CIRRUS AIRPLANE MAINTENANCE MANUAL

Transcription

1 MAIN FRAME 1. DESCRIPTION This section describes those structural components which make up the main frame including vertical stabilizer, firewall, bulkheads, spar cover, and roll cage. A. Firewall The firewall is designed to separate the engine compartment from the rest of the fuselage and support various airplane components on both the forward and aft sides. The firewall, constructed of a fiberglass composite sandwich, includes metal fittings for supporting the engine mount, and incorporates several hardpoints for support of various engine components. In addition the firewall assembly also supports the compression tube that is used to absorb CAPS deployment loads. Fire protection is provided by a layer of aluminum foil, FiberFrax paper, and a stainless steel sheet mounted on the bulkhead s forward side. Serials 1423 & subs: The lower firewall is beveled aft about 20 from the bottom of the floor to improve crashworthiness. B. FS 222 Bulkhead The FS 222 bulkhead is constructed of fiberglass composite sandwich and solid laminate. The upper portion of the bulkhead is reinforced with additional fiberglass to support reaction loads during CAPS deployment and to support passenger seat shoulder harness attachments. The bulkhead also contains hardpoints which support cargo attachment loads. C. FS 289 Bulkhead The bulkhead at FS 289 is fabricated from fiberglass laminate. This bulkhead provides buckling support to the empennage. D. FS 306 Bulkhead The FS 306 bulkhead, located below the horizontal stabilizer, is fabricated from either fiberglass laminate (Serials 1005 thru 1300, 1302 thru 1306) or machined aluminum (Serials 1301, 1307 & subs) to carry loads generated by the attached rudder/elevator actuation system. E. Spar Cover The spar cover is comprised of solid laminate and supports wing reaction loads. In addition, seat track attachment channels are mounted to the front and rear face of the spar box. F. Roll Cage The roll cage is composed primarily of bi-directional fiberglass but also contains unidirectional fiberglass to add bending strength. Serials 1005 thru 1422: The main structural components of the roll cage are side longerons, which support in-flight bending loads, and hoop sections surrounding the right and left doors. Serials 1423 & subs: The main structural components of the roll cage are incorporated into the fuselage skin by using a cast core to create the desired shape in the laminate. The remaining components provide local stiffening to cutout regions of the fuselage. All Page 1

2 2. MAINTENANCE PRACTICES A. Repair - Vertical Spar Bond (See Figure 1) (1) Repair - Vertical Spar Bond In the event of a tail strike, a visual inspection of the airframe and the components involved must be accomplished to determine the type and extent of damage. The Unscheduled Maintenance Check for Hard/Overweight Landings should be completed. (Refer to 05-50) The Vertical Spar Bond Repair may be used to repair disbonding between lower vertical spar and empennage skin. Bond depressions are filled with filler paste to ensure a smooth layup transition. Glass fabric repair plies are then wet-layed over area where disbonding has occurred. (a) Determine type and extent of damage. If necessary, contact Cirrus Design for disposition. (Refer to AMM-Intro-) (b) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Serials 1005 thru 1422: Tin Plated Copper Tape, 4 Inch Serials 1423 & subs: Expanded Metal Mesh (EMM) Instrument Specialties Euless,TX (Refer to 51-30) (Refer to 51-30) General repair. Lightning protection. Tie Down Bracket Cirrus Design Duluth, MN Tie Down Eye Bolt Cirrus Design Duluth, MN Nut Cirrus Design Duluth, MN Tie down eye bolt attachment. Tie down airplane. Tie down eye bolt attachment. Isopropyl Alcohol 99% or higher purity Any Source General cleaning. Orbital Sander 39825A12 Any Source Prepare repair surface. Angle Grinder 80-grit Any Source Remove laminate from vertical spar. Release Film (Refer to 51-30) (Refer to 51-30) Protect lay-up surface. Peel Ply (Refer to 51-30) (Refer to 51-30) Makes smooth and contaminate free repair surface. Glass Repair Fabric (Refer to 51-30) (Refer to 51-30) Repair composite structures. Structural Resin Repair System (Refer to 51-30) (Refer to 51-30) Bond plies over puncture. Page 2 15 Dec 2014 Sandpaper 120-grit or finer Any Source Paint and primer removal. All

