Earlier, Ed Wischmeyer wrote:

what's the source that the anodized spars
have half the fatigue life? and why? Is
that true in general, or only for these
spars?

http://www.matronics.com/rv-list/hov...s/AlAnDef.html

Search this page on "Fatigue." It references a 1991 RVator article by Van:

http://www.matronics.com/rv-list/hov...s/AlAnDef.html

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com/hp-24