1-1-691.pdf

TO 1-1-691

TECHNICAL MANUAL

CLEANING AND CORROSION PREVENTION

AND CONTROL,

AEROSPACE AND NON-AEROSPACE EQUIPMENT

F42620-00-D-0038

FA8501-07-F-A080

DISTRIBUTION STATEMENT A - Approved for public release; distribution is unlimited. PA Case Number PA04-11-96. Submit recommended changes or problems with this Technical Order to 406 SCMS/GUEE. Questions concerning technical content shall be referred to AFRL/RXSSR.

Published Under Authority of the Secretary of the Air Force

2 NOVEMBER 2009 CHANGE 4 - 14 MARCH 2013

BASIC AND ALL CHANGES HAVE BEEN MERGED TO MAKE THIS A COMPLETE PUBLICATION.

Dates of issue for original and changed pages are:

Original. . . . . . . .0. . . .2 November 2009 Change . . . . . . . . 1. . . . . . .12 April 2010 Change . . . . . . . . 2 . . . . . . . 11 May 2011

Change . . . . . . . . 3. . . . .15 January 2013 Change . . . . . . . . 4. . . . . .14 March 2013

TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 392, CONSISTING OF THE FOLLOWING:

Page *Change No. No.

Page *Change No. No.

Page *Change No. No.

Title A i ii iii iv v vi vii viii - xii xiii xiv - xvi xvii xviii Blank 1-1 1-2 2-1 - 2-7 2-8 2-9 - 2-20 3-1 - 3-2 3-2.1 Added 3-2.2 Blank 3-3 3-4 3-5 - 3-6 3-7 3-8 - 3-10 3-11 3-12 3-13 3-14 3-15 3-16 3-17 - 3-19 3-20 3-21 3-22 3-23 - 3-41 3-42 - 3-43 3-44 - 3-46 3-47 - 3-48 3-48.1 - 3-48.2 Added 3-49 3-50 - 3-53

3-54 - 3-55 3-56 - 3-59 3-60 - 3-63 3-64 4-1 4-2 - 4-18 5-1 - 5-15 5-16 5-17 - 5-26 5-27 - 5-28 5-29 5-30 5-31 - 5-41 5-42 - 5-50 5-51 - 5-52 Added 6-1 - 6-2 6-3 - 6-5 6-6 - 6-31 6-32 6-33 - 6-36 7-1 - 7-2 7-3 7-4 - 7-6 7-7 7-8 - 7-9 7-10 7-11 - 7-13 7-14 7-15 - 7-19 7-20 Blank 8-1 - 8-5 8-6 8-7 - 8-8 8-9 8-10 - 8-11 8-12 - 8-14 8-14.1 Added 8-14.2 Blank 8-15 - 8-16 8-16.1 Added 8-16.2 Blank 8-17 8-18 Blank 9-1 - 9-3

9-4 Blank 10-1 - 10-3 Added 10-4 Blank A-1 - A-20 A-21 A-22 - A-57 A-58 Blank B-1 - B-18 B-19 - B-20 B-20.1 Added B-20.2 Blank B-21 - B-41 B-42 B-43 - B-45 B-46 Blank Glossary 1 - Glossary 4 Index 1 - Index 6 Index 7 Index 8 Index 8.1 Added Index 8.2 Blank Index 9 Index 10 Index 11 - Index 13 Index 14 Blank

TO 1-1-691

LIST OF EFFECTIVE PAGES

INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.

NOTE The portion of the text affected by the changes is indicated by a vertical line in the outer margins of the page. Changes to illustrations are indicated by shaded or screened areas, or by miniature pointing hands.

* Zero in this column indicates an original page.

