Front Matter

Aviation Maintenance Technician Handbook—Airframe 2023 U.S. Department of Transportation Federal Aviation Administration Flight Standards Service

Preface

The Aviation Maintenance Technician Handbook—Airframe (FAA-H-8083-31B) is one of a series of three handbooks for persons preparing for certification as an airframe or powerplant mechanic. This handbook provides 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 their 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-8083-32B).

This handbook 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 manufacturers’ manuals or other textbooks if more detail is desired. This handbook is not intended to replace, substitute for, or supersede official regulations or manufacturers’ 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).

The subject of Human Factors is contained in the Aviation Maintenance Technician Handbook—General (FAA-H-8083-30) (as revised).

This handbook is available for download, in PDF format, from www.faa.gov.

This handbook is published by the United States Department of Transportation, Federal Aviation Administration, Airman Testing Standards Branch, AFS-630, P.O. Box 25082, Oklahoma City, OK 73125.

Comments regarding this publication should be emailed to AFS630comments@faa.gov.

Acknowledgments

The Aviation Maintenance Technician Handbook—Airframe (FAA-H-8083-31B) was produced by the Federal Aviation Administration (FAA). The FAA wishes to acknowledge the following contributors:

Mr. Chris Brady (www.b737.org.uk) for images used throughout this handbook Captain Karl Eiríksson for image used in Chapter 1

Cessna Aircraft Company for image used in Chapter 1 Mr. Andy Dawson (www.mossie.org) for images used throughout Chapter 1 Mr. Bill Shemley for image used in Chapter 1

Mr. Bruce R. Swanson for image used in Chapter 1 Mr. Burkhard Domke (www.b-domke.de) for images used throughout Chapter 1 and 2 Mr. Chris Wonnacott (www.fromtheflightdeck.com) for image used in Chapter 1 Mr. Christian Tremblay (www.zodiac640.com) for image used in Chapter 1 Mr. John Bailey (www.knots2u.com) for image used in Chapter 1

Mr. Rich Guerra (www.rguerra.com) for image used in Chapter 1

Mr. Ronald Lane for image used in Chapter 1

Mr. Tom Allensworth (www.avsim.com) for image used in Chapter 1 Navion Pilots Association’s Tech Note 001 (www.navionpilots.org) for image used in Chapter 1 U.S. Coast Guard for image used in Chapter 1 Mr. Tony Bingelis and the Experimental Aircraft Association (EAA) for images used throughout Chapter 2 Mr. Benoit Viellefon (www.johnjohn.co.uk/compare-tigermothflights/html/tigermoth_bio_aozh.html) for image used in Chapter 3 Mr. Paul Harding of Safari Seaplanes–Bahamas (www.safariseaplanes.com) for image used in Chapter 3 Polyfiber/Consolidated Aircraft Coatings for images used throughout Chapter 3 Stewart Systems for images used throughout Chapter 3

Superflite for images used throughout Chapter 3 Cherry Aerospace (www.cherryaerospace.com) for images used in Chapters 4 and 7 Raytheon Aircraft (Structural Inspection and Repair Manual) for information used in Chapter 4 Mr. Scott Allen of Kalamazoo Industries, Inc. (www.kalamazooind.com) for image used in Chapter 4 Miller Electric Mfg. Co. (www.millerwelds.com) for images used in Chapter 5 Mr. Aaron Novak, contributing engineer, for charts used in Chapter 5 Mr. Bob Hall (www.pro-fusiononline.com) for image used in Chapter 5 Mr. Kent White of TM Technologies, Inc. for image used in Chapter 5 Safety Supplies Canada (www.safetysuppliescanada.com) for image used in Chapter 5 Smith Equipment (www.smithequipment.com) for images used in Chapter 5

Alcoa (www.alcoa.com) for images used in Chapter 7

Mr. Chuck Scott (www.itwif.com) for images used throughout Chapter 8 Mr. John Lagerlof of Paasche Airbrush Co. (paascheairbrush.com) for image used in Chapter 8 Mr. Philip Love of Turbine Products, LLC (www.turbineproducts.com) for image used in Chapter 8 Consolidated Aircraft Coatings for image used in Chapter 8 Tianjin Yonglida Material Testing Machine Co., Ltd for image used in Chapter 8 Mr. Jim Irwin of Aircraft Spruce & Specialty Co. (www.aircraftspruce.com) for images used in Chapters 9, 10, 11, 13, 14, 15

Mr. Kevan Hashemi for image used in Chapter 9 Mr. Michael Leasure, Aviation Multimedia Library (www2.tech.purdue.edu/at/courses/aeml) for images used in Chapters 9, 13, 14 Aircraft Owners and Pilots Association (AOPA) (www.aopa.org) for image used in Chapter 10 Cobra Systems Inc. (www.cobrasys.com) for image used in Chapter 10 www.free-online-private-pilot-ground-school.com for image used in Chapters 10, 16 DAC International (www.dacint.com) for image used in Chapter 10 Dawson Aircraft Inc. (www.aircraftpartsandsalvage.com) for images used throughout Chapter 10

Mr. Kent Clingaman for image used in Chapter 10

TECNAM (www.tecnam.com) for image used in Chapter 10 TGH Aviation-FAA Instrument Repair Station (www.tghaviation.com) for image used in Chapter 10 The Vintage Aviator Ltd. (www.thevintageaviator.co.nz) for image used in Chapter 10 ACK Technologies Inc. (www.ackavionics.com) for image used in Chapter 11 ADS-B Technologies, LLC (www.ads-b.com) for images used in Chapter 11 Aviation Glossary (www.aviationglossary.com) for image used in Chapter 11 AT&T Archives and History Center for image used in Chapter 11 Electronics International Inc. (www.buy-ei.com) for image used in Chapter 11 Excelitas Technologies (www.excelitas.com) for image used in Chapter 11 Freestate Electronics, Inc. (www.fse-inc.com) for image used in Chapter 11 AirTrafficAtlanta.com for image used in Chapter 11 Western Historic Radio Museum, Virginia City, Nevada (www.radioblvd.com) for image used in Chapter 11 Avidyne Corporation (www.avidyne.com) for image used in Chapter 11 Kintronic Laboratories (www.kintronic.com) for image used in Chapter 11 Mr. Dan Wolfe (www.flyboysalvage.com) for image used in Chapter 11 Mr. Ken Shuck (www.cessna150.net) for image used in Chapter 11

Mr. Paul Tocknell (www.askacfi.com) for image used in Chapter 11 Mr. Stephen McGreevy (www.auroralchorus.com) for image used in Chapter 11 Mr. Todd Bennett (www.bennettavionics.com) for image used in Chapter 11 National Oceanic and Atmospheric Administration, U.S. Department of Commerce for image used in Chapter 11 RAMI (www.rami.com) for image used in Chapter 11 Rockwell Collins (www.rockwellcollins.com) for image used in Chapter 11, Figure 11-73 Sarasota Avionics International (www.sarasotaavionics.com) for images used in Chapter 11

Southeast Aerospace, Inc. (www.seaerospace.com) for image used in Chapter 11 Sporty’s Pilot Shop (www.sportys.com) for image used in Chapter 11 Watts Antenna Company (www.wattsantenna.com) for image used in Chapter 11 Wings and Wheels (www.wingsandwheels.com) for image used in Chapter 11 Aeropin, Inc. (www.aeropin.com) for image used in Chapter 13 Airplane Mart Publishing (www.airplanemart.com) for image used in Chapter 13 Alberth Aviation (www.alberthaviation.com) for image used in Chapter 13 AVweb (www.avweb.com) for image used in Chapter 13 Belle Aire Aviation, Inc. (www.belleaireaviation.com) for image used in Chapter 13 Cold War Air Museum (www.coldwarairmuseum.org) for image used in Chapter 13 Comanche Gear (www.comanchegear.com) for image used in Chapter 13 CSOBeech (www.csobeech.com) for image used in Chapter 13 Desser Tire & Rubber Co., Inc. (www.desser.com) for image used in Chapter 13 DG Flugzeugbau GmbH (www.dg-flugzeugbau.de) for image used in Chapter 13 Expedition Exchange Inc. (www.expeditionexchange.com) for image used in Chapter 13 Fiddlers Green (www.fiddlersgreen.net) for image used in Chapter 13 Hitchcock Aviation (hitchcockaviation.com) for image used in Chapter 13 KUNZ GmbH aircraft equipment (www.kunz-aircraft.com) for images used in Chapter 13 Little Flyers (www.littleflyers.com) for images used in Chapter 13 Maple Leaf Aviation Ltd. (www.aircraftspeedmods.ca) for image used in Chapter 13 Mr. Budd Davisson (Airbum.com) for image used in Chapter 13 Mr. C. Jeff Dyrek (www.yellowairplane.com) for images used in Chapter 13 Mr. Jason Schappert (www.m0a.com) for image used in Chapter 13 Mr. John Baker (www.hangar9aeroworks.com) for image used in Chapter 13 Mr. Mike Schantz (www.trailer411.com) for image used in Chapter 13 Mr. Robert Hughes (www.escapadebuild.co.uk) for image used in Chapter 13 Mr. Ron Blachut for image used in Chapter 13 Owls Head Transportation Museum (www.owlshead.org) for image used in Chapter 13 PPI Aerospace (www.ppiaerospace.com) for image used in Chapter 13 Protective Packaging Corp. (www.protectivepackaging.net, 1-800-945-2247) for image used in Chapter 13 Ravenware Industries, LLC (www.ravenware.com) for image used in Chapter 13 Renold (www.renold.com) for image used in Chapter 13 Rotor F/X, LLC (www.rotorfx.com) for image used in Chapter 13 SkyGeek (www.skygeek.com) for image used in Chapter 13 Taigh Ramey (www.twinbeech.com) for image used in Chapter 13 Texas Air Salvage (www.texasairsalvage.com) for image used in Chapter 13 The Bogert Group (www.bogert-av.com) for image used in Chapter 13 W. B. Graham, Welded Tube Pros LLC (www.thefabricator.com) for image used in Chapter 13 Zinko Hydraulic Jack (www.zinkojack.com) for image used in Chapter 13

