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Aviation Maintenance Technician Handbook–Airframe (FAA-H-8083-31A) Volume 1

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Aviation Maintenance Technician Handbook–Airframe (FAA-H-8083-31A) Volume 1
US Depatment of Transportation
Federal Aviation Administration
2018
584 pages

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Aviation Maintenance Technician Handbook–Powerplant (FAA-H-8083-32A) Volume 1
Aviation Maintenance Technician Handbook–Powerplant (FAA-H-8083-32A) Volume 2

The Aviation Maintenance Technician Handbook—Airframe (FAA-H-8083-31A) is one of a series of three handbooks for persons preparing for certification as an airframe or powerplant mechanic. It is intended that this handbook provide the basic information on principles, fundamentals, and technical procedures in the subject matter areas relating to the airframe rating. It is designed to aid students enrolled in a formal course of instruction, as well as the individual who is studying on his or her own. Since the knowledge requirements for the airframe and powerplant ratings closely parallel each other in some subject areas, the chapters which discuss fire protection systems and electrical systems contain some material which is also duplicated in the Aviation Maintenance Technician Handbook—Powerplant (FAA-H-8083-32A).

This volume contains information on airframe construction features, assembly and rigging, fabric covering, structural repairs, and aircraft welding. The handbook also contains an explanation of the units that make up the various airframe systems. Because there are so many different types of aircraft in use today, it is reasonable to expect that differences exist in airframe components and systems. To avoid undue repetition, the practice of using representative systems and units is carried out throughout the handbook. Subject matter treatment is from a generalized point of view and should be supplemented by reference to manufacturer's manuals or other textbooks if more detail is desired. This handbook is not intended to replace, substitute for, or supersede official regulations or the manufacturer’s instructions. Occasionally the word “must” or similar language is used where the desired action is deemed critical. The use of such language is not intended to add to, interpret, or relieve a duty imposed by Title 14 of the Code of Federal Regulations (14 CFR).

TOC

Volume Contents. ...................................................V
Preface..................................................................VII
Acknowledgments. ................................................IX
Table of Contents. ................................................XV

Chapter 1
Aircraft Structures. ...............................................1-1A
Brief History of Aircraft Structures. ...........................1-1
General. ...........................................................................1-5
Major Structural Stresses. ...............................................1-6
Fixed-Wing Aircraft. .......................................................1-8
Fuselage. ......................................................................1-8
Truss-Type. ..............................................................1-8
Monocoque Type. ....................................................1-9
Semimonocoque Type. ............................................1-9
Pressurization. ...........................................................1-10
Wings. ...........................................................................1-10
Wing Configurations. ................................................1-10
Wing Structure. .........................................................1-11
Wing Spars. ...............................................................1-13
Wing Ribs. .................................................................1-15
Wing Skin. .................................................................1-17
Nacelles. ....................................................................1-19
Empennage. ...................................................................1-22
Flight Control Surfaces. ................................................1-24
Primary Flight Control Surfaces...............................1-24
Ailerons. .................................................................1-26
Elevator. .................................................................1-27
Rudder. ...................................................................1-27
Dual Purpose Flight Control Surfaces. ......................1-27
Secondary or Auxiliary Control Surfaces. ................1-28
Flaps. ......................................................................1-28
Slats. .......................................................................1-30
Spoilers and Speed Brakes. ....................................1-30
Tabs. .......................................................................1-31
Other Wing Features. ................................................1-34
Landing Gear. ...............................................................1-35
Tail Wheel Gear Configuration. ................................1-37
Tricycle Gear Configuration. ....................................1-38
Maintaining the Aircraft. ..............................................1-38
Location Numbering Systems. ..................................1-39
Access and Inspection Panels. ...................................1-40
Helicopter Structures. ...................................................1-40
Airframe. ...................................................................1-40
Fuselage. ....................................................................1-42
Landing Gear or Skids. ..............................................1-42
Powerplant and Transmission. ..................................1-42
Turbine Engines. ....................................................1-42
Transmission. .........................................................1-43
Main Rotor System. ...................................................1-43
Rigid Rotor System. ...............................................1-44
Semirigid Rotor System. ........................................1-44
Fully Articulated Rotor System. ................................1-44
Antitorque System. ....................................................1-45
Controls. ....................................................................1-46

Chapter 2
Aerodynamics, Aircraft Assembly, and Rigging
Introduction. ....................................................................2-1
Basic Aerodynamics. ......................................................2-2
The Atmosphere. .............................................................2-2
Pressure. ......................................................................2-2
Density. .......................................................................2-3
Humidity. .....................................................................2-3
Aerodynamics and the Laws of Physics. ........................2-3
Velocity and Acceleration. ..........................................2-3
Newton’s Laws of Motion. ..........................................2-3
Bernoulli’s Principle and Subsonic Flow. ...................2-4
Airfoil. .............................................................................2-4
