On Fri, 20 Feb 2004 09:17:43 -0900, "Ron Webb"
wrote:

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.


Ron
when the spruce is dried to 12% moisture content you are looking for
20 lb per cubic ft for A grade and 24 lb per cubic ft for B grade.
(among all the other criteria)
your stuff would probably be too dense. it might just be ok for
propellors if you can get knot free lengths though.

I have a similar problem in Australia. all the Queensland Hoop Pine
that I can lay my hands on comes in at 34 to 36 lbs per cubic ft. It
is just too heavy for aircraft work.
I've been looking at a single seat Corby Starlet and the difference is
enough to turn a limited aerobatic aircraft into a curvature of the
earth climb out dog.

Frank Rodgers in Australia reworked the french Jodel D18 to use oregon
pine (douglas fir) instead of spruce and I believe this entailed a
complete redesign.

......ohhhh drat.
Stealth Pilot
Australia