Aviation Institute of Maintenance (www.aimschool.com) for image used in Chapter 14 Aviation Laboratories (www.avlab.com) for image used in Chapter 14 AVSIM (www.avsim.com) for image used in Chapter 14 Eggenfellner (www.eggenfellneraircraft.com) for image used in Chapter 14 FlightSim.Com, Inc. (www.flightsim.com) for image used in Chapter 14 Fluid Components International LLC (www.fluidcomponents.com) for image used in Chapter 14 Fuel Quality Services, Inc. (www.fqsinc.com) for image used in Chapter 14 Hammonds Fuel Additives, Inc. (www.biobor.com) for image used in Chapter 14 Jeppesen (www.jeppesen.com) for image used in Chapter 14 MGL Avionics (www.mglavionics.com) for image used in Chapter 14 Mid-Atlantic Air Museum (www.maam.org) for image used in Chapter 14 MISCO Refractometer (www.misco.com) for image used in Chapter 14 Mr. Gary Brossett via the Aircraft Engine Historical Society (www.enginehistory.org) for image used in Chapter 14 Mr. Jeff McCombs (www.heyeng.com) for image used in Chapter 14 NASA for image used in Chapter 14 On-Track Aviation Limited (www.ontrackaviation.com) for image used in Chapter 14 Stewart Systems for image used in Chapter 14 Prist Aerospace Products (www.pristaerospace.com) for image used in Chapter 14 The Sundowners, Inc. (www.sdpleecounty.org) for image used in Chapter 14 Velcon Filters, LLC (www.velcon.com) for image used in Chapter 14 Aerox Aviation Oxygen Systems, Inc. (www.aerox.com) for image used in Chapter 16 Biggles Software (www.biggles-software.com) for image used in Chapter 16 C&D Associates, Inc. (www.aircraftheater.com) for image used in Chapter 16 Cobham (Carleton Technologies Inc.) (www.cobham.com) for image used in Chapter 16 Cool Africa (www.coolafrica.co.za) for image used in Chapter 16 Cumulus Soaring, Inc. (www.cumulus-soaring.com) for image used in Chapter 16 Essex Cryogenics of Missouri, Inc. (www.essexind.com) for image used in Chapter 16 Flightline AC, Inc. (www.flightlineac.com) for image used in Chapter 16 IDQ Holdings (www.idqusa.com) for image used in Chapter 16 Manchester Tank & Equipment (www.mantank.com) for image used in Chapter 16 Mountain High E&S Co. (www.MHoxygen.com) for images used throughout Chapter 16 Mr. Bill Sherwood (www.billzilla.org) for image used in Chapter 16 Mr. Boris Comazzi (www.flightgear.ch) for image used in Chapter 16 Mr. Chris Rudge (www.warbirdsite.com) for image used in Chapter 16 Mr. Richard Pfiffner (www.craggyaero.com) for image used in Chapter 16 Mr. Stephen Sweet (www.stephensweet.com) for image used in Chapter 16 Precise Flight, Inc. (www.preciseflight.com) for image used in Chapter 16 SPX Service Solutions (www.spx.com) for image used in Chapter 16 SuperFlash Compressed Gas Equipment (www.oxyfuelsafety.com)

Mr. Tim Mara (www.wingsandwheels.com) for images used in Chapter 16

Mr. Bill Abbott for image used in Chapter 17 Additional appreciation is extended to Dr. Ronald Sterkenburg, Purdue University; Mr. Bryan Rahm, Dr. Thomas K. Eismain, Purdue University; Mr. George McNeill, Mr. Thomas Forenz, Mr. Peng Wang, and the National Oceanic and Atmospheric Administration (NOAA) for their technical support and input.

• Table of Contents
• Chapter 1
• Aircraft Structures
• A Brief History of Aircraft Structures ...................... 1-1

General.................................................................. 1-4

Major Structural Stresses ...................................... 1-5

Fixed-Wing Aircraft ................................................ 1-7

Fuselage ............................................................ 1-7

• Truss-Type ...................................................... 1-7
• Monocoque Type............................................. 1-7
• Semimonocoque Type .................................... 1-8
• Reinforced Shell Type ..................................... 1-9
• Pressurization ................................................... 1-9

Wings..................................................................... 1-9

• Wing Configurations........................................... 1-9
• Wing Structure ................................................... 1-9
• Wing Spars....................................................... 1-12

Wing Ribs......................................................... 1-14

Wing Skin ......................................................... 1-16

Nacelles ........................................................... 1-17

Empennage ........................................................ 1-19

Flight Control Surfaces ........................................ 1-21

Primary Flight Control Surfaces ....................... 1-23

Ailerons ......................................................... 1-24

• Elevator......................................................... 1-25
• Rudder ......................................................... 1-25
• Dual Purpose Flight Control Surfaces.............. 1-26
• Secondary or Auxiliary Control Surfaces ......... 1-26

Flaps ............................................................. 1-26

Slats ............................................................. 1-29

Spoilers & Speed Brakes .............................. 1-29

Tabs ............................................................. 1-30

Other Wing Features........................................ 1-32

Landing Gear....................................................... 1-33

• Tail Wheel Gear Configuration ......................... 1-35
• Tricycle Gear Configuration.............................. 1-36
• Maintaining the Aircraft ........................................ 1-36
• Location Numbering Systems .......................... 1-37
• Access & Inspection Panels............................. 1-38
• Helicopter Structures ........................................... 1-39

Airframe............................................................ 1-39

Fuselage .......................................................... 1-40

• Landing Gear or Skids ..................................... 1-40
• Powerplant & Transmission.............................. 1-40
• Turbine Engines ............................................ 1-40
• Transmission................................................. 1-41
• Main Rotor System........................................... 1-42
• Rigid Rotor System ....................................... 1-42
• Semirigid Rotor System ................................ 1-42
• Fully Articulated Rotor System ......................... 1-42
• Antitorque System............................................ 1-44

Controls............................................................ 1-45

• Chapter 2
• Aerodynamics, Aircraft Assembly, & Rigging

Introduction............................................................ 2-1

Basic Aerodynamics ............................................. 2-1

The Atmosphere .................................................... 2-1

Pressure............................................................. 2-1

Density ............................................................... 2-2

Humidity ............................................................. 2-2

• Aerodynamics & the Laws of Physics.................... 2-2
• Velocity & Acceleration....................................... 2-3
• Newton’s Laws of Motion ................................... 2-3
• Bernoulli’s Principle & Subsonic Flow ................ 2-3

Airfoil...................................................................... 2-3

• Shape of the Airfoil ............................................. 2-4
• Angle of Incidence.............................................. 2-5
• Angle of Attack (AOA) ........................................ 2-5
• Boundary Layer.................................................. 2-6

Thrust & Drag ........................................................ 2-6

Center of Gravity (CG)........................................... 2-8

The Axes of an Aircraft ......................................... 2-8

Stability & Control ................................................. 2-8

Static Stability..................................................... 2-8

• Dynamic Stability.............................................. 2-10
• Longitudinal Stability ........................................ 2-10
• Directional Stability........................................... 2-10

Lateral Stability................................................. 2-10

Dutch Roll......................................................... 2-10

Primary Flight Controls ........................................ 2-10

Trim Controls ........................................................2-11

Auxiliary Lift Devices ............................................2-11

Lift Augmenting .................................................2-11

Lift Decreasing ................................................. 2-12

Winglets ........................................................... 2-13

• Canard Wings .................................................. 2-13
• Wing Fences ................................................... 2-13
• Control Systems for Large Aircraft....................... 2-13
• Mechanical Control .......................................... 2-13
• Hydromechanical Control................................. 2-13
• Fly-By-Wire Control ......................................... 2-14

• High-Speed Aerodynamics .................................. 2-14
• Rotary-Wing Aircraft Assembly & Rigging ........... 2-15
• Configurations of Rotary-Wing Aircraft ................ 2-16

Autogyro........................................................... 2-16

• Single Rotor Helicopter .................................... 2-16
• Dual Rotor Helicopter....................................... 2-17
• Types of Rotor Systems ...................................... 2-17
• Fully Articulated Rotor ...................................... 2-17
• Semirigid Rotor ................................................ 2-17

Rigid Rotor ....................................................... 2-17

• Forces Acting on the Helicopter........................... 2-17
• Torque Compensation ...................................... 2-18
• Gyroscopic Forces ........................................... 2-19
• Helicopter Flight Conditions ................................ 2-19
• Hovering Flight ................................................. 2-19
• Translating Tendency or Drift ........................ 2-21
• Ground Effect ................................................ 2-21
• Coriolis Effect (Law of Conservation of
• Angular Momentum) .................................... 2-21

Vertical Flight.................................................... 2-22

• Forward Flight .................................................. 2-22
• Translational Lift............................................ 2-23
• Effective Translational Lift (ETL) ................... 2-23
• Dissymmetry of Lift ....................................... 2-23

Autorotation...................................................... 2-26

Rotorcraft Controls .............................................. 2-27

• Swash Plate Assembly..................................... 2-27
• Collective Pitch Control .................................... 2-27
• Throttle Control ................................................ 2-28
• Governor/Correlator ........................................ 2-28
• Cyclic Pitch Control .......................................... 2-28
• Antitorque Pedals............................................. 2-29

Stabilizer Systems ............................................... 2-29

• Bell Stabilizer Bar System................................ 2-29
• Offset Flapping Hinge....................................... 2-29
• Stability Augmentation Systems (SAS) ............ 2-30
• Helicopter Vibration .......................................... 2-30
• Extreme Low Frequency Vibration ................ 2-30
• Low Frequency Vibration .............................. 2-30
• Medium Frequency Vibration ........................ 2-30
• High Frequency Vibration.............................. 2-30
• Rotor Blade Tracking........................................ 2-30
• Flag & Pole ................................................... 2-30
• Electronic Blade Tracker ............................... 2-30
• Tail Rotor Tracking ........................................... 2-32
• Marking Method ............................................ 2-32
• Electronic Method ......................................... 2-32
• Rotor Blade Preservation & Storage ................ 2-33
• Helicopter Power Systems .................................. 2-33

Powerplant ....................................................... 2-33

• Reciprocating Engine ....................................... 2-33
• Turbine Engine ................................................. 2-34
• Transmission System .......................................... 2-34
• Main Rotor Transmission ................................. 2-34

Clutch ............................................................... 2-34

• Centrifugal Clutch ......................................... 2-35
• Belt Drive Clutch ........................................... 2-35
• Freewheeling Unit ............................................ 2-35
• Airplane Assembly & Rigging .............................. 2-36
• Rebalancing of Control Surfaces ..................... 2-36
• Static Balance ............................................... 2-36
• Dynamic Balance .......................................... 2-36
• Rebalancing Procedures ................................. 2-37
• Rebalancing Methods ...................................... 2-37

Aircraft Rigging .................................................... 2-38

• Rigging Specifications...................................... 2-38
• Type Certificate Data Sheet .......................... 2-38
• Maintenance Manual..................................... 2-38
• Structural Repair Manual (SRM)................... 2-39
• Manufacturer’s Service Information .............. 2-39
• Airplane Assembly ........................................... 2-39
• Aileron Installation ........................................ 2-39
• Flap Installation............................................. 2-39
• Empennage Installation ................................ 2-39
• Control Operating Systems .............................. 2-39
• Cable Systems.............................................. 2-39
• Cable Inspection ........................................... 2-41
• Cable System Installation ............................. 2-41
• Push Rods (Control Rods) ............................ 2-44
• Torque Tubes ................................................ 2-46
• Cable Drums ................................................. 2-46
• Rigging Checks ................................................ 2-46
• Structural Alignment...................................... 2-47
• Cable Tension ............................................... 2-50
• Control Surface Travel .................................. 2-50
• Checking & Safetying the System................. 2-52
• Biplane Assembly & Rigging................................ 2-55

Aircraft Inspection................................................ 2-58

• Purpose of Inspection Programs ..................... 2-58
• Performing an Airframe Conformity &
• Airworthiness Inspection .................................. 2-58
• Required Inspections ....................................... 2-59

Preflight......................................................... 2-59

• Periodic Maintenance Inspections ................ 2-59
• Altimeter & Static System Inspections in
• Accordance with 14 CFR Part 91, Section

91.411 ........................................................... 2-61

• Air Traffic Control (ATC) Transponder
• Inspections.................................................... 2-61
• Emergency Locator Transmitter (ELT)

• Operational & Maintenance Practices in
• Accordance with Advisory Circular (AC)