Shape of the Airfoil. ....................................................2-5
Angle of Incidence. .....................................................2-5
Angle of Attack (AOA). ..............................................2-6
Boundary Layer. ..........................................................2-7
Thrust and Drag. .............................................................2-7
Center of Gravity (CG). ..................................................2-9
The Axes of an Aircraft. .................................................2-9
Stability and Control. ......................................................2-9
Static Stability. ............................................................2-9
Dynamic Stability. .......................................................2-9
Longitudinal Stability. .................................................2-9
Directional Stability. .................................................2-10
Lateral Stability. ........................................................2-11
Dutch Roll. ................................................................2-11
Primary Flight Controls. ...............................................2-11
Trim Controls. ...............................................................2-11
Auxiliary Lift Devices. .................................................2-12
Lift Augmenting. .......................................................2-12
Lift Decreasing. .........................................................2-12
Winglets. ...................................................................2-13
Canard Wings. ...........................................................2-13
Wing Fences. .............................................................2-14
Control Systems for Large Aircraft. .............................2-14
Mechanical Control. ..................................................2-14
Hydromechanical Control. ........................................2-14
Fly-By-Wire Control. ................................................2-14
High-Speed Aerodynamics. ..........................................2-15
Rotary-Wing Aircraft Assembly and Rigging. .............2-16
Configurations of Rotary-Wing Aircraft. .....................2-17
Autogyro. ...................................................................2-17
Single Rotor Helicopter. ............................................2-17
Dual Rotor Helicopter. ..............................................2-18
Types of Rotor Systems. ...............................................2-18
Fully Articulated Rotor. ............................................2-18
Semirigid Rotor. ........................................................2-18
Rigid Rotor. ...............................................................2-18
Forces Acting on the Helicopter. ..................................2-18
Torque Compensation. ..............................................2-19
Gyroscopic Forces. ....................................................2-19
Helicopter Flight Conditions . .......................................2-20
Hovering Flight. ........................................................2-20
Translating Tendency or Drift. ..............................2-22
Ground Effect. .......................................................2-22
Coriolis Effect (Law of Conservation of Angular Momentum). ............................................2-22
Vertical Flight...........................................................2-23
Forward Flight. ..........................................................2-23
Translational Lift. ..................................................2-24
Effective Translational Lift (ETL). ........................2-24
Dissymmetry of Lift. .............................................2-25
Autorotation. .............................................................2-27
Rotorcraft Controls. ......................................................2-28
Swash Plate Assembly. .............................................2-28
Collective Pitch Control. ...........................................2-28
Throttle Control. ........................................................2-29
Governor/Correlator. .................................................2-29
Cyclic Pitch Control. .................................................2-29
Antitorque Pedals. .....................................................2-30
Stabilizer Systems. ........................................................2-30
Bell Stabilizer Bar System. .......................................2-30
Offset Flapping Hinge. ..............................................2-31
Stability Augmentation Systems (SAS). ...................2-31
Helicopter Vibration. .................................................2-31
Extreme Low Frequency Vibration. ......................2-31
Low Frequency Vibration. .....................................2-31
Medium Frequency Vibration. ...............................2-31
High Frequency Vibration. ....................................2-31
Rotor Blade Tracking. ...............................................2-31
Flag and Pole. ........................................................2-31
Electronic Blade Tracker. ......................................2-32
Tail Rotor Tracking. ..................................................2-33
Marking Method. ...................................................2-33
Electronic Method. ................................................2-33
Rotor Blade Preservation and Storage......................2-34
Helicopter Power Systems. ...........................................2-34
Powerplant. ................................................................2-34
Reciprocating Engine. ...............................................2-34
Turbine Engine. .........................................................2-35
Transmission System. ...................................................2-35
Main Rotor Transmission. .........................................2-35
Clutch. .......................................................................2-35
Centrifugal Clutch. ................................................2-36
Belt Drive Clutch. ..................................................2-36
Freewheeling Unit. ....................................................2-36
Airplane Assembly and Rigging. ..................................2-37
Rebalancing of Control Surfaces. ..............................2-37
Static Balance. .......................................................2-37
Dynamic Balance. ..................................................2-38
Rebalancing Procedures. ...........................................2-38
Rebalancing Methods. ...............................................2-38
Aircraft Rigging. ...........................................................2-39
Rigging Specifications. .............................................2-39
Type Certificate Data Sheet. ..................................2-39
Maintenance Manual. ............................................2-40
Structural Repair Manual (SRM). ..........................2-40
Manufacturer’s Service Information. .....................2-40
Airplane Assembly. ...................................................2-40
Aileron Installation. ...............................................2-40
Flap Installation. ....................................................2-40
Empennage Installation. ........................................2-40
