Advisory Circular TITLE 14 OF THE CODE OF FEDERAL REGULATIONS (14 CFR) GUIDANCE MATERIAL Subject: ACCEPTABLE METHODS, Date: 9/8/98 AC No: 43.13-1B TECHNIQUES, AND PRACTICES AIRCRAFT Initiated by: AFS-640 Change: 1
INSPECTION AND REPAIR
1. PURPOSE. This advisory circular (AC) contains methods, techniques, and practices acceptable to the Administrator for the inspection and repair of nonpressurized areas of civil aircraft, only when there are no manufacturer repair or maintenance instructions. This data generally pertains to minor repairs. The repairs identified in this AC may only be used as a basis for FAA approval for major repairs. The repair data may also be used as approved data, and the AC chapter, page, and paragraph listed in block 8 of FAA form 337 when:
a. the user has determined that it is appropriate to the product being repaired;
b. it is directly applicable to the repair being made; and
c. it is not contrary to manufacturer’s data.
2. CANCELLATION. The AC 43.13-1A dated 1988 is canceled.
3. REFERENCE: Title 14 of the Code of Federal Regulations part 43, section 43.13(a) states that each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer’s maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, or practices acceptable to the Administrator, except as noted in section 43.16. FAA inspectors are prepared to answer questions that may arise in this regard. Persons engaged in the inspection and repair of civil aircraft should be familiar with 14 CFR part 43, Maintenance, Preventive Maintenance, Rebuilding, and Alteration, and part 65, Subparts A, D, and E of Certification: Airmen Other Than Flight Crewmembers, and the applicable airworthiness requirements under which the aircraft was type certificated.
4. ACKNOWLEDGMENTS. The FAA would like to thank the following persons and organization for their assistance in producing AC 43.13-1B: Richard Finch, Richard Fischer, Michael Grimes, Ray Stits, William A.
Watkins, and the SAE, Aerospace Electronics and Electrical Systems Division. Acknowledgment is also extended to all in the aviation community who commented on the document.
5. COMMENTS INVITED. Comments regarding this AC should be directed to DOT/FAA;
ATTN: Airworthiness Programs Branch, AFS-610; PO Box 25082; Oklahoma City, OK 73125 Acting Deputy Director, Flight Standards Service
CONTENTS Paragraph Page CHAPTER 1. WOOD STRUCTURE SECTION 1. MATERIALS AND PRACTICES
1-1. General1-1
1-2. Woods1-1
Figure 1-1. Relative Shrinkage of Wood Member Due to Drying1-1
Table 1-1. Selection and Properties of Aircraft Wood1-3
Figure 1-2. Tapering of Faceplate1-3
1-3. Modified Wood Products1-3
1-4. Adhesives1-3
1-5. Bonding Precautions1-5
1-6. Preparation of Wood Surfaces for Bonding1-5
1-7. Applying the Adhesive1-6
1-8. Assembly Time in Bonding1-6
1-9. Bonding Temperature1-6
1-10. Clamping Pressure1-7
1-11. Method of Applying Pressure1-7
1-12.1-17. [RESERVED.]1-8
SECTION 2. HEALTH AND SAFETY
1-18. General1-9