91-44............................................................. 2-61

• Annual & 100-Hour Inspections ....................... 2-62
• Preparation ................................................... 2-62
• Other Aircraft Inspection & Maintenance

Programs.......................................................... 2-64

Continuous Airworthiness Maintenance

Program (CAMP) .......................................... 2-65

Title 14 CFR part 125, section 125.247, Inspection Programs & Maintenance ............ 2-65

Piston-Engine & Turbine-Powered

Helicopter Inspections................................... 2-66

Light Sport Aircraft & Aircraft Certificated as Experimental ........................................... 2-66

• Chapter 3
• Aircraft Fabric Covering

General History...................................................... 3-1

Fabric Terms.......................................................... 3-2

Legal Aspects of Fabric Covering.......................... 3-2

Approved Materials ............................................... 3-3

Fabric ................................................................ 3-3

• Other Fabric Covering Materials ........................ 3-4
• Anti-Chafe Tape .............................................. 3-4
• Reinforcing Tape ............................................. 3-4
• Rib Bracing ..................................................... 3-4
• Surface Tape ................................................... 3-4
• Rib Lacing Cord .............................................. 3-5
• Sewing Thread ................................................ 3-5
• Special Fabric Fasteners ................................ 3-5
• Grommets ....................................................... 3-6
• Inspection Rings ............................................. 3-6

Primer ............................................................. 3-6

Fabric Cement ................................................ 3-6

Fabric Sealer................................................... 3-6

Fillers .............................................................. 3-6

• Topcoats.......................................................... 3-6
• Available Covering Processes............................... 3-8
• Determining Fabric Condition—Repair or

Recover? ............................................................... 3-8

Fabric Strength ...................................................... 3-8

• How Fabric Breaking Strength is Determined .... 3-9
• Fabric Testing Devices ..................................... 3-10
• General Fabric Covering Process ....................... 3-10
• Blanket Method vs. Envelope Method ..............3-11
• Preparation for Fabric Covering Work...............3-11
• Removal of Old Fabric Coverings .................... 3-12

Preparation of the Airframe Before Covering ... 3-12 Attaching Polyester Fabric to the Airframe....... 3-14

• Seams........................................................... 3-14
• Fabric Cement .............................................. 3-17
• Fabric Heat Shrinking ................................... 3-17
• Attaching Fabric to the Wing Ribs.................... 3-18
• Rib Lacing ..................................................... 3-18
• Rings, Grommets, & Gussets ...................... 3-19
• Finishing Tapes ............................................. 3-20
• Coating the Fabric......................................... 3-21
• 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
• Aircraft Metal Structural Repair ............................. 4-1
• Stresses in Structural Members ......................... 4-1

Tension............................................................ 4-2

Compression................................................... 4-2

Shear .............................................................. 4-3

Bearing............................................................ 4-3

Torsion ........................................................... 4-3

Bending .......................................................... 4-3

Tools for Sheet Metal Construction & Repair......... 4-3

Layout Tools ....................................................... 4-3

Scales ............................................................. 4-3

Combination Square ....................................... 4-3

Dividers ........................................................... 4-4

Rivet Spacers.................................................. 4-4

Marking Tools ..................................................... 4-4

Pens................................................................ 4-4

Scribes ............................................................ 4-4

Punches ............................................................. 4-4

• Prick Punch..................................................... 4-5
• Center Punch .................................................. 4-5
• Automatic Center Punch ................................. 4-5
• Transfer Punch................................................ 4-6
• Drive Punch .................................................... 4-6
• Pin Punch........................................................ 4-6
• Chassis Punch ................................................ 4-6

Awl .................................................................. 4-6

Hole Duplicator................................................... 4-7

Cutting Tools....................................................... 4-7

• Circular-Cutting Saws ..................................... 4-7
• Kett Saw ......................................................... 4-7
• Pneumatic Circular-Cutting Saw ..................... 4-7
• Reciprocating Saw .......................................... 4-8
• Cut-off Wheel .................................................. 4-8

Nibblers........................................................... 4-8

Shop Tools.......................................................... 4-9

• Squaring Shear ............................................... 4-9
• Throatless Shear ............................................ 4-9
• Scroll Shears................................................. 4-10
• Rotary Punch Press ...................................... 4-10
• Band Saw...................................................... 4-10
• Disc Sander ...................................................4-11
• Belt Sander ....................................................4-11
• Notcher ..........................................................4-11
• Wet or Dry Grinder .........................................4-11
• Grinding Wheels ........................................... 4-12
• Hand Cutting Tools ........................................... 4-12
• Straight Snips................................................ 4-12
• Aviation Snips ............................................... 4-13

Files .............................................................. 4-13

Die Grinder.................................................... 4-13

Burring Tool ................................................... 4-14

Hole Drilling ......................................................... 4-14

• Portable Power Drills........................................ 4-14
• Pneumatic Drill Motors.................................. 4-14
• Right Angle & 45° Drill Motors....................... 4-14
• Two Hole ...................................................... 4-15

Drill Press......................................................... 4-15

• Drill Extensions & Adapters ............................. 4-15
• Extension Drill Bits ........................................ 4-16
• Straight Extension......................................... 4-16
• Angle Adapters ............................................. 4-16
• Snake Attachment......................................... 4-16
• Types of Drill Bits ............................................ 4-16
• Step Drill Bits ................................................ 4-16
• Cobalt Alloy Drill Bits..................................... 4-17
• Twist Drill Bits................................................ 4-17

Drill Bit Sizes .................................................... 4-17

Drill Lubrication ................................................ 4-17

Reamers........................................................... 4-17

Drill Stops......................................................... 4-17

• Drill Bushings & Guides ................................... 4-17
• Drill Bushing Holder Types ............................... 4-19
• Drilling Large Holes....................................... 4-20
• Chip Chasers ................................................... 4-20

Forming Tools ...................................................... 4-20

• Bar Folding Machine ........................................ 4-21
• Cornice Brake .................................................. 4-21
• Box & Pan Brake (Finger Brake)...................... 4-22
• Press Brake...................................................... 4-22
• Slip Roll Former ............................................... 4-22
• Rotary Machine ................................................ 4-23
• Stretch Forming................................................ 4-24
• Drop Hammer................................................... 4-24
• Hydropress Forming......................................... 4-25
• Spin Forming.................................................... 4-25
• Forming with an English Wheel........................ 4-25
• Piccolo Former ................................................. 4-26
• Shrinking & Stretching Tools ............................ 4-26
• Shrinking Tools.............................................. 4-26
• Stretching Tools............................................. 4-26

Manual Foot-Operated Sheet Metal Shrinker 4-26 Hand-Operated Shrinker & Stretcher............ 4-27

• Dollies & Stakes............................................ 4-27
• Hardwood Form Blocks................................. 4-27
• V-Blocks ........................................................ 4-27
• Shrinking Blocks ........................................... 4-27
• Sandbags...................................................... 4-27
• Sheet Metal Hammers & Mallets .................. 4-28
• Sheet Metal Holding Devices .............................. 4-28
• Clamps & Vises ............................................... 4-28
• C-Clamps ...................................................... 4-28

Vises ............................................................. 4-28

• Reusable Sheet Metal Fasteners..................... 4-28
• Cleco Fasteners............................................ 4-29
• Hex Nut & Wing Nut Temporary Sheet
• Fasteners ...................................................... 4-29

Aluminum Alloys .................................................. 4-29

• Structural Fasteners ........................................... 4-30
• Solid Shank Rivet ............................................ 4-30
• Description .................................................... 4-30
• Installation of Rivets...................................... 4-32
• Rivet Installation Tools .................................. 4-35
• Riveting Procedure ...................................... 4-39
• Countersunk Rivets....................................... 4-40
• Evaluating the Rivet ...................................... 4-43
• Removal of Rivets......................................... 4-44
• Replacing Rivets ........................................... 4-45
• National Advisory Committee for
• Aeronautics (NACA) Method of Double
• Flush Riveting ............................................... 4-45
• Special Purpose Fasteners .............................. 4-45
• Blind Rivets ................................................... 4-47
• Pin Fastening Systems (High-Shear
• Fasteners) .................................................... 4-49
• Lockbolt Fastening Systems ........................ 4-51
• Blind Bolts ..................................................... 4-53
• Rivet Nut ....................................................... 4-55
• Blind Fasteners (Nonstructural) .................... 4-56
• Forming Process ................................................. 4-56
• Forming Operations & Terms............................... 4-57

Stretching ......................................................... 4-57

Shrinking .......................................................... 4-57

Bumping ........................................................... 4-58

Crimping........................................................... 4-58

• Folding Sheet Metal ......................................... 4-58
• Layout & Forming ................................................ 4-58
• Terminology ..................................................... 4-58
• Layout or Flat Pattern Development ................ 4-59
• Making Straight Line Bends ............................. 4-60
• Bending a U-Channel.................................... 4-61
• Using a J-Chart to Calculate Total
• Developed Width........................................... 4-67
• Using a Sheet Metal Brake to Fold Metal......... 4-68
• Step 1: Adjustment of Bend Radius .............. 4-68
• Step 2: Adjusting Clamping Pressure ........... 4-69
• Step 3: Adjusting the Nose Gap.................... 4-70
• Folding a Box ................................................... 4-71
• Relief Hole Location...................................... 4-72
• Layout Method .............................................. 4-72
• Open & Closed Bends...................................... 4-72
• Open End Bend (Less Than 90°).................. 4-73
• Closed End Bend (More Than 90°)............... 4-73
• Hand Forming .................................................. 4-73
• Straight Line Bends....................................... 4-73
• Formed or Extruded Angles .......................... 4-74
• Flanged Angles ............................................. 4-75
• Shrinking ....................................................... 4-75
• Stretching...................................................... 4-76
• Curved Flanged Parts ................................... 4-76
• Forming by Bumping..................................... 4-78
• Joggling......................................................... 4-80
• Lightening Holes ........................................... 4-81
• Working Stainless Steel ................................... 4-82
• Working Inconel® Alloys 625 & 718.................. 4-82
• Working Magnesium......................................... 4-82
• Working Titanium.............................................. 4-84
• Description of Titanium ................................. 4-84
• Basic Principles of Sheet Metal Repair ............... 4-85
• Maintaining Original Strength........................... 4-86
• Shear Strength & Bearing Strength.................. 4-86
• Maintaining Original Contour............................ 4-86
• Keeping Weight to a Minimum ......................... 4-86
• Flutter & Vibration Precautions......................... 4-87
• Inspection of Damage ..................................... 4-88
• Types of Damage & Defects ............................ 4-89
• Classification of Damage ................................. 4-90
• Negligible Damage........................................ 4-90
• Damage Repairable by Patching .................. 4-90
• Damage Repairable by Insertion .................. 4-90
• Damage Necessitating Replacement of

Parts.............................................................. 4-90

• Repairability of Sheet Metal Structure ................. 4-90
• Structural Support During Repair ..................... 4-91
• Assessment of Damage ................................... 4-91
• Inspection of Riveted Joints ............................. 4-91
• Inspection for Corrosion ................................... 4-92
• Damage Removal ............................................ 4-92
• Repair Material Selection.............................. 4-92
• Repair Parts Layout ..................................... 4-92
• Rivet Selection ............................................. 4-92
• Rivet Spacing & Edge Distance .................... 4-92
• Corrosion Treatment .................................... 4-92
• Approval of Repair ........................................... 4-92
• Repair of Stressed Skin Structure ................... 4-93
• Patches ........................................................ 4-93
• Typical Repairs for Aircraft Structures ............. 4-97

