO or DTO along with any instruction that is not for the issue or renewal of a licence or rating including: the one hour with an instructor, any revalidation training; differences training; familiarisation training and FI renewal training.
So long as it is legal to give instruction, i.e. the instructor is qualified in accordance with PART FCL, then what is or isn’t instruction is entirely up to the Instructor on board who by virtue of being there as an instructor may log the flight as PIC and therefore make all decisions in relation to that flight. It matters not one iota if its instruction for a licence rating or simply to provide a bit of companionship for the student.
If the pilot is fully qualified and the “Instructor” not a qualified instructor, whilst he could still give the flying pilot instruction, he would have no legal capacity with regard to decision making and any attempt to take control would be unlawful interference. Such an instructor could not log his operating capacity as he has none.
AMC-FCL.050
(iii) the holder of an instructor certificate may log as PIC all flight time
during which he or she acts as an instructor in an aircraft;
Snoopy, if this is going to be an “instruction” and if the flight hours wanted to be loggable “dual” or “PUT” , I presume you are going to be PIC, and responsibility is on your shoulders. On the other hand, the other question is that can you give any instruction as freelance , not connected to an ATO? It is not legal in Turkey, the most of our civil aviation rules are derived from EASA rules, for better coordination.