Control Operating Systems. ......................................2-40
Cable Systems. .......................................................2-40
Cable Inspection. ...................................................2-42
Cable System Installation. .....................................2-43
Push Rods (Control Rods). ....................................2-46
Torque Tubes. ........................................................2-47
Cable Drums. .........................................................2-47
Rigging Checks. ........................................................2-48
Structural Alignment. ............................................2-48
Cable Tension. .......................................................2-51
Control Surface Travel. .........................................2-53
Checking and Safetying the System. .....................2-54
Biplane Assembly and Rigging. ...................................2-55
Aircraft Inspection. .......................................................2-59
Purpose of Inspection Programs. ...............................2-59
Perform an Airframe Conformity and Airworthiness Inspection. ..........................................2-59
Required Inspections. ................................................2-60
Preflight. ................................................................2-60
Periodic Maintenance Inspections. ........................2-60
Altimeter and Static System Inspections. ..............2-62
Air Traffic Control (ATC) Transponder Inspections. ............................................................2-62
Emergency Locator Transmitter (ELT) Operational and Maintenance Practices in Accordance With Advisory Circular (AC) 91-44. .....................................................................2-62
Annual and 100-Hour Inspections. ............................2-63
Preparation. ............................................................2-63
Other Aircraft Inspection and Maintenance Programs. ...................................................................2-65
Continuous Airworthiness Maintenance Program (CAMP). ..................................................2-67
Title 14 CFR part 125, section 125.247, Inspection Programs and Maintenance. .................2-67
Helicopter Inspections, Piston-Engine and Turbine-Powered. ..................................................2-67
Light Sport Aircraft and Aircraft Certificated as Experimental. ....................................................2-68

Chapter 3
Aircraft Fabric Covering. .....................................3-1
General History. ..............................................................3-1
Fabric Terms. ..................................................................3-3
Legal Aspects of Fabric Covering. .................................3-3
Approved Materials. .......................................................3-4
Fabric. ..........................................................................3-4
Other Fabric Covering Materials. ................................3-5
Anti-Chafe Tape. .....................................................3-5
Reinforcing Tape. ....................................................3-5
Rib Bracing. .............................................................3-5
Surface Tape. ...........................................................3-5
Rib Lacing Cord. .....................................................3-5
Sewing Thread. ........................................................3-6
Special Fabric Fasteners. .........................................3-6
Grommets. ...............................................................3-6
Inspection Rings. .....................................................3-6
Primer. .....................................................................3-7
Fabric Cement. .........................................................3-7
Fabric Sealer. ...........................................................3-7
Fillers. ......................................................................3-7
Topcoats. ..................................................................3-7
Available Covering Processes. ........................................3-8
Determining Fabric Condition—Repair or Recover?. ....3-9
Fabric Strength. ...............................................................3-9
How Fabric Breaking Strength is Determined. .........3-10
Fabric Testing Devices. .............................................3-11
General Fabric Covering Process. .................................3-12
Blanket Method vs. Envelope Method. .....................3-12
Preparation for Fabric Covering Work. .....................3-12
Removal of Old Fabric Coverings............................3-14
Preparation of the Airframe Before Covering. ..........3-14
Attaching Polyester Fabric to the Airframe. .............3-16
Seams. ....................................................................3-16
Fabric Cement. .......................................................3-16
Fabric Heat Shrinking. ...........................................3-17
Attaching Fabric to the Wing Ribs. .......................3-18
Rib Lacing. ............................................................3-18
Rings, Grommets, and Gussets. .............................3-21
Finishing Tapes. .....................................................3-21
Coating the Fabric. .................................................3-22
Polyester Fabric Repairs. ..............................................3-23
Applicable Instructions.............................................3-23
Repair Considerations. ..............................................3-23
Cotton-Covered Aircraft. ..............................................3-24
Fiberglass Coverings. ....................................................3-24

Chapter 4
Aircraft Metal Structural Repair. .........................4-1
Aircraft Metal Structural Repair. ....................................4-1
Stresses in Structural Members. ..................................4-2
Tension. ...................................................................4-2
Compression. ...........................................................4-3
Shear. .......................................................................4-3
Bearing. ....................................................................4-3
Torsion. ....................................................................4-3
Bending. ...................................................................4-4
Tools for Sheet Metal Construction and Repair. ............4-4
Layout Tools. ..............................................................4-4
Scales. ......................................................................4-4
Combination Square. ...............................................4-4
Dividers. ...................................................................4-4
Rivet Spacers. ..........................................................4-4
Marking Tools. ............................................................4-4
Pens. .........................................................................4-4
Scribes. .....................................................................4-5
Punches. .......................................................................4-5
Prick Punch. .............................................................4-6
Center Punch. ...........................................................4-6