1-19. Sanding in Areas of Existing Bond Joints and Finishes1-9
1-20. Handling of Adhesives and Finishes1-9
1-21.1-26. [RESERVED.]1-9
SECTION 3. INSPECTION
1-27. General1-11
1-28. Types of Deterioration and Damage1-11
1-29. Inspection Methods1-11
Figure 1-3. Likely Areas to Incur Structural Damage1-13
1-30.1-35. [RESERVED.]1-14
SECTION 4. REPAIRS
1-36. General1-15
1-37. Replacement of Drain Holes and Skin Stiffeners1-15
1-38. Control Surface Flutter Precautions1-15
1-39. Scarf Joints1-15
Figure 1-4. Consideration of Grain Direction When Making Scarf Joints1-15
1-40. Splicing of Spars1-15
Figure 1-5. Method of Splicing Solid or Laminated Rectangular Spars1-17
Figure 1-6. Method of Splicing Solid “I” Spars1-18
Figure 1-7. Repairs to Built-Up “I” Spar1-19
Figure 1-8. Method of Splicing Box Spar Flanges (Plate Method)1-20
1-41. Spar Replacement1-16
1-42. Splicing of Box Spar Webs1-16
Figure 1-9. Method of Splicing Box Spar Webs1-21
1-43. Replacing Solid-Type Spars With Laminated-Type Spars1-16
Page iii
CONTENTS (CONTINUED) Paragraph Page
1-44. Spar Longitudinal Cracks and Local Damage1-16
Figure 1-10. Method of Reinforcing a Longitudinal Crack and/or Local Damage in a Solid Spar1-22
1-45. Elongated Holes in Spars1-18
1-46. Rib Repairs1-18
Figure 1-11. Repair of Wood Ribs1-23
Figure 1-12. Typical Wing Compression Rib Repairs1-24
1-47. Plywood Skin Repair1-20
1-48. Determination of Single or Double Curvature1-20
1-49. Repairs to Single Curvature Plywood Skin1-20
Table 1-2. Minimum Recommended Bend Radii for Aircraft Plywood1-25
1-50. Repairs to Double Curvature Plywood Skin1-22
1-51. Types of Patches1-25
Figure 1-13. Splayed Patch1-27
Figure 1-14. Surface Patches1-28
Figure 1-15. Scarf Patches (Back of Skin Accessible)1-29
Figure 1-16. Scarf Patches (Back of Skin Not Accessible)1-30
Figure 1-17. Oval Plug Patch Assembly1-32
Figure 1-18. Round Plug Patch Assembly1-33
1-52. Fabric Patch1-31
1-53.1-63. [RESERVED.]1-33
SECTION 5. FINISHING WOOD STRUCTURES
1-64. General1-35
1-65. Acceptable Finishes1-35
1-66. Precautions1-35
1-67. Finishing of Interior Surfaces1-36
1-68. Finishing of Exterior Surfaces1-36
1-69. Finishing of End Grain Surfaces1-36
1-70. Finishing with Fabric or Tape1-37
1-71. Sealing of Bolt Holes1-37
1-72.1-79. [RESERVED.]1-37
CHAPTER 2. FABRIC COVERING SECTION 1. PRACTICES AND PRECAUTIONS
2-1.
2-2.
2-3.
2-4.
2-5.
2-6.
2-7.
2-8.
General2-1
Problem Areas2-1
Aircraft Fabric-Synthetic2-1
Aircraft Fabric-Natural2-2
Table 2-1. Cotton and Linen Fabrics2-3
Recovering Aircraft2-2
Table 2-2. Cotton and Linen, Tapes and Threads2-4
Preparation of the Structure for Covering2-2
Fabric Seams2-5
Figure 2-1. Fabric Seams2-7
Figure 2-2. Typical Methods of Attaching Fabric2-8
Covering Methods2-9
Page iv
CONTENTS (CONTINUED) Paragraph Page
2-9. Reinforcing Tape2-10
Figure 2-3. Exploded Side View of Rib2-10
2-10. Lacing2-11
Figure 2-4. Standard External Modified Seine Knot Used for Single and Double Rib Lacing2-11