Floats ............................................................ 4-97

• Corrugated Skin Repair ................................ 4-97
• Replacement of a Panel................................ 4-97
• Outside the Member .................................... 4-99
• Inside the Member ........................................ 4-99
• Edges of the Panel ....................................... 4-99
• Repair of Lightening Holes.......................... 4-100
• Repairs to a Pressurized Area .................... 4-100
• Stringer Repair............................................ 4-101
• Former or Bulkhead Repair......................... 4-102
• Longeron Repair ......................................... 4-103
• Spar Repair................................................. 4-103
• Rib & Web Repair ....................................... 4-104
• Leading Edge Repair .................................. 4-105
• Trailing Edge Repair ................................... 4-106
• Specialized Repairs .................................... 4-108
• Inspection Openings ................................... 4-108
• Chapter 5
• Aircraft Welding

Introduction............................................................ 5-1

Types of Welding ................................................... 5-1

• Gas Welding....................................................... 5-1
• Electric Arc Welding ........................................... 5-1
• Shielded Metal Arc Welding (SMAW).............. 5-2
• Gas Metal Arc Welding (GMAW)..................... 5-2
• Gas Tungsten Arc Welding (GTAW)................ 5-4
• Electric Resistance Welding .............................. 5-4
• Spot Welding................................................... 5-4
• Seam Welding................................................. 5-4
• Plasma Arc Welding (PAW) ................................ 5-4
• Plasma Arc Cutting ............................................ 5-6
• Gas Welding & Cutting Equipment ........................ 5-6
• Welding Gases .................................................. 5-6

Acetylene ........................................................ 5-6

Argon .............................................................. 5-6

Helium............................................................. 5-6

• Hydrogen ........................................................ 5-7
• Oxygen............................................................ 5-7
• Pressure Regulators .......................................... 5-7
• Welding Hose ..................................................... 5-7
• Check Valves & Flashback Arrestors ................. 5-7

Torches............................................................... 5-8

• Equal Pressure Torch...................................... 5-8
• Injector Torch................................................... 5-8
• Cutting Torch ................................................... 5-8

Torch Tips........................................................... 5-8

Welding Eyewear ............................................... 5-8

Torch Lighters ................................................. 5-9

Filler Rod......................................................... 5-9

• Equipment Setup.............................................. 5-10
• Gas Cylinders ............................................... 5-10
• Regulators..................................................... 5-10
• Hoses............................................................ 5-10
• Connecting Torch .......................................... 5-10
• Select the Tip Size ........................................ 5-10

Adjusting the Regulator Working Pressure ... 5-12 Lighting & Adjusting the Torch ......................... 5-12

• Different Flames ............................................... 5-12
• Neutral Flame ............................................... 5-12
• Carburizing Flame......................................... 5-12
• Oxidizing Flame ............................................ 5-12
• Soft or Harsh Flames .................................... 5-13
• Handling of the Torch .................................... 5-13
• Oxy-acetylene Cutting ......................................... 5-13
• Shutting Down the Gas Welding Equipment .... 5-14
• Gas Welding Procedures & Techniques .............. 5-14
• Correct Forming of a Weld ............................... 5-15
• Characteristics of a Good Weld........................ 5-15
• Oxy-Acetylene Welding of Ferrous Metals ......... 5-15
• Steel (Including SAE 4130) .............................. 5-15
• Chrome Molybdenum....................................... 5-16
• Stainless Steel ................................................. 5-16
• Oxy-Acetylene Welding of Nonferrous Metals..... 5-17
• Aluminum Welding ........................................... 5-17
• Magnesium Welding ........................................ 5-18
• Brazing & Soldering............................................. 5-19
• Torch Brazing of Steel ...................................... 5-19
• Torch Brazing of Aluminum .............................. 5-19

Soldering .......................................................... 5-20

• Aluminum Soldering...................................... 5-20
• Silver Soldering............................................. 5-20
• Gas Tungsten Arc Welding (TIG Welding)........... 5-21
• TIG Welding 4130 Steel Tubing ....................... 5-22
• TIG Welding Stainless Steel............................. 5-22
• TIG Welding Aluminum..................................... 5-23
• TIG Welding Magnesium.................................. 5-23
• TIG Welding Titanium....................................... 5-23
• Arc Welding Procedures, Techniques, &
• Welding Safety Equipment .................................. 5-24
• Multiple Pass Welding ...................................... 5-26
• Techniques of Position Welding ....................... 5-26
• Flat Position Welding........................................ 5-27
• Bead Weld..................................................... 5-27
• Groove Weld ................................................. 5-27
• Fillet Weld ..................................................... 5-27
• Lap Joint Weld .............................................. 5-28
• Vertical Position Welding ................................. 5-28
• Overhead Position Welding.............................. 5-28
• Expansion & Contraction of Metals ..................... 5-28
• Welded Joints Using Oxy-Acetylene Torch.......... 5-29

Butt Joints ........................................................ 5-29

Tee Joints ......................................................... 5-30

Edge Joints ...................................................... 5-30

Corner Joints.................................................... 5-30

Lap Joints......................................................... 5-30

Repair of Steel Tubing Aircraft Structure by

Welding................................................................ 5-31

• Dents at a Cluster Weld ................................... 5-31
• Dents Between Clusters................................... 5-31
• Tube Splicing with Inside Sleeve
• Reinforcement.................................................. 5-32
• Tube Splicing with Outer Split Sleeve
• Reinforcement.................................................. 5-32
• Landing Gear Repairs ...................................... 5-33
• Engine Mount Repairs...................................... 5-35
• Rosette Welding ............................................... 5-35
• Chapter 6
• Aircraft Wood & Structural Repair

Introduction............................................................ 6-1

• Wood Aircraft Construction & Repairs ................... 6-1
• Inspection of Wood Structures .......................... 6-2
• External & Internal Inspection ......................... 6-2
• Glued Joint Inspection .................................... 6-3
• Wood Condition .............................................. 6-4
• Repair of Wood Aircraft Structures ........................ 6-6

Materials............................................................. 6-7

• Suitable Wood .................................................... 6-7
• Defects Permitted ........................................... 6-7
• Defects Not Permitted..................................... 6-7
• Glues (Adhesives)........................................... 6-9
• Definition of Terms Used in the Glue
• Process ....................................................... 6-10

• Preparation of Wood for Gluing........................ 6-10
• Preparing Glues for Use ................................6-11
• Applying the Glue/Adhesive ..........................6-11
• Pressure on the Joint .....................................6-11
• Testing Glued Joints ..................................... 6-12
• Repair of Wood Aircraft Components............... 6-12
• Wing Rib Repairs ......................................... 6-12
• Wing Spar Repairs ....................................... 6-14
• Bolt & Bushing Holes .................................... 6-18
• Plywood Skin Repairs ...................................... 6-19
• Fabric Patch ................................................ 6-19
• Splayed Patch............................................... 6-20
• Surface Patch ............................................... 6-20
• Plug Patch..................................................... 6-20
• The Back of the Skin is Accessible for
• Repair .......................................................... 6-23
• The Back of the Skin Is Not Accessible for

Repair ........................................................... 6-24

• Chapter 7
• Advanced Composite Materials
• Description of Composite Structures ..................... 7-1

Introduction ........................................................ 7-1

• Laminated Structures ......................................... 7-1
• Major Components of a Laminate................... 7-1
• Strength Characteristics.................................. 7-1
• Fiber Orientation ............................................. 7-1
• Warp Clock...................................................... 7-2

Fiber Forms........................................................ 7-2

Roving............................................................. 7-2

• Unidirectional (Tape) ....................................... 7-3
• Bidirectional (Fabric) ....................................... 7-3
• Nonwoven (Knitted or Stitched) ...................... 7-3

Types of Fiber .................................................... 7-5

Fiberglass ....................................................... 7-5

Kevlar.............................................................. 7-5

Carbon/Graphite ............................................. 7-5

Boron .............................................................. 7-5

• Ceramic Fibers................................................ 7-5
• Lightning Protection Fibers ............................. 7-5
• Matrix Materials.................................................. 7-6
• Thermosetting Resins ..................................... 7-6
• Thermoplastic Resins ..................................... 7-7
• Curing Stages of Resins .................................... 7-7
• Pre-Impregnated Products (Prepregs) ............... 7-8
• Dry Fiber Material............................................... 7-8
• Thixotropic Agents.............................................. 7-8

Adhesives........................................................... 7-8

• Film Adhesives................................................ 7-8
• Paste Adhesives ........................................... 7-10
• Foaming Adhesives....................................... 7-10
• Description of Sandwich Structures..................... 7-10

Properties......................................................... 7-10

• Facing Materials............................................... 7-10
• Core Materials...................................................7-11
• Honeycomb....................................................7-11
• Foam..............................................................7-11
• Balsa Wood................................................... 7-12
• Manufacturing & In-Service Damage................... 7-12
• Manufacturing Defects ..................................... 7-12
• Fiber Breakage ............................................. 7-13
• Matrix Imperfections ..................................... 7-13
• Delamination & Debonds .............................. 7-13
• Combinations of Damages............................ 7-13
• Flawed Fastener Holes ................................. 7-13
• In-Service Defects............................................ 7-13

Corrosion.......................................................... 7-15

Nondestructive Inspection (NDI) of Composites.. 7-15 Visual Inspection .............................................. 7-15

• Audible Sonic Testing (Coin Tapping) .............. 7-15
• Automated Tap Test ...................................... 7-15
• Ultrasonic Inspection........................................ 7-16

Through Transmission Ultrasonic Inspection 7-16 Pulse Echo Ultrasonic Inspection ................ 7-16

• Ultrasonic Bond Tester Inspection................. 7-17
• Phased Array Inspection ............................... 7-17
• Radiography..................................................... 7-18
• Thermography.................................................. 7-18
• Neutron Radiography ....................................... 7-18
• Moisture Detector ............................................ 7-18
• Composite Repairs .............................................. 7-19
• Layup Materials................................................ 7-19
• Hand Tools .................................................... 7-19

Air Tools ........................................................ 7-19

• Caul Plate .................................................... 7-19
• Support Tooling & Molds ............................... 7-19
• Vacuum Bag Materials .................................... 7-19
• Release Agents............................................. 7-19
• Bleeder Ply.................................................... 7-19
• Peel Ply......................................................... 7-21
• Layup Tapes.................................................. 7-21
• Perforated Release Film ............................... 7-21
• Solid Release Film ........................................ 7-21
• Breather Material .......................................... 7-21
• Vacuum Bag ................................................. 7-21
• Vacuum Equipment .......................................... 7-22
• Vacuum Compaction Table ........................... 7-22
• Heat Sources .................................................. 7-22

Oven ............................................................. 7-22

• Autoclave ...................................................... 7-22
• Heat Bonder & Heat Lamps .......................... 7-23
• Heat Press Forming ...................................... 7-24
• Thermocouples ............................................. 7-24
• Types of Layups ............................................... 7-25
• Wet Layups .................................................. 7-25
• Prepreg ......................................................... 7-25
• Co-curing ...................................................... 7-27
• Secondary Bonding....................................... 7-27
• Co-bonding ................................................... 7-28

