Thanks, Eric. A bit of googling turned up some information - it's
hard-to-spot damage that can come from a tree growing at an angle,
being felled onto a slope, a whole range of things. I was actually
looking for something on the compression *strength* of hoop pine vs
birch to respond to a post elsewhere, but "compression damage" kept
coming up in the list.

I also just received the 1994 EAA publication on wood building
techniques - appears to be a collection of reprinted articles. On
page 11 is a reprint of an article by Volksplane designer W.S. Evans
that goes into some detail on the subject, with the conclusion that
it's not worth the risk for spars and longerons to use
non-certificated (and possibly compression-damaged) wood. Even so, he
advocates cutting off 2" of each end of the stock and inspecting it
for obvious fiber damage. THAT could get expensive!

Corrie

"Eric Miller" wrote in message .net...
"Corrie" wrote in message
om...
Thanks for the detailed response. Can you explain more about
compression damage and how to spot it?

I've seen more extensive articles on this that I can't find/recall right
now, but I know Ron Alexander covered it in Sport Aviation Feb '99.

Eric