3 Description P/N or Spec. Supplier Purpose Sandpaper 60 to 80-grit Any Source Abrade bonding surfaces. Aerosil (Refer to 51-30) (Refer to 51-30) Resin filler. Sil-Cell (Refer to 51-30) (Refer to 51-30) Resin filler. Diamond Coated Hole Saw 0.75 inch (19.05 mm) Any Source Drill aft tie down installation hole. (c) Remove rudder. (Refer to 55-40) (d) Remove lower top and bottom vertical hinge. (Refer to 55-50) (e) Remove aft tie down. (Refer to 53-20) (f) Remove aft tie down bracket. (Refer to 53-20) (g) Serials 1005 thru 1422: Remove copper tape from vertical spar. CAUTION: Never use a grinder for removal of outer surface coats. A grinder will gouge the surface creating more damage. Chemical strippers should not be used as they may become trapped, damage the laminate, or leave a residue. Multi-action orbital type sanders or simple hand-sanding are the preferred methods of paint removal. Fine-grit paper (120-grit or finer) should be selected to minimize the potential for accidental damage. (h) Remove paint finish from repair area. (Refer to 51-20) (i) Serials 1423 & subs: Remove Expanded Metal Mesh (EMM) lightning protection from repair area. (Refer to 51-20) Serials 1423 & subs: Remove lip of aft vertical spar to tangent at least 0.5 inch (12.7 mm) beyond damaged area. (j) Serials 1423 & subs: Carefully trim away lip of aft vertical spar using a small angle grinder with 80-grit or similar disk to remove the laminate from the fuselage skin. (k) Solvent clean with isopropyl alcohol. (Refer to 20-30) (l) Mix MGS L418-based filler paste. (Refer to 51-30) At junction between vertical spar and fuselage skin, ensure filler paste does not exceed maximum radius of 0.5 inch (12.7 mm). (m) Using a clean spatula or wooden applicator, fill bond depressions with filler paste to ensure smooth layup transition. Ensure plies extend at least 1.0 inch (2.54 cm) beyond dis-bond. Ensure each ply overlaps the previous ply by at least 0.5 inch (12.7 mm). All (n) Cut three glass-fiber repair plies at ±45. (Refer to 51-20) (o) Mix MGS L418-based structural resin. (Refer to 51-30) (p) Layup glass fabric repair plies. (Refer to 51-20) (q) Cure repair plies. (Refer to 51-20) (r) Serials 1423 & subs: Install Expanded Metal Mesh (EMM) lightning protection. (Refer to 51-20) Page 3

4 (s) (t) (u) (v) Match drill hinge installation holes covered by glass fabric repair layup. Match drill aft tie down installation hole covered by glass fabric repair layup. Using 0.75 inch (19.05 mm) hole saw, cut aft tie down installation hole through skin and centered on BL0. Serials 1423 thru 1472: From aft tangent of tie down installation hole to aft edge of empennage skin, cut a 0.18 inch (4.57 mm) wide slot centered on BL0. (w) Prepare the surface for primer and paint. (Refer to 51-20) (x) Paint repair area. (Refer to 51-20) (y) Serials 1005 thru 1422: Apply copper tape to vertical spar. Increase bolt length as required to ensure correct grip requirements. Threads not allowed in load bearing structure. It is permissible to remove up to inch (1.600 mm) at a 45 angle to improve tie down bracket fit. (z) Install aft tie down bracket. (Refer to 53-20) (aa) Install aft tie down. (Refer to 53-20) (ab) Serials 1423 & subs: To ensure electrical contact, sand or burnish EMM where sides of upper vertical hinge contact the vertical spar. (Refer to 51-20) (ac) Install lower top and bottom vertical hinge. (Refer to 55-50) (ad) Install rudder. (Refer to 55-40) Page 4 All