Figure 2-5. Starting Stitch for Rib Lacing2-12
Figure 2-6. Standard Single-Loop Lacing2-13
Figure 2-7. Standard Knot for Double-Loop Lacing2-14
Figure 2-8. Standard Double-Loop Lacing (Optional)2-15
Figure 2-9a. Alternate Sequence to Tie a Modified Seine Knot for Rib Lacing2-16
Figure 2-9b. Alternate Sequence to Tie a Modified Seine Knot for Rib Lacing2-17
Figure 2-9c. Alternate Sequence to Tie a Modified Seine Knot for Rib Lacing2-18
Figure 2-10. Splice Knot2-19
Figure 2-11. Blindstitch Lacing - Square Knot Secured with Half Hitches2-20
2-11. Stitch Spacing2-19
Figure 2-12. Fabric Attachment Spacing2-21
2-12. Fasteners2-21
2-13. Finishing Tape2-22
2-14. Inspection Rings and Drain Grommets2-22
2-15.2-19. [RESERVED.]2-23
SECTION 2. APPLICATION OF DOPE
2-20. General2-25
Table 2-3. Safety Tips for Dope/Paint2-26
Table 2-4. Tips for Doping2-26
2-21. Dope Application Procedure (Natural Fabrics)2-26
2-22. Covering Over Plywood2-28
2-23. Coating Application Defects2-29
2-24.2-29. [RESERVED.]2-31
SECTION 3. INSPECTION AND TESTING
2-30. General2-33
2-31. Fabric Identification2-34
2-32. Coating Identification2-34
2-33. Strength Criteria for Aircraft Fabric2-35
2-34. Fabric Testing2-35
2-35. Rejuvenation of Dope Film2-36
2-36.2-41. [RESERVED.]2-36
SECTION 4. REPAIRS TO FABRIC COVERING
2-42. General2-37
2-43. Repair of Tears and Access Openings2-37
Figure 2-13 Repair of Tears in Fabric2-38
2-44. Sewn-Patch Repair2-38
Figure 2-14 Hand-Stitch Detail2-39
2-45. Doped-On Patch Repair2-39
2-46.2-51. [RESERVED.]2-40
Page v
CONTENTS (CONTINUED) Paragraph Page CHAPTER 3. FIBERGLASS AND PLASTICS SECTION 1. REPAIR OF LIGHT LOAD LAMINATE STRUCTURES
3-1. General3-1
3-2. Fiberglass Laminate Repairs3-1
Figure 3-1. Typical Laminate (Facing) Repair3-2
Figure 3-2. Typical Core and Facing Repair3-2
Figure 3-3. Typical Stepped Joint Repair3-3
3-3. Repairing Holes3-3
Figure 3-4. Preparing the Fiberglass Sandwich3-3
Figure 3-5. Scarfed Repair to a Nonstructural Laminated Fiberglass Component3-4
Figure 3-6. Balanced Layup Same as Original Number of Plies, Plus One Extra Ply3-4
Figure 3-7. Typical Scarf Joint Repair3-5
Figure 3-8. Carefully Cut Through Each Layer of Fiberglass Cloth and
Remove it From the Damaged Area3-5
3-4. Sample Bagging and Curing Process3-5
Figure 3-9. Sample Bagging Layup Cross Section3-6
3-5.3-9. [RESERVED.]3-8
SECTION 2. METALLIC SANDWICH SECONDARY STRUCTURE REPAIRS
3-10. Repairs to Metallic Sandwich Secondary Structure3-9
Figure 3-10. Typical Types of Core Replacement3-10
Figure 3-11. Typical Undercut Core Material Cavity3-10
Figure 3-12. Cross Section of Bonded and Bolted Overlap Repairs3-11
Figure 3-13. Honeycomb Core Removal3-11
Figure 3-14. Removing Honeycomb Core from a Tapered Control Surface3-11
Figure 3-15. Removal of Core with Core Knife3-11
Figure 3-16. Details of Core Repair3-12
3-11. Finishing3-12
3-12.3-17. [RESERVED.]3-13
SECTION 3. TRANSPARENT PLASTICS
3-18. General3-15
3-19. Storage and Handling3-15
