Hangar 9 P-51D 1.50 ARF Assembly Manual page 13

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. . . .Step 7
Tie.the.string.onto.the.servo.extension..Gently.pull.the.
extension.through.the.wing.using.the.string..Untie.the.
string.when.the.servo.lead.has.been.pulled.through..Use.
tape.to.secure.the.servo.lead.to.the.wing.to.prevent.it.from.
falling.back.into.the.wing.panel.
Section 2: Aileron and Flap Servo Installation
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. . . .Step 8
Place.the.hatch.in.position.on.the.wing..Measure.in.1/8".
on.all.four.sides.of.the.hatch,.as.the.intersection.of.these.
lines.will.be.on.the.hard.points.located.underneath.the.
hatch..Drill.four.1/16".holes.at.the.intersections.of.the.
lines.and.into.the.hard.points..Remove.the.hatch.and.
enlarge.the.holes.using.a.7/64".drill.bit.
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. . . .Step 9
Secure.the.hatch.using.four.#2.x.1/2".screws.
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