Gordon Arnaut wrote:

There are many types of wood that can be used in constructing a proper
airframe, as per AC-43.13b.

I happen to like northern white pine, which has nearly the same
strength-to-weight ratio as spruce -- and better than that of Douglas
fir. NWP is about 15 percent lighter and about 15 percent less strong
than spruce, so if your plans specify spruce you will want to increase
the dimensions by about 15 percent.

Trouble is it isn't that simple. Strength of many load bearing members
(those loaded in bending or torsion, for example), is a linear function
of size. It would take virtually a re-engineering of the structure to
change species in most cases.


Matt