5 1 AFT TIE DOWN BRACKET NOTE It is permissible to remove up to inch (1.600 mm) at a 45 angle to improve tie down bracket fit. Serials 1005 thru LEGEND 1. Copper Tape SR20_MM53_1797D Serials 1005 thru 1422 Figure 1 Vertical Spar Bond Repair - Serials 1005 thru 1422 (Sheet 1 of 4) Page 5

6 TANGENT 0.5 inch (12.7 mm) AFT VERTICAL SPAR DAMAGED AREA FUSELAGE SKIN 1 B B 0.18 inch (4.57 mm) NOTE Remove lip of aft vertical spar to tangent at least 0.5 inch (12.7 mm) beyond damaged area. Serials 0821 thru 1153: From aft tangent of tie down installation hole to aft edge of empennage skin, cut a 0.18 inch (4.57 mm) wide slot centered on BL0. LEGEND 1. EMM SR20_MM53_1770C Page 6 Figure 1 Vertical Spar Bond Repair - Serials 1423 & subs (Sheet 2 of 4) Serials 1423 & subs

7 1.0 inch (25.4 mm) A FUSELAGE SKIN 1.0 inch (25.4 mm) 0.5 inch (12.7 mm) (AFT VERTICAL SPAR) 0-45 AFT VERTICAL SPAR A VIEW LOOKING FORWARD AFT VERTICAL SPAR FUSELAGE SKIN AFT TIE DOWN INSTALLATION HOLE FUSELAGE SKIN AFT VERTICAL SPAR FUSELAGE SKIN PLY PLY TABLE ORIENTATION +/- 45 +/- 45 +/- 45 NOTE Fill bond depressions with gap filler, creating a smooth layup transition area with a maximum radius of 0.5 inch (12.7 mm). Layup repair at least 1.0 inch (25.4 mm) beyond disbond. Layup each ply so it overlaps previous ply by at least 0.5 inch (12.7 mm). (FUSELAGE) VIEW LOOKING DOWN Serials 1005 thru SR20_MM53_1530C Serials 1005 thru 1422 Figure 1 Vertical Spar Bond Repair - Serials 1005 thru 1422 (Sheet 3 of 4) Page 7

8 1.0 inch (25.4 mm) C FUSELAGE SKIN 1.0 inch (25.4 mm) EMM 0.5 inch (12.7 mm) EMM (AFT VERTICAL SPAR) AFT VERTICAL SPAR C -45 VIEW LOOKING FORWARD AFT VERTICAL SPAR FUSELAGE SKIN AFT TIE DOWN INSTALLATION HOLE FUSELAGE SKIN FUSELAGE SKIN AFT VERTICAL SPAR PLY PLY TABLE ORIENTATION +/- 45 +/- 45 +/- 45 NOTE Fill bond depressions with gap filler, creating a smooth layup transition area with a maximum radius of 0.5 inch (12.7 mm). Layup repair at least 1.0 inch (25.4 mm) beyond disbond. (FUSELAGE) Layup each ply so it overlaps previous ply by at least 0.5 inch (12.7 mm). VIEW LOOKING DOWN SR20_MM53_1788B Page 8 Figure 1 Vertical Spar Bond Repair - Serials 1423 & subs (Sheet 4 of 4) Serials 1423 & subs

9 B. Repair - Vertical Spar Patch - Serials 1423 & subs (See Figure 2) (1) Repair - Vertical Spar Patch - Serials 1423 & subs The Vertical Spar Patch Repair may be used to replace a portion of the lower vertical spar damaged by the tie down eye bolt pulling back through empennage skin. The damaged area of the vertical spar is cut away and removed. A repair patch is created from a replacement vertical spar and bonded over the damaged area. Glass fabric repair plies are then wet-layed over repair patch area. CAUTION: If damage to vertical spar extends above inspection hole, the airplane is not repairable and Cirrus Design must be contacted for disposition. (Refer to AMM- Intro-) If damage has also occurred to outer fuselage skin aft of the lower vertical spar, perform Repair - Fuselage Skin when completing the Vertical Spar Patch Repair. (Refer to ) (a) (b) Determine type and extent of damage. If necessary, contact Cirrus Design for disposition. (Refer to AMM-Intro-) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Vertical Spar or Cirrus Design Create repair patch for damaged portion of vertical spar. Duluth, MN Backing Plate Cirrus Design Bridge damage cutout area in Duluth, MN the vertical spar Lower Vertical Hinge Cirrus Design Rudder attachment. Duluth, MN Tie Down Bracket Cirrus Design Tie down eye bolt attachment. Duluth, MN Tie Down Eye Bolt Cirrus Design Tie down airplane. Duluth, MN Nut Cirrus Design Tie down eye bolt attachment. Duluth, MN Expanded Metal Mesh (EMM) (Refer to 51-30) (Refer to 51-30) Lightning protection. Isopropyl Alcohol 99% or higher purity Any Source General cleaning. Orbital Sander 39825A12 Any Source Prepare repair surface. Release Film (Refer to 51-30) (Refer to 51-30) Protect lay-up surface. Serials 1423 & subs Page 9 01 Jan 2016