Layup Process (Typical Laminated Wet Layup)7-28 Layup Techniques ......................................... 7-28

• Bleedout Technique....................................... 7-28
• No Bleedout .................................................. 7-28
• Ply Orientation Warp Clock ........................... 7-29
• Mixing Resins .................................................. 7-29
• Saturation Techniques...................................... 7-29
• 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 ......................... 7-31
• Shrink Tape ................................................... 7-31
• C-Clamps ...................................................... 7-31
• Shotbags & Weights...................................... 7-31
• Curing of Composite Materials......................... 7-31
• Room Temperature Curing............................ 7-32
• Elevated Temperature Curing ....................... 7-32
• Composite Honeycomb Sandwich Repairs ......... 7-33
• Damage Classification ..................................... 7-33
• Sandwich Structures ........................................ 7-34
• Minor Core Damage (Filler & Potting
• Repairs) ........................................................ 7-34
• Damage Requiring Core Replacement &
• Repair to One or Both Faceplates ................ 7-35
• Solid Laminates................................................ 7-38
• Bonded Flush Patch Repairs ........................ 7-38
• Trailing Edge & Transition Area Patch
• Repairs.......................................................... 7-39
• Resin Injection Repairs ................................. 7-39
• Composite Patch Bonded to Aluminum
• Structure ....................................................... 7-40
• Fiberglass Molded Mat Repairs .................... 7-40
• Radome Repairs ........................................... 7-40
• External Bonded Patch Repairs.................... 7-41
• Bolted Repairs .............................................. 7-43
• Fasteners Used with Composite Laminates..... 7-45
• Corrosion Precautions .................................. 7-45
• Fastener Materials ....................................... 7-45
• Fastener System for Sandwich Honeycomb
• Structures (SPS Technologies Comp Tite).... 7-45

Hi-Lok® & Huck-Spin® Lockbolt Fasteners .. 7-45 Eddie-Bolt® Fasteners.................................. 7-46

Cherry’s E-Z Buck® (CSR90433) Hollow

Rivet.............................................................. 7-47

Blind Fasteners ............................................. 7-47

Blind Bolts .................................................... 7-48

Fiberlite ......................................................... 7-49

Screws & Nutplates in Composite Structures 7-49 Machining Processes & Equipment ................. 7-49

Drilling ........................................................... 7-49

• Countersinking .............................................. 7-51
• Cutting Processes & Precautions ................. 7-52
• Cutting Equipment ........................................ 7-52
• Repair Safety ................................................... 7-52
• Eye Protection............................................... 7-53
• Respiratory Protection .................................. 7-53
• Skin Protection.............................................. 7-53
• Fire Protection............................................... 7-53
• Transparent Plastics............................................ 7-53
• Optical Considerations ..................................... 7-53

Identification ..................................................... 7-53

• Storage & Handling....................................... 7-53
• Forming Procedures & Techniques .................. 7-54
• Heating.......................................................... 7-54
• Forms............................................................ 7-54
• Forming Methods .......................................... 7-54
• Sawing & Drilling .............................................. 7-55
• Sawing .......................................................... 7-55

Drilling ........................................................... 7-55

Cementing........................................................ 7-55

Application of Cement................................... 7-56

Repairs............................................................. 7-56

Cleaning ........................................................... 7-56

Polishing........................................................... 7-57

• Windshield Installation ..................................... 7-57
• Installation Procedures..................................... 7-57
• Chapter 8
• Aircraft Painting & Finishing

Introduction ........................................................... 8-1

Finishing Materials ................................................ 8-1

Acetone .............................................................. 8-1

Alcohol ............................................................... 8-1

Benzene ............................................................. 8-1

Methyl Ethyl Ketone (MEK) ................................ 8-1

Methylene Chloride ............................................ 8-2

Toluene............................................................... 8-2

Turpentine .......................................................... 8-2

Mineral Spirits .................................................... 8-2

Naphtha.............................................................. 8-2

Linseed Oil ......................................................... 8-2

Thinners ............................................................. 8-2

Varnish ............................................................... 8-2

Primers .................................................................. 8-2

• Wash Primers..................................................... 8-3
• Red Iron Oxide ................................................... 8-3
• Gray Enamel Undercoat..................................... 8-3

Urethane ........................................................... 8-3

Epoxy ................................................................. 8-3

Zinc Chromate.................................................... 8-3

Identification of Paints ........................................... 8-3

Dope................................................................... 8-3

Synthetic Enamel ............................................... 8-4

Lacquers ............................................................ 8-4

Polyurethane ...................................................... 8-4

• Urethane Coating ............................................... 8-4
• Acrylic Urethanes ............................................... 8-4
• Methods of Applying Finish.................................... 8-4

Dipping ............................................................... 8-4

Brushing ............................................................. 8-4

Spraying ............................................................. 8-4

Finishing Equipment .............................................. 8-5

Paint Booth......................................................... 8-5

Air Supply........................................................... 8-5

• Spray Equipment................................................ 8-5
• Air Compressors ............................................. 8-5
• Large Coating Containers ............................... 8-6
• System Air Filters ............................................ 8-6
• Miscellaneous Painting Tools & Equipment........ 8-6
• Spray Guns ..................................................... 8-6
• Fresh Air Breathing Systems .......................... 8-8
• Viscosity Measuring Cup................................. 8-8
• Mixing Equipment ........................................... 8-9

Preparation ........................................................... 8-9

Surfaces ............................................................. 8-9

Primer & Paint .................................................... 8-9

• Spray Gun Operation........................................... 8-10
• Adjusting the Spray Pattern ............................. 8-10
• Applying the Finish............................................8-11
• Common Spray Gun Problems ........................ 8-12
• Sequence for Painting a Single-Engine or Light

Twin Airplane ....................................................... 8-12

Common Paint Troubles ...................................... 8-12

Poor Adhesion.................................................. 8-12

Blushing ........................................................... 8-13

Pinholes ........................................................... 8-13

Sags & Runs .................................................... 8-13

Orange Peel ..................................................... 8-13

Fisheyes........................................................... 8-14

Sanding Scratches ........................................... 8-14

Wrinkling........................................................... 8-14

Spray Dust ....................................................... 8-15

• Painting Trim & Identification Marks .................... 8-15
• Masking & Applying the Trim............................ 8-15
• Masking Materials ......................................... 8-15
• Masking for the Trim ..................................... 8-15
• Display of Nationality & Registration Marks .... 8-16
• Display of Marks ........................................... 8-16
• Location & Placement of Marks .................... 8-17
• Size Requirements for Different Aircraft........ 8-17

Decals.................................................................. 8-17

• Paper Decals.................................................... 8-17
• Metal Decals with Cellophane Backing ............ 8-17
• Metal Decals With Paper Backing.................... 8-17
• Metal Decals with No Adhesive........................ 8-18
• Vinyl Film Decals.............................................. 8-18
• Removal of Decals .......................................... 8-18
• Paint System Compatibility.................................. 8-18
• Paint Touchup................................................... 8-18
• Identification of Paint Finishes ...................... 8-18
• Surface Preparation for Touchup .................. 8-19
• Stripping the Finish .......................................... 8-20
• Chemical Stripping........................................ 8-20
• Plastic Media Blasting (PMB)........................ 8-20
• New Stripping Methods................................. 8-20
• Safety in the Paint Shop ...................................... 8-20
• Storage of Finishing Materials.......................... 8-21
• Protective Equipment for Personnel .................... 8-21
• Chapter 9
• Aircraft Electrical System

Introduction............................................................ 9-1

Ohm’s Law ......................................................... 9-1

Current ............................................................... 9-2

Conventional Current Theory & Electron

Theory ............................................................ 9-3

Electromotive Force (Voltage)............................ 9-3

Resistance ......................................................... 9-3

• Factors Affecting Resistance........................... 9-4
• Electromagnetic Generation of Power ............... 9-4
• Alternating Current (AC) Introduction ................ 9-8

Definitions ....................................................... 9-9

• Opposition to Current Flow of AC......................9-11
• Resistance .....................................................9-11
• Inductive Reactance ......................................9-11

• Capacitive Reactance ................................... 9-13
• Impedance ................................................... 9-14
• Parallel AC Circuits ....................................... 9-18
• Power in AC Circuits ..................................... 9-19
• True Power.................................................... 9-19
• Apparent Power ........................................... 9-19
• Power Factor ................................................... 9-19

Aircraft Batteries .................................................. 9-20

• Types of Batteries ............................................ 9-20
• Lead-Acid Batteries....................................... 9-20
• NiCd Batteries............................................... 9-21
• Capacity ........................................................ 9-22
• Aircraft Battery Ratings by Specification....... 9-22
• Storing & Servicing Facilities ........................ 9-22
• Battery Freezing............................................ 9-22
• Temperature Correction ................................ 9-22
• Battery Charging .......................................... 9-22
• Battery Maintenance ..................................... 9-23
• Battery & Charger Characteristics ................ 9-24
• Aircraft Battery Inspection............................. 9-25
• Ventilation Systems....................................... 9-25
• Installation Practices ..................................... 9-25
• Troubleshooting ............................................ 9-27
• DC Generators & Controls ............................... 9-27
• Generators .................................................... 9-27
• Construction Features of DC Generators ..... 9-28
• Types of DC Generators ............................... 9-30
• Generator Ratings......................................... 9-31
• DC Generator Maintenance .......................... 9-32
• Generator Controls........................................... 9-33
• Theory of Generator Control ......................... 9-33
• Functions of Generator Control Systems...... 9-33
• Generator Controls for High-Output
• Generators .................................................... 9-34
• Generator Controls for Low-Output
• Generators .................................................... 9-34
• DC Alternators & Controls ................................ 9-37
• DC Alternators .............................................. 9-37
• Alternator Voltage Regulators ...................... 9-39
• Solid-State Regulators .................................. 9-39
• Power Systems ................................................ 9-40
• AC Alternators .................................................. 9-40
• Alternator Drive ............................................... 9-43
• AC Alternators Control Systems ...................... 9-44
• Aircraft Electrical Systems................................... 9-46
• Small Single-Engine Aircraft............................. 9-46
• Battery Circuit ............................................... 9-46
• Generator Circuit........................................... 9-47
• Alternator Circuit ........................................... 9-47
• External Power Circuit .................................. 9-48
• Starter Circuit ................................................ 9-49
• Avionics Power Circuit .................................. 9-49
• Landing Gear Circuit ..................................... 9-50
• AC Supply ..................................................... 9-53
• Light Multiengine Aircraft.................................. 9-55
• Paralleling Alternators or Generators............ 9-56

Power Distribution on Multiengine Aircraft ... 9-56 Large Multiengine Aircraft ................................ 9-59

AC Power Systems ....................................... 9-59

Wiring Installation ................................................ 9-64

• Wiring Diagrams .............................................. 9-64
• Block Diagrams............................................. 9-64
• Pictorial Diagrams......................................... 9-64
• Schematic Diagrams..................................... 9-64

