Procedure 3.155A WING CLOSE-OUT PROCEDURES In this procedure The lower wing skin will be bonded to the upper wing For this procedure, the following parts will be required: Part Number Description Qty 111-11-060-01 Lower Left Wing Skin 1 111-11-060-02 Lower Right Wing Skin 1 Step 1. ENSURE WING FIXTURES ARE LEVEL. Recheck the alignment of the wing saddle jig to ensure that all saddles are level to prevent an undesirable twist in the wing. Once the wing is closed you cannot remove any twist or alignment problems. Step 2. CUT GROOVE FOR MILLED-FIBER SQUASH IN ALL UNFLANGED RIBS AND SHEARWEBS. Use a box knife and cut a ¼ deep cut between the fiberglass skin and the foam on the rib. Make a second 45 º cut down the center of the rib with the blade slanting outward to the skin. Remove the triangle shaped piece of foam. Repeat this cut on the other side of the rib. These grooves will be used to hold the Milled-Fiber material during the close-out. Hard points are too hard to cut with a box knife and can be V grooved with a right angle hand grinder. (Fig. 155.1 through 155.8) (Note: Do not cut grooves in the cut out area of the fuel baffle ribs that were sealed with resin and Q-cell in section 3.010) 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-1
Fig. 155.1 Fig. 155.2 GROOVE CUTOUT DETAIL Fig. 155.3 Fig. 155.4 Fig. 155.5 Fig. 155.6 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-2
Fig. 155.7 Fig. 155.8 Step 3. CHECK FUEL FILLER CAP INSTALLATION. Check the fuel filler cap installation to ensure a proper seal and that attachment nuts are secure and properly sealed. Step 4. INSPECT FUEL BAYS. Inspect the four fuel bays to ensure there are no holes in the wing skins, which will allow fuel to leak into foam core. Ensure that exposed foam in cutouts on baffle ribs is coated with resin to prevent fuel from seeping into foam. Check laminations on forward shearweb, and the inboard and outboard ribs to ensure a good seal is present. Step 5. INSPECT NAV ANTENNA. Inspect the Nav antenna to ensure cable is secure and that copper tape has not been damaged. (Fig. 155.5) Fig. 155.9 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-3
Step 6. INSPECT TIE-DOWN BRACKET. Inspect the tie-down bracket to ensure all laminates have been installed. Step 7. FABRICATE AND INTALL TEMPORARY TIE-DOWN BRACKET ALIGNMENT PIN. Locate one spare bolt of equal size as threaded tie-down insert (approx. 2 in length). Remove head and cut slot across shank end of bolt. This slot must be wide enough to accommodate slotted screwdriver. Grind (sharpen) slotted end to cone shape. This bolt will serve as a temporary alignment pin during wing close-out. Thread alignment pin into threaded hole in tiedown. Fig. 155.10 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-4
Step 8. PREPARE LOWER WING SKIN FOR ALIGNMENT AND FIT. Place the lower wing skin on the wing assembly. Align unpainted strip on wing skin with spar cap. Check the outboard end of the wing to ensure that the lower wing skin joggle aligns with the upper wing skin joggle (as it sets in the jig). Slide the wing skin in or out to align joggles. Once aligned, locate tie-down area and tap with a rubber hammer over tie-down alignment pin to score inside of wing skin. Temporarily remove wing skin and drill hole for tie-down alignment pin. Relocate the wing skin over the wing assembly, using newly-drilled tie-down hole in wing skin and tie-down bracket pin for alignment. Recheck spar and outboard joggle alignment. Press wing skin down and check all visible areas for rib fit. If necessary sand ribs to ensure a proper fit. Laminates will be completed on ribs G and A after close-out. A small gap between the rear shearweb and the skin is normal. This gap will be pulled down during the squash. Once wing skin alignment is established, drill alignment holes through the wing skin, into spar cap and shearwebs. On inboard end, drill Cleco holes through wing skin, into shearwebs, ½ - ¾ in from inboard edge of wing skin. On outboard end, drill Cleco hole through wing skin, into spar cap, 1 in from joggle and through spar cap flange. Remove wing skin and prepare for wing close-out. Step 9. PREPARE MATING SURFACES. Sand white all mating areas with 36 grit sandpaper and wipe with acetone (Fig. 155.11-12). This includes Ribs, spar cap, shearwebs, and the contact areas on the lower wing skin. Vacuum the wing bays and wipe with acetone. Pay particular attention to the fuel bay. Fig. 155.11 Fig. 155.12 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-5
Step 10. INSTALL PROTECTIVE COVER IN ACCESSIBLE AREAS In bays where access is available (gas cap, inspection covers, etc.) cover bay, tubes, cables, brackets, etc. with protective material that can be removed through access holes after wing closeout ( Fig. 155.13-16). This helps to catch as much excess resin as possible in order to prevent drips of resin from coming loose in the future, especially in the fuel cells. Fig. 155.13 Fig. 155.14 Fig. 155.15 Fig. 155.16 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-6