10 Description P/N or Spec. Supplier Purpose Peel Ply (Refer to 51-30) (Refer to 51-30) Makes smooth and contaminate free repair surface. Glass Repair Fabric (Refer to 51-30) (Refer to 51-30) Repair composite structures. Structural Resin Repair System (Refer to 51-30) (Refer to 51-30) Bond plies over puncture. Sandpaper 120-grit or finer Any Source Paint and primer removal. Sandpaper 60 to 80-grit Any Source Abrade bonding surfaces. Aerosil (Refer to 51-30) (Refer to 51-30) Resin filler. Sil-Cell (Refer to 51-30) (Refer to 51-30) Resin filler. Angle Grinder 80-grit Any Source Remove laminate from aft vertical spar. Diamond Coated Hole Saw 0.75 inch (19.05 mm) Any Source Drill aft tie down installation hole. (c) Remove rudder. (Refer to 55-40) (d) Remove lower top and bottom vertical hinge. (Refer to 55-50) (e) Remove aft tie down. (Refer to 53-20) (f) Remove aft tie down bracket. (Refer to 53-20) CAUTION: Never use a grinder for removal of outer surface coats. A grinder will gouge the surface creating more damage. Chemical strippers should not be used as they may become trapped, damage the laminate, or leave a residue. Multi-action orbital type sanders or simple hand-sanding are the preferred methods of paint removal. Fine-grit paper (120-grit or finer) should be selected to minimize the potential for accidental damage. (g) Remove paint finish from repair area. (Refer to 51-20) (h) Remove Expanded Metal Mesh (EMM) lightning protection from repair area. (Refer to 51-20) (i) Use rivets to attach tiedown backing plate to vertical spar repair patch. (See Figure ) (j) Remove damaged portion of lower vertical spar. (See Figure 2) A new tiedown backing plate will be attached to the vertical spar repair patch. The damage cutout area in the vertical spar must be large enough to allow insertion of the tiedown backing plate. 1 Use tiedown backing plate to determine size and shape of vertical spar damage cutout area. 2 Ensure minimum radius of 0.5 inch (1.3 cm) at all corners of damage cutout area. 3 Maintain maximum amount of bonding surface possible between damage cutout area and vertical spar radius tangent. 4 Carefully cut and remove damaged portion of lower vertical spar. Page 10 Serials 1423 & subs