A Change 4 USAF

TABLE OF CONTENTS

Chapter Page

LIST OF ILLUSTRATIONS . . . . . . . . . . . . . x

LIST OF TABLES . . . . . . . . . . . . . . . . . . . . xi

FOREWORD . . . . . . . . . . . . . . . . . . . . . . . xiii

SAFETY SUMMARY . . . . . . . . . . . . . . . . . xvii

1 INTRODUCTION . . . . . . . . . . . . . . . . . . . 1-1

1.1 CORROSION CONTROL

PROGRAM. . . . . . . . . . . . . . . 1-1

1.1.1 Training . . . . . . . . . . . . . . . . . . . 1-1

1.1.2 Maintenance . . . . . . . . . . . . . . . . 1-1

1.1.3 Facilities . . . . . . . . . . . . . . . . . . . 1-1

1.2 SAFETY. . . . . . . . . . . . . . . . . . . 1-1

1.2.1 Responsibility of Supervisors . . . . . 1-1

1.2.2 Materials Handling . . . . . . . . . . . . 1-1

1.3 MATERIALS . . . . . . . . . . . . . . . 1-2

2 CORROSION THEORY . . . . . . . . . . . . . . . 2-1

2.1 INTRODUCTION TO CORRO-

SION THEORY . . . . . . . . . . . . 2-1

2.2 DEFINITION OF

CORROSION . . . . . . . . . . . . . 2-1

2.3 CHEMICAL DEFINITIONS . . . . . 2-1

2.3.1 Atom . . . . . . . . . . . . . . . . . . . . . 2-1

2.3.2 Electron . . . . . . . . . . . . . . . . . . . 2-1

2.3.3 Ions . . . . . . . . . . . . . . . . . . . . . . 2-1

2.3.4 Electrolyte. . . . . . . . . . . . . . . . . . 2-1

2.4 THEORY OF CORROSION . . . . . 2-1

2.4.1 Anode . . . . . . . . . . . . . . . . . . . . 2-1

2.4.2 Cathode . . . . . . . . . . . . . . . . . . . 2-1

2.4.3 Electrolyte. . . . . . . . . . . . . . . . . . 2-1

2.4.4 Electrical Contact . . . . . . . . . . . . . 2-1

2.4.4.1 Elimination of Anode, Cathode, Electrolyte, or Electrical Contact. . . . . . . . . . . . . . . . . . 2-1

2.5 DEVELOPMENT OF

CORROSION . . . . . . . . . . . . . 2-2

2.5.1 Corrosion Under Painted

Surfaces . . . . . . . . . . . . . . . . . 2-2

2.6 FACTORS INFLUENCE

CORROSION . . . . . . . . . . . . . 2-2

2.6.1 Type of Metal . . . . . . . . . . . . . . . 2-2

2.6.2 Dissimilar Metal Coupling (Galvanic

Corrosion). . . . . . . . . . . . . . . . 2-2

2.6.3 Anode and Cathode Surface

Area. . . . . . . . . . . . . . . . . . . . 2-3

2.6.4 Temperature . . . . . . . . . . . . . . . . 2-4

2.6.5 Heat Treatment and Grain

Direction. . . . . . . . . . . . . . . . . 2-4

Chapter Page

2.6.6 Electrolytes . . . . . . . . . . . . . . . . . 2-4

2.6.7 Oxygen. . . . . . . . . . . . . . . . . . . . 2-5

2.6.8 Electrolyte Concentration. . . . . . . . 2-5

2.6.9 Biological Organisms . . . . . . . . . . 2-5

2.6.10 Mechanical Stress. . . . . . . . . . . . . 2-5

2.6.11 Time . . . . . . . . . . . . . . . . . . . . . 2-5

2.7 TYPES OF CORROSION . . . . . . . 2-5

2.7.1 Uniform Surface Corrosion . . . . . . 2-5

2.7.2 Galvanic Corrosion. . . . . . . . . . . . 2-5

2.7.3 Pitting Corrosion . . . . . . . . . . . . . 2-6

2.7.4 Intergranular Corrosion . . . . . . . . . 2-6

2.7.5 Exfoliation Corrosion . . . . . . . . . . 2-6

2.7.6 Crevice/Concentration Cell

Corrosion . . . . . . . . . . . . . . . . 2-6

2.7.6.1 Metal Ion Concentration Cells . . . . 2-7

2.7.6.2 Oxygen Concentration Cells. . . . . . 2-7

2.7.6.3 Active/Passive Cells . . . . . . . . . . . 2-8

2.7.6.4 Stress Corrosion Cracking . . . . . . . 2-8

2.7.6.5 Associated Hazards. . . . . . . . . . . . 2-8

2.7.6.6 Causes . . . . . . . . . . . . . . . . . . . . 2-8

2.7.7 Corrosion Fatigue. . . . . . . . . . . . . 2-8

2.7.8 Filiform Corrosion . . . . . . . . . . . . 2-8

2.7.9 Fretting Corrosion . . . . . . . . . . . . 2-10

2.7.10 High Temperature Oxidation (Hot

Corrosion). . . . . . . . . . . . . . . . 2-11

2.8 METALS AFFECTED BY

CORROSION . . . . . . . . . . . . . 2-11

2.8.1 Magnesium . . . . . . . . . . . . . . . . . 2-11

2.8.2 Steel. . . . . . . . . . . . . . . . . . . . . . 2-12

2.8.3 Aluminum. . . . . . . . . . . . . . . . . . 2-12

2.8.4 Anodized Aluminum. . . . . . . . . . . 2-12

2.8.5 Titanium . . . . . . . . . . . . . . . . . . . 2-12

2.8.6 Copper and Copper Alloys. . . . . . . 2-13

2.8.7 Cadmium . . . . . . . . . . . . . . . . . . 2-16

2.8.8 CRES/Stainless Steel . . . . . . . . . . 2-16

2.8.9 Nickel and Chromium. . . . . . . . . . 2-16

2.8.10 Silver, Platinum, and Gold. . . . . . . 2-16

2.8.11 Graphite/Carbon Fiber

Composites . . . . . . . . . . . . . . . 2-16

2.9 CORROSIVE

ENVIRONMENTS. . . . . . . . . . 2-16

2.9.1 Moisture . . . . . . . . . . . . . . . . . . . 2-16

2.9.1.1 Condensed Moisture . . . . . . . . . . . 2-17

2.9.1.2 Effect of Moisture . . . . . . . . . . . . 2-17

2.9.2 Temperature . . . . . . . . . . . . . . . . 2-17

2.9.3 Salt Atmospheres . . . . . . . . . . . . . 2-17

2.9.4 Ozone . . . . . . . . . . . . . . . . . . . . 2-17

2.9.5 Other Industrial Pollutants . . . . . . . 2-17

2.9.6 Sand, Dust, and Volcanic Ash. . . . . 2-18

2.9.7 Solar Radiation . . . . . . . . . . . . . . 2-18

2.9.8 Climate. . . . . . . . . . . . . . . . . . . . 2-18

2.9.8.1 Desert . . . . . . . . . . . . . . . . . . . . 2-18

2.9.8.2 Temperate Zones . . . . . . . . . . . . . 2-18

Change 4 i

2.9.8.3 Tropics . . . . . . . . . . . . . . . . . . . . 2-18

2.9.9 Factors of Influence in Tropical

Environments . . . . . . . . . . . . . 2-18

