I'm joining in on this one a bit. Years ago I too tried to get plans
for the built up spar the Brits have. As far as I as able to find out
there is simply no legal way of doing it and that is the end of that.
However EAA has (or had) publications on built up spars. Also there are
a number successful home built aircraft that use built up spars.
Molt Taylor designed aircraft made largely out of cardboard, fiberglass
and epoxy. They used a built spar that probably didn't cost a hundred
bucks. Zenith Aircraft Company uses built up aluminum spars that are
(IMHO) probably cheaper that aircraft quality Sitka Spruce, stronger and
weigh less too.
The Skypup Ultra-lite does not have the classic beauty of a Piet, but it
uses just one built up spar and the removable three piece wing is fully
cantilevered. IMHO the Skypup designer is in the same league as Bernie
Pietenpol. A simple straight forward design using commonly available
materials. Only this man is a professional aeronautical engineer. If
anyone wants to see something about it there is a video called
"Machnone" on youtube that shows a lot of the construction methodology
of the Skypup. I bought a set of plans from the designer's son just to
see how it was constructed. (Over the years I have collected a number
of plans for the same reason.) Due to personal responsibilities that I
have, building my own Piet is not possible so I stand on the sidelines
wishing others well.
Hopefully, someone will be inspired by all that is out there on low cost
built up spars and the sky will be darkened with Pietenpol Air Campers
being flown by happy pilots before too long.
Back to lurking,
Bob B.