11 (k) If necessary, use sand paper to remove any delaminated, loose, or damaged plies on the vertical spar. (Refer to 51-20) (l) Prepare vertical spar repair patch. (See Figure 2) 1 From lower radius of replacement vertical spar, measure 7.4 inches (18.8 cm) up vertical spar and mark horizontal line across face of vertical spar. 2 Cut vertical spar at mark to create repair patch. 3 Remove flange from repair patch by cutting along tangent line +0.0, -0.1 inch (+0.0, -2.5 mm) on all sides. 4 Verify patch does not interfere with upper vertical hinge. If necessary, trim top edge of patch. 5 Bevel outer edges of patch to approximately 60 degrees. (m) Bond repair patch into position. 1 Solvent clean with isopropyl alcohol. (Refer to 20-30) 2 Mix MGS L418-based structural adhesive. (Refer to 51-30) 3 Using a clean spatula or wooden applicator, apply adhesive to repair area to obtain bond thickness of to inch (0.13 to 1.50 mm). CAUTION: Movement during cure may cause bond voids. Do not move or pull repair patch away from the vertical spar after squish-out is achieved or voids will form. 4 Place repair patch into position by aligning lower vertical hinge holes in patch with lower vertical hinge holes in existing spar. Secure with fixturing as required to prevent movement during cure. 5 Cure repair patch bond. (Refer to 51-20) (n) Mix MGS L418-based filler paste. (Refer to 51-30) Ensure filler paste does not exceed maximum radius of 0.5 inch (12.7 mm). (o) Using a clean spatula or wooden applicator, apply filler paste to corner between repair patch and vertical spar flanges. (p) Cut three glass-fiber repair plies based on the following criteria: 1 Ply orientation is ±45. (Refer to 51-20) 2 Plies butt to upper edge of repair patch and extend aft to trailing edge of vertical spar on all sides except for bottom. 3 At bottom, plies extend to trailing edge of fuselage skin 1.0 inch (2.54 cm) minimum on either side of BL0. (q) Mix MGS L418-based structural resin. (Refer to 51-30) (r) Layup glass fabric repair plies. (Refer to 51-20) (s) Cure repair plies. (Refer to 51-20) (t) Install Expanded Metal Mesh (EMM) lightning protection over repair area. (Refer to 51-20) CAUTION: Use caution when drilling tie down bracket installation holes to avoid damage to backing plate nutplates on back of patch. (u) (v) (w) (x) Match drill tie down bracket installation holes covered by glass fabric repair layup. Match drill hinge installation holes covered by glass fabric repair layup. Match drill pass-through hole covered by glass fabric repair layup. Match drill inspection hole covered by glass fabric repair layup. Serials 1423 & subs Page 11

12 Increase bolt length as required to ensure correct grip requirements. Threads not allowed in load bearing structure. (y) Install aft tie down bracket. (Refer to 53-20) (z) To ensure electrical contact, sand or burnish EMM where sides of upper vertical hinge contact the vertical spar. (Refer to 51-20) (aa) Install lower top and bottom vertical hinge. (Refer to 55-50) (ab) Match drill rudder installation hole in lower vertical hinge. (ac) Trim profile of lower vertical hinge to profile of upper vertical hinge to allow for proper rudder clearance. (ad) Using 0.75 inch (19.05 mm) hole saw, cut aft tie down installation hole through skin and centered on BL0. (ae) Serials 1423 thru 1472: From aft tangent of tie down installation hole to aft edge of empennage skin, cut a 0.18 inch (4.57 mm) wide slot centered on BL0. (af) Prepare the surface for primer and paint. (Refer to 51-20) (ag) Paint repair area. (Refer to 51-20) (ah) Install aft tie down. (Refer to 53-20) (ai) Install rudder. (Refer to 55-40) Page 12 Serials 1423 & subs

13 NOTE Burnish EMM where sides of lower vertical hinge contact vertical spar. Trim profile of lower vertical hinge to match profile of upper vertical hinge. Match drill rudder installation hole in lower vertical hinge. Serials 1423 thru 1472: From aft tangent of tie down installation hole to aft edge of empennage skin, cut a 0.18 inch (4.57 mm) wide slot centered on BL0. LOWER VERTICAL HINGE UPPER VERTICAL HINGE UPPER VERTICAL HINGE LOWER VERTICAL HINGE AFT TIE DOWN BRACKET 0.18 inch (4.57 mm) 1 LEGEND 1. EMM SR20_MM53_2047B Serials 1423 & subs Figure 2 Vertical Spar Patch Repair - Serials 1423 & subs (Sheet 1 of 3) Page 13

