On Fri, 30 Dec 2005 13:38:06 +0000, Chris Wells
wrote:


A few questions, for those in the know:

Both of the radio-controlled biplanes I've owned were designed with
the lower wing at a higher AOA, so that it stalled first. They also had
the upper wing farther forward than the lower.

well they got it backwards then. the concept is a pair of lifting
wings on opposite sides of the CG.
the idea is to get the wing in front of the cg to stall first so that
the aft wing which is still flying automatically causes the nose to
drop and recover from the stall.

If the lower wing stalls, the CG will be a little on the aft side of
the upper wing. Wouldn't it be better for the upper wing to be behind,
so that the CG is a little more forward? I've seen some biplanes like
this, such as the Beech Staggerwing, but most seem to have the upper
wing in front.

dont be guided by full size aircraft. full size has handling
characteristics related to the capabilities of a trained pilot.
models are generally built with some form of stability to make them
easier to fly.

While my R/C had the ailerons on the lower wing (my other one had no
ailerons), it seems most of the biplanes have them mounted on the upper
wing.
model aircraft are setup with simple linkages that lend themselves to
being poked through the fuselage into the bottom wing.

most biplanes actually have ailerons on upper and lower wings that are
interconnected by a strut.

It would seem to me that the lower wing would be safer, because
you'd have a harder time tip stalling that way - the upper wing would
be able to keep flying after you tip-stalled the lower one. Why is it
the other way around on most biplanes?

tip stall has nothing to do with dihedral.
tip stall is controlled by washout or some leading edge jiggery
pokery.
The full size aircraft considerations are considerably different to
those of RC models.

Also, it would seem only necessary to put washout in the upper wing,
keeping the lower wing flat. Is this the case with most biplanes, or do
they put washout in both the wings?

go and read some aeronautical theory books. with your emerging level
of interest you'll find them fascinating.

Stealth Pilot