Bernoulli, I downloaded the AC you reference here:

http://www.flyelite.ch/downloads/docs/ac61_136.pdf

You quote "AC 61-136 Appendix 2, #2" but you leave out that is subparagraph (a). Read subparagraph (b) just below. In my mind, "Use in performing instrument recency of experience requirements of § 61.57(c)(1)", would make me tend to agree with Lance. So, the big question is, does subparagraph (a) apply to ALL of subparagraph (b), or is it seperate? You'll notice the verbage in (b) does mention training time with respect to use under 61 and 141, but, the word "training" is missing from the 61.57 verbage. That would be my argument that yes, you can use the BATD without a CFI for 61.57 currency.

Interesting stuff and total news to me. I've always felt you HAD to have a CFII to use a ground trainer, period.

RickAir. You mention needing FSDO approval and a "letter on the wall". In page 8 of this AC, it does mention local FSDO approval for each unit but that is only for part 141, not 61. Here is the reference:

"NOTE: A part 141 certificated pilot school must obtain a specific authorization for the use of the ATD as part of that pilot school’s approved training curriculum. This authorization must come from the FAA FSDO assigned to that pilot school"