Tale of Two Airplanes
Mike Phillips, a good friend of mine, owns a locally kitted R/C aircraft
called the A Model. It is a typical .40 size Stik model.
Each plane is powered by an O.S. .52 four-stroke engine. Both
models have a wing area of approximately 600 in2. Those are
the only similarities.
Rustik's wing is built up, fully sheeted and has approximately twice the number of ribs
as the A Model. The A Model wing is
D-tube construction with cap strips.
Mike's A Model has 1/8" thick solid
balsa wood sheet tail surfaces. Rustik has a 3/4" thick built up
and sheeted airfoiled stabilizer. The fin and rudder are approximately 1/2"
thick and are also built up and sheeted.
Mike's model is covered with Monokote. My model is
fiberglassed and top-coated with several sprayed coats of clear
polyurethane. Additionally, my model has 8
inlaid Maltese crosses made from 1/64"
plywood. The four crosses on the wing are 8" square.
Mike's plane has a pair of 1" wide x 1/8" thick strip ailerons
powered by a single servo mounted in the center of the wing. Rustik
has separate flaps and ailerons (4 surfaces in total) that are
2" wide. Each of the four surfaces has its own servo, hatch, mount and
servo extension. Each surface is built up, sheeted and approximately
Mike's model has a carbon fiber landing gear. Mine has a
laminated plywood landing gear.
I don't know the exact measurements of Mike's fuselage, but it is shorter
and smaller around than Rustik's.
Correction - 12/2004
Apparently I mis-disremembered Rustik's overall weight.
Mike and I weighed Rustik again to double-check. The airframe
weighs 4 lbs 9 oz less fuel — 2 ounces less
than what I originally reported.
We are going to weigh Mike's plane again as well.
I also plan to take a photo of the planes side by side which should
help put all of this in context.
Mike's airplane weighs 4 lbs 10 oz. ready-to-fly. Rustik weighs 4
lbs 11 oz. The sheeting, painted finish, extra servos, built up tail
surfaces and other embellishments only cost 1 oz over the weight of the A
Model. So did Mike build a heavy model or did I build a light model?
Yes is the correct answer to both questions.
My model is very light for what it is. Most builders would have had
trouble building Rustik to a ready-to-fly weight of under 6 lbs.
Mike's model is very heavy for what it is. It should have weighed
about one pound less. Mike says the wood that came in the kit could
have been used to make hockey sticks and he used it anyway. To get the
weight down, he would have had to use the kit parts as patterns and replace
them all with lighter wood.
Both models have reasonable wing loadings and they both fly well.
But the A Model could have had a substantially lower wing loading (20% less) and been a
stellar performer (except for its bizarre airfoil which is a completely