2.9.10 Manufacturing . . . . . . . . . . . . . . . 2-19

2.9.11 Storage . . . . . . . . . . . . . . . . . . . . 2-19

2.9.12 Shipment . . . . . . . . . . . . . . . . . . 2-19

2.9.13 Industrial and Ship Emitted Air

Pollutants . . . . . . . . . . . . . . . . 2-19

2.9.14 Animal Damage . . . . . . . . . . . . . . 2-19

2.9.15 Microorganisms . . . . . . . . . . . . . . 2-19

2.9.15.1 Bacteria . . . . . . . . . . . . . . . . . . . 2-19

2.9.15.2 Microbial Growth

Requirements. . . . . . . . . . . . . . 2-19

2.9.15.3 Microbial Nutrients. . . . . . . . . . . . 2-19

2.10 DEGRADATION OF

NON-METALS . . . . . . . . . . . . 2-20

2.11 PREVENTIVE

MAINTENANCE. . . . . . . . . . . 2-20

3 PREVENTIVE MAINTENANCE . . . . . . . . . 3-1

SECTION I INTRODUCTION. . . . . . . . . . . 3-1

3.1 PREVENTIVE MAINTENANCE

PROGRAM. . . . . . . . . . . . . . . 3-1

3.1.1 Preventive Maintenance. . . . . . . . . 3-1

SECTION II CLEANING . . . . . . . . . . . . . . 3-6

3.2 INTRODUCTION . . . . . . . . . . . . 3-6

3.2.1 Reasons for Cleaning . . . . . . . . . . 3-6

3.2.2 When to Accomplish Work . . . . . . 3-7

3.2.2.1 Cleaning Frequency . . . . . . . . . . . 3-7

3.2.3 Aircraft Clear Water Rinse (CWR)

Requirements. . . . . . . . . . . . . . 3-7

3.2.3.1 Aircraft Stationed Within 1.25 Miles

of Salt Water . . . . . . . . . . . . . . 3-7

3.2.3.2 Low Level (Below 3,000 Feet) Salt

Water Runway Approach . . . . . . 3-8

3.2.3.3 Search, Rescue, and Recovery Mis-

sions and Low-Level Flight Op-erations Under 3,000 Feet . . . . . 3-8

3.2.4 Immediate Cleaning . . . . . . . . . . . 3-8

3.2.5 Deployed Aircraft Wash

Requirements. . . . . . . . . . . . . . 3-8

3.3 CLEANING COMPOUNDS . . . . . 3-9

3.3.1 Alkaline Cleaners . . . . . . . . . . . . . 3-9

3.3.1.1 MIL-PRF-87937, Type I and MIL-

PRF-85570, Type I . . . . . . . . . . 3-9

3.3.1.2 MIL-PRF-87937, Type IV and MIL-

PRF-85570, Type II . . . . . . . . . 3-9

3.3.1.3 MIL-PRF-87937, Type III and MIL-

PRF-85570, Type V . . . . . . . . . 3-9

3.3.1.4 MIL-PRF-87937, Type IV . . . . . . . 3-9

3.3.1.5 MIL-PRF-85570, Type IV . . . . . . . 3-9

Chapter Page

3.3.1.6 MIL-PRF-85570, Type III . . . . . . . 3-10

3.3.2 Solvent Emulsion and Aqueous

Cleaners for Turbine Engine Gas Path and General Area Cleaning . . . . . . . . . . . . . . . . . 3-10

3.3.2.1 MIL-PRF-85704, Type I . . . . . . . . 3-10

3.3.2.2 MIL-C-43616, Class 1 and Class

1A . . . . . . . . . . . . . . . . . . . . . 3-10

3.3.3 Aqueous Parts Washer Cleaning

Solutions. . . . . . . . . . . . . . . . . 3-10

3.3.4 Solvents . . . . . . . . . . . . . . . . . . . 3-11

3.3.4.1 MIL-PRF-680 Degreasing Solvent

and A-A-59601 Dry Cleaning and Degreasing Solvent, P-D-680 . . . . . . . . . . . . . . . . . 3-11

3.3.4.2 TT-I-735 Isopropyl Alcohol . . . . . . 3-11

3.3.4.3 ASTM D 740 Methyl Ethyl Ketone

(MEK) . . . . . . . . . . . . . . . . . . 3-11

3.3.4.4 Aliphatic Naphtha . . . . . . . . . . . . 3-11

3.3.4.5 MIL-T-81772, Type I (Polyurethane)

and Type II (Epoxy) Thinner. . . . . . . . . . . . . . . . . . 3-11

3.3.5 Miscellaneous Cleaning Agents . . . 3-11

3.3.6 Steam Cleaning . . . . . . . . . . . . . . 3-12

3.3.7 Dilution . . . . . . . . . . . . . . . . . . . 3-12

3.4 CLEANING EQUIPMENT . . . . . . 3-29

3.4.1 High Pressure/Hot Water Wash

Equipment. . . . . . . . . . . . . . . . 3-29

3.4.2 Portable, 15 Gallon, Foam Generat-

ing, Cleaning Unit . . . . . . . . . . 3-29

3.4.3 Portable, 45 Gallon, Foam Generat-

ing Cleaning Unit. . . . . . . . . . . 3-32

3.4.4 Turbine Engine Compressor Clean-

ing Equipment . . . . . . . . . . . . . 3-33

3.4.5 Miscellaneous Large Cleaning

Equipment. . . . . . . . . . . . . . . . 3-33

3.4.6 Spray Cleaning Guns for

Solvents . . . . . . . . . . . . . . . . . 3-33

3.4.7 Pneumatic Vacuum Cleaner . . . . . . 3-33

3.4.8 Universal Wash Unit . . . . . . . . . . . 3-33

3.4.9 Aqueous Parts Washers . . . . . . . . . 3-34

3.4.9.1 Effectiveness of Cleaning in Aque-

ous Parts Washers. . . . . . . . . . . 3-34

3.4.9.2 Determination of Capacity of the

Aqueous Parts Washer. . . . . . . . 3-35

3.4.10 Miscellaneous Equipment . . . . . . . 3-35

3.5 CLEANING PROCEDURES . . . . . 3-36

3.5.1 Warnings and Cautions . . . . . . . . . 3-36

3.5.1.1 Electrical . . . . . . . . . . . . . . . . . . 3-36

3.5.1.2 Personal Protection . . . . . . . . . . . . 3-37

3.5.1.3 Use of Solvents . . . . . . . . . . . . . . 3-37

3.5.1.4 Use of Cleaners . . . . . . . . . . . . . . 3-37

3.5.1.5 Water Intrusion . . . . . . . . . . . . . . 3-38

3.5.1.6 Oxygen Systems . . . . . . . . . . . . . 3-38

3.5.1.7 Special Precautions. . . . . . . . . . . . 3-38

TO 1-1-691

TABLE OF CONTENTS - CONTINUED

ii

3.5.1.8 Preparation for Cleaning . . . . . . . . 3-38

3.5.1.9 Pre-Wash Lubrication Point

Protection . . . . . . . . . . . . . . . . 3-38

3.5.1.10 Water/Cleaning Compound

Intrusion . . . . . . . . . . . . . . . . . 3-38

3.5.2 Cleaning Methods . . . . . . . . . . . . 3-39

3.5.2.1 Alkaline Detergent and/or Solvent

Emulsion Cleaning, Painted and Unpainted Surfaces; Fresh Water Readily Available . . . . . . . . . . . 3-39