Automatic Center Punch. .........................................4-6
Transfer Punch. ........................................................4-6
Drive Punch. ............................................................4-6
Pin Punch. ................................................................4-7
Chassis Punch. .........................................................4-7
Awl. .........................................................................4-7
Hole Duplicator. ..........................................................4-7
Cutting Tools. ..............................................................4-8
Circular-Cutting Saws. ............................................4-8
Kett Saw. ..................................................................4-8
Pneumatic Circular-Cutting Saw. ............................4-8
Reciprocating Saw. ..................................................4-8
Cut-off Wheel. .........................................................4-9
Nibblers. ...................................................................4-9
Shop Tools. ..................................................................4-9
Squaring Shear. ........................................................4-9
Throatless Shear. ....................................................4-10
Scroll Shears. .........................................................4-10
Rotary Punch Press. ...............................................4-11
Band Saw. ..............................................................4-11
Disk Sander. ...........................................................4-11
Belt Sander. ............................................................4-12
Notcher. .................................................................4-12
Wet or Dry Grinder. ...............................................4-12
Grinding Wheels. ...................................................4-13
Hand Cutting Tools. ..................................................4-13
Straight Snips. ........................................................4-13
Aviation Snips. ......................................................4-13
Files. .......................................................................4-13
Die Grinder. ...........................................................4-14
Burring Tool. .........................................................4-14
Hole Drilling. ................................................................4-14
Portable Power Drills. ...............................................4-15
Pneumatic Drill Motors. ........................................4-15
Right Angle and 45° Drill Motors. ........................4-15
Two Hole. ..............................................................4-15
Drill Press. .................................................................4-15
Drill Extensions and Adapters. ..................................4-16
Extension Drill Bits. ..............................................4-16
Straight Extension. .................................................4-16
Angle Adapters. .....................................................4-16
Snake Attachment. .................................................4-16
Types of Drill Bits. ....................................................4-17
Step Drill Bits. .......................................................4-17
Cobalt Alloy Drill Bits. ..........................................4-17
Twist Drill Bits. .....................................................4-17
Drill Bit Sizes. ...........................................................4-18
Drill Lubrication. .......................................................4-18
Reamers. ....................................................................4-19
Drill Stops. ................................................................4-19
Drill Bushings and Guides. .......................................4-19
Drill Bushing Holder Types. .....................................4-19
Drilling Large Holes. .............................................4-20
Chip Chasers. ............................................................4-21
Forming Tools. ..............................................................4-21
Bar Folding Machine. ................................................4-21
Cornice Brake. ...........................................................4-22
Box and Pan Brake (Finger Brake). ..........................4-22
Press Brake. ...............................................................4-23
Slip Roll Former. .......................................................4-23
Rotary Machine. ........................................................4-24
Stretch Forming. ........................................................4-24
Drop Hammer. ...........................................................4-24
Hydropress Forming. .................................................4-25
Spin Forming. ............................................................4-26
Forming with an English Wheel. ...............................4-26
Piccolo Former. .........................................................4-26
Shrinking and Stretching Tools. ................................4-27
Shrinking Tools. ....................................................4-27
Stretching Tools. ....................................................4-27
Manual Foot-Operated Sheet Metal Shrinker. .......4-27
Hand-Operated Shrinker and Stretcher. .................4-27
Dollies and Stakes. .................................................4-27
Hardwood Form Blocks. ........................................4-28
V-Blocks. ...............................................................4-28
Shrinking Blocks. ..................................................4-28
Sandbags. ...............................................................4-28
Sheet Metal Hammers and Mallets. .......................4-28
Sheet Metal Holding Devices. ......................................4-28
Clamps and Vises. .....................................................4-29
C-Clamps. ..............................................................4-29
Vises. .....................................................................4-29
Reusable Sheet Metal Fasteners. ...............................4-29
Cleco Fasteners. .....................................................4-30
Hex Nut and Wing Nut Temporary Sheet Fasteners. ...............................................................4-30
Aluminum Alloys.........................................................4-30
Structural Fasteners. ......................................................4-31
Solid Shank Rivet . ....................................................4-31
Description. ............................................................4-31
Installation of Rivets. .............................................4-33
Rivet Installation Tools. .........................................4-36
Riveting Procedure. ...............................................4-40
Countersunk Rivets. ...............................................4-41
Evaluating the Rivet. .............................................4-44
Removal of Rivets. ................................................4-45
Replacing Rivets. ...................................................4-46
National Advisory Committee for Aeronautics. ....4-46
(NACA) Method of Double Flush Riveting. .........4-46
Special Purpose Fasteners. ........................................4-47
