The retracts and struts are mounted and the 3/16 piano wire extensions have been installed. Block
in around the strut with scrap balsa and basswood.
The main left panel is nearly complete. The
top 1/8-inch basswood stringers will be added
after the two wing halves are joined.
The 1/16-inch balsa sheeting has been added. The LE’s
overhang will be trimmed.
position, noting the angle according to
the plans. Add F-7A and F-8A at this
Glue the tail wheel mounting plates
together and install both the tail
wheel retract and the steering servo.
Trim away plate material for the strut
and test to ensure retraction and left/
right movement. With the strut in the
extended position, dry fit the tail wheel
assembly into F-8A and test fit F-9A.
Sand or bevel the parts as needed for a
good fit, then glue into place.
Add the remaining bottom formers,
wing saddle bottom, and hatch rail
lowers according to the plans. Add the
bottommost (center) 3/16-inch balsa
stringer from F-1A to F-10A. Alternating
sides, add the remaining bottom
When it is complete, cut the belly
pan and the hatch from the fuselage
and sand as needed. From F-3/F-3A
forward, sheet with 1/32-inch balsa. Using
scrap 1/8-inch balsa, infill behind F- 3 and
around the tail wheel area and remove a
precut section of F-9A for the tail wheel
retraction. Sheet the lower rear section
vertical according to the plans with 1/32-
inch balsa. Build the cowl ring per the
plans, glue it in place, and contour.
The wing also has several
subassemblies. Create the wingtips and
the wing mounting plates. Following the
notes on the wing plan main spar detail,
glue a 1/2 x 1/8-inch basswood plank to
the bottom of both main spars and trim
according to the plans. Cut two strips of
1/2 x 1/2-inch balsa and trim following the
plans for the wing’s TE. Glue a 1/8-inch
square basswood stringer to the forward
edge and add W- 10, but allow a little
extra length at the center section (wing
mounting plate 3 will sit on top of this
Pin the main spar, main
1/8-inch square basswood
stringers, and the rear spar
over the plans. Note the
rear spar’s height tabs on
the bottom. Slide the sub
spar into the forward slot
on W- 4, and then slide this
assembly into place.
On the wing plans, review
the retract plate detail.
Make a left and a right set.
Test fit the remaining ribs,
retract mounting plate, and
aileron LE according to
the plans. Test fit the LE then slide the
TE assembly into the slots on the ribs.
When you are satisfied with the fit and
alignment, glue the parts. There will be
some gap between the surfaces of the
ribs and the rear spar/aileron LE. Use
scrap balsa to fill in these areas and sand
the components flush.
Bevel the top of the LE to match the
contour of the ribs and sheet the “top
front” of the wing with 1/16-inch balsa.
This will butt up against the main spar
and will overhang the top of the LE. The
overhang will later be trimmed off.
Add the top 1/8-inch square basswood
stringers at this time. Remove the wing
half from the board, trim the sheeting,
and sand the LE smooth.
Remove the precut section from the
retract mounting plates. Repeat the same
for the other half of the wing. Add the
bottom 1/4 x 1/8-inch basswood beam
according to the main spar detail, step 5,
on one wing panel.
Place one wing half over the plans,
raising the tip 31/8 inches off the board.
Slide W- 1 in place and ensure that the
main spar is at the rear of the slot in W- 1
with a 1/8-inch gap in the slot in front
of the main spar. The main spar doubler
will be added later.
Test fit the wing mounting plates,
removing the precut parts of W- 1. Pin
the other wing half to the board with
the same 31/8 inches raised at the tip.
Ensure that the main spar edges are
flush against each other and resting on
top of the bottom beam (1/4 x 1/8-inch
When you are satisfied with the fit
and alignment, glue them together
with wood glue. Add the LE center and
sheet the top front center section with
1/16-inch balsa. Add the center rear spar
and main spar doubler. Add the 1/8-inch
square basswood stringers “bottom only”
as directed on the plans, and remove
the precut sections on W- 1 outer and
the rib/spar tabs. Test fit the retracts and
If using the FMS wheels and struts,
make strut extenders from 3/16 piano
wire and note the bend. Sheet the
underside of the wing the same way as
39 Model Aviation APRIL 2017 www.ModelAviation.com