Wire Types ....................................................... 9-64

Conductor ..................................................... 9-66

Plating ........................................................... 9-66

• Insulation....................................................... 9-67
• Wire Shielding............................................... 9-67
• Wire Substitutions ......................................... 9-67
• Areas Designated as Severe Wind &
• Moisture Problem (SWAMP) ........................ 9-68
• Wire Size Selection .......................................... 9-68
• Current Carrying Capacity ............................ 9-68
• Allowable Voltage Drop................................. 9-74
• Wire Identification............................................. 9-76
• Placement of Identification Markings ............ 9-76
• Types of Wire Markings ............................... 9-76
• Wire Installation & Routing............................... 9-77
• Open Wiring .................................................. 9-77
• Wire Groups & Bundles & Routing................ 9-77
• Conduit.......................................................... 9-82
• Wire Shielding............................................... 9-84
• Lacing & Tying Wire Bundles ........................... 9-86

Tying ............................................................. 9-87

• Wire Termination .............................................. 9-87
• Stripping Wire .............................................. 9-87
• Terminal Strips .............................................. 9-90
• Terminal Lugs................................................ 9-90
• Emergency Splicing Repairs......................... 9-91
• Junction Boxes ............................................. 9-91
• AN/MS Connectors ....................................... 9-92
• Coaxial Cable................................................ 9-95
• Wire Inspection ................................................ 9-95
• Electrical System Components............................ 9-95

Switches........................................................... 9-95

Type of Switches........................................... 9-97

• Toggle & Rocker Switches ............................ 9-97
• Rotary Switches ............................................ 9-98
• Precision (Micro) Switches............................ 9-98
• Relays & Solenoids (Electromagnetic

Switches).......................................................... 9-98

Solenoids ...................................................... 9-98

Relays ........................................................... 9-98

Current Limiting Devices .................................. 9-98

Fuses ............................................................ 9-99

• Circuit Breakers ............................................ 9-99
• Aircraft Lighting Systems................................... 9-100
• Exterior Lights ................................................ 9-100
• Position Lights............................................. 9-100
• Anticollision Lights ...................................... 9-101
• Landing & Taxi Lights .................................. 9-101
• Wing Inspection Lights................................ 9-103

Interior Lights ................................................. 9-103

Maintenance & Inspection of Lighting

Systems ......................................................... 9-103

• Chapter 10
• Aircraft Systems

Introduction.......................................................... 10-1

• Classifying Instruments ....................................... 10-2
• Flight Instruments............................................. 10-2
• Engine Instruments .......................................... 10-3
• Navigation Instruments .................................... 10-3
• Pressure Measuring Instruments......................... 10-3
• Types of Pressure ............................................ 10-6
• Pressure Instruments ....................................... 10-7
• Engine Oil Pressure ...................................... 10-7
• Manifold Pressure ......................................... 10-8
• Engine Pressure Ratio (EPR) ....................... 10-9
• Fuel Pressure................................................ 10-9
• Hydraulic Pressure...................................... 10-10
• Vacuum Pressure........................................ 10-10
• Pressure Switches ...................................... 10-10
• Pitot-Static Systems .......................................10-11
• Pitot Tubes & Static Vents............................10-11
• Air Data Computers (ADC) & Digital Air
• Data Computers (DADC) ............................ 10-15
• Pitot-Static Pressure-Sensing Flight
• Instruments .................................................... 10-15
• Altimeters & Altitude.................................... 10-15
• Vertical Speed Indicator .............................. 10-21
• Airspeed Indicators ..................................... 10-23
• Remote Sensing & Indication ............................ 10-24
• Synchro-Type Remote-Indicating
• Instruments ................................................... 10-25
• DC Selsyn Systems .................................... 10-25
• AC Synchro Systems .................................. 10-26
• Remote Indicating Fuel & Oil Pressure
• Gauges ....................................................... 10-27
• Mechanical Movement Indicators ...................... 10-28
• Tachometers................................................... 10-28
• Mechanical Tachometers ............................ 10-28
• Electric Tachometers................................... 10-29
• Synchroscope ................................................ 10-31
• Accelerometers .............................................. 10-31
• Stall Warning & Angle of Attack (AOA)

Indicators........................................................ 10-32

Temperature Measuring Instruments................. 10-34

Non-Electric Temperature Indicators .............. 10-34

Electrical Temperature Measuring Indication . 10-35 Electrical Resistance Thermometer ............ 10-36

• Ratiometer Electrical Resistance
• Thermometers............................................. 10-36
• Thermocouple Temperature Indicators........... 10-37
• Turbine Gas Temperature Indicating
• Systems ...................................................... 10-39
• Total Air Temperature Measurement .............. 10-40
• Direction Indicating Instruments ........................ 10-41
• Magnetic Compass ........................................ 10-41
• Vertical Magnetic Compass............................ 10-43
• Remote Indicating Compass .......................... 10-43
• Remote Indicating Slaved Gyro Compass
• (Flux Gate Compass) ..................................... 10-44
• Solid State Magnetometers............................ 10-45

Sources of Power for Gyroscopic Instruments .. 10-45 Vacuum Systems............................................ 10-45

• Venturi Tube Systems ................................. 10-46
• Engine-Driven Vacuum Pump ..................... 10-46
• Typical Pump-Driven System...................... 10-47
• Twin-Engine Aircraft Vacuum System
• Operation .................................................... 10-49
• Pressure-Driven Gyroscopic Instrument

Systems ......................................................... 10-50

Electrically-Driven Gyroscopic Instrument

Systems ......................................................... 10-51

• Principles of Gyroscopic Instruments ................ 10-51
• Mechanical Gyros .......................................... 10-51
• Solid State Gyros & Related Systems............ 10-52
• Ring Laser Gyros (RLG) ............................. 10-52
• Microelectromechanical-Based Attitude &
• Directional Systems .................................... 10-53
• Other Attitude & Directional Systems.......... 10-54
• Common Gyroscopic Instruments ..................... 10-54
• Vacuum-Driven Attitude Gyros ....................... 10-54
• Electric Attitude Indicators.............................. 10-55

Gyroscopic Direction Indicator or Directional Gyro (DG)....................................................... 10-56

• Turn Coordinators .......................................... 10-56
• Turn-and-Slip Indicator .................................. 10-57
• Autopilot Systems.............................................. 10-58
• Basis for Autopilot Operation.......................... 10-59
• Autopilot Components ....................................... 10-60
• Sensing Elements .......................................... 10-60
• Computer & Amplifier ..................................... 10-60
• Output Elements ............................................ 10-60
• Command Elements....................................... 10-60
• Feedback or Follow-up Element .................... 10-61
• Autopilot Functions......................................... 10-62
• Yaw Dampening ............................................. 10-63
• Automatic Flight Control System (AFCS) .......... 10-63
• Flight Director Systems ..................................... 10-64
• Electronic Instruments ....................................... 10-64

Electronic Attitude Director Indicator (EADI) .. 10-64 Electronic Horizontal Situation Indicators (EHSI) ............................................................ 10-66

Electronic Flight Information Systems ............... 10-67

Electronic Flight Instrument System (EFIS) ... 10-68 Electronic Centralized Aircraft Monitor (ECAM) ....................................................... 10-68

Engine Indicating & Crew Alerting System

(EICAS) .......................................................... 10-70

• Flight Management System (FMS).................... 10-72
• Warnings & Cautions......................................... 10-73
• Annunciator Panels ........................................ 10-73
• Aural Warning Systems.................................. 10-74

Clocks................................................................ 10-74

• Instrument Housings & Handling ....................... 10-76
• Instrument Installations & Markings................... 10-77
• Instrument Panels .......................................... 10-77
• Instrument Mounting ...................................... 10-79
• Instrument Power Requirements.................... 10-79
• Instrument Range Markings ........................... 10-79
• Maintenance of Instruments & Instrument

Systems............................................................. 10-80

• Altimeter Tests................................................ 10-81
• Pitot-Static System Maintenance & Tests....... 10-81
• Tachometer Maintenance............................... 10-81
• Magnetic Compass Maintenance &
• Compensation ................................................ 10-82
• Vacuum System Maintenance........................ 10-83
• Autopilot System Maintenance....................... 10-83
• LCD Display Screens ..................................... 10-84
• Chapter 11
• Communication & Navigation

Introduction...........................................................11-1

• Avionics in Aviation Maintenance ......................11-1
• History of Avionics .............................................11-1
• Fundamentals of Electronics ................................11-3
• Analog Versus Digital Electronics .....................11-3

Noise..............................................................11-3

• Analog Electronics ............................................11-4
• Electron Control Valves..................................11-4
• Basic Analog Circuits ...................................11-17
• Digital Electronics .......................................11-24
• Radio Communication ........................................11-29
• Radio Waves ...................................................11-29
• Types of Radio Waves .................................11-30
• Loading Information onto a Radio Wave .........11-31
• Amplitude Modulation (AM)..........................11-31
• Frequency Modulation (FM).........................11-31
• Single Sideband (SSB) ...............................11-33
• Radio Transmitters & Receivers......................11-35
• Transmitters .................................................11-35
• Receivers .....................................................11-36
• Transceivers.................................................11-36

Antennas .........................................................11-36

• Length ..........................................................11-37
• Polarization, Directivity, & Field Pattern .......11-38
• Types ...........................................................11-38
• Transmission Lines ......................................11-39
• Radio Navigation ................................................11-40
• VOR Navigation System .................................11-40
• Automatic Direction Finder (ADF) ...................11-44
• Radio Magnetic Indicator (RMI) ......................11-47
• Instrument Landing Systems (ILS)..................11-47
• Localizer.......................................................11-48
• Glideslope ....................................................11-48
• Compass Locators .......................................11-48
• Marker Beacons...........................................11-48
• Distance Measuring Equipment (DME)...........11-50
• Area Navigation (RNAV)..................................11-52
• Radar Beacon Transponder ............................11-53
• Transponder Tests & Inspections.................11-55
• Altitude Encoders.........................................11-55
• Collision Avoidance Systems ..........................11-55

Traffic Collision Avoidance Systems (TCAS)11-56 ADS-B ..........................................................11-57

• Radio Altimeter................................................11-59
• Weather Radar ................................................11-60
• Emergency Locator Transmitter (ELT) ............11-63

Testing Considerations for 406 MHz ELTs ...11-65 406 MHz Testing ..........................................11-67

• Long Range Aid to Navigation System
• (LORAN) .........................................................11-67
• Global Positioning System (GPS) ...................11-68
• Wide Area Augmentation System (WAAS)...11-69

• Inertial Navigation System (INS)/Inertial
• Reference System (IRS).....................................11-69
• Aircraft Communication Addressing &
• Reporting System (ACARS)............................11-70
• Installation of Communication & Navigation

Equipment ..........................................................11-70

Approval of New Avionics Equipment

Installations .....................................................11-70

• Considerations ................................................11-71
• Cooling & Moisture .........................................11-71
• Vibration Isolation............................................11-72
• Reducing Radio Interference..............................11-72

Shielding .........................................................11-72

Isolation...........................................................11-73

Bonding ..........................................................11-73

• Static Discharge Wicks ...................................11-73
• Installation of Aircraft Antenna Systems .............11-73
• Transmission Lines .........................................11-74
• Maintenance Procedures ................................11-75
• Chapter 12
• Hydraulic & Pneumatic Power Systems
• Aircraft Hydraulic Systems .................................. 12-1

