The FARs are not exactly clear if I (holding a commercial - single/multi engine instrument) can receive a tailwheel endorsement in a LSA(J-3 Cub) from a CFI-SP, and that endorsement be valid for non-LSA aircraft. Anyone have an official answer or ruling on this?
As I read 61.413(a)(5), you could do that, but then you would have only sport pilot privileges in tailwheel airplanes, i.e., only fly an LSA tailwheel plane exercising only sport pilot privileges. Beyond that, I suggest you ask an Ops Inspector at the FSDO, who may have to get a determination from FAA Legal, as I know of no published FAA guidance on point.
Why not just find a CFI with an Airplane rating to give the tail wheel training and endorsement in a J-3 Cub?
A CFI-ASE can give training in LSA's for privileges not available to Sport Pilots, so a CFI-ASE could give an unrestricted 61.31 tailwheel endorsement in a tailwheel LSA just as they could give Private or even (with an IA rating on that CFI ticket) Instrument training in an LSA which meets the relevant requirements.
Now, I'm still not 100% sure a CFI-SP cannot give a 61.31 tailwheel endorsement valid in a non-LSA, but absent something in writing from the FAA to the contrary, I would not recommend flying a Standard tailwheel airplane on a tailwheel endorsement earned in an LSA from a CFI-SP.
The following can be found in the Advisory Circular AC 61-65H.
A.71 To act as pilot in command in a tailwheel airplane: § 61.31(i). This endorsement may be given in a sport pilot aircraft by a sport pilot instructor, or in an airplane by a flight instructor with a rating other than a sport pilot rating.
I certify that [First name, MI, Last name], [grade of pilot certificate], [certificate number], has received the required training of § 61.31(i) in a [make and model] of tailwheel airplane. I have determined that [he or she] is proficient in the operation of a tailwheel airplane.
@Island Boy At AOPA
What is interesting is, that language did not appear in 61-65G or previous revisions. It was purposely added to the current version.
I gave many tailwheel endorsements in an Aeronca 7DC, which meets the criteria for a Light Sport airplane. There were no Light Sport airplanes when I began instructing. There is no difference in the training requirements for the tailwheel endorsement based on the level of the instructor's certificate or the aircraft.
A tailwheel endorsement in a J-3 or 7DC does not prepare a pilot to fly an airplane like a Stearman or T-6, but there is no additional endorsement required.
I would rather get the endorsement from a Sport Instructor who has been flying tailwheel airplanes regularly for years, than a Subpart H instructor who just got the endorsement himself.
I see no provisions for restrictions or limitations on the 61.31(i) endorsement in 61-65H, as I do for the 61.31(d)(2) endorsement right below it.