3-20. Forming Procedures and Techniques3-15
3-21. Heating3-16
Figure 3-17. Hanging of Acrylic Sheets3-16
3-22. Forms3-16
3-23. Forming Methods3-17
Table 3-1. Typical Temperatures for Forming Acrylic Sheets3-17
Figure 3-18. Drill Having an Included Angle of Approximately 150°,
Used to Drill Acrylic Plastics3-18
Figure 3-19. Unibit Drill for Drilling Acrylic Plastics3-18
Figure 3-20. Applying Pressure to Acrylic Plastics3-19
Page vi
CONTENTS (CONTINUED) Paragraph Page
3-24. Repair of Plastics3-19
Figure 3-21. Stop-Drilling Cracks3-20
Figure 3-22. Surface Patches3-20
Figure 3-23. Plug Patch Repair3-21
3-25. Cleaning and Polishing Transparent Plastic3-21
3-26. Replacement Panels3-21
3-27. Installation Procedures3-22
3-28.3-39. [RESERVED.]3-22
SECTION 4. WINDSHIELDS, ENCLOSURES, AND WINDOWS
3-40. General3-23
Figure 3-24. Temporary Repairs to Cracked Windshields or Windows3-24
3-41. Protection3-24
3-42. Windshield Installation3-24
3-43.3-47. [RESERVED.]3-25
CHAPTER 4. METAL STRUCTURE, WELDING, AND BRAZING SECTION 1. IDENTIFICATION OF METALS
4-1. General4-1
Table 4-1. Ferrous (Iron) Alloy Materials4-1
4-2. Identification of Steel Stock4-1
Table 4-2. Numerical System for Steel Identification4-2
Table 4-3. Examples of Stainless and Heat-Resistant Steels Nominal Composition (Percent)4-3
4-3. Interchangeability of Steel Tubing4-2
4-4. Identification of Aluminum4-2
Table 4-4. Basic Temper Designations and Subdivisions from Aluminum Alloys4-4
4-5.4-15. [RESERVED.]4-4
SECTION 2. TESTING OF METALS
4-16. Hardness Testing4-5
4-17. Rockwell Hardness Test4-5
4-18. Brinell Hardness Test4-5
4-19. Vickers Hardness Test4-6
4-20. Microhardness Testing4-6
4-21. Indentions4-7
Figure 4-1. Comparison of Indentation Made by Knoop and Vickers Indenters
in the Same Work Metal and at the Same Loads4-7
4-22. Magnetic Testing4-8
4-23. Aluminum Testing4-8
Table 4-5. Hardness Values for Aluminum Alloys. (Reference MIL-H-6088G.)4-8
4-24.4-35. [RESERVED.]4-8
Page vii
CONTENTS (CONTINUED) Paragraph Page SECTION 3. PRECAUTIONARY MEASURES
4-36. Flutter and Vibration Precautions4-9
4-37. Load Factors for Repairs4-10
4-38. Transfer of Stresses Within a Structure4-10
4-39.4-49. [RESERVED.]4-10
SECTION 4. METAL REPAIR PROCEDURES
4-50. General4-11
Table 4-9. Number of Rivets Required for Splices (Single-Lap Joint)
in Bare 2014-T6, 2024-T3, 2024-T3, and 7075-T6 Sheet, Clad 2014-T6,
2024-T3, 2024-T36, and 7075-T6 Sheet, 2024-T4, and 7075-T6 Plate,
Table 4-10. Number of Rivets Required for Splices (Single-Lap Joint)
in 2017, 1017 Alclad, 2024-T3 Alclad Sheet, Plate, Bar, Rod,
Table 4-11. Number of Rivets Required for Splices (Single-Lap Joint)
4-51. Riveted (or Bolted) Steel Truss-Type Structures4-11
4-52. Aluminum Alloy Structures4-11
4-53. Selection of Aluminum for Replacement Parts4-12
4-54. Heat Treatment of Aluminum Alloy Parts4-12
4-55. Bending Metal4-13
Table 4-6. Recommended Radii for 90-Degree Bends in Aluminum Alloys4-14
4-56. Setback4-13
