sheet trailing edge to the aileron area. These should be cut 1/8” taller than the rear edge of
the rib to allow for the cap strips. One important note, make sure you groove the trailing
edge of this piece so that you can slide in and out your 9/32” diameter aluminum torque
tube guides. Your next task is to cut to shape and install your wing bolt blocks. Now
sheet the center section out to the second full size rib and return the wing to its saddle.
Drill, tap and bolt down the wing. Now drill the holes for the wing dowels through the
front of the fuselage, through the front spar, and into the wing mount blocks. Install the
dowels and refit the wing. If you are satisfied at this time, cap strip the wing with 1/16” x
¼” balsa and set it aside for now. The top wing is very similar to the bottom; I will only
touch on a couple of special notes. First and most importantly, DO NOT INSTALL OR
DRILL THE CABANE STRUT MOUNTS UNTIL YOU TRIAL FIT THE WING! Once
the wing is built and cap stripped, set it upon its cabane struts on the fuselage with the
lower wing installed. If everything appears in order, Install the cabane mount plates as
shown on the plans (above the cap strips). If things do not line up, find out why. It is my
opinion that at this time it will be easier for you to adapt your wing to the struts rather
than the opposite. Now with your cabane mounts installed, lay the wing in its correct
position taking great care that the leading edge is parallel with that of the lower wing.
Once you are satisfied with the top wing’s location, mark through the strut mount the
location of the hole. Drill through the mount plate at that location and install a blind nut
for an 8-32 bolt. Return the wing to its struts and bolt it in place with the one bolt. Once
you are again satisfied that the leading edges of both wings are parallel. Mark the location
of the three remaining bolts. Install the final blind nuts and bolt the wing in place. Check
the incidence of the wings. If both wings have the same incidence, (+/- ½ degree) use
balsa to build up the cabane mount plates to the cap strips. If the wings have different
incidences, shim the top wing until it is correct. On my model I left the front strut flush to
the plywood mount while building up the rear flush with cap strip to correct an incidence
issue. This method provides a better-finished appearance than jacking the wing up above
the strut. Now that everything is together, this is an excellent time to check the fit of your
interplane struts. These are a laminate of 3/32” balsa, 1/8” lite ply, and another layer of
3/32” balsa sanded to a streamlined shape. Once they have been adequately fit in place
(do not drill any mount holes at this time), let’s look at the ailerons. There are only a
couple of noteworthy points as the ailerons are pretty straightforward. The most important
note is that when trial fitting the aileron, you will find a curved gap out by the aero
counter balance (dog-ear shaped extension). This needs to be filled. I glued a piece of
1/8” balsa slightly longer than the gap and blended it using sandpaper. The second item is
to build up the leading edge at the hinge points (use a piece of ¼” scrap) and do the same
at the point where the torque rod enters it. Please ensure that your hinges are installed
upon the centerline of the torque tube. Now groove the aileron so it is clear of the torque
rod guide. All that remains is to make the torque rods. These are pieces of ¼” diameter
brass tubing cut to length. Plug the end about ½” deep using a slightly sanded piece of ¼”
hardwood dowel. Drill and tap one end 4-40 as shown on the plans. Slide the torque tube
to its full depth and install a piece of threaded rod through the bottom of the wing. Tape
the piece of threaded rod so that it is centered in its opening, now mark align on the
exposed end which will go straight into the center of the aileron. Remove the torque rod
and drill and tap a 4-40 hole 1/8” in from the end using the line you drew as a guide.
Reinstall the torque rod and the aileron. Press the aileron firmly against the torque rod
and this will leave an imprint where to drill your aileron for the threaded rod. Repeat this
procedure for the other three torque tubes. The wings are now ready for covering. I used
Arizona Model Aircrafters lozenge five-color fabric as it provides the scale appearance I
desired. There are a couple of paint schemes which do not require lozenge (Ernst Udet’s
plane was almost all red) and I recommend contacting Dan-San Abbott for more
information.