Blind Rivets. ..........................................................4-47
Pin Fastening Systems (High-Shear Fasteners) ...4-50
Lockbolt Fastening Systems. .................................4-52
Blind Bolts. ............................................................4-53
Rivet Nut. ...............................................................4-56
Blind Fasteners (Nonstructural). ............................4-56
Forming Process...........................................................4-57
Forming Operations and Terms. ...................................4-57
Stretching. .................................................................4-58
Shrinking. ..................................................................4-58
Bumping. ...................................................................4-58
Crimping. ...................................................................4-58
Folding Sheet Metal. .................................................4-58
Layout and Forming. .....................................................4-59
Terminology. .............................................................4-59
Layout or Flat Pattern Development. ........................4-60
Making Straight Line Bends.....................................4-60
Bending a U-Channel. ...........................................4-61
Using a J-Chart To Calculate Total Developed Width. ....................................................................4-67
How To Find the Total Developed Width Using a J-Chart. .....................................................4-68
Using a Sheet Metal Brake to Fold Metal. ................4-69
Step 1: Adjustment of Bend Radius. ......................4-69
Step 2: Adjusting Clamping Pressure. ...................4-70
Step 3: Adjusting the Nose Gap. ............................4-71
Folding a Box. ...........................................................4-72
Relief Hole Location. .............................................4-73
Layout Method. ......................................................4-73
Open and Closed Bends. ...........................................4-73
Open End Bend (Less Than 90°)..........................4-74
Closed End Bend (More Than 90°)......................4-74
Hand Forming. ..........................................................4-74
Straight Line Bends. ..............................................4-74
Formed or Extruded Angles. ..................................4-75
Flanged Angles. .....................................................4-76
Shrinking. ...............................................................4-76
Stretching. ..............................................................4-77
Curved Flanged Parts. ............................................4-77
Forming by Bumping. ............................................4-79
Joggling. .................................................................4-81
Lightning Holes. ....................................................4-82
Working Stainless Steel............................................4-83
Working Inconel® Alloys 625 and 718. ....................4-83
Working Magnesium. ................................................4-84
Working Titanium. ....................................................4-85
Description of Titanium. ........................................4-85
Basic Principles of Sheet Metal Repair. .......................4-86
Maintaining Original Strength..................................4-87
Shear Strength and Bearing Strength. .......................4-88
Maintaining Original Contour. ..................................4-89
Keeping Weight to a Minimum. ................................4-89
Flutter and Vibration Precautions.............................4-89
Inspection of Damage. ...............................................4-90
Types of Damage and Defects..................................4-90
Classification of Damage. .........................................4-91
Negligible Damage. ...............................................4-91
Damage Repairable by Patching. ...........................4-91
Damage Repairable by Insertion. ..........................4-92
Damage Necessitating Replacement of Parts. .......4-92
Repairability of Sheet Metal Structure. ........................4-92
Structural Support During Repair.............................4-92
Assessment of Damage. ............................................4-92
Inspection of Riveted Joints. .....................................4-92
Inspection for Corrosion. ...........................................4-93
Damage Removal. .....................................................4-93
Repair Material Selection. .....................................4-93
Repair Parts Layout. ..............................................4-93
Rivet Selection. ......................................................4-94
Rivet Spacing and Edge Distance. .........................4-94
Corrosion Treatment. .............................................4-94
Approval of Repair. ...................................................4-94
Repair of Stressed Skin Structure. .............................4-94
Patches. ..................................................................4-97
Typical Repairs for Aircraft Structures. ....................4-98
Floats. .....................................................................4-99
Corrugated Skin Repair. ........................................4-99
Replacement of a Panel. ........................................4-99
Outside the Member. .............................................4-99
Inside the Member. ................................................4-99
Edges of the Panel. ................................................4-99
Repair of Lightning Holes. ....................................4-99
Repairs to a Pressurized Area. .............................4-101
Stringer Repair. ....................................................4-102
Former or Bulkhead Repair. ................................4-103
Longeron Repair. .................................................4-104
Spar Repair. .........................................................4-104
Rib and Web Repair. ............................................4-105
Leading Edge Repair. ..........................................4-106
Trailing Edge Repair. ...........................................4-107
Specialized Repairs. .............................................4-107
Inspection Openings. ...........................................4-108

Chapter 5
Aircraft Welding. ...................................................5-1
Introduction. ....................................................................5-1
Types of Welding. ...........................................................5-2
Gas Welding. ...............................................................5-2
Electric Arc Welding. ..................................................5-2
Shielded Metal Arc Welding (SMAW). ..................5-2
Gas Metal Arc Welding (GMAW). .........................5-3
Gas Tungsten Arc Welding (GTAW). .....................5-3
Electric Resistance Welding. .......................................5-6
Spot Welding. ..........................................................5-6
Seam Welding. .........................................................5-6
Plasma Arc Welding (PAW). ......................................5-6
Plasma Arc Cutting. ....................................................5-7
