Turboprop aircraft perfect
for FAC FF Scale
Designer Walter Extra’s full-scale Extra EA- 500 was created as
a luxurious, pressurized,
general aviation aircraft.
Mark Fineman felt it begged to be
modeled as a rubber-powered Flying
Aces Club (FAC) Scale aircraft, because
it was “so sleek and so beautiful that it
makes the usual strut-braced types look
clumsy by comparison.”
Mark’s EA-500 had the same general
30-inch wingspan proportions as a P- 30
competition model. The construction
was conventional, with only a few
The fuselage was built using a half-shell method. Top and bottom keels
were laid out, each consisting of two 1/16-
inch square stringers that were soaked
in hot or boiling water, then joined
with 50-50 diluted white glue that was
applied with a brush.
The former halves were 1/16-inch sheet
balsa. The former halves in the cockpit
and nose area were built in two pieces
for added strength. After the formers
were glued into position and dry, the
main 1/16-inch square side stringer was
glued in and the rest of the stringers
were laid in from nose to tail, working
out from the main stringer. This was
repeated for the remaining side. Nose
and landing gear locations were filled
between the stringers with 1/16-inch
sheet balsa from former A to former C
below the main side stringer.
Mark noted that inlets could be
drawn, but more convincing ones could
be created using a card template tack-glued into place, and cutting around the
pattern. Landing gear doors were carved
from 3/32-inch sheet balsa shapes. The
area between the lower formers E and
F was sheet-filled to hold the bulging
doors. All sheeted areas were sanded
smooth, filled where needed, and given
two coats of sanding sealer.
The wing was straightforward. For each wing half, Mark laid down a leading
edge (LE) and trailing edge (TE) then glued in the wing ribs. The airfoil was a
Rhode-Saint-Genese 30 with a slightly upward curve on the bottom surface as it
approached the LE, but the curve could be omitted by cutting the bottom of each
rib flat. After the dihedral angle for the LE, TE, and wing spars was sanded in, wing
panels could be glued together with CA glue.
The radar pod on the left wingtip should be kept as lightweight as possible, using a
small circular former and a light balsa wingtip. The radar dome was a turned piece of
balsa. Tail surfaces were constructed from 1/16-inch sheet balsa.
Several color schemes could be found on the Extra Aircraft website. Mark finished
his in the first prototype’s scheme of an aluminum base with a red-and-black side
stripe using Japanese tissue shrunk with rubbing alcohol and clear doped, followed
by a mixture of clear dope and aluminum powder. Control surface and landing gear
door outlines were drawn with a fine-tip Sharpie. Black tissue was used for windows,
and clear acetate for the windshield.
Mark said the 91/2-inch Peck-Polymers plastic propeller was satisfactory, but a
carved balsa propeller might be better. Power was supplied by two 26-inch loops of
FAI Tan Super Sport rubber, one at 3/16-inch wide and the other at 1/8-inch wide.
“The model takes off in a fast left-hand turn and quickly climbs out. This is
followed by a gentle right-turning glide,” he said. “The EA-500 is certainly a thing of
beauty on the ground and in the air.”
The Extra EA-500 was featured in the October 2008 issue of Model Aviation
as AMA Plans Service number 1021 for $9, plus shipping and handling. AMA
members can access the MA Digital Library on the magazine’s website to read more
about this airplane and its construction. See page 153 or go to www.modelaircraft.
org/ plans.aspx for ordering information.
101 Model Aviation JANUARY 2016 www.ModelAviation.com