Figure 4-2. Setback for a 90-Degree Bend4-13
Table 4-7. K-Chart for Determining Setback for Bends Other Than 90 Degrees4-15
Figure 4-3. Methods of Determining Setbacks for Bends Other Than 90 Degrees4-16
4-57. Riveting4-14
Figure 4-4. Rivet Identification and Part Number Breakdown4-16
Table 4-8. Aircraft Rivet Identification4-17
Figure 4-5. Rivet Hole Spacing and Edge Distance for Single-Lap Sheet Splices4-20
Figure 4-6. Riveting Practice and Rivet Imperfections4-21
Figure 4-7. Self Plugging Friction-Lock Cherry Rivets4-22
Figure 4-8. Mechanical-Lock (Bulbed Cherry) Cherry Rivet4-23
Figure 4-9. Cherry Max Rivet4-24
Figure 4-10. Olymic-Lok Rivet4-25
Figure 4-11. Huck Rivet4-26
4-58. Repair Methods and Precautions for Aluminum Structure4-25
Figure 4-12. Typical Repair Method for Tubular Members of Aluminum Alloy4-28
Figure 4-13. Typical Repair for Buckled or Cracked Metal Wing Rib Capstrips4-29
Figure 4-14. Typical Metal Rib Repairs (Usually Found on Small and Medium-Size Aircraft)4-30
Figure 4-15. Typical Repairs of Trailing Edges4-31
Figure 4-16. Typical Repairs of Stressed Sheet Metal Coverings4-32
Figure 4-17. Typical Stringer and Flange Splices4-33
Figure 4-18. Example of Stringer Splice (Material-2017 Alloy)4-34
Figure 4-19. Application of Typical Flange Splices and Reinforcement4-35
Bar, Rod, Tube, and Extrusions, 2014-T6 Extrusions4-37
Tube, and Extrusions4-38
in 5032 (All Hardnesses) Sheet4-39
Page viii
CONTENTS (CONTINUED) Paragraph Page
4-59. Repairing Cracked Members4-40
Figure 4-20. Example of Intermediate Frame Stringer Splice (Material 2017-T3 AL Alloy)4-41
Figure 4-21. Typical Methods of Repairing Cracked Leading and Trailing Edges
and Rib Intersections4-42
Figure 4-22. Typical Methods of Replacing Cracked Member at Fittings4-43
Figure 4-23. Typical Methods of Repairing Cracked Frame and Stiffener Combination4-44
Figure 4-24. Typical Repairs to Rudder and to Fuselage at Tail Post4-45
4-60. Steel and Aluminum Fittings4-40
Figure 4-25. Typical Methods of Repairing Elongated or Worn Bolt Holes4-46
4-61. Castings4-40
4-62. Selective Plating in Aircraft Maintenance4-40
4-63.4-73. [RESERVED.]4-51
SECTION 5. WELDING AND BRAZING
4-74. General4-53
Table 4-12. Current and Polarity Selection for Inert Gas Welding4-54
Figure 4-26. Common Defects to Avoid when Fitting and Welding Aircraft Certification Cluster4-55
Table 4-13. Torch Tip Sizes4-55
Figure 4-27 Butt-Welding Strength Calculations4-56
4-75. Equipment Selection4-53
4-76. Accurately Identify the Type of Material to be Repaired4-54
4-77. Preparation for Welding4-54
4-78. Inspection of a Completed Weld4-54
4-79. Microfissures4-55
4-80. Nondestructive Testing4-55
4-81. Practices to Guard Against4-55
4-82. Torch Size (Oxyacetylene welding)4-55
4-83. Welding Rods and Electrodes4-56
4-84. Rosette Welds4-56
4-85. Heat-Treated Members4-56
4-86. Types of Welding4-56
Figure 4-28. Basic Gas-Welding Flames: Each has Distinctive Shape, Color and Sound.
