Contents (continued) Paragraph Page
Page xii
3-24....................................................................................................REPAIR OF PLASTICS
.3-19
FIGURE 3- 21...................................................STOP-DRILLING CRACKS 3-20 FIGURE 3-22........................................................... SURFACE PATCHES 3-20 FIGURE 3- 23......................................................... PLUG PATCH REPAIR 3-21
3-25..............................................CLEANING AND POLISHING TRANSPARENT PLASTIC
.3-21
3-26............................................................................................... REPLACEMENT PANELS
.3-21
3-27..................................................................................... INSTALLATION PROCEDURES
.3-22
3-28.3-39. [RESERVED.]3-22
SECTION 4. WINDSHIELDS, ENCLOSURES, AND WINDOWS
3-40GENERAL
.3-23
FIGURE 3-24.TEMPORARY REPAIRS TO CRACKED WINDSHIELDS OR WINDOWS 3-24
3-41PROTECTION
.3-24
3-42........................................................................................WINDSHIELD INSTALLATION
.3-24
3-43.3-47. [RESERVED.]3-25
Chapter 4. Metal Structure, Welding, And Brazing SECTION 1. IDENTIFICATION OF METALS
4-1GENERAL
.4-1
TABLE 4-1.................................. FE RROUS (IRON) ALLOY MATERIALS 4-1
4-2...............................................................................IDENTIFICATION OF STEEL STOCK
.4-1
TABLE 4-2.......... NUMERICAL SYSTEM FOR STEEL IDENTIFICATION 4-2 TABLE 4-3.EXAMPLES OF STAINL ESS AND HEAT-RESISTANT STEELS
NOMINAL COMPOSITION (PERCENT)4-2
4-3...................................................................INTERCHANGEABILITY OF STEEL TUBING
.4-2
4-4.................................................................................... IDENTIFICATION OF ALUMINUM
.4-2
TABLE 4-4.BASIC TEMPER DESIGNAT IONS AND SUBDIVISIONS FROM
ALUMINUM ALLOYS4-3
4-5.4-15. [RESERVED.]4-3
SECTION 2. TESTING OF METALS
4-16.....................................................................................................HARDNESS TESTING
.4-5
4-17......................................................................................ROCKWELL HARDNESS TEST
.4-5
4-18........................................................................................... BRINELL HARDNESS TEST
.4-5
Contents (continued) Paragraph Page
Page xiii
4-19.......................................................................................... VICKERS HARDNESS TEST
.4-6
4-20.........................................................................................MICROHARDNESS TESTING
.4-6
4-21INDENTIONS
.4-7
FIGURE 4-1.COMPARISON OF INDENTATION MADE BY KNOOP AND
VICKERS INDENTERS ..................... IN THE SAME WORK META L AND AT THE SAME LOADS 4-7
4-22......................................................................................................MAGNETIC TESTING
.4-8
4-23......................................................................................................ALUMINUM TESTING
.4-8
TABLE 4-5.HARDNESS VALUES FOR ALUMINUM ALLOYS. (REFERENCE MIL-H-6088G.) 4-8
4-24.4-35. [RESERVED.]4-8
Contents (continued) Paragraph Page
Page xiv SECTION 3. PRECAUTIONARY MEASURES
4-36.................................................................FLUTTER AND VIBRATION PRECAUTIONS
.4-9
4-37....................................................................................LOAD FACTORS FOR REPAIRS
.4-10
4-38................................................... TRANSFER OF STRESSES WITHIN A STRUCTURE
.4-10
4-39.4-49. [RESERVED.]4-10
SECTION 4. METAL REPAIR PROCEDURES
4-50GENERAL
.4-11
4-51................................... RIVETED (OR BOLTED) STEEL TRUSS-TYPE STRUCTURES
.4-11
4-52................................................................................ALUMINUM ALLOY STRUCTURES
.4-11
4-53.........................................SELECTION OF ALUMINUM FOR REPLACEMENT PARTS
.4-12
4-54.....................................................HEAT TREATMENT OF ALUMINUM ALLOY PARTS
