Fit The Flaps - Top Flite P-47D THUNDERBOLT User Manual

will see the punch marks in the ribs that can be
used as a guideline as well. Reference the cross
sections of the wing plans.
4. Carefully remove the flap from the wing. If
CA has glued the waxed paper layers together, cut
the inboard and outboard ends of the flaps free
with a razor saw.
5. Sand the LE of the Flap Ribs flush (and at
the same angle) with the Flap Spar. Use a long
T-bar or sanding block to maintain a straight LE.
NOTE: Stop sanding when the T-Bar contacts the
flap sheeting. Do not sand the flap sheeting as this
will change the height of your flaps and cause the
flaps to fit the wing improperly.
6. Set the flap over the plans and mark the
location of the 1/16" die-cut birch ply Flap Horn.
NOTE: There is a different Flap Horn location for
each flap. Insert but do not glue the Flap Horn
into the flap.
7. Cut the 5/8" x 1-3/8" x 14-1/4" balsa Flap
LE to fit on both sides of the Flap Horn. Cut a 1/16"
deep notch in one of the Flap LE sections to allow
passage of the Flap Horn. Glue the longest Flap
LE in position exactly as shown on the plan, with
the top of the Flap flush with the top of the Flap LE.
8. Remove the plywood flap horn and tack
glue the other, shorter flap LE in position.
9. Cut out the cross sections of the flap root
and tip from the wing plans and tack glue them to
each end of the flap (3M 75 Repositionable Spray
Adhesive recommended). Shape the flap LE to
match the cross section on the plans (now on the
ends of your flap). A razor plane and a long
sanding bar with coarse sandpaper help the job go
quickly and accurately. Save the cutouts for the
other flap.
10. Remove the shorter tack glued flap
leading edge. Install and permanently glue in the
plywood flap horn, then permanently glue the flap
leading edge back in place.
11. Trim off the excess ribs from the Inner Aft
Spar, then use a 3/4" dowel wrapped with 220 grit
sandpaper to sand a radius on the protruding
portions of the ribs. Use a #11 blade to carefully
shave the remnants of W-2F and W-7B from the
ribs. Cut a 1/4" x 1/2" slot in the aft Inner spar to
allow the Flap Horn and Clevis to pass (be careful
if you're using a Dremel tool–don't cut into the top
wing sheeting).
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12. Reinforce the underside of the wing
sheeting (where it overhangs the aft inner spar at
the Flaps) by gluing leftover 1/16" x 1/4" balsa
strips between the ribs on the underside of the
top sheeting.
13. Repeat steps 1 - 12 for the other Flap.

FIT THE FLAPS

1. Test fit the flaps to the wing. "Fine tune" the
ribs, ends of the flaps and top wing sheeting in the
flap section until you get a good fit between the flap
and the wing. Sand a bevel along the trailing edge
of the wing sheeting in the flap section to allow the
flap to clear when it's in the up position.
2. Assemble the two Flap Drill Guides (A & B)
by gluing the six die-cut 1/8" ply pieces as shown.
Hint: Glue a piece of 7/32" brass tubing to
the drill guides for even more accurate drilling of
the holes.
3. Position the wing flap drill guide on the wing
at each hinge block (you marked earlier) and drill
the holes for the hinge points in the wing. Hint:
Instead of a drill bit, use a piece of 3/16" tubing
sharpened at one end to make the holes.