Neutral Flame is the Most Used4-57
Figure 4-29. Set TIG Welder to DC Current, Straight Polarity for Welding Mild Steel,
Stainless Steel and Titanium4-58
Figure 4-30. Set TIG to AC Current for Welding Aluminum and Magnesium4-58
4-87. Electric-Resistance Welding4-58
Figure 4-31. In Spot Welding, Heat is Produced by Electrical Resistance Between
Copper Electrodes. Pressure is Simultaneously Applied to Electrode Tips
to Force Metal Together to Complete Fusing Process. Spot-Weld-Nugget Size
is Directly Related to Tip Size4-58
4-88. Brazing4-59
Table 4-14. Calculated Allowable Strength of Base Metal4-60
Figure 4-32. Silver Brazing Joints4-60
Figure 4-33. Electric Soldering Iron4-61
4-89. Aircraft Parts Not to be Welded4-62
4-90. Welding Rod Selection4-62
Table 4-15. Chart Showing Welding Filler Rod Selection4-63
4-91. Repair of Tubular Members4-62
Figure 4-34. Finger Patch Repairs for Members Dented at a Cluster4-64
4-92. Repair by Welded Sleeve4-65
Figure 4-35. Members Dented in a Bay (Repairs by Welded Sleeve)4-66
Page ix
CONTENTS (CONTINUED) Paragraph Page
4-93. Repair by Bolted Sleeve4-65
4-94. Welded-Patch Repair4-65
Figure 4-36. Welded Patch Repair4-67
4-95. Splicing Tubing by Inner-Sleeve Method4-65
Figure 4-37. Splicing by Inner-Sleeve Method4-67
4-96. Splicing Tubing by Outer-Sleeve Method4-65
Figure 4-38. Splicing by Outer-Sleeve Method (Replacement by Welded Outside Sleeve)4-69
Figure 4-39. Tube Replacement at a Station by Welded Outer Sleeves4-69
Page ix-a
CONTENTS (CONTINUED) Paragraph Page
4-97. Splicing Using Larger Diameter Replacement Tubes4-68
Figure 4-40. Splicing Using Larger Diameter Replacement Tube4-70
4-98. Repairs at Built-In Fuselage Fittings4-71
Figure 4-41. Repairs at Built-In Fuselage Fittings4-72
4-99. Engine-Mount Repairs4-71
4-100. Built-Up Tubular Wing or Tail-Spars4-73
Figure 4-42. Streamline Tube Splice Using Round Tube (Applicable to Landing Gear)4-74
4-101. Wing-Brace Struts and Tail-Brace Struts4-73
Figure 4-43. Streamline Tube Splice Using Split Sleeve
(Applicable to Wing and Tail Surface Brace Struts and Other Members)4-75
4-102. Landing Gear Repair4-73
Figure 4-44. Streamline Tube Splice Using Split Insert (Applicable to Landing Gear)4-76
Figure 4-45. Streamline Tube Splice Using Plates (Applicable to Landing Gear)4-77
Figure 4-46. Representative Types of Repairable Axle Assemblies4-78
Figure 4-47. Landing Gear Assemblies that Cannot be Repaired by Welding4-79
4-103. Repairs to Welded Assemblies4-74
4-104. Stainless Steel Structure4-75
4-105.4-110. [RESERVED.]4-79
SECTION 6. WELDING AND BRAZING SAFETY
4-111. General4-81
4-112. Fire and Explosion Safety4-81
4-113. Welding Work Area4-81
4-114. Fire Protection4-81
4-115. Protective Apparel4-82
4-116. First-Aid Kits4-82
4-117.4-128. [RESERVED.]4-82
CHAPTER 5. NONDESTRUCTIVE INSPECTION (NDI) SECTION 1. GENERAL
5-1. General5-1
5-2. Approved Procedures5-1
5-3. NDT Levels5-1
5-4. Training, Qualification, and Certification5-2
5-5. Flaws5-2
5-6. Selecting the NDI Method5-5
Table 5-1. Advantages and Disadvantages of NDI Methods5-7
5-7. Types of Inspections5-6
5-8.5-14. [RESERVED.]5-7
SECTION 2. VISUAL INSPECTION
5-15. General5-9
5-16. Simple Visual Inspection Aids5-9
5-17. Borescopes5-10
Figure 5-1. Typical Borescope Designs5-11
Page ix-b (and x)
CONTENTS (CONTINUED) Paragraph Page
5-18. Visual Inspection Procedures5-10
Figure 5-2. Using a flashlight to Inspect for Cracks5-13
5-19.5-24. [RESERVED.]5-13
SECTION 3. EDDY CURRENT INSPECTION
5-25. Eddy Current Inspection5-15