.4-12
4-55............................................................................................................ BENDING METAL
.4-13
TABLE 4-6.RECOMMENDED RADII FO R 90-DEGREE BENDS IN ALUMINUM ALLOYS 4-14
4-56SETBACK
.4-13
FIGURE 4-2. .................................. SETBACK FOR A 90-DEGREE BEND 4-13 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
4-57RIVETING
.4-14
FIGURE 4-4.RIVET IDENTIFICA TION AND PART NUMBER BREAKDOWN 4-16 TABLE 4-8....................................... AIRCRAFT RIVET IDENTIFICATION 4-17 FIGURE 4-5.RIVET HOLE SPACING A ND EDGE DISTANCE FOR SINGLE-LAP
SHEET SPLICES4-20
FIGURE 4-6......... RIVETING PRACTICE AND RIVET IMPERFECTIONS 4-21 FIGURE 4-7........SELF PLUGGING FRICTION-LOCK CHERRY RIVETS 4-22 FIGURE 4-8.MECHANICAL-LOCK (BULBED CHERRY) CHERRY RIVET 4-23 FIGURE 4-9.............................................................CHERRY MAX RIVET 4-24 FIGURE 4- 10.............................................................OLYMIC-LOK RIVET 4-25 FIGURE 4- 11.........................................................................HUCK RIVET 4-26
Contents (continued) Paragraph Page
Page xv
4-58.................REPAIR METHODS AND PRECAUTIONS FOR ALUMINUM STRUCTURE
.4-25
FIGURE 4-12.TYPICAL REPAIR ME THOD FOR TUBULAR MEMBERS OF
ALUMINUM ALLOY4-28
FIGURE 4-13.TYPICAL REPAIR FOR BUCKLED OR CRACKED METAL WING RIB CAPSTRIPS 4-29 FIGURE 4-14.TYPICAL METAL RIB REPAIRS (USUALLY FOUND ON SMALL
AND MEDIUM-SIZE AIRCRAFT)4-30
FIGURE 4-15. ........................ TYPICAL REPAIRS OF TRAILING EDGES 4-31 FIGURE 4-16.TYPICAL REPAIRS OF STRESSED SHEET METAL COVERINGS 4-32 FIGURE 4-17................... TYPICAL ST RINGER AND FLANGE SPLICES 4-33 FIGURE 4-18.EXAMPLE OF STRING ER SPLICE (MATERIAL-2017 ALLOY) 4-34 FIGURE 4-19........ APPLICATION OF TYPICAL FLANGE SPLICES AND
REINFORCEMENT4-35
TABLE 4-9.NUMBER OF RIVETS REQU IRED FOR SPLICES (SINGLE-LAP JOINT) IN BARE 2014-T6, 2024-T3, 2024-T3, A ND 7075-T6 SHEET, CLAD 2014-T6, 2024-T3, 2024-T36, AND 7075-T6 SHEET, 2024-T4, AND 7075-T6 PLATE, ............. BAR, ROD, TUBE, AND EXTRUSIONS, 2014-T6 EXTRUSIONS 4-37 TABLE 4-10.NUMBER OF RIVETS RE QUIRED FOR SPLICES (SINGLE-LAP JOINT) . IN 2017, 1017 ALCLAD, 2024-T3 ALCL AD SHEET, PLATE, BAR, ROD, .........................................................................TUBE, A ND EXTRUSIONS 4-38 TABLE 4-11.NUMBER OF RIVETS RE QUIRED FOR SPLICES (SINGLE-LAP JOINT) ....................................................... IN 5032 (ALL HARDNESSES) SHEET 4-39
Contents (continued) Paragraph Page
Page xvi
4-59................................................................................REPAIRING CRACKED MEMBERS
.4-40
FIGURE 4-20.EXAMPLE OF INTERM EDIATE FRAME STRINGER SPLICE
(MATERIAL 2017-T3 AL ALLOY)4-41
FIGURE 4-21.TYPICAL METHODS OF REPAIRING CRACKED LEADING AND
TRAILING EDGES
AND RIB INTER SECTIONS4-42
FIGURE 4-22.TYPICAL METHODS OF REPLACING CRACKED MEMBER AT FITTINGS 4-43 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 POST 4-45
4-60................................................................................STEEL AND ALUMINUM FITTINGS
.4-40
FIGURE 4-25.TYPICAL METHODS OF REPAIRING ELONGATED OR WORN BOLT HOLES 4-46
4-61CASTINGS
.4-40
4-62.................................................. SELECTIVE PLATING IN AIRCRAFT MAINTENANCE
.4-40
4-63.4-73. [RESERVED.]4-51
SECTION 5. WELDING AND BRAZING
4-74GENERAL
.4-53
TABLE 4-12.CURRENT AND POLARITY SELECTION FOR INERT GAS WELDING 4-54 FIGURE 4-26.COMMON DEFECTS TO AVOID WHEN FITTING AND WELDING
AIRCRAFT CERTIFICATION CLUSTER4-55
TABLE 4-13.................................................................. TORCH TIP SIZES 4-55 FIGURE 4-27................. BU TT-WELDING STRENGTH CALCULATIONS 4-56
4-75......................................................................................................TYPES OF WELDING
.4-56
FIGURE 4-28.BASIC GAS-WELDING FLAMES: EACH HAS DISTINCTIVE SHAPE, COLOR AND SOUND.