14 FLANGE RADIUS TANGENT inches (18.8 cm) DAMAGE CUTOUT (APPROXIMATE) 9 PASS-THROUGH HOLE B B A EMM 0.20 inch (5.08 mm) inches (38.1 mm) INSPECTION HOLE 12 NOTE 10 Remove damaged portion of lower vertical spar. Ensure minimum radius of 0.5 inch (1.3 cm) at all corners of damage cutout area. A VIEW LOOKING FORWARD Cut repair patch from new vertical spar. Remove flange from repair patch by cutting along tangent line +0.0, inch (+0.0, mm) on all sides. Bevel repair patch edges to 60 degrees. Bond repair patch to vertical spar. After repair plies have cured, match drill lower vertical hinge, inspection, and pass-through holes. LEGEND 9. Vertical Spar 10. Repair Patch 11. Tiedown Backing Plate 12. Rivet Apply EMM from upper tangent of inspection hole to 0.20 inch (5.08 mm) beyond upper edge of repair patch. Page 14 Figure 2 Vertical Spar Patch Repair - Serials 1423 & subs (Sheet 2 of 3) Serials 1423 & subs SR20_MM53_2048B

15 VERTICAL SPAR EMM VERTICAL SPAR PATCH (SPAR) (PATCH) UP AFT TRAILING EDGE OF VERTICAL SPAR EMM (SPAR) (FUSELAGE) TRAILING EDGE OF FUSELAGE 1.0 inch (25.4 mm) 1.0 inch (25.4 mm) FUSELAGE SKIN Serials 1423 thru VERTICAL SPAR EMM UP VERTICAL SPAR PATCH AFT (SPAR) (FUSELAGE) TRAILING EDGE OF VERTICAL SPAR (SPAR) (PATCH) EMM FUSELAGE SKIN Serials 1473 & subs. NOTE Fill bond depressions with gap filler, creating a smooth layup transition area with a maximun radius of 0.5 inch (12.7 mm). Extend plies to top edge of repair patch. Extend plies to trailing edge of vertical spar. PLY PLY TABLE ORIENTATION ± 45 ± 45 ± 45 SR20_MM53_2049A Serials 1423 & subs Figure 2 Vertical Spar Patch Repair - Serials 1423 & subs (Sheet 3 of 3) Page 15

16 C. Repair - Fuselage Skin (See Figure 3) (1) Repair - Fuselage Skin The Fuselage Skin Repair may be used to replace a damaged portion of the outer fuselage skin aft of the lower vertical spar. Glass fabric repair plies are wet-layed over area where disbonding has occurred. Any other damage to the empennage skin is not field repairable and Cirrus Design must be contacted for disposition. (Refer to AMM-Intro-) (a) Determine type and extent of damage. If necessary, contact Cirrus Design for disposition. (b) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Serials 1423 & subs: Expanded Metal Mesh (EMM) (Refer to 51-30) (Refer to 51-30) Lightning protection. Tie Down Bracket Cirrus Design Tie down eye bolt attachment. Tie Down Eye Bolt Cirrus Design Tie down airplane. Nut Cirrus Design Tie down eye bolt attachment. Isopropyl Alcohol 99% or higher purity Any Source General cleaning. Orbital Sander 39825A12 Any Source Prepare repair surface. Release Film (Refer to 51-30) (Refer to 51-30) Protect lay-up surface. Peel Ply (Refer to 51-30) (Refer to 51-30) Makes smooth and contaminate free repair surface. Glass Repair Fabric Structural Resin Repair System (Refer to 51-30) (Refer to 51-30) (Refer to 51-30) (Refer to 51-30) Repair composite structures. Bond plies over puncture. Sandpaper 120-grit or finer Any Source Paint and primer removal. Sandpaper 60 to 80-grit Any Source Abrade bonding surfaces. Aerosil (Refer to 51-30) (Refer to 51-30) Resin filler. Sil-Cell (Refer to 51-30) (Refer to 51-30) Resin filler. Diamond Coated Hole Saw 0.75 inch (19.05 mm) Any Source Drill aft tie down installation hole. (c) Remove rudder. (Refer to 55-40) (d) Remove lower top and bottom vertical hinge. (Refer to 55-50) (e) Remove aft tie down. (Refer to 53-20) (f) Remove aft tie down bracket. (Refer to 53-20) Page Dec 2014 CAUTION: Never use a grinder for removal of outer surface coats. A grinder will gouge the surface creating more damage. Chemical strippers should not be used as they may become trapped, damage the laminate, or leave a residue. All