Figure 5-3. Generating an Eddy Current5-15
Figure 5-4. Detecting an Eddy Current5-15
Figure 5-5. Typical Instrument Displays5-16
5-26. Eddy Current Coils and Probes5-15
5-27. Field Application of Eddy Current Inspection5-15
5-28. Surface Inspection5-16
Figure 5-6. Typical Surface Cracks5-16
5-29. Subsurface Inspection5-17
Figure 5-7. Typical Subsurface Cracks5-18
5-30. Corrosion Inspection5-17
Figure 5-8. Typical Structural Corrosion5-18
5-31. Establishing Eddy Current Inspection Procedures5-17
5-32.5-39. [RESERVED.]5-18
SECTION 4. MAGNETIC PARTICLE INSPECTION
5-40. General5-19
5-41. Principles of Operation5-19
Figure 5-9. Magnetic field Disrupted5-19
Figure 5-10. Crack Detection by Magnetic Particle Inspection5-19
5-42. Applications5-20
5-43. Electrical Magnetizing Equipment5-20
5-44. Materials Used in Magnetic Particle Inspection5-20
Table 5-2. Listing of Commonly Accepted Standards and
Specifications for Magnetic Particle Inspection5-21
5-45. Preparation of Surface5-22
5-46. Methods of Examination5-22
5-47. Application of Magnetic Particles5-22
5-48. Magnetization5-23
Figure 5-11. Circular Magnetization5-23
Figure 5-12. Longitudinal Magnetization5-24
5-49. Determination of Field Strength5-25
5-50. Special Examination Techniques5-25
5-51. Demagnetization and Post-Examination Cleaning5-27
5-52.5-59. [RESERVED.]5-28
SECTION 5. PENETRANT INSPECTION
5-60. General5-29
Figure 5-13. Penetrant and Developer Action5-30
5-61. Equipment Used in the Penetrant Inspection Process5-29
Table 5-3. Classification of Penetrant Inspection Materials Covered by MIL-I-25135E5-30
Page xi
CONTENTS (CONTINUED) Paragraph Page
5-62. Basic Steps to Perform Penetration Inspection5-29
Table 5-4. Fluorescent and Visible Penetrant Inspection
General Processing Procedures Flowsheet5-31
Table 5-5. Pre-Cleaning Methods for Penetrant Inspection5-32
5-63. Cleaners and Applicators5-33
5-64. Technical Standards5-34
Table 5-6. Listing of Commonly Accepted Standards and Specifications for
Penetrant Inspection5-35
5-65.5-72. [RESERVED.]5-35
SECTION 6. RADIOGRAPHY (X-RAY) INSPECTION
5-73. General5-37
Figure 5-14. Radiography5-38
5-74. Limitations5-37
5-75. Film or Paper Radiography5-37
5-76. Real-Time Radiography5-37
5-77. Advantage of Real-Time Radiography Over Film Radiography5-37
5-78. Computed Tomography (CT)5-37
5-79. Uses of Radiography5-38
5-80. Comparison with Other NDI Methods5-38
5-81. Flaws5-39
5-82. Field Inspection5-39
5-83. Safety5-39
5-84.5-88. [RESERVED.]5-39
SECTION 7. ULTRASONIC INSPECTION
5-89. General5-41
Figure 5-15. Ultrasound5-42
5-90. Sound Reflection5-41
5-91. Ultrasonic Inspection Techniques5-41
Figure 5-16. Pulse-Echo and through-Transmission Ultrasonic Inspection Techniques5-42
5-92. Flaw Detection5-41
5-93. Basic Equipment5-41
Figure 5-17. Typical Portable Ultrasonic Inspection Instrument5-43
Figure 5-18. Example of Position fixture and Shoe5-44
Figure 5-19. Example of the Use if a Transducer Positioning Fixture5-44
Figure 5-20. Example of a Typical Reference Standard5-44
5-94. Inspection of Bonded Structures5-43
Figure 5-21. Examples of Bonded Structure Configurations and Suggested Inspection Coverage5-47
Table 5-7. Acceptable Ultrasonic Inspection Methods Associated with the
Example Bonded Structure Configurations Shown in Figure 5-215-48
Table 5-8. Ultrasonic Inspection Methods for Bonded Structures5-49
5-95. Bond Testing Instruments5-46
5-96. Thickness Measurements5-50
5-97. Leak Testing5-50
5-98.5-104. [RESERVED.]5-51
Page xii