Gas Welding and Cutting Equipment. ............................5-7
Welding Gases. ............................................................5-7
Acetylene. ................................................................5-7
Argon. ......................................................................5-7
Helium. ....................................................................5-7
Hydrogen. ................................................................5-7
Oxygen. ....................................................................5-7
Pressure Regulators. ....................................................5-7
Welding Hose. .............................................................5-8
Check Valves and Flashback Arrestors. ......................5-8
Torches. .......................................................................5-8
Equal Pressure Torch. ..............................................5-8
Injector Torch. .........................................................5-9
Cutting Torch. ..........................................................5-9
Torch Tips. ..................................................................5-9
Welding Eyewear. .......................................................5-9
Torch Lighters. ......................................................5-10
Filler Rod. ..............................................................5-10
Equipment Setup. ......................................................5-10
Gas Cylinders. ........................................................5-10
Regulators. .............................................................5-10
Hoses. .....................................................................5-11
Connecting Torch. .................................................5-11
Select the Tip Size. ................................................5-11
Adjusting the Regulator Working Pressure. ..........5-12
Lighting and Adjusting the Torch . ...........................5-13
Different Flames. .......................................................5-13
Neutral Flame. .......................................................5-13
Carburizing Flame. ................................................5-13
Oxidizing Flame. ...................................................5-13
Soft or Harsh Flames. ............................................5-13
Handling of the Torch. ...........................................5-13
Oxy-acetylene Cutting. .................................................5-14
Shutting Down the Gas Welding Equipment. ...........5-14
Gas Welding Procedures and Techniques. ....................5-15
Correct Forming of a Weld. ......................................5-16
Characteristics of a Good Weld................................5-16
Oxy-Acetylene Welding of Ferrous Metals. .................5-16
Steel (Including SAE 4130). .....................................5-16
Chrome Molybdenum. ..............................................5-17
Stainless Steel. ...........................................................5-17
Oxy-Acetylene Welding of Nonferrous Metals. ...........5-17
Aluminum Welding. ..................................................5-18
Magnesium Welding. ................................................5-19
Brazing and Soldering. ..................................................5-19
Torch Brazing of Steel. .............................................5-19
Torch Brazing of Aluminum. ....................................5-20
Soldering. ..................................................................5-21
Aluminum Soldering. ............................................5-21
Silver Soldering. ....................................................5-21
Gas Tungsten Arc Welding (TIG Welding). .................5-22
TIG Welding 4130 Steel Tubing. ..............................5-23
TIG Welding Stainless Steel. ....................................5-23
TIG Welding Aluminum. ..........................................5-24
TIG Welding Magnesium. .........................................5-24
TIG Welding Titanium. .............................................5-24
Arc Welding Procedures, Techniques, and Welding Safety Equipment. ..........................................5-25
Multiple Pass Welding. .............................................5-26
Techniques of Position Welding. ..............................5-27
Flat Position Welding. ...............................................5-28
Bead Weld. ............................................................5-28
Groove Weld. .........................................................5-28
Fillet Weld. ............................................................5-29
Lap Joint Weld. ......................................................5-29
Vertical Position Welding. ........................................5-29
Overhead Position Welding......................................5-29
Expansion and Contraction of Metals. ..........................5-29
Welded Joints Using Oxy-Acetylene Torch. ................5-30
Butt Joints. .................................................................5-30
Tee Joints. ..................................................................5-31
Edge Joints. ...............................................................5-31
Corner Joints. ............................................................5-31
Lap Joints. .................................................................5-32
Repair of Steel Tubing Aircraft Structure by Welding. ........................................................................5-32
Dents at a Cluster Weld. ............................................5-32
Dents Between Clusters............................................5-32
Tube Splicing with Inside Sleeve Reinforcement. ....5-33
Tube Splicing with Outer Split Sleeve Reinforcement. ..........................................................5-33
Landing Gear Repairs. ...............................................5-34
Engine Mount Repairs. ..............................................5-36
Rosette Welding. .......................................................5-36

Chapter 6
Aircraft Wood and Structural Repair. .................6-1
Aircraft Wood and Structural Repair. .............................6-1
Wood Aircraft Construction and Repairs. ......................6-2
Inspection of Wood Structures . ..................................6-3
External and Internal Inspection. .............................6-3
Glued Joint Inspection. ............................................6-4
Wood Condition .....................................................6-5
Repair of Wood Aircraft Structures. ...............................6-7
Materials. .....................................................................6-7
Suitable Wood. ............................................................6-7
Defects Permitted ...................................................6-9
Defects Not Permitted. .............................................6-9
Glues (Adhesives). .................................................6-10
Definition of Terms Used in the Glue Process. .....6-10
Preparation of Wood for Gluing. ...............................6-11
Preparing Glues for Use. ........................................6-11
Applying the Glue/Adhesive. ................................6-11
Pressure on the Joint. .............................................6-12
Testing Glued Joints. .............................................6-13
