09/11/2018
RANS S-21 OUTBOUND
TEXT MANUAL
46
HORIZONTAL STABILIZER
Refer to section
4
of parts and figure drawings.
FRAME ASSEMBLY
1.
Lay ribs on a flat table with the flanges up. Use fluting pliers to straighten the ribs
so they lay flat on the table. Nose ribs may require re-shaping where the metal
has bulged out at a rivet hole. Take a duck bill pliers to flatten and use a fluting
on either side of the hole to shape to contour.
2.
Cleco the frame assembly together as shown in the PARTS MANUAL
DRAWING. Note although the spars look identical, there is a forward and aft. For
quick and easy reference, the rear spar, has only one mounting hole near the
center. During assembly of the horizontal stabilizer the second hole will be
transfer drilled once the stabilizer is square with aircraft. Ensure the pre-drilled
holes in the spars and doublers match with each other and the pre-drilled holes
in the spars are on one side. This will orientate the spars so that both undrilled
flanges are on the same side.
3.
Rivet outboard and middle ribs to the front spar, front spar doubler, and nose
ribs. This allows the outboard and middle ribs to be flexed to allow the riveter
access.
NOTE:
There are 2 different ribs (outboard and middle) that vary in length
depending on if the spar doublers are between the spar and rib.
4.
Rivet the Spar Doubler to each Front Spar using the indicated rivets in all #30
holes. Do not rivet through the #11 holes.
5.
Press the bronze flange bushings into the hinges before assembly. See part
drawing (ELEVATOR AND ELEVATOR TRIM TAB INSTALLATION) for
orientation.
Ream the bushings to #11, if a 3/16” bolt will not insert into the
bushings.
6.
Rivet the ribs, Doubler and hinges to the aft spar. Use same procedure as before
for rib and doubler attachment.