09/11/2018
RANS S-21 OUTBOUND
TEXT MANUAL
82
10.
To check for square, measure from the top engine mount bushings on the firewall
to a common place in the tailcone. A hole on the aircraft centerline on the large
inspection hole on the bottom skin works well.
11.
Check the angle between the firewall and the top surface of the middle longeron.
This angle should be 88.9° ± 0.2° with the longeron sloping up toward the tail
when the firewall is perfectly vertical.
12.
If any adjustments were made to meet the above requirements, make all
measurements again to ensure the cage and tailcone are mated correctly. Check
the fit of the bottom tailcone skin to the bottom of the cage for height.
13.
Match drill through the gussets on the cage through the longerons and skins.
Cleco and remove clamps as you progress.
14.
Once all the gussets have been drilled and clecos inserted in all the gusset
holes, the fuselage can safely be moved or rotated as needed. If placed on saw
horses, the fuselage with clecos will easily support itself but care should be taken
not to put a lot of weight in the plane until the structure is riveted at a later time.
15.
Fabricate and cleco the middle longeron support angle as shown in
FIGURE 07-03
.
16.
Fabricate and install the lower longeron support angle and S-3 to S-4 Support as
shown in
FIGURE 07-04
and the PARTS MANUAL DRAWING.
17.
Fabricate and install the tailcone spacer strips. These are provided as raw stock
and must be trimmed just shy of the attach gussets at station 3. They may be
fabricated to lengths referenced below.
2 Top sides = 16-3/16
”
2 Lower sides = 18-3/8
”
1 Top = 36-5/16
”
1 Bottom = 35-5/8
””
18.
The Spacer Strips will reinforce the tailcone skin all the way around where the
tailcone attaches to the cage and are placed between the tailcone skins and the
tabs on the cage as well as the tailcone stringers.
19.
Position the Upper Side Spacer Strips flush with the AFT side of the welded tabs.
Refer to
FIGURE 07-04A
.
20.
Position the Lower Side Spacer Strips 1/4
” AFT of the welded tab.
21.
Position the Bottom Spacer Strip 3/8
” AFT of the welded tab.
22.
Position the Top Spacer Strip 1/4
” AFT of the Top FWD Skin’s pre-drilled holes.
23.
Transfer drill from the tabs on the cage to the spacer strips and side/bottom
skins. Cleco in place. Do not rivet at this time. Several holes will be transfer
drilled from the fuselage side and bottom skins after they are fit up.
24.
The front of the S-3 to S-4 support rest on the nut plate tab on S-3. A hole should
be drilled in the aft flange of the S-3 to S-4 support and riveted to S-4 bulkhead.