On Sep 16, 9:39*pm, "Flash" wrote:

I have a set of plans for the "Bounsall Super Prospector", and the wing is
designed with two spruce or DougFir spars, plywood ribs, 4130 tube members
between the spars (placed mid-point between ribs) and wire drag/antidrag
meeting at a plate at the end of the tube, bolted through the spars. *Is
this "Ison-type" wing?
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Dear Flash,

No. You have described a common truss-type wing using compression
struts and tensioned wires as the drag- & anti-drag elements. You
will find similar designs in the Volksplane, Fly Baby and, I
believe, the Ryan 'NYP'.

What I've referred to as the 'Ison-type' of wing structure (because I
first saw it in one of Wayne's drawings) uses re-enforced ribs as the
compression members and a SINGLE wooden strut per bay to carry the
drag- and anti-drag loads. Engineering-wise this is a very smart
design although it is limited to relatively small loads... such as
you'll encounter in a Primary glider. Within the constraints of this
project, the Ison-type of wing structure is clearly the most
APPROPRIATE since it does not use turn-buckles, Nicopress sleeves nor
metal fittings.

-R.S.Hoover