17 Multi-action orbital type sanders or simple hand-sanding are the preferred methods of paint removal. Fine-grit paper (120-grit or finer) should be selected to minimize the potential for accidental damage. (g) Remove paint finish from repair area. (Refer to 51-20) (h) Serials 1423 & subs: If affected by repair area, remove Expanded Metal Mesh (EMM) lightning protection. (Refer to 51-20) Sand outboard fuselage skin at least 0.5 inch (12.7 mm) beyond damaged area. (i) If necessary, use sandpaper to remove any delaminated, loose, or damaged plies on the fuselage skin. (Refer to 51-20) (j) Solvent clean with isopropyl alcohol. (Refer to 20-30) On contoured surfaces it will be necessary to apply enough pressure to maintain contact between skin portions. Small weights may be used to apply enough pressure to maintain contact. (k) Lightly clamp skin portions together, ensuring that pressure is applied uniformly. Do not release clamping pressure until initial cure is complete. (l) Allow resin to initial cure. (Refer to 51-20) Ensure plies extend at least 1.0 inch (2.54 cm) beyond dis-bond. Ensure each ply overlaps the previous ply by at least 0.5 inch (12.7 mm). (m) Cut three glass-fiber repair plies at ±45. (Refer to 51-20) (n) Mix MGS L418-based structural resin. (Refer to 51-30) (o) Layup glass fabric repair plies. (Refer to 51-20) (p) Cure repair plies. (Refer to 51-20) (q) Serials 1423 & subs: If affected by repair area, install Expanded Metal Mesh (EMM) lightning protection. (Refer to 51-20) (r) Match drill aft tie down installation hole covered by glass fabric repair layup. (s) Using 0.75 inch (19.05 mm) hole saw, cut aft tie down installation hole through skin and centered on BL0. (t) Serials 1423 thru 1472: From aft tangent of tie down installation hole to aft edge of empennage skin, cut a 0.18 inch (4.57 mm) wide slot centered on BL0. (u) Prepare the surface for primer and paint. (Refer to 51-20) (v) Paint repair area. (Refer to 51-20) (w) Install aft tie down bracket. (Refer to 53-20) (x) Install aft tie down. (Refer to 53-20) (y) Serials 1423 & subs: If EMM was replaced, to ensure electrical contact, sand or burnish EMM where sides of upper vertical hinge contact the vertical spar. (Refer to 51-20) (z) Install lower top and bottom vertical hinge. (Refer to 55-50) (aa) Install rudder. (Refer to 55-40) All Page 17

18 0.18 inch (4.57 mm) NOTE Serials 1423 thru : From aft tangent of tie down installation hole to aft edge of empennage skin, cut a 0.18 inch (4.57 mm) wide slot centered on BL0. SR20_MM53_2069A Page 18 Figure 3 Fuselage Skin Repair (Sheet 1 of 2) All

19 AFT VERTICAL SPAR PLY TABLE PLY ORIENTATION ± 45 ± 45 ± 45 (FUSELAGE) 0.5 inch (12.7 mm) 0.5 inch (12.7 mm) NOTE Layup each ply so it overlaps previous ply by at least 0.5 inch (12.7 mm). Use 0.75 inch (19.05 mm) drill bit to drill through hole after repair. Serials 1423 thru 1742: From aft tangent of tie down installation hole to aft edge of empennage skin, cut a 0.18 inch (4.57 mm) wide slot centered on BL inch (4.57 mm) BL 0.00 SECTION A-A AFT VERTICAL SPAR inches (50.8 mm) A A 0.5 inch (12.7 mm) 0.5 inch (12.7 mm) 0.5 inch (12.7 mm) VIEW LOOKING UP SR20_MM53_2071 All Figure 3 Fuselage Skin Repair (Sheet 2 of 2) Page 19