Hydraulic Fluid..................................................... 12-1

Viscosity ........................................................... 12-1

Chemical Stability............................................. 12-1

Flash Point ....................................................... 12-2

Fire Point.......................................................... 12-2

• Types of Hydraulic Fluids .................................... 12-2
• Mineral-Based Fluids ....................................... 12-2
• Polyalphaolefin-Based Fluids........................... 12-2
• Phosphate Ester-Based Fluid .......................... 12-3
• Intermixing of Fluids ......................................... 12-3
• Compatibility with Aircraft Materials ................. 12-3
• Hydraulic Fluid Contamination ......................... 12-3
• Contamination Check ................................... 12-3
• Contamination Control .................................. 12-4
• Hydraulic System Flushing............................... 12-5
• Health & Handling ............................................ 12-5
• Basic Hydraulic Systems .................................... 12-5
• Open Center Hydraulic Systems...................... 12-5
• Closed-Center Hydraulic Systems ................... 12-6
• Hydraulic Power Systems.................................... 12-7
• Evolution of Hydraulic Systems........................ 12-7
• Hydraulic Power Pack System ......................... 12-7
• Hydraulic System Components........................ 12-7
• Reservoirs..................................................... 12-7

Filters ............................................................. 12-12

• Micron-Type Filters ..................................... 12-13
• Maintenance of Filters................................. 12-13
• Filter Bypass Valve ..................................... 12-14
• Filter Differential Pressure Indicators ......... 12-14

Pumps ............................................................ 12-14

• Hand Pumps ................................................. 12-15
• Power-Driven Pumps ..................................... 12-15
• Classification of Pumps............................... 12-16
• Constant-Displacement Pumps .................. 12-16
• Gear-Type Power Pump ............................. 12-16
• Gerotor Pump ............................................. 12-17
• Piston Pump................................................ 12-17
• Vane Pump.................................................. 12-18
• Variable-Displacement Pump ..................... 12-19

Valves ............................................................ 12-22

• Flow Control Valves .................................... 12-22
• Pressure Control Valves.............................. 12-27
• Shuttle Valves ............................................. 12-29
• Accumulators ................................................. 12-29
• Types of Accumulators................................ 12-30
• Heat Exchangers............................................ 12-31

Actuators ........................................................ 12-32

• Linear Actuators .......................................... 12-32
• Rotary Actuators ......................................... 12-33
• Hydraulic Motor .......................................... 12-33
• Ram Air Turbine (RAT) .................................. 12-33
• Power Transfer Unit (PTU)............................. 12-34

Hydraulic Motor-Driven Generator (HMDG) ... 12-34 Seals .............................................................. 12-34

• V-Ring Packings.......................................... 12-35
• U-Ring ........................................................ 12-35
• O-Rings....................................................... 12-35
• Backup Rings.............................................. 12-36
• Gaskets....................................................... 12-36
• Seal Materials ............................................. 12-36
• O-Ring Installation ...................................... 12-37
• Wipers ........................................................ 12-37
• Large Aircraft Hydraulic Systems ...................... 12-37
• Boeing 737 Next Generation Hydraulic

System ........................................................... 12-37

• Reservoirs................................................... 12-37
• Pumps......................................................... 12-39
• Filter Units................................................... 12-39
• Power Transfer Unit (PTU).......................... 12-39
• Landing Gear Transfer Unit......................... 12-41
• Standby Hydraulic System.......................... 12-41
• Indications................................................... 12-41
• Boeing 777 Hydraulic System ........................ 12-41
• Left & Right System Description ................. 12-42
• Center Hydraulic System ............................ 12-44
• Aircraft Pneumatic Systems .............................. 12-46
• High-Pressure Systems ................................. 12-47

• Pneumatic System Components................. 12-47
• Emergency Backup Systems ...................... 12-49
• Medium-Pressure Systems ............................ 12-51
• Low-Pressure Systems ................................. 12-51
• Pneumatic Power System Maintenance ........ 12-51
• Chapter 13
• Aircraft Landing Gear Systems
• Landing Gear Types ............................................ 13-1
• Landing Gear Arrangement.............................. 13-2
• Tail Wheel-Type Landing Gear ..................... 13-2
• Tandem Landing Gear .................................. 13-2
• Tricycle-Type Landing Gear .......................... 13-3
• Fixed & Retractable Landing Gear................... 13-4
• Shock Absorbing & Non-Shock Absorbing
• Landing Gear .................................................. 13-6
• Leaf-Type Spring Gear.................................. 13-6

Rigid ............................................................. 13-7

• Bungee Cord................................................. 13-7
• Shock Struts ................................................. 13-7
• Shock Strut Operation.................................... 13-10
• Servicing Shock Struts ................................... 13-12
• Bleeding Shock Struts.................................... 13-14

Landing Gear Alignment, Support, & Retraction 13-14 Alignment ....................................................... 13-14

Support........................................................... 13-16

• Small Aircraft Retraction Systems.................. 13-17
• Large Aircraft Retraction Systems ................. 13-20
• Emergency Extension Systems ..................... 13-21
• Landing Gear Safety Devices ........................ 13-22
• Safety Switch .............................................. 13-22
• Ground Locks.............................................. 13-22
• Landing Gear Position Indicators................ 13-23
• Nose Wheel Centering................................ 13-24
• Landing Gear System Maintenance .................. 13-24
• Landing Gear Rigging & Adjustment .............. 13-26
• Adjusting Landing Gear Latches ................ 13-26
• Gear Door Clearances ................................ 13-26
• Drag & Side Brace Adjustment .................. 13-27
• Landing Gear Retraction Test .................... 13-28
• Nose Wheel Steering Systems.......................... 13-29
• Small Aircraft ................................................. 13-29
• Large Aircraft.................................................. 13-29
• Shimmy Dampers........................................... 13-30
• Steering Damper......................................... 13-30
• Piston-Type ................................................. 13-32
• Vane-Type ................................................... 13-32
• Non-Hydraulic Shimmy Damper ................. 13-33

Aircraft Wheels .................................................. 13-33

• Wheel Construction........................................ 13-34
• Inboard Wheel Half ..................................... 13-34
• Outboard Wheel Half .................................. 13-35
• Wheel Inspection............................................ 13-36
• On Aircraft Inspection.................................. 13-36
• Proper Installation ....................................... 13-36
• Off Aircraft Wheel Inspection ...................... 13-37

Aircraft Brakes ................................................... 13-42

• Types & Construction of Aircraft Brakes ........ 13-42
• Single Disc Brakes...................................... 13-42
• Dual-Disc Brakes ........................................ 13-46
• Multiple-Disc Brakes ................................... 13-46
• Segmented Rotor-Disc Brakes .................. 13-46
• Carbon Brakes ............................................ 13-49
• Expander Tube Brakes ............................... 13-49
• Brake Actuating Systems ............................... 13-50
• Independent Master Cylinders ................... 13-51
• Boosted Brakes........................................... 13-54
• Power Brakes ............................................. 13-55
• Emergency Brake Systems ........................... 13-58
• Parking Brake ............................................. 13-58
• Brake Deboosters ....................................... 13-59

Anti-Skid......................................................... 13-60

• System Operation ....................................... 13-60
• Wheel Speed Sensors ................................ 13-61
• Control Units ............................................... 13-61
• Anti-Skid Control Valves.............................. 13-63
• Touchdown & Lock Wheel Protection ......... 13-64
• Auto Brakes ................................................ 13-64
• Anti-Skid System Tests ............................... 13-65
• Anti-Skid System Maintenance ................... 13-66
• Brake Inspection & Service ............................ 13-66
• On Aircraft Servicing ................................... 13-66
• Lining Wear ................................................. 13-66
• Air in the Brake System .............................. 13-67

Bleeding Master Cylinder Brake Systems... 13-67 Bleeding Power Brake Systems.................. 13-69

Off Aircraft Brake Servicing & Maintenance 13-70 Replacement of Brake Linings .................... 13-71

• Brake Malfunctions & Damage ...................... 13-72
• Overheating ............................................... 13-72
• Dragging .................................................... 13-72
• Chattering or Squealing ............................. 13-73
• Aircraft Tires & Tubes ........................................ 13-74
• Tire Classification ........................................... 13-74
• Types .......................................................... 13-74
• Ply Rating.................................................... 13-75
• Tube-Type or Tubeless ............................... 13-75
• Bias Ply or Radial........................................ 13-75

• Tire Construction ............................................ 13-76
• Bead ........................................................... 13-76
• Carcass Plies .............................................. 13-76
• Tread........................................................... 13-76
• Sidewall....................................................... 13-78
• Tire Inspection on the Aircraft......................... 13-78

Inflation ....................................................... 13-78

• Tread Condition........................................... 13-79
• Sidewall Condition ...................................... 13-83
• Tire Removal .................................................. 13-83
• Tire Inspection Off of the Aircraft.................... 13-85
• Tire Repair & Retreading................................ 13-86
• Tire Storage ................................................... 13-86
• Aircraft Tubes ................................................. 13-87
• Tube Construction & Selection.................... 13-87
• Tube Storage & Inspection.......................... 13-87
• Tire Inspection ............................................ 13-87
• Tire Mounting ................................................. 13-87
• Tubeless Tires............................................. 13-87
• Tube-Type Tires .......................................... 13-89
• Tire Balancing ............................................... 13-90
• Operation & Handling Tips................................. 13-90

Taxiing ........................................................... 13-91

• Braking & Pivoting.......................................... 13-91
• Landing Field & Hangar Floor Condition ....... 13-91
• Takeoffs & Landings ....................................... 13-91
• Hydroplaning .................................................. 13-92
• Chapter 14
• Aircraft Fuel Systems
• Basic Fuel System Requirements ....................... 14-1
• Fuel System Independence ............................. 14-1
• Fuel System Lightning Protection .................... 14-1

Fuel Flow.......................................................... 14-2

• Fuel Storage System ........................................... 14-2
• Fuel Storage Refilling or Recharging System...... 14-3
• Types of Aviation Fuel ......................................... 14-3
• Reciprocating Engine Fuel—AVGAS ............... 14-3

Volatility......................................................... 14-3

• Vapor Lock .................................................... 14-3
• Carburetor Icing ............................................ 14-3
• Aromatic Fuels .............................................. 14-4
• Detonation..................................................... 14-4
• Surface Ignition & Preignition........................ 14-5
• Octane & Performance Number Rating ........ 14-5
• Fuel Identification.......................................... 14-6

Purity............................................................. 14-7

• Turbine Engine Fuels ....................................... 14-7
• Turbine Fuel Volatility.................................... 14-7
• Turbine Engine Fuel Types ........................... 14-8
• Turbine Engine Fuel Issues .......................... 14-9
• Aircraft Fuel Systems .......................................... 14-9
• Small Single-Engine Aircraft Fuel Systems...... 14-9
• Gravity Feed Systems................................... 14-9
• Pump Feed Systems................................... 14-10
• High-Wing Aircraft with Fuel Injection
• System ........................................................ 14-10
• Small Multiengine (Reciprocating) Aircraft
• Fuel Systems ..................................................14-11
• Low-Wing Twin.............................................14-11
• High-Wing Twin ........................................... 14-12
• Large Reciprocating-Engine Aircraft Fuel

Systems ......................................................... 14-12

• Jet Transport Aircraft Fuel Systems ............... 14-13
• Helicopter Fuel Systems ................................ 14-16
• Fuel System Components ................................. 14-18

