09/11/2018
RANS S-21 OUTBOUND
TEXT MANUAL
74
FLAP ASSEMBLY
1.
Remove the bend guides as shown in
FIGURE 06-15.
Carefully use a pair of
snips to cut them off close and finish with a file.
2.
Remove the attach tabs of the Flap Hinge - Part Assembly to make individual
Flap Hinges. Trim off close and finish with a file. Refer to
FIGURE 06-15A
.
3.
Lay the flap skin on a table.
4.
Lay out the ribs, hinges and doublers in the proper locations.
5.
Drill the aileron and flap hinges and hinge arms using a 5/16" drill to allow the
bronze flange bushings to be pressed in. Use a drill press if available. If a drill
press is not available, a hand drill may be used, but care must be taken to stay
square to the parts. If there is any play detectable between the bronze flange
bushing and the hole, the damaged hinge must be replaced. (This may have
been done in a previous step.) Ream the bushings to #11,
if a 3/16” bolt will not
insert into the bushings.
6.
Double check the location and orientation of the ribs, hinges, and Push-Pull Tube
Attach and rivet the hinges and Push-Pull Tube Attach to the appropriate ribs.
7.
Determine which side of the hinges to press in the bronze flange bushing. Refer
to
FIGURE 06-16
for typical orientation. Use a bench vice or similar to press in
the bronze flange bushings. Ream the bushings to #11, if a 3
/16” bolt will not
insert into the bushings.
NOTE:
If any of the bronze flange bushings do not stay pressed into the
hole, set them aside and wait until assembling the flap to the wing. Once
in place on the wing the bushings will be retained by the hinge bolts.
Green Loctite may be used to retain the bronze flange bushings.
IMPORTANT:
Check for play between the bronze flange bushings and the
hinges. If play is present, the hinges must be replaced.
8.
Use a sharpie to draw a line on the bottom flange of the ribs. The line should be
.2" from the edge of the flange.
9.
Cleco the ribs in place to the top side of the skin. Use a 2X4 or similar to space
the flap off the table and prevent damage due to resting on the clecos in future
steps.
10.
Place the flap with the bottom side up.
11.
Fixture or weight the flap to remove any twist.
12.
The hinges must not contact the skin. Enlarge the slots in the flap skin if needed.
13.
Transfer drill using a #30 drill from the skin to the bottom flange of the ribs.
Reach in from the front and move the ribs as needed. Use the line drawn on the
ribs to ensure proper edge distance. Cleco as holes are drilled.
14.
Slide the flap spar into place from either side.
15.
Place the flap right side up on the 2X4s.
