Hangar 9 P-51 Mustang ARF Assembly Manual page 17

 
Step 9
Attach the control horn to the wing using two 2mm x
16mm screws near the hinge line of the control horn and
one 2mm x 11mm screw at the trailing edge of the aileron
wing. The screws go into the control horn backplate which
is located on the top of the aileron.
Note: If you have difficulty getting the screws
to line up with the backplate, just use your
drill bit to oval out the holes slightly. Just
remember to apply some thin CA to harden the
holes again.
Section 3: Installing the Aileron Linkage
 
Step 10
Locate the flap control horn. Thread the horn onto the flap
linkage so the top of the horn is 7/8" (22mm) from the top
surface of the wing.

Step 11
Repeat Steps 2 through 10 for the remaining
aileron linkage.
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