Hi Steve, I have a bit of info you might be interested in regarding the AD's of the 15. This stuff came with mine when I bought it. It includes what I think is what you are looking for. TN 23 has 3 parts. and yes they deal with spar inspection and preservation. It discusses the fungal infestation that can happen(almost never does to the extent of damage),and the inspection and anti fungal treatment required. If your plane has been flying legally since 1988, the required core sample and fungal treatment will already have been done and should be in it's records somewhere. The AD I have is the one that was released in 1995 superseeding the one from 1988. I believe it is current as I obtained it last year from the guy doing my annual. If you have no records of compliance then look for the inspection/fungal treatment ports in the spars close to the root, and in the spoiler boxes, if they are there you are fine, if they are not you have some work ahead of you. To visually inspect for the fungus you look into the ports for a " white powerdery looking growth on surface of the balsa"
I can send you the copy I have of the AD and some other AD's and a listing of the open AD's in english if you like. Email me your Addy at kamakinzie@msn.com
Gil