................................................... NEUT RAL FLAME IS THE MOST USED 4-57 FIGURE 4-29.SET TIG WELDER TO DC CURRENT, STRAIGHT POLARITY
FOR WELDING MILD STEEL, ..........................................................STAINLESS STEEL AND TITANIUM 4-57 FIGURE 4-30.SET TIG TO AC CURRE NT FOR WELDING ALUMINUM AND MAGNESIUM 4-58
4-76............................................................................. ELECTRIC-RESISTANCE WELDING
.4-58
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
Contents (continued) Paragraph Page
Page xvii .......................................................IS DIRECT LY RELATED TO TIP SIZE 4-58
4-77BRAZING
.4-58
TABLE 4-14.CALCULATED ALLO WABLE STRENGTH OF BASE METAL 4-59 FIGURE 4-32. ..................................................SILVER BRAZING JOINTS 4-60 FIGURE 4-33. ........................................... ELECTRIC SOLDERING IRON 4-61
4-78..................................................................... AIRCRAFT PARTS NOT TO BE WELDED
.4-61
4-79..........................................................................................WELDING ROD SELECTION
.4-62
TABLE 4-15....CHART SHOWING WELDING FILLER ROD SELECTION 4-62
4-80.................................................................................REPAIR OF TUBULAR MEMBERS
.4-62
FIGURE 4-34.FINGER PATCH REPAIRS FOR MEMBERS DENTED AT A CLUSTER 4-63
4-81.......................................................................................REPAIR BY WELDED SLEEVE
.4-64
FIGURE 4-35.MEMBERS DENTED IN A BAY (REPAIRS BY WELDED SLEEVE) 4-65
4-82........................................................................................REPAIR BY BOLTED SLEEVE
.4-64
4-83..............................................................................................WELDED-PATCH REPAIR
.4-64
FIGURE 4- 36. ................................................. WELDED PATCH REPAIR 4-66
4-84........................................................SPLICING TUBING BY INNER-SLEEVE METHOD
.4-64
FIGURE 4-37. ...........................SPLICING BY INNER-SLEEVE METHOD 4-67
4-85...................................................... SPLICING TUBING BY OUTER-SLEEVE METHOD
.4-66
FIGURE 4-38.SPLICING BY OUTE R-SLEEVE METHOD (REPLACEMENT BY
WELDED OUTSIDE SLEEVE)4-68
FIGURE 4-39.TUBE REPLACEMENT AT A STATION BY WELDED OUTER SLEEVES 4-69
Contents (continued) Paragraph Page
Page xviii
4-86............................... SPLICING USING LARGER DIAMETER REPLACEMENT TUBES
.4-67
FIGURE 4-40.SPLICING USING LARG ER DIAMETER REPLACEMENT TUBE 4-69
4-87.............................................................. REPAIRS AT BUILT-IN FUSELAGE FITTINGS
.4-70
FIGURE 4-41................... REPAIRS AT BUILT-IN FUSELAGE FITTINGS 4-71
4-88............................................................................................ ENGINE-MOUNT REPAIRS
.4-70
4-89................................................................BUILT-UP TUBULAR WING OR TAIL-SPARS
.4-72
FIGURE 4-42......... STREAMLINE TUBE SPLICE USING ROUND TUBE
(APPLICABLE TO LANDING GEAR)4-73
4-90....................................................WING-BRACE STRUTS AND TAIL-BRACE STRUTS
.4-72
FIGURE 4-43........ STREAMLINE TUBE SPLICE USING SPLIT SLEEVE (APPLICABLE TO WING AND TAIL SURFACE BRACE STRUTS AND OTHER MEMBERS) 4-74
4-91................................................................................................LANDING GEAR REPAIR
.4-72
FIGURE 4-44......... STREAMLINE TUBE SPLICE USING SPLIT INSERT
(APPLICABLE TO LANDING GEAR)4-75
FIGURE 4-45.STREAMLINE TUBE SPL ICE USING PLATES (APPLICABLE TO
LANDING GEAR)4-76
FIGURE 4-46.REPRESENTATI VE TYPES OF REPAIRABLE AXLE ASSEMBLIES 4-77 FIGURE 4-47.LANDING GEAR ASSEMBLIES THAT CANNOT BE REPAIRED BY WELDING 4-78
4-92...........................................................................REPAIRS TO WELDED ASSEMBLIES
.4-73
4-93..................................................................................STAINLESS STEEL STRUCTURE
.4-74
4-94.4-103. [RESERVED.]4-78
SECTION 6. WELDING AND BRAZING SAFETY
4-104GENERAL
.4-79
4-105..................................................................................FIRE AND EXPLOSION SAFETY
.4-79
