Do you know what varieties of spruce will make good airplane parts?

Tha NACA report server has several good reports on the subject. Here is one

http://naca.larc.nasa.gov/reports/1931/naca-report-354/

The upshot is that Sitka Spruce is not magic. There are several other
varieties that would work as well. It was originally settled on mainly
because it was cheap, back in the '30s. But the value of a "standard" is
such that even though the stuff is now up to $1000 per spar, we keep
insisting on it.

I live in Fairbanks, Alaska. Up here there are literally 10's of thousands
of square miles of old growth black spruce forests. Really slow growing,
tight grained wood that HAS to be tougher'n HELL. I've often wondered if
there might be a market for it.