3.5.2.2 Waterless Wipe Down. . . . . . . . . . 3-42

3.5.2.3 Alkaline Detergent Cleaning with

Only Limited Fresh Water Available . . . . . . . . . . . . . . . . 3-42

3.5.2.4 Solvent Cleaning . . . . . . . . . . . . . 3-42

3.5.2.5 Interior Cleaning (Vacuum) . . . . . . 3-43

3.5.2.6 Low Temperature Cleaning . . . . . . 3-45

3.5.3 Clear Water Rinsing of Aircraft . . . 3-46

3.5.3.1 Requirements. . . . . . . . . . . . . . . . 3-46

3.5.3.2 Taxi-Through Rinsing . . . . . . . . . . 3-46

3.5.3.3 Manual Application . . . . . . . . . . . 3-46

3.5.3.4 Rinsing Procedures . . . . . . . . . . . . 3-46

3.5.4 Post Cleaning Procedures . . . . . . . 3-46

3.5.4.1 Post Cleaning Task Sequence . . . . . 3-46

3.5.5 Treatment and Disposal of Wash

Rack Waste . . . . . . . . . . . . . . . 3-47

3.5.6 Fungus Growth Removal . . . . . . . . 3-47

3.5.7 Soil Barriers . . . . . . . . . . . . . . . . 3-48.2

3.5.7.1 Materials. . . . . . . . . . . . . . . . . . . 3-49

3.5.7.2 Application . . . . . . . . . . . . . . . . . 3-49

3.5.7.3 Removal . . . . . . . . . . . . . . . . . . . 3-49

3.5.8 Bird Strike Cleaning . . . . . . . . . . . 3-49

3.5.8.1 Bird Strike Cleanup . . . . . . . . . . . 3-50

3.5.8.2 Internal/Enclosed (Water Sensitive)

Area Cleanup . . . . . . . . . . . . . 3-51

3.5.9 Bodily Fluids Contamination

Cleanup . . . . . . . . . . . . . . . . . 3-51

3.5.9.1 Bodily Fluid Containment During

Flight . . . . . . . . . . . . . . . . . . . 3-51

3.5.9.2 Bodily Fluid Cleanup . . . . . . . . . . 3-51

3.5.9.3 Disinfection of Contaminated

Areas . . . . . . . . . . . . . . . . . . . 3-52

SECTION III LUBRICATION . . . . . . . . . . . 3-53

3.6 INTRODUCTION . . . . . . . . . . . . 3-53

3.6.1 Conventional Lubricants . . . . . . . . 3-53

3.6.2 Solid Film Lubricants . . . . . . . . . . 3-54

3.6.2.1 Surface Preparation for Solid Film

Lubricants . . . . . . . . . . . . . . . . 3-54

3.6.2.2 SAE AS5272

(MIL-PRF-46010) . . . . . . . . . . 3-54

3.6.2.3 MIL-PRF-46147 and/or

MIL-L-23398 . . . . . . . . . . . . . 3-54

Chapter Page

3.6.3 Application of Conventional

Lubricants . . . . . . . . . . . . . . . . 3-54

3.6.3.1 Grease Gun Application . . . . . . . . 3-55

SECTION IV PRESERVATION . . . . . . . . . . 3-56

3.7 INTRODUCTION . . . . . . . . . . . . 3-56

3.7.1 Operational Preservation . . . . . . . . 3-56

3.7.2 Non-Operational Preservation. . . . . 3-56

3.7.3 Types of CPC’s . . . . . . . . . . . . . . 3-56

3.7.3.1 Water Displacing Compounds. . . . . 3-56

3.7.3.2 Non-Water Displacing

Compounds . . . . . . . . . . . . . . . 3-56

3.7.4 Time Limitations of CPC’s . . . . . . 3-57

3.7.5 Description of CPC’s . . . . . . . . . . 3-57

3.7.5.1 MIL-PRF-81309, Corrosion Preven-

tive Compound, Water Displac-ing, Ultra Thin Film and MIL-L- 87177, Lubricants, Corrosion Preventive, Water Displacing, Synthetic. . . . . . . . . . . . . . . . . 3-59