4-106................................................................................................WELDING WORK AREA
.4-79
4-107.......................................................................................................FIRE PROTECTION
.4-79
4-108...............................................................................................PROTECTIVE APPAREL
.4-80
4-109.............................................................................................................FIRST-AID KITS
.4-80
4-110.4-128. [RESERVED.]4-80
Chapter 5. NonDestructive Inspection (Ndi) SECTION 1. GENERAL
Contents (continued) Paragraph Page
Page xix
5-1GENERAL
.5-1
5-2.............................................................................................APPROVED PROCEDURES
.5-1
5-3......................................................................................................................NDT LEVELS
.5-1
5-4...................................................... TRAINING, QUALIFICATION, AND CERTIFICATION
.5-2
5-5FLAWS
.5-2
5-6.......................................................................................SELECTING THE NDI METHOD
.5-5
TABLE 5-1. ADVANTAGES AND DI SADVANTAGES OF NDI METHODS 5-7
5-7................................................................................................ TYPES OF INSPECTIONS
.5-6
5-8.5-14. [RESERVED.]5-7
SECTION 2. VISUAL INSPECTION
5-15GENERAL
.5-9
5-16..............................................................................SIMPLE VISUAL INSPECTION AIDS
.5-9
5-17BORESCOPES
.5-10
FIGURE 5-1. ....................................... TYPICAL BORESCOPE DESIGNS 5-11
Contents (continued) Paragraph Page
Page xx
5-18........................................................................... VISUAL INSPECTION PROCEDURES
.5-10
FIGURE 5-2...........USING A FLASH LIGHT TO INSPECT FOR CRACKS 5-13
5-19.5-24. [RESERVED.]5-13
SECTION 3. EDDY CURRENT INSPECTION
5-25......................................................................................EDDY CURRENT INSPECTION
.5-15
FIGURE 5-3. ....................................GENERATING AN EDDY CURRENT 5-15 FIGURE 5-4. .......................................DETECTING AN EDDY CURRENT 5-15 FIGURE 5-5. ..................................... TYPICAL INSTRUMENT DISPLAYS 5-16
5-26........................................................................ EDDY CURRENT COILS AND PROBES
.5-15
5-27........................................... FIELD APPLICATION OF EDDY CURRENT INSPECTION
.5-15
5-28................................................................................................. SURFACE INSPECTION
.5-16
FIGURE 5-6. .............................................. TYPICAL SURFACE CRACKS 5-16
5-29..........................................................................................SUBSURFACE INSPECTION
.5-17
FIGURE 5-7. .......................................TYPICAL SUBSURFACE CRACKS 5-18
5-30............................................................................................CORROSION INSPECTION
.5-17
FIGURE 5-8. ................................TYPICAL STRUCTURAL CORROSION 5-18
5-31................................ESTABLISHING EDDY CURRENT INSPECTION PROCEDURES
.5-17
5-32.5-39. [RESERVED.]5-18
SECTION 4. MAGNETIC PARTICLE INSPECTION
5-40GENERAL
.5-19
5-41........................................................................................PRINCIPLES OF OPERATION
.5-19
FIGURE 5-9. ........................................... MAGNETIC FIELD DISRUPTED 5-19 FIGURE 5-10.CRACK DETECTION BY MAGNETIC PARTICLE INSPECTION 5-19
5-42APPLICATIONS
.5-20
5-43...................................................................ELECTRICAL MAGNETIZING EQUIPMENT
.5-20
5-44....................................... MATERIALS USED IN MAGNETIC PARTICLE INSPECTION
.5-20
TABLE 5-2... LISTING OF COMMONLY ACCEPTED STANDARDS AND ................SPECIFICATIONS FOR MA GNETIC PARTICLE INSPECTION 5-21
Contents (continued) Paragraph Page
Page xxi
5-45....................................................................................... PREPARATION OF SURFACE
.5-22
5-46........................................................................................METHODS OF EXAMINATION
.5-22
5-47.................................................................. APPLICATION OF MAGNETIC PARTICLES
