09/11/2018
RANS S-21 OUTBOUND
TEXT MANUAL
89
FUSELAGE SIDE AND BOTTOM SKINS
NOTE:
The sliding seat position rails must be installed before final riveting
of the bottom skin. Refer to
Sliding Seat Assembly
in the parts manual
and
FIGURE 09D-01
. Check to be sure seat belt bolts will slide into seat
belt bushings of fuselage. Clean or drill out powder coat as needed.
NOTE:
Orientate all seams on the fuselage/tailcone so that the forward or
upper skins overlap onto the aft or lower skins. This is to prevent air and
water from entering the fuselage either in flight or on the ground.
1.
Flip the fuselage upside down for ease of fitting the belly skin.
2.
Fit up the fuselage bottom skin as shown in
FIGURE 10E-30
. Transfer drill from
the inside of the cage through the tabs to the fuselage bottom skin. Use a wood
block to back skin where transfer drilling. Cleco skin as holes are drilled. To
locate where the landing gear bolts penetrate the belly skin use 5/16 and 3/8" drill
bits inserted into the bushing and spin by hand until a center mark is made.
3.
Flip the fuselage right side up.
4.
Prior to fitting and transfer drilling the side skins, make a paper template for any
tabs that will not be accessible transfer drilling inside. Key the template by using
other holes that can be drilled from the inside. Make a template for each side and
mark left and right.
5.
Fit up the AFT and FWD fuselage side skins to the cage. The bottom flange of
the side skins slips between the cage and the belly skin. Hold pressure rearward
while transfer drilling from inside the cage through the tabs welded on the cage to
the AFT and FWD side skins. Cleco in place. The purpose of holding pressure
rearward is to ensure the top bent flange holds some pressure to the tube after
the skin is final installed. Using a sharpie, mark from the inside where the
fuselage cage tubes (both bottom longerons and crossing tubes) are located.
This is to prevent drilling into the fuselage cage tubes. This line will be used to
set the edge distance of the rivet holes for attaching the belly and skins. Use a
.30" ED from this line. To locate where the landing gear bolts penetrate the side
skins use a 5/16 drill bits inserted into the bushing and spin by hand until a center
mark is made.
6.
Trim the side skins as needed. The top corner of the AFT side skin and the place
where the FWD side skin overlaps the weld on the taildragger gear truss are
likely places where trimming will be needed.
7.
With the side and bottom skins clecoed in place, transfer drill from the fuselage
side and bottom skins to the tailcone side and bottom skins and spacer strips.
8.
Refer to
FIGURE 10E-30A.
Cut stringer material to given lengths and quantities.
Ap
ply 1/2” Acrylic tape to widest flange of each stringer. Position stringers on the
inside of the Bottom Skin in locations shown. Make sure to press firmly to allow
the tape to bond.