3.7.5.2 MIL-DTL-85054, Corrosion Preven-

tive Compound, Clear . . . . . . . . 3-59

3.7.5.3 MIL-PRF-16173, Corrosion Preven-

tive Compound, Solvent Cutback, Cold Application . . . . . . . . . . . 3-60

3.7.5.4 MIL-PRF-63460, Lubricant, Cleaner, and Preservative for Weapons and Weapon Systems . . . . . . . . . . . 3-63

3.7.5.5 MIL-PRF-32033, Lubricating Oil, General Purpose, Preservative, Water Displacing . . . . . . . . . . . 3-63

3.7.6 Preservation of Specific Areas . . . . 3-64

3.7.7 Preservation Application

Methods . . . . . . . . . . . . . . . . . 3-64

3.7.7.1 Brushing . . . . . . . . . . . . . . . . . . . 3-64

3.7.7.2 Dipping . . . . . . . . . . . . . . . . . . . 3-64

3.7.7.3 Spraying . . . . . . . . . . . . . . . . . . . 3-64

3.8 APPLICATION OF POLISH AND

WAX . . . . . . . . . . . . . . . . . . . 3-64

4 INSPECTION AND CORROSION PRONE

AREAS. . . . . . . . . . . . . . . . . . . . . . . . . 4-1

SECTION I INSPECTION . . . . . . . . . . . . . 4-1

4.1 Purpose . . . . . . . . . . . . . . . . . . . 4-1

4.1.1 Responsibility . . . . . . . . . . . . . . . 4-1

4.1.2 Frequency of Inspections . . . . . . . . 4-1

4.1.3 General Inspections . . . . . . . . . . . 4-1

4.1.4 Detailed Inspections . . . . . . . . . . . 4-1

4.2 INSPECTION METHODS. . . . . . . 4-1

TO 1-1-691

Change 2 iii

4.2.1 Visual inspection . . . . . . . . . . . . . 4-1

4.2.1.1 Evidence of Corrosion . . . . . . . . . 4-2

4.2.2 Depth Gauge . . . . . . . . . . . . . . . . 4-2

4.2.2.1 Use of Depth Gauges . . . . . . . . . . 4-2

4.2.3 Visual Inspection with a

Borescope . . . . . . . . . . . . . . . . 4-3

4.2.4 Optical Depth Micrometers . . . . . . 4-3

4.2.4.1 Analog Mechanical Read-Out

Type. . . . . . . . . . . . . . . . . . . . 4-4

4.2.4.2 Digital Read-Out Type . . . . . . . . . 4-4

4.2.5 Fluorescent Penetrant

Inspection . . . . . . . . . . . . . . . . 4-5

4.2.5.1 Limitations of Penetrant

Inspection . . . . . . . . . . . . . . . . 4-5

4.2.6 Eddy Current Inspection . . . . . . . . 4-6

4.2.7 Ultrasonic Inspection . . . . . . . . . . 4-6

4.2.8 Radiographic Inspection . . . . . . . . 4-6

4.3 EVALUATION OF CORROSION

DAMAGE. . . . . . . . . . . . . . . . 4-6

4.4 DEGREES OF CORROSION . . . . 4-6

4.4.1 Light Corrosion . . . . . . . . . . . . . . 4-9

4.4.2 Moderate Corrosion . . . . . . . . . . . 4-9

4.4.3 Severe Corrosion . . . . . . . . . . . . . 4-9

SECTION II CORROSION PRONE AREAS . 4-9

4.5 COMMON AREAS . . . . . . . . . . . 4-9

4.5.1 Fasteners. . . . . . . . . . . . . . . . . . . 4-9

4.5.2 Faying Surfaces and Crevices. . . . . 4-9

4.5.3 Spot Welded Assemblies . . . . . . . . 4-9

4.5.4 Engine Exhaust and Gun Gas Im-

pingement Areas . . . . . . . . . . . 4-10

4.5.5 Wheel Wells and Landing Gear . . . 4-10

4.5.6 Flap and Slat Recesses . . . . . . . . . 4-11

4.5.7 Engine Frontal Areas and Air Inlet

Ducts . . . . . . . . . . . . . . . . . . . 4-11

4.5.8 Wing/Fin-Fold Joints and Wing and

Control Surface Leading Edges . . . . . . . . . . . . . . . . . . . 4-14

4.5.9 Hinges . . . . . . . . . . . . . . . . . . . . 4-14

4.5.10 Control Cables. . . . . . . . . . . . . . . 4-14

4.5.11 Relief Tube Outlets. . . . . . . . . . . . 4-14

4.5.12 Water Entrapment Areas . . . . . . . . 4-14

4.5.13 Bilge Areas . . . . . . . . . . . . . . . . . 4-14

4.5.14 Battery Compartments and Battery

Vent Openings . . . . . . . . . . . . . 4-14

4.5.15 Magnesium Parts . . . . . . . . . . . . . 4-15

4.5.16 Electrical Connectors and Other

Components . . . . . . . . . . . . . . 4-15

5 CORROSION REMOVAL AND SURFACE

TREATMENT . . . . . . . . . . . . . . . . . . . . 5-1

SECTION I CORROSION REMOVAL . . . . . 5-1

Chapter Page

5.1 PURPOSE. . . . . . . . . . . . . . . . . . 5-1

5.2 RESPONSIBILITY. . . . . . . . . . . . 5-1

5.3 CORRECTIVE ACTIONS. . . . . . . 5-1

5.4 PAINT REMOVAL. . . . . . . . . . . . 5-1

5.5 CORROSION REMOVAL. . . . . . . 5-1

5.5.1 Mechanical Methods . . . . . . . . . . . 5-2

5.5.1.1 Mechanical Compatibility . . . . . . . 5-2

5.5.1.2 Material Compatibility . . . . . . . . . 5-2

5.5.2 Non-Powered Tools and

Materials. . . . . . . . . . . . . . . . . 5-2

5.5.2.1 Abrasive Mats . . . . . . . . . . . . . . . 5-2

5.5.2.2 Abrasive Cloth. . . . . . . . . . . . . . . 5-2

5.5.2.3 Abrasive Paper . . . . . . . . . . . . . . 5-2

5.5.2.4 Metallic Wools. . . . . . . . . . . . . . . 5-2

5.5.2.5 Wire Brushes. . . . . . . . . . . . . . . . 5-3

5.5.2.6 Pumice Powder . . . . . . . . . . . . . . 5-3

5.5.2.7 Scrapers . . . . . . . . . . . . . . . . . . . 5-3