20 D. Repair - Belly Burn (See Figure 4) (1) Repair - Belly Burn Belly burn is defined as burn damage that occurs to the fuselage belly due to incorrect adjustment of the exhaust system. The affected area lies just aft of the tail pipe and occurs when the tail pipe is positioned too close to the fuselage. Visually inspect for discoloration and perform a coin tap test to determine the type and extent of damage. The fuselage skin may be restored using standard composite repair techniques. (a) Remove tail pipe. (Refer to 78-20) (b) Determine type and extent of damage. If necessary, contact Cirrus Design for disposition. (Refer to AMM-Intro-) (c) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Compressed Air (contaminate free) - Any Source General repair. Liquid Dish Soap - Any Source General cleaning. Isopropyl Alcohol 99% or higher purity Any Source General cleaning. Orbital Sander 39825A12 Any Source Prepare repair surface. Masking Tape 2.0 inches (5.0 cm) Any Source Limit repair area. Permanent Marker Release Film Peel Ply Glass Repair Fabric Structural Resin Repair System (Refer to 51-30) (Refer to 51-30) Identify repair area. (Refer to 51-30) (Refer to 51-30) Protect lay-up surface and make template of repair ply. (Refer to 51-30) (Refer to 51-30) Makes smooth and contaminate free repair surface. (Refer to 51-30) (Refer to 51-30) Repair composite structures. (Refer to 51-30) (Refer to 51-30) Bond plies over puncture. Sandpaper 120-grit or finer Any Source Paint and primer removal. Sandpaper 60 to 80-grit Any Source Abrade bonding surfaces. Rigid Closed Cell Foam Aerosil Sil-Cell (Refer to 51-30) (Refer to 51-30) Stiffen laminate. (Refer to 51-30) (Refer to 51-30) Resin filler. (Refer to 51-30) (Refer to 51-30) Resin filler. Page Dec 2014 (d) To prevent water from contaminating composite, cover damaged area with release film and seal edges with tape. (e) Clean the area surrounding the damage with hot soapy water. Rinse with clean water and dry. Remove release film from damaged area. (f) Solvent clean damaged area with isopropyl alcohol. (Refer to 20-30) (g) Determine repair area through visible inspection and coin tap test. (Refer to 51-10) (h) Mark perimeter of repair area. All

21 (i) (j) Determine and mark 0 o axis. Carefully trim away damaged laminate using a small angle grinder with 80-grit. Grind edge of damaged laminate to a 50:1 taper. (k) Remove paint, primer, and body filler from area surrounding damage. (Refer to 51-20) (l) Perform core replacement repair. (Refer to 51-20) Ensure each ply overlaps the previous ply by at least 0.5 inch (12.7 mm). (m) Cut two glass-fiber repair plies at ±45. (Refer to 51-20) (n) Mix MGS L418-based structural resin. (Refer to 51-30) (o) Layup glass fabric repair plies. (Refer to 51-20) (p) Cure repair plies. (Refer to 51-20) (q) Prepare the surface for primer and paint. (Refer to 51-20) (r) Paint repair area. (Refer to 51-20) (s) Install tail pipe. (Refer to 78-20) (t) Perform Adjustment/Test - Forward Ball Joints to ensure correct tail pipe orientation. (Refer to 78-20) All Page 21

22 FIREWALL inches (28.32 cm) ACCEPTABLE BELLY BURN REPAIR AREA inches (93.35 cm) inches (6.35 cm) inches (41.28 cm) LEGEND 1. Tail Pipe 2. Belly Fire Shield 3. Drain Holes Serials 1005 thru SR20_MM53_1536C Page 22 Figure 4 Belly Burn Repair - Serials 1005 thru 1422 (Sheet 1 of 2) Serials 1005 thru 1422

23 FIREWALL inches (28.32 cm) inches (93.35 cm) ACCEPTABLE BELLY BURN REPAIR AREA 3.98 inches (10.11 cm) inches (41.28 cm) LEGEND 1. Tail Pipe 2. Belly Fire Shield SR20_MM53_1790A Serials 1423 & subs Figure 4 Belly Burn Repair - Serials 1423 & subs (Sheet 2 of 2) Page 23

24 Intentionally Left Blank Page 24 All