.5-22
5-48MAGNETIZATION
.5-23
FIGURE 5-11. ............................................ CIRCULAR MAGNETIZATION 5-23 FIGURE 5-12. .................................... LONGITUDINAL MAGNETIZATION 5-24
5-49.....................................................................DETERMINATION OF FIELD STRENGTH
.5-25
5-50........................................................................SPECIAL EXAMINATION TECHNIQUES
.5-25
5-51......................................DEMAGNETIZATION AND POST-EXAMINATION CLEANING
.5-27
5-52.5-59. [RESERVED.]5-28
SECTION 5. PENETRANT INSPECTION
5-60GENERAL
.5-29
FIGURE 5- 13.......................... PENETRANT AND DEVELOPER ACTION 5-30
5-61........................... EQUIPMENT USED IN THE PENETRANT INSPECTION PROCESS
.5-29
TABLE 5-3.CLASSIFICATION OF PENETRANT INSPECTION MATERIALS
COVERED BY MIL-I-25135E5-30
Contents (continued) Paragraph Page
Page xxii
5-62.......................................BASIC STEPS TO PERFORM PENETRATION INSPECTION
.5-29
TABLE 5-4.. FLUORESCENT AND VI SIBLE PENETRANT INSPECTION ........................GENERAL PR OCESSING PROCEDURES FLOWSHEET 5-31 TABLE 5-5.PRE-CLEANING METH ODS FOR PENETRANT INSPECTION 5-32
5-63CLEANERS
.5-33
5-64. TECHNICAL STANDARDS5-34
TABLE 5-6... LISTING OF COMMONLY ACCEPTED STANDARDS AND
SPECIFICATIONS FOR ........................................................................PENET RANT INSPECTION 5-35
5-65.5-72. [Reserved.]5-35
SECTION 6. RADIOGRAPHY (X-RAY) INSPECTION
5-73GENERAL
.5-37
FIGURE 5-14RADIOGRAPHY
5-38
5-74LIMITATIONS
.5-37
5-75..................................................................................FILM OR PAPER RADIOGRAPHY
.5-37
5-76...........................................................................................REAL-TIME RADIOGRAPHY
.5-37
5-77.............ADVANTAGE OF REAL-TIME RADIOGRAPHY OVER FILM RADIOGRAPHY
.5-37
5-78.................................................................................COMPUTED TOMOGRAPHY (CT)
.5-37
5-79..............................................................................................USES OF RADIOGRAPHY
.5-38
5-80...............................................................COMPARISON WITH OTHER NDI METHODS
.5-38
5-81FLAWS
.5-39
5-82........................................................................................................ FIELD INSPECTION
.5-39
5-83SAFETY
.5-39
5-84.5-88. [RESERVED.]5-39
SECTION 7. ULTRASONIC INSPECTION
5-89GENERAL
.5-41
FIGURE 5- 15ULTRASOUND
5-42
5-90.....................................................................................................SOUND REFLECTION
.5-41
5-91..................................................................ULTRASONIC INSPECTION TECHNIQUES
.5-41
FIGURE 5-16.PULSE-ECHO AND T HROUGH-TRANSMISSION ULTRASONIC
INSPECTION TECHNIQUES5-42
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Page xxiii
5-92..........................................................................................................FLAW DETECTION
.5-41
5-93........................................................................................................ BASIC EQUIPMENT
.5-41
FIGURE 5-17.TYPICAL PORTABLE ULTRASONIC INSPECTION INSTRUMENT 5-43 FIGURE 5-18.................EXAMPLE OF POSITION FIXTURE AND SHOE 5-44 FIGURE 5-19.EXAMPLE OF THE U SE IF A TRANSDUCER POSITIONING FIXTURE 5-44 FIGURE 5-20........EXAMPLE OF A TYPICAL REFERENCE STANDARD 5-44
5-94................................................................... INSPECTION OF BONDED STRUCTURES
.5-43
FIGURE 5-21.EXAMPLES OF BONDED STRUCTURE CONFIGURATIONS
AND SUGGESTED INSPECTION COVERAGE5-47
TABLE 5-7........ ACCEPTABLE UL TRASONIC INSPECTION METHODS
ASSOCIATED WITH THE EXAMPLE BONDED STRUCTURE CONFIGURATIONS SHOWN IN FIGURE 5-
21. 5-48 TABLE 5-8.ULTRASONIC INSPECTION METHODS FOR BONDED STRUCTURES 5-49
5-95................................................................................... BOND TESTING INSTRUMENTS
.5-46
5-96..................................................................................... THICKNESS MEASUREMENTS
.5-50
5-97................................................................................................................LEAK TESTING
.5-50
5-98.5-104. [RESERVED.]5-51