5.5.3 Power Tools and Materials. . . . . . . 5-4

5.5.3.1 Pneumatic Drill Motors . . . . . . . . . 5-5

5.5.3.2 Pneumatic Sanders . . . . . . . . . . . . 5-5

5.5.3.3 3M Co. Scotch-BriteTM Finishing

Flap Brushes . . . . . . . . . . . . . . 5-6

5.5.3.4 Abrasive Flap Wheels . . . . . . . . . . 5-6

5.5.3.5 Abrasive Cloth and Paper . . . . . . . 5-6

5.5.3.6 Powered Wire Brushes . . . . . . . . . 5-6

5.5.3.7 Rotary Files. . . . . . . . . . . . . . . . . 5-7

5.5.3.8 3M Co. RolocTM Disc and Radial

Disc Abrasives. . . . . . . . . . . . . 5-7

5.5.4 Abrasive Blasting . . . . . . . . . . . . . 5-7

5.5.4.1 Conventional Equipment . . . . . . . . 5-8

5.5.4.2 Portable Vacuum Abrasive Blast

Equipment. . . . . . . . . . . . . . . . 5-9

5.5.4.3 Wet Abrasive Blasting

Equipment. . . . . . . . . . . . . . . . 5-9

5.6 SURFACE FINISH. . . . . . . . . . . . 5-11

5.7 PITTING ON CRITICAL

STRUCTURE . . . . . . . . . . . . . 5-11

5.8 CORROSION REMOVAL

PROCEDURES-MECHANICAL 5-11

5.8.1 Warnings and Cautions . . . . . . . . . 5-11

5.8.1.1 Personal Protection . . . . . . . . . . . . 5-12

5.8.1.2 Mechanical Damage . . . . . . . . . . . 5-14

5.8.2 Non-Powered Mechanical Corrosion

Removal . . . . . . . . . . . . . . . . . 5-14

5.8.3 Powered Mechanical Corrosion

Removal . . . . . . . . . . . . . . . . . 5-15

5.8.4 Abrasive Blasting Corrosion

Removal . . . . . . . . . . . . . . . . . 5-15

5.8.4.1 Abrasive Blasting Procedures . . . . . 5-15

5.9 CORROSION

REMOVAL-CHEMICAL. . . . . . 5-17

5.9.1 Aluminum Alloys . . . . . . . . . . . . . 5-17

5.9.1.1 Preparation . . . . . . . . . . . . . . . . . 5-17

TO 1-1-691

iv

5.9.1.2 Chemical Corrosion Removal Mate-

rials for Aluminum Alloys . . . . . 5-17

5.9.1.3 Application of Organic

Coatings . . . . . . . . . . . . . . . . . 5-20

5.9.2 Magnesium Alloys . . . . . . . . . . . . 5-20

5.9.2.1 Preparation . . . . . . . . . . . . . . . . . 5-20

5.9.2.2 Chemical Corrosion Removal Mate-

rials for Magnesium Alloys . . . . 5-20

5.9.2.3 Application of Organic

Coatings . . . . . . . . . . . . . . . . . 5-21

5.9.3 Ferrous Metal (Steel) Alloys Other

Than Stainless Steels

(CRES). . . . . . . . . . . . . . . . . . 5-21

5.9.3.1 Preparation . . . . . . . . . . . . . . . . . 5-21

5.9.3.2 Chemical Corrosion Removing Ma-

terials for Ferrous Metal Alloys Other Than Stainless Steels

(CRES). . . . . . . . . . . . . . . . . . 5-22

5.9.3.3 Application of Organic

Coatings . . . . . . . . . . . . . . . . . 5-26

5.9.4 Stainless Steel (CRES) and Nickel

Based Alloys . . . . . . . . . . . . . . 5-26

5.9.4.1 Preparation . . . . . . . . . . . . . . . . . 5-26

5.9.4.2 Chemical Corrosion Removing Ma-

terials for Stainless Steel (CRES) and Nickel Based Alloys . . . . . . 5-27

5.9.4.3 Passivation of Stainless Steel

(CRES) Alloy Parts . . . . . . . . . 5-30

5.9.4.4 Application of Organic

Coatings . . . . . . . . . . . . . . . . . 5-30

5.9.5 Copper and Copper Based

Alloys . . . . . . . . . . . . . . . . . . 5-30

5.9.5.1 Preparation . . . . . . . . . . . . . . . . . 5-30

5.9.5.2 Chemical Corrosion Removing Ma-

terials for Copper and Copper Based Alloys . . . . . . . . . . . . . . 5-30

5.9.5.3 Application of Organic

Coatings . . . . . . . . . . . . . . . . . 5-32

5.9.6 Titanium and Titanium Based

Alloys . . . . . . . . . . . . . . . . . . 5-32

5.9.6.1 Preparation . . . . . . . . . . . . . . . . . 5-32

5.9.6.2 Chemical Corrosion Removal Mate-

rials for Titanium and Titanium Based Alloys . . . . . . . . . . . . . . 5-32

5.9.6.3 Application of Organic

Coatings . . . . . . . . . . . . . . . . . 5-33

5.9.7 Plated and Phosphated Surfaces . . . 5-33

5.9.7.1 Preparation . . . . . . . . . . . . . . . . . 5-34

5.9.7.2 Treatment of Corroded Areas on

Cadmium or Zinc Plated Surfaces . . . . . . . . . . . . . . . . . 5-34

5.9.7.3 Treatment of Corroded Areas on

Plated Surfaces Except Cadmium or Zinc Plating. . . . . . . . . . . . . 5-35

Chapter Page

5.9.7.4 Treatment of Corroded Areas on

Phosphated Surfaces . . . . . . . . . 5-35

5.9.7.5 Application of Organic

Coatings . . . . . . . . . . . . . . . . . 5-35

SECTION II SURFACE TREATMENT . . . . . 5-36

5.10 PURPOSE. . . . . . . . . . . . . . . . . . 5-36

5.10.1 Chemical Prepaint Treatments . . . . 5-36

5.10.1.1 MIL-DTL-81706 Chemical Conver-

sion Materials for Coating Alumi-num and Aluminum Alloys . . . . 5-36

5.10.1.2 SAE AMS-M-3171 (MIL-M-3171),

Type VI Magnesium Alloy, Pro-cesses for Pretreatment and Pre-vention of Corrosion on; Chromic Acid Brush-On Treatment . . . . . 5-37

