BRYAN AIRCRAFT COMPANY
BUILDING THE TAIL-SURFACES
1. File the rear main spar attachment fittings to fit the inside flange radius.
2. Clamp and drill fittings, spacers and spar. It is recommended that #30 pilot holes be first drilled in the fittings. Make sure that fittings are securely clamped in a flat plane so that they will mate properly with the fuselage fitting after riveting.
3. Mount stabilizer root rib in position and clamp to rear spar.
4. Ream all spar fitting holes to correct rivet size with a #12 drill.
5. Rivet rear spar fittings.
6. Clamp front spar fitting to spar, drill rivet holes with #30 drill and rivet fitting to spar. Omit 3 rivets attaching spar to root rib.
7. Attach front spar and tip rib to rear spar and root rib assembly.
8. If you are making your own stabilizer skin, square up stabilizer assembly so that rear edge of top flange of rear spar makes 90 degree angle with centerline through front and top rear spar attach fitting holes.
9. Make paper pattern 1/4" oversize on all edges to allow for variations and trim.
10. Cut out .032" 2024 T-3 Alclad skin to match pattern.
11. Mark center of leading edge bend at each end of sheet. Double sheet over with trailing edges touching. Place board on top of bent sheet so that even pressure can be applied for the full length of the skin and begin to flatten doubled skin after checking to make sure center of bend is coming on both marks. When bend is partially completed, move board so that outer edge is even with the skin leading edge and complete bend by pushing skin as flat as required. Apply more pressure to center of leading edge bend as ends will flatten more readily than center. Test skin shape by inserting spar and rib assembly. Hold skin down on ribs and spars. Skin will complete required airfoil shape if bend is correct.
12. Trim top rear edge of skin even with spar edge. Make sure this is a straight line.
13. Clamp skin to rear spar top flange. Clamp extruded hinge sections in place. Edge of hinge cutouts should be even with edge of spar flange to insure proper hinge operating gap.
14. Drill for 3/32 rivets making sure that holes in hinges are centered in the strip behind each hinge finger.
15. Countersink all holes with a 3/32 micrometer stop countersink and rivet.
16. Align and clamp skin to end ribs. Make sure that rear hinge and attach fitting holes still make a 90 degree angle and that assembly is reasonably free of twist.
17. Drill, countersink and rivet front spar and end ribs.
18. Clamp bottom side of skin to end ribs and rear spar.
19. Attach straightedges to the conterlines of both end ribs-and sight extensions of straightedges to insure freedom from twist.
20. Drill. countersink and rivet bottom skin. Front spar rivets are bucked with a long steel bar which will extend through the leading edge of the stabilizer.
1. Lay cut and bend elevator skin from .025 2024 T-3 -Alclad.
2. Clean inside areas of trailing edge with steel wool and solvent. Apply two part epoxy metal adhesive to inside trailing edge surface. Clamp between two 1/2 x 1 inch steel or aluminum bars. Sight assembly for straightness and freedom from twist.
3. Rivet trailing edge.
4. Install hinges to match stabilizer hinges.
5. Install 3/16 drive angle in root rib.
6. Drill, countersink and rivet root rib into elevator.
7. Install tip rib in elevator.
8. Install mass balance weight in tip rib.
9. Install fairing in tip rib between mass balance and elevator.
10. Drill inside surface of mass balance to achieve perfect horizontal equilibrium when elevator is balanced on hinge axis.