Step 11. PREPARE TOOLS AND RESIN FOR CLOSE-OUT. Arrange all clamps, angle bars, Cleco s, sand bags and wood planks (use as load spreaders) so that they are readily available when needed (Fig. 155.17-18). It is best to familiarize at least three able-bodied personnel with this procedure and make a dry-run prior to continuing on. You will need approximately 3200 grams of resin and 1400 grams of Milled-Fiber. Do not catalyze all the resin at once. Pour resin into 300 to 400 gram cups and catalyze as needed. Mix Milled-Fiber to a consistency of oatmeal for ribs and shearwebs. For the spar cap, mix Cabosil to the thicker consistency of peanut butter. Use cake decorator bags to apply Cabosil. Fig. 155.17 Fig. 155.18 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-7
Step 12. APPLY RESIN AND MILLED-FIBER TO ALL CONTACT AREAS. Add catalyst to resin and brush resin on all contact areas, including those on the lower wing skin. No pooling. Brush out resin in thin layer ensuring 100% coverage of contact areas (Fig. 155.19). Fig. 155.19 Place 4 mat over resin full-length of spar cap from inboard edge of wing skin to outboard end of spar. Wet out with resin and repeat with second mat in same manner. Wet out with resin. Add third mat in same manner from inboard edge of wing skin to BL 91.12. Wet out with resin. Apply (2) layers of 4 mat on flanged rib R (BL 36.00) in same manner as spar cap (Fig. 155.20-23). Fig. 155.20 Fig. 155.21 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-8
Fig. 155.22 Fig. 155.23 Mix the Milled-Fiber Cabosil to the consistency of oatmeal and with cake decorator bag, apply to ribs and shearwebs. Ensure that the Milled-Fiber fills the V cutouts in the ribs and shearwebs. The Cabosil bead should extend approx. ½ above the rib and shearwebs (Fig. 155.24-27). Spread an even layer of cabosil on the rib R flange. Fig. 155.24 Fig. 155.25 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-9
Fig. 155.26 Fig. 155.27 Mix the Milled-Fiber Cabosil to a thicker consistency of peanut butter and with cake decorator bag, squeeze out approx. 1-1 ½ bead down center of spar cap full length of wing skin contact area. Do not spread. Cabosil will spread slightly on its own. Fig. 155.28 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-10
Step 13. INSTALL LOWER WING SKIN. With the help of assistants (preferably three) lift the lower wing skin over the wing and place in position, using tie-down bracket pin and previously drilled Cleco holes for alignment (Fig. 155.29-30). Try to place the skin in position with minimal horizontal movement. Install Clecos in alignment holes. Fig. 155.29 Fig. 155.30 Place 1 x6 board full-length over spar and cover with shot bags laid end-to-end, full-length of spar. Place heavy bars (square tube or 2 x6 lumber) full-length over both forward and aft shearwebs. Tape bars at both ends to keep in place. Place shot bags over rib R, inboard ribs, and over areas requiring additional weight for proper bond (Fig. 155.31) Fig. 155.31 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-11
Check Cabosil for proper bond under wing skin. Radius cabosil with tongue depressor all around underside of wing skin. Remove protective coverings through access holes and vacuum inside wing where possible. Step 14. INSTALL UNI-DIRECTIONAL CLOTH AND 7781 CLOSEOUT LAMINATES A. Apply Q-Cell radius to newly bonded wing skin and shearwebs. B. Sand white entire forward and aft shearweb faces and wing skin surface with 36 grit sand paper. C. From BL 74.50 to inboard end of shearwebs, apply (2) layers each of 6 uni-directional tape onto outside face of forward and aft shearwebs to radius at wing skin. D. On forward shearweb, apply (3) 7781 close-out laminates entire length, overlapping radius onto wing skin and covering entire uni-directional tape layers. Overlap butt joints 2. E. On aft shearweb, apply (4) 7781 close-out laminates entire length, overlapping radius onto wing skin and covering entire uni-directional tape layers. Overlap butt joints 2. Recheck alignment. Clean all excess Milled-Fiber from accessible areas. Allow wing to cure for 24 hours. See Step 15 for FG Landing Gear Cutout in wing skin. 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-12
Step 15. CUTOUT FG LANDING GEAR OPENING IN WING SKIN. Measure 3.25 aft from centerline of spar and mark forward edge of cutout. From this mark, measure 7 aft and mark aft edge of cutout. Measure 5 outboard from BL 36.00 line in wingskin and mark inboard edge of cutout. From this mark, measure 6.5 outboard and mark outboard edge of cutout. Using these marks, draw rectangle and cutout for FG landing gear installation (Fig. 155.32). Fig. 155.32 2000 Express Aircraft Co LLC Rev.7/10 Page 3.155-13