The CFI should be concerned about liability. When I write "flying on my
certificate" the student or transition pilot is effectively doing that
subject to the limitations stated in the FARs/CFRs and the endorsement in
the logbook. Should a student pilot/transition pilot violate those
limitations, then the CFI has some protection should a lawsuit arise.
As Judy wisely wrote, common sense needs to be applied. If I knew one of my
students knowingly and repeatedly violated a limitation I would ask for
their logbook and rescind the endorsement. If they refused, I would contact
the FAA and let them deal with the recalcitrant pilot who clearly has no
business flying.
You are correct in one sense that I cannot show the detail wording in a CFR,
but then there are other sources. I encourage you to wade through the FAA's
FAQ on Part 61. See
http://www1.faa.gov/AVR/AFS/AFS800/DOCS/pt61FAQ.doc
See page 28. The guys that wrote part 61 state, and I quote... ANSWER:
Ref. § 61.31(d)(3), § 61.87(l)(2) and Endorsement #35 in Appendix 1 of
Advisory Circular 61-65D; The person is not a student pilot and only needs
to have received Endorsement #35 in order to solo a glider. The person does
not need Endorsement #4 as this 90-day limitation [§ 6187(l)(2)] only
applies to student pilots. The person may continue to perform solo flight
operations on the basis of Endorsement #35. However, as a flight
instructor, even though the rules do not specifically state any requirement
for limiting your endorsement to 90 days, it would be legally prudent of you
to place such a limitation if you have any doubts about this person's
judgment or his propensity to enjoy suing you. However, the rules do not
specifically require you to place such a limitation, because those of us who
rewrote Part 61 did not think it was necessary to attempt to regulate good
vs. irrational judgment.
"Michael" wrote in message
m...
"Paul Lynch" wrote
This particular chapter and verse comes from the secret handshake that
CFIs
get when they become CFIs. 
That's so fascinating. I must not have gotten my secret handshake.
"35. To act as PIC of an aircraft in solo operations when the pilot
who
does not hold an appropriate category/class rating: § 61.31(d)(3)
I certify that (First name, MI, Last name) has received the training
as
required by § 61.31(d)(3) to serve as a PIC in a (category and class of
aircraft). I have determined that he/she is prepared to serve as PIC in
that
(make and model of aircraft). "
Funny, I got this part.
Note that the transition pilot is not a student pilot. Also note that
unlike the student pilot endorsement (under 61.87), there is no stated
expiration in the regs.
Nor is there a stated requirement to comply with any limitation his
instructor might place in his logbook. So I repeat my question - what
makes you think the transition pilot is required to comply with any
additional limitations, such as expiration date, crosswind limitation,
etc?
Sorry I can't provide a more detailed chapter and verse.
In other words, you believe it to be true but can't actually support
your belief in any way.
Michael