5.10.2 Surface Preparation. . . . . . . . . . . . 5-38

5.10.3 Precautions . . . . . . . . . . . . . . . . . 5-38

5.10.4 Application of Surface

Treatments . . . . . . . . . . . . . . . 5-39

5.10.4.1 Conversion Coating Using TNP

Pens . . . . . . . . . . . . . . . . . . . . 5-39

5.10.5 Notes on Conversion Coating/Sur-

face Treatment . . . . . . . . . . . . . 5-40

5.10.6 Post Treatment. . . . . . . . . . . . . . . 5-40

5.10.7 Temporary Preservation. . . . . . . . . 5-41

SECTION III SHOT

PEENING/ROTO-PEENING . . . . . . . . . . . 5-42

5.11 PEENING OF METAL

SURFACES. . . . . . . . . . . . . . . 5-42

5.11.1 Types of Peening . . . . . . . . . . . . . 5-43

5.11.1.1 Shot Peening and Glass or Ceramic

Bead Peening . . . . . . . . . . . . . 5-43

5.11.1.2 Roto-Peening (Rotary Flap

Peening) . . . . . . . . . . . . . . . . . 5-43

5.11.2 Roto-Peening (Rotary Flap Peening)

Procedures . . . . . . . . . . . . . . . 5-44

5.11.2.1 Equipment. . . . . . . . . . . . . . . . . . 5-44

5.11.2.2 Surface Preparation Procedure . . . . 5-44

5.11.3 Determining Peening/Intensity . . . . 5-45

5.11.3.1 Arc Height Conversion . . . . . . . . . 5-45

5.11.4 Peening Process Preparation. . . . . . 5-45

5.11.4.1 Rotary Tool Speed . . . . . . . . . . . . 5-45

5.11.4.2 Flap Operation. . . . . . . . . . . . . . . 5-45

5.11.4.3 Coverage . . . . . . . . . . . . . . . . . . 5-45

5.11.4.4 Part Peening Time . . . . . . . . . . . . 5-45

5.11.5 Post Peening Surface Finish . . . . . . 5-45

6 SEALANTS . . . . . . . . . . . . . . . . . . . . . . . 6-1

6.1 PURPOSE. . . . . . . . . . . . . . . . . . 6-1

TO 1-1-691

Change 3 v

6.2 APPLICATIONS . . . . . . . . . . . . . 6-1

6.3 SEALING COMPOUNDS. . . . . . . 6-1

6.3.1 Sealant Packaging . . . . . . . . . . . . 6-1

6.3.1.1 Two-Part Kit (KT) . . . . . . . . . . . . 6-1

6.3.1.2 Cartridge (CA). . . . . . . . . . . . . . . 6-1

6.3.1.3 Pre-Mixed and Frozen (PMF). . . . . 6-1

6.3.2 Polysulfide, Polyurethane, and Poly-

thioether Sealing Compounds . . . . . . . . . . . . . . . 6-1

6.3.3 Silicone Sealing Compounds . . . . . 6-2

6.3.4 Adhesion Promoters . . . . . . . . . . . 6-2

6.3.5 SAE AMS 3255 Oil and Water Re-

sistant, Expanded Polytetrafluoro-ethylene Sealing Tape (EPTFE) Skyflex . . . . . . . . . . . . . . . . . . 6-2

6.3.6 Av-Dec® Polyurethane Sealant

Tapes and Two Component Sealants . . . . . . . . . . . . . . . . . 6-2

6.4 EQUIPMENT . . . . . . . . . . . . . . . 6-2

6.4.1 Sealant Gun. . . . . . . . . . . . . . . . . 6-2

6.4.2 Application Nozzles . . . . . . . . . . . 6-3

6.4.3 Injection Gun . . . . . . . . . . . . . . . 6-3

6.4.4 Sealant Kits (Semkits®) . . . . . . . . 6-3

6.4.5 Sealant Removal and Application

Tools . . . . . . . . . . . . . . . . . . . 6-3

6.5 SEALANT MIXING. . . . . . . . . . . 6-3

6.5.1 Application Life. . . . . . . . . . . . . . 6-3

6.5.1.1 Enhancement of Sealant Curing . . . 6-4

6.5.2 Storage Instructions . . . . . . . . . . . 6-4

6.5.3 Mixing MIL-PRF-81733, Type III

Sprayable Sealant Coating . . . . . 6-5

6.6 SEALANT APPLICATION

PROCEDURES . . . . . . . . . . . . 6-22

6.6.1 Cleaning . . . . . . . . . . . . . . . . . . . 6-22

6.6.2 Masking . . . . . . . . . . . . . . . . . . . 6-22

6.6.3 Adhesion Promoters . . . . . . . . . . . 6-25

6.6.4 Brush Spatula or Caulking Gun

Application . . . . . . . . . . . . . . . 6-25

6.6.5 Spray Gun Application . . . . . . . . . 6-26

6.6.6 Peel and Stick Application; SAE

AMS 3255 EPTFE Skyflex® and Av-Dec® HT3935-7 and HT3000 Sealing Tapes . . . . . . . . . . . . . 6-26

6.7 SEALING OF SPECIFIC

AREAS . . . . . . . . . . . . . . . . . 6-27

6.7.1 Faying Surface Sealing . . . . . . . . . 6-27

6.7.2 Fillet Sealing . . . . . . . . . . . . . . . . 6-28

6.7.3 Injection Sealing . . . . . . . . . . . . . 6-28

6.7.4 Fastener Sealing. . . . . . . . . . . . . . 6-29

6.7.5 Integral Fuel Cells/Tanks and Re-

movable Fuel Tanks . . . . . . . . . 6-29

6.7.6 Form-In-Place (FIP) Gasket Sealant

Repair . . . . . . . . . . . . . . . . . . 6-29

Chapter Page

6.7.7 SAE AMS 3255 EPTFE (Skyflex®)

and Av-Dec® HT3000 and HT3935-7 Sealing Tape Gasket Repair . . . . . . . . . . . . . . . . . . 6-30

