Stage 4 - Install Flap Wiring Harness (WHF) - For VMA-J210X JU52 Trimotor
 
a) Review the Read Me First documentation and the Assembly and Operations Manual that came with your model. Complete Stage 1 and Stage 2 from the Assembly and Operations Manual. Once completed you will have assembled the wing.
 
b) Review Stage 13 from the Assembly and Operations Manual. Pay particular attention to the larger warning label and note the color conventions used for different manufacturers. This will be important when you plug in your servos and when you plug into your receiver. Locate the Flap Wiring Harness parts bag and remove the harness. 
 
c) Read all labels attached to the Flap Wiring Harness. See Figure 4A and the green "path" as a reference to guide you as you proceed with the installation.
 

4A - Flap Wiring Harness Installed - Viewed from Top Side of Wing

 
d) Turn the wing upright so that you can see the large access cavity near the center of the wing. Support the wing with a sheet of foam rubber or folded up fluffy towel.
 
e) Position the wing so that the trailing edge (thin) is closer to you and the leading edge (thick) is further away. When oriented in this manner, the wing panel on your left will be the left wing panel in flight and the wing panel on your right will be the right wing panel in flight. This consistent definition of left and right makes it much easier to install the flap servos and flap wiring harness properly.
 
f) Thread the end of the wire marked "Flap Servo Left" through the left side of the large access cavity near the center of the wing and through the internal wiring access tube to the left flap servo cavity located about 8.5 in. (215 mm) outboard from the center of the wing. Pull the loose end of the wire out of the tube so that it exits the downward facing bottom surface of the wing through the left flap servo cavity. Connect the left flap servo to this wire. Use the supplied "Flap Left" sticker to wrap the connection securely. Gently pull the wire back from the source and install the left flap servo into position as shown in Stage 13 of the Assembly & Operations Manual.
 
g) Repeat this process for the wire marked "Flap Servo Right", working from the right side of the large access cavity near the center of the wing and the internal wiring access tube that runs to the right servo cavity. Connect the right flap servo to this wire. Use the supplied "Flap Right" sticker to wrap the connection securely. Gently pull the wire back from the source and install the right flap servo into position as shown in Stage 13 of the Assembly & Operations Manual.
 
h) Once completed, both flap servos will be installed into the bottom of the wing and the end of the Flap Wiring Harness that is labeled "Flap Channel ==> ==>" will be hanging loose near the center of the wing ready to be plugged into the flap channel of your receiver.