Great Planes Learjet 40 Kit - GPMA0439 - Manual (Page 15)

D 2. Check that the taper of the 1 -3/8" x 6" balsa center
TE piece matches the shape of the airfoil.
NOTE: When installing the center trailing edge pieces
make sure they line up with the top and bottom surface of
the wing.
If necessary, sand the aft edge of the wing to correct the
problem. Trim and sand the ends to match the angles on
the wing plan. Cut a notch in the top surface of a balsa
center TE piece 1/2" from the root end. Fit an aileron
torque rod assembly into the groove with the threaded end
protruding through the notch. Prepare another center TE for
the other wing panel. Be sure to make a left and a right
side as shown.
D 4. Cut the ailerons to fit between the center TE and the
tip TE. Hold the aileron in position, then mark the location
of the torque rod arm. Drill a 1/8" hole, 3/4" deep, into the
LE of the aileron at the mark. Cut a groove for the torque
rod to fit into the aileron's LE. Sand the leading edge of
both ailerons to a "V" as shown on the plan.
D 5. Finish cutting out the aileron servo opening (and
retract servo opening if using retracts) that is partially
die-cut in both W-1 ribs. Mark the location of the servo
opening(s) on the top surface of both wing panels but don't
cut out the sheeting until after the wing has been joined.
D 3. Sand the mating root surfaces of the center TE pieces
to allow for the dihedral angle. Roughen the nylon torque
rod tubes with coarse sandpaper, then apply a dab of
petroleum jelly to the exposed wire at both ends of the
tube. Use 6-minute epoxy to glue the nylon torque rod
tubes into the center TE, then, before the epoxy cures, glue
the center TE assemblies to the aft edge of each wing at
the root with the threaded ends protruding through the top
of the wing. Be sure that the taper of the trailing edge
matches the shape of the airfoil.
D 6. Insert the landing gear strut wire into the retract
mechanism. Measure and cut the main retract struts to
4-7/16" long (measured from the surface of the wing).
Install the 2" main wheels (not included, GPMQ4221)
using adjustable 1-1/4" x 5/32" wheel axles (not included,
GPMQ4280) and 5/32" wheel collars (not included,
GPMQ4306). Verify that there is no toe-in or toe-out when
the retracts are extended, then tighten the locking screws.
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