Repair of Wood Aircraft Components. .....................6-13
Wing Rib Repairs. .................................................6-13
Wing Spar Repairs ...............................................6-15
Bolt and Bushing Holes. ........................................6-19
Plywood Skin Repairs. ..............................................6-20
Fabric Patch. ..........................................................6-20
Splayed Patch. ........................................................6-20
Surface Patch. ........................................................6-20
Plug Patch. .............................................................6-21
Scarf Patch. ............................................................6-24
The Back of the Skin is Accessible for Repair. .....6-24
The Back of the Skin Is Not Accessible for Repair. ....................................................................6-26

Chapter 7
Advanced Composite Materials. .........................7-1
Description of Composite Structures. .............................7-1
Introduction. ................................................................7-1
Laminated Structures. ..................................................7-2
Major Components of a Laminate. ..........................7-2
Strength Characteristics. ..........................................7-2
Fiber Orientation. .....................................................7-2
Warp Clock. .............................................................7-3
Fiber Forms. ................................................................7-3
Roving. .....................................................................7-3
Unidirectional (Tape). ..............................................7-3
Bidirectional (Fabric). ..............................................7-3
Nonwoven (Knitted or Stitched). .............................7-4
Types of Fiber. ............................................................7-4
Fiberglass. ................................................................7-4
Kevlar®...................................................................................................7-4
Carbon/Graphite. .....................................................7-5
Boron. ......................................................................7-6
Ceramic Fibers. ........................................................7-6
Lightning Protection Fibers. ....................................7-6
Matrix Materials. .........................................................7-6
Thermosetting Resins. .............................................7-6
Thermoplastic Resins. ..............................................7-8
Curing Stages of Resins. .............................................7-8
Pre-Impregnated Products (Prepregs). ........................7-8
Dry Fiber Material. ......................................................7-8
Thixotropic Agents. .....................................................7-9
Adhesives. ...................................................................7-9
Film Adhesives. .......................................................7-9
Paste Adhesives. ......................................................7-9
Foaming Adhesives. ..............................................7-10
Description of Sandwich Structures. .............................7-10
Properties. ..................................................................7-11
Facing Materials. .......................................................7-11
Core Materials. ..........................................................7-11
Honeycomb. ...........................................................7-11
Foam. .....................................................................7-12
Balsa Wood. ...........................................................7-13
Manufacturing and In-Service Damage. .......................7-13
Manufacturing Defects. .............................................7-13
Fiber Breakage. ......................................................7-13
Matrix Imperfections. ............................................7-13
Delamination and Debonds. ...................................7-14
Combinations of Damages. ....................................7-14
Flawed Fastener Holes. ..........................................7-14
In-Service Defects. ....................................................7-14
Corrosion. ..................................................................7-15
Nondestructive Inspection (NDI) of Composites. ........7-15
Visual Inspection. ......................................................7-15
Audible Sonic Testing (Coin Tapping). ....................7-16
Automated Tap Test. .............................................7-16
Ultrasonic Inspection. ................................................7-17
Through Transmission Ultrasonic Inspection. .......7-17
Pulse Echo Ultrasonic Inspection. .........................7-17
Ultrasonic Bondtester Inspection. ..........................7-18
Phased Array Inspection. .......................................7-18
Radiography. .............................................................7-18
Thermography. ..........................................................7-19
Neutron Radiography. ...............................................7-19
Moisture Detector. .....................................................7-19
Composite Repairs. .......................................................7-19
Layup Materials. ........................................................7-19
Hand Tools. ............................................................7-19
Air Tools. ...............................................................7-19
Caul Plate. ..............................................................7-20
Support Tooling and Molds. ..................................7-20
Vacuum Bag Materials. .............................................7-21
Release Agents. ......................................................7-21
Bleeder Ply. ............................................................7-21
Peel Ply. .................................................................7-21
Layup Tapes. ..........................................................7-21
Perforated Release Film. ........................................7-21
Solid Release Film. ................................................7-21
Breather Material. ..................................................7-21
Vacuum Bag. .........................................................7-22
Vacuum Equipment. ..................................................7-22
Vacuum Compaction Table. ..................................7-22
Heat Sources. .............................................................7-22
Oven. ......................................................................7-22
Autoclave. ..............................................................7-23
Heat Bonder and Heat Lamps. ...............................7-23
Heat Press Forming. ...............................................7-24
Thermocouples. .....................................................7-25
Types of Layups. .......................................................7-26
Wet Layups. ...........................................................7-26
Prepreg. ..................................................................7-27
Co-curing. ..............................................................7-28
