Great Planes Giant Aeromaster Kit - GPMA0502 - Manual (Page 14)

D D 1. Cover the bottom right wing plan with wax paper.
Then use the cross-pinning technique (see sketch above)
to pin a 3/16" x 1/2" x 36" hardwood main bottom spar
over the wing plan. The spar should be flush with the
outside face of rib R-6.
D D 5. Position the 36" shaped balsa leading edge (LE)
on the front of the ribs. The LE should be centered on all
ribs and the tip end should extend past rib R-6 by at least
1-5/8". Make sure all the jig tabs are contacting the
building board, then use thin CA to glue the LE to the front
of the ribs.
D D 2. Place the die-cut wing ribs R-1B, R-2B, R-5, R-
5A, R-5B, R-PB and R-6 on the top of the spar, over their
locations on the plan.
Note: While the jig tabs should be contacting the plan,
you should check rib alignment with a straightedge. Shim
the forward or aft jig tabs with paper to raise any ribs that
are low. Use small T-pins to pin the forward and aft jig
tabs to the building board over their location on the plan.
On the aft jig tabs, insert the T-pins at an angle from the
rear so they can be removed after the TE and sheet is
glued in position.
D D 6. Cut the 36" balsa trailing edge (TE) 17" long.
Use thin CA, to glue the TE to the ends of ribs R-1B, R-2B
and R-5.
D D 3. Place the 3/16" x 1/2" x 36" hardwood main top
spar in the notches of the ribs. The end of the spar should
be flush with the outside face of rib R-6 and with the top of
the ribs. With the ribs perpendicular to the building board,
glue the ribs to the top and bottom spars with thin CA.
D D 4. Insert the 1/4" x 1/4" x 36" balsa aft spars in the
notches in the aft end of the ribs. The end of the spar
should be flush with the outside face of rib R-6 and with
the edges of the ribs. As you are gluing the spars to the
ribs with thin CA, check that the ribs are perpendicular
to the building board and the jig tabs are against the
building board. (See note above.)
D D 7. From the 3/32" x 3" x 24" balsa sheets, make
shear webs to fit on the front of the main spar starting at
rib R-2B to R-6, behind the main spar from rib R-2B to
R-5B and to the front of the aft spar from rib R-2B to the
a i l e r o n bay. The grain of the shear webs runs
perpendicular to the spars and the shear webs must be
glued securely to the spars.
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