Fuel Tanks ...................................................... 14-18

• Rigid Removable Fuel Tanks ...................... 14-18
• Bladder Fuel Tanks ..................................... 14-21
• Integral Fuel Tanks...................................... 14-21
• Fuel Lines & Fittings....................................... 14-23
• Fuel Valves .................................................... 14-24
• Hand-Operated Valves................................ 14-25
• Cone Valves ................................................ 14-25
• Poppet Valves ............................................. 14-26
• Manually-Operated Gate Valves ................. 14-26
• Motor-Operated Valves ............................... 14-26
• Solenoid-Operated Valves .......................... 14-27
• Fuel Pumps .................................................... 14-27
• Hand-Operated Fuel Pumps ....................... 14-27
• Centrifugal Boost Pumps ............................ 14-28
• Ejector Pumps............................................. 14-29
• Pulsating Electric Pumps ............................ 14-30
• Vane-Type Fuel Pumps............................... 14-31

Fuel Filters ..................................................... 14-32

• Fuel Heaters & Ice Prevention ....................... 14-35
• Fuel System Indicators................................... 14-36
• Fuel Quantity Indicating Systems ............... 14-36
• Fuel Flow Meters ........................................ 14-39
• Fuel Temperature Gauges .......................... 14-43
• Fuel Pressure Gauges ................................ 14-43
• Pressure Warning Signal ............................ 14-44
• Valve-In-Transit Indicator Lights ................. 14-44
• Fuel System Repair .......................................... 14-45
• Troubleshooting the Fuel System................... 14-45
• Location of Leaks & Defects ....................... 14-45
• Fuel Leak Classification .............................. 14-45
• Replacement of Gaskets, Seals, &
• Packings ..................................................... 14-46

• Fuel Tank Repair ............................................ 14-46
• Welded Tanks.............................................. 14-46
• Riveted Tanks.............................................. 14-47
• Soldered Tanks ........................................... 14-47
• Bladder Tanks ............................................. 14-47
• Integral Tanks.............................................. 14-47
• Fire Safety................................................... 14-48
• Fuel System Servicing....................................... 14-49
• Checking for Fuel System Contaminants....... 14-49
• Water........................................................... 14-50
• Solid Particle Contaminants........................ 14-50
• Surfactants.................................................. 14-51
• Microorganisms........................................... 14-51
• Foreign Fuel Contamination........................ 14-51
• Detection of Contaminants.......................... 14-52
• Fuel Contamination Control ........................ 14-54
• Fueling & Defueling Procedures........................ 14-55

Fueling ........................................................... 14-55

Defueling ........................................................ 14-56

• Fire Hazards When Fueling or Defueling ....... 14-57
• Chapter 15
• Ice & Rain Protection
• Ice Control Systems ............................................ 15-1

Icing Effects...................................................... 15-1

• Ice Detector System ............................................ 15-3
• Ice Prevention .................................................. 15-3
• Wing & Stabilizer Anti-Icing Systems................... 15-3
• Thermal Pneumatic Anti-icing .......................... 15-4
• Wing Anti-Ice (WAI) System.......................... 15-4
• Leading Edge Slat Anti-Ice System............... 15-5
• Thermal Electric Anti-Icing ............................... 15-9
• Chemical Anti-Icing .......................................... 15-9
• Wing & Stabilizer Deicing Systems ....................15-11
• Sources of Operating Air ................................ 15-12
• Turbine Engine Bleed Air ............................ 15-12

Pneumatic Deice Boot System for GA Aircraft 15-12 GA System Operation ................................. 15-12

• Deice System for Turboprop Aircraft .............. 15-13
• Deicing System Components......................... 15-15
• Wet-Type Engine-Driven Air Pump ............. 15-16
• Dry-Type Engine-Driven Air Pump .............. 15-16
• Oil Separator............................................... 15-16
• Control Valve............................................... 15-16
• Deflate Valve ............................................... 15-16
• Distributor Valve .......................................... 15-16
• Timer/Control Unit ....................................... 15-17
• Regulators & Relief Valves.......................... 15-17
• Manifold Assembly ...................................... 15-18

Inlet Filter .................................................... 15-18

Construction & Installation of Deice Boots ..... 15-18

Inspection, Maintenance, & Troubleshooting of Rubber Deicer Boot Systems..................... 15-20

• Operational Checks .................................... 15-20
• Adjustments ................................................ 15-20
• Troubleshooting .......................................... 15-20
• Inspection.................................................... 15-21
• Deice Boot Maintenance ................................ 15-21
• Electric Deice Boots ....................................... 15-22
• Propeller Deice System ..................................... 15-22
• Electrothermal Propeller Device System ....... 15-22
• Chemical Propeller Deice............................... 15-23
• Ground Deicing of Aircraft ................................. 15-23
• Frost Removal................................................ 15-24
• Deicing & Anti-icing of Transport Type

Aircraft......................................................... 15-24

• Ice & Snow Removal...................................... 15-25
• Rain Control Systems........................................ 15-26
• Windshield Wiper Systems ........................... 15-26
• Chemical Rain Repellent................................ 15-26
• Windshield Surface Seal Coating ............... 15-27
• Pneumatic Rain Removal Systems................ 15-27

Windshield Frost, Fog, & Ice Control Systems .. 15-28 Electric ........................................................... 15-28

Pneumatic ...................................................... 15-30

Chemical ........................................................ 15-30

• Water & Waste Tank Ice Prevention .................. 15-30
• Chapter 16
• Cabin Environmental Control Systems

Physiology of Flight ............................................. 16-1

• Composition of the Atmosphere ....................... 16-1
• Human Respiration & Circulation ..................... 16-1
• Oxygen & Hypoxia ........................................ 16-1
• Hyperventilation ............................................ 16-2
• Carbon Monoxide Poisoning......................... 16-2
• Aircraft Oxygen Systems ..................................... 16-3
• Forms of Oxygen & Characteristics ................. 16-3
• Gaseous Oxygen .......................................... 16-3
• Liquid Oxygen ............................................... 16-4
• Chemical or Solid Oxygen ........................... 16-4
• Onboard Oxygen Generating Systems
• (OBOGS) ...................................................... 16-5
• Oxygen Systems & Components ..................... 16-5
• Gaseous Oxygen Systems ........................... 16-5
• Chemical Oxygen Systems......................... 16-15
• LOX Systems .............................................. 16-16
• Oxygen System Servicing .............................. 16-16
• Servicing Gaseous Oxygen ........................ 16-16

• Filling LOX Systems.................................... 16-19
• Inspection of Masks & Hoses...................... 16-19
• Replacing Tubing, Valves, & Fittings........... 16-19
• Prevention of Oxygen Fires or Explosions ..... 16-20
• Oxygen System Inspection & Maintenance 16-20
• Aircraft Pressurization Systems......................... 16-21
• Pressure of the Atmosphere........................... 16-21
• Temperature & Altitude................................... 16-22
• Pressurization Terms...................................... 16-22
• Pressurization Issues ..................................... 16-23
• Sources of Pressurized Air............................. 16-24
• Reciprocating Engine Aircraft ..................... 16-24
• Turbine Engine Aircraft ............................... 16-25
• Control of Cabin Pressure ............................. 16-27
• Pressurization Modes ................................. 16-27
• Cabin Pressure Controller........................... 16-29
• Cabin Air Pressure Regulator & Outflow

Valve ........................................................... 16-30

Cabin Air Pressure Safety Valve Operation 16-31 Pressurization Gauges................................ 16-32

• Pressurization Operation ........................... 16-32
• Air Distribution............................................. 16-33
• Cabin Pressurization Troubleshooting ........ 16-34
• Air Conditioning Systems .................................. 16-34
• Air Cycle Air Conditioning............................... 16-34
• System Operation ....................................... 16-34
• Pneumatic System Supply .......................... 16-34
• Component Operation................................. 16-36
• Water Separator.......................................... 16-39
• Cabin Temperature Control System ............ 16-40
• Vapor Cycle Air Conditioning.......................... 16-42
• Theory of Refrigeration ............................... 16-42
• Vapor Cycle Air Conditioning System
• Components................................................ 16-44
• Vapor Cycle Air Conditioning Servicing
• Equipment................................................... 16-50
• System Servicing ........................................ 16-54
• Technician Certification ............................... 16-57

Aircraft Heaters.................................................. 16-57

• Bleed Air Systems .......................................... 16-57
• Electric Heating Systems ............................... 16-58
• Exhaust Shroud Heaters ................................ 16-58
• Combustion Heaters ...................................... 16-59
• Combustion Air System............................... 16-59
• Ventilating Air System ................................ 16-59
• Ignition System ........................................... 16-60
• Controls....................................................... 16-60
• Safety Features .......................................... 16-61
• Maintenance & Inspection........................... 16-61
• Chapter 17
• Fire Protection Systems

Introduction.......................................................... 17-1

Classes of Fires ............................................... 17-1

Requirements for Overheat & Fire Protection

Systems ........................................................... 17-1

• Fire Detection/Overheat Systems........................ 17-2
• Thermal Switch System ................................... 17-2
• Thermocouple System ..................................... 17-2
• Continuous-Loop Systems ............................... 17-3
• Fenwal System ............................................. 17-3
• Kidde System................................................ 17-3
• Pressure Type Sensor Responder Systems .... 17-6
• Pneumatic Continuous-Loop Systems.......... 17-6

Fire Zones ........................................................ 17-7

Smoke, Flame, & Carbon Monoxide Detection

Systems............................................................... 17-8

• Smoke Detectors.............................................. 17-8
• Light Refraction Type .................................... 17-8
• Ionization Type .............................................. 17-8
• Flame Detectors............................................... 17-8
• Carbon Monoxide Detectors ............................ 17-8
• Extinguishing Agents & Portable Fire

Extinguishers ....................................................... 17-9

• Halogenated Hydrocarbons ............................. 17-9
• Inert Cold Gases .............................................. 17-9
• Dry Powders................................................... 17-10

Water.............................................................. 17-10

• Flight Deck & Cabin Interiors ......................... 17-10
• Extinguisher Types...................................... 17-10
• Installed Fire Extinguishing Systems..................17-11
• CO₂ Fire Extinguishing Systems .....................17-11
• Halogenated Hydrocarbons Fire
• Extinguishing Systems ....................................17-11
• Containers ......................................................17-11
• Discharge Valves.............................................17-11
• Pressure Indication .........................................17-11
• Two-Way Check Valve ................................... 17-12
• Discharge Indicators ...................................... 17-12
• Thermal Discharge Indicator (Red Disc)..... 17-13
• Yellow Disc Discharge Indicator.................. 17-13

Fire Switch ..................................................... 17-13

• Cargo Fire Detection ......................................... 17-13
• Cargo Compartment Classification ................ 17-13
• Class A........................................................ 17-13
• Class B........................................................ 17-13
• Class C ....................................................... 17-13
• Class E........................................................ 17-14
• Cargo & Baggage Compartment Fire
• Detection & Extinguisher System................... 17-14
• Smoke Detector System ............................. 17-14

• Lavatory Smoke Detectors ................................ 17-16
• Lavatory Smoke Detector System ................. 17-16
• Lavatory Fire Extinguisher System ................ 17-17
• Fire Detection System Maintenance.................. 17-17
• Fire Detection System Troubleshooting............. 17-18
• Fire Extinguisher System Maintenance ............. 17-19
• Container Pressure Check ............................. 17-19
• Discharge Cartridges ..................................... 17-19
• Agent Containers ........................................... 17-20

Fire Prevention .................................................. 17-20

Glossary ..............................................................G-1

Index ......................................................................I-1