Secondary Bonding. ...............................................7-28
Co-bonding. ...........................................................7-28
Layup Process (Typical Laminated Wet Layup). ......7-28
Layup Techniques. .................................................7-28
Bleedout Technique. ..............................................7-29
No Bleedout. ..........................................................7-29
Ply Orientation Warp Clock. .................................7-29
Mixing Resins. ..........................................................7-30
Saturation Techniques. ..............................................7-30
Fabric Impregnation With a Brush or Squeegee. ...7-30
Fabric Impregnation Using a Vacuum Bag. ..........7-30
Vacuum Bagging Techniques. ..................................7-31
Single Side Vacuum Bagging. ...............................7-31
Envelope Bagging. .................................................7-31
Alternate Pressure Application. .................................7-32
Shrink Tape. ...........................................................7-32
C-Clamps. ..............................................................7-32
Shotbags and Weights. ...........................................7-32
Curing of Composite Materials. ................................7-32
Room Temperature Curing. ...................................7-32
Elevated Temperature Curing. ...............................7-32
Composite Honeycomb Sandwich Repairs. ..................7-33
Damage Classification. ..............................................7-34
Sandwich Structures. .................................................7-34
Minor Core Damage (Filler and Potting Repairs). .................................................................7-34
Damage Requiring Core Replacement and Repair to One or Both Faceplates. .........................7-34
Solid Laminates. ........................................................7-37
Bonded Flush Patch Repairs. .................................7-37
Trailing Edge and Transition Area Patch Repairs. ..................................................................7-40
Resin Injection Repairs. .........................................7-40
Composite Patch Bonded to Aluminum
Structure. ................................................................7-40
Fiberglass Molded Mat Repairs. ............................7-40
Radome Repairs. ....................................................7-41
External Bonded Patch Repairs. ............................7-41
Bolted Repairs. ......................................................7-44
Fasteners Used with Composite Laminates..............7-46
Corrosion Precautions. ...........................................7-46
Fastener Materials . ................................................7-46
Fastener System for Sandwich Honeycomb Structures (SPS Technologies Comp Tite). ...........7-46
Hi-Lok® and Huck-Spin® Lockbolt Fasteners. ....7-46
Eddie-Bolt® Fasteners. ..........................................7-46
Cherry’s E-Z Buck® (CSR90433) Hollow Rivet. ......................................................................7-47
Blind Fasteners. .....................................................7-47
Blind Bolts. ............................................................7-48
Fiberlite. .................................................................7-48
Screws and Nutplates in Composite Structures. ....7-48
Machining Processes and Equipment. .......................7-49
Drilling. ..................................................................7-49
Countersinking. ......................................................7-52
Cutting Processes and Precautions. .......................7-52
Cutting Equipment. ................................................7-52
Repair Safety. ............................................................7-53
Eye Protection. .......................................................7-53
Respiratory Protection. ..........................................7-53
Skin Protection. ......................................................7-53
Fire Protection. ......................................................7-53
Transparent Plastics. .....................................................7-54
Optical Considerations. .............................................7-54
Identification. ............................................................7-54
Storage and Handling. ...........................................7-54
Forming Procedures and Techniques. .......................7-54
Heating. ..................................................................7-54
Forms. ....................................................................7-55
Forming Methods. ..................................................7-55
Sawing and Drilling. .................................................7-55
Sawing. ..................................................................7-55
Drilling. ..................................................................7-55
Cementing. ................................................................7-56
Application of Cement. ..........................................7-56
Repairs. ......................................................................7-57
Cleaning. ...................................................................7-57
Polishing. ...................................................................7-57
Windshield Installation.............................................7-57
Installation Procedures. .............................................7-57

Chapter 8
Aircraft Painting and Finishing. ..........................8-1
Introduction. ....................................................................8-1
Finishing Materials. ........................................................8-2
Acetone. .......................................................................8-2
Alcohol. .......................................................................8-2
Benzene. ......................................................................8-2
Methyl Ethyl Ketone (MEK). ......................................8-2
Methylene Chloride. ....................................................8-2
Toluene. .......................................................................8-2
Turpentine. ..................................................................8-3
Mineral Spirits. ............................................................8-3
Naphtha. ......................................................................8-3
Linseed Oil. .................................................................8-3
Thinners. ......................................................................8-3
Varnish. .......................................................................8-3
Primers. ...........................................................................8-3
Wash Primers. .............................................................8-3
Red Iron Oxide. ...........................................................8-3
Gray Enamel Undercoat. .............................................8-4
Urethane. .....................................................................8-4
Epoxy. .........................................................................8-4
Zinc Chromate. ............................................................8-4
Identification of Paints. ...................................................8-4
Dope. ............................