6.7.8 External Aircraft Structure . . . . . . . 6-31

6.7.9 Depressions . . . . . . . . . . . . . . . . . 6-31

6.7.10 Damaged Sealant . . . . . . . . . . . . . 6-31

6.7.11 Extensive Repair . . . . . . . . . . . . . 6-32

6.7.12 High Temperature Areas . . . . . . . . 6-32

6.7.13 Low Temperature Curing. . . . . . . . 6-32

6.8 STORAGE/SHELF LIFE CON-

TROL OF SEALANTS . . . . . . . 6-32

7 TREATMENT OF SPECIFIC AREAS . . . . . . 7-1

7.1 INTRODUCTION . . . . . . . . . . . . 7-1

7.2 BATTERY COMPARTMENTS,

BOXES, AND ADJACENT

AREAS . . . . . . . . . . . . . . . . . 7-1

7.2.1 Preparation of Solutions for Clean-

ing and Neutralizing Battery Electrolytes . . . . . . . . . . . . . . . 7-1

7.2.1.1 Litmus Indicating Solution. . . . . . . 7-1

7.2.1.2 Bromothymol Blue Indicating

Solution . . . . . . . . . . . . . . . . . 7-2

7.2.1.3 Sodium Bicarbonate Neutralizing

Solution . . . . . . . . . . . . . . . . . 7-2

7.2.1.4 Boric Acid and/or Monobasic So-

dium Phosphate Neutralizing Solutions. . . . . . . . . . . . . . . . . 7-2

7.2.2 Cleaning and Neutralizing

Procedures . . . . . . . . . . . . . . . 7-2

7.2.3 Paint Systems . . . . . . . . . . . . . . . 7-2

7.3 RELIEF TUBE AREAS . . . . . . . . 7-2

7.4 CORROSION TREATMENT FOR

STEEL CABLES . . . . . . . . . . . 7-3

7.5 PIANO TYPE HINGES . . . . . . . . 7-3

7.6 INTEGRAL AND EXTERNAL

FUEL TANKS AND DROP

TANKS . . . . . . . . . . . . . . . . . 7-3

7.6.1 Corrosion Removal and Rework of

Pitted Areas of Integral Fuel Tanks . . . . . . . . . . . . . . . . . . . 7-3

7.6.2 Removal of Corrosion and Rework

of Aluminum External Fuel Tanks/Drop Tanks. . . . . . . . . . . 7-4

7.6.2.1 Tank Exterior Surfaces . . . . . . . . . 7-4

7.6.2.2 Tank Interior Surfaces . . . . . . . . . . 7-5

7.7 FAYING SURFACES AND AT-

TACHMENT POINTS . . . . . . . 7-5

7.7.1 Faying Surfaces, Joints, and

Seams . . . . . . . . . . . . . . . . . . 7-5

TO 1-1-691

vi Change 2

7.7.2 Attaching Parts and Hardware . . . . 7-5

7.7.3 Severely Corroded (Rusted)

Hardware . . . . . . . . . . . . . . . . 7-6

7.8 NATURAL AND SYNTHETIC

RUBBER PARTS. . . . . . . . . . . 7-7

7.9 POTABLE WATER TANKS . . . . . 7-7

7.10 SURFACES AND COMPONENTS

EXPOSED TO EXHAUST

GASES, GUN GASES, AND

ROCKET BLAST . . . . . . . . . . 7-7

7.11 ELECTRICAL AND ELECTRONIC

EQUIPMENT . . . . . . . . . . . . . 7-7

7.11.1 Grounding and Bonding

Connections. . . . . . . . . . . . . . . 7-7

7.11.2 Conduit and Junction Boxes. . . . . . 7-7

7.11.3 Wires and Cables . . . . . . . . . . . . . 7-7

7.11.4 Corrosion Protection for Electrical

Connectors, Lead-Ins, etc . . . . . 7-7

7.11.5 Moisture and Fungus Proofing of

Electrical and Electronic Equipment. . . . . . . . . . . . . . . . 7-7

7.11.6 Antennas. . . . . . . . . . . . . . . . . . . 7-7

7.12 STRUCTURAL TUBING MEM-

BERS AND ASSEMBLIES . . . . 7-8

7.12.1 Structural Aluminum Alloy

Tubing . . . . . . . . . . . . . . . . . . 7-8

7.12.2 Structural Magnesium Alloy

Tubing . . . . . . . . . . . . . . . . . . 7-8

7.12.3 Structural Copper Alloys, Stainless

Steel (CRES) Alloys, and Heat Resistant Alloy Tubing . . . . . . . 7-8

7.12.4 Structural Carbon Steel Tubing. . . . 7-8

7.12.4.1 Exterior . . . . . . . . . . . . . . . . . . . 7-8

7.12.4.2 Interior . . . . . . . . . . . . . . . . . . . . 7-8

7.12.4.3 Sealing . . . . . . . . . . . . . . . . . . . . 7-8

7.13 NON-STRUCTURAL TUBING

MEMBERS AND

ASSEMBLIES. . . . . . . . . . . . . 7-8

7.13.1 Aluminum Alloy Tubing . . . . . . . . 7-8

7.13.2 Stainless Steel (CRES) Tubing . . . . 7-9

7.13.3 Cadmium Plated Steel Tubing . . . . 7-10

7.13.4 Special Instructions for Tubing Fit-

tings and Sleeves . . . . . . . . . . . 7-10

7.13.5 Removable Installations. . . . . . . . . 7-10

7.14 CORROSION REMOVAL FROM

THIN METAL (0.0625 INCH

THICKNESS AND LESS). . . . . 7-11

7.15 AIR INTAKE DUCTS FOR JET

AIRCRAFT. . . . . . . . . . . . . . . 7-11

Chapter Page

7.16 CLOSELY COILED SPRINGS . . . 7-11

7.17 CORROSION PREVENTION ON

ASSEMBLIES AND PARTS RE-

MOVED FROM AIRCRAFT

DURING MAINTENANCE, 30

DAY SHORT TERM STORAGE,

AND OVER 30 DAY LONG

TERM STORAGE

REQUIREMENTS . . . . . . . . . . 7-11

7.17.1 Short Term Storage. . . . . . . . . . . . 7-11

7.17.2 Long Term Storage. . . . . . . . . . . . 7-12

7.18 DEPLETED URANIUM

COUNTERWEIGHTS. . . . . . . . 7-12

7.18.1 Corrosion and Finish Damage Treat-

ment Procedures. . . . . . . . . . . . 7-13

7.19 MONEL RIVETS. . . . . . . . . . . . . 7-14

7.20 BERYLLIUM-COPPER ALLOYS,

BERYLLIUM-ALUMINUM AL-

LOYS, AND BERYLLIUM

OXIDE. . . . . . . . . . . . . . . . . . 7-14

7.20.1 Corrosion Removal and

Treatment . . . . . . . . . . . . . . . . 7-14

7.20.2 Depot Maintenance. . . . . . . . . . . . 7-14

7.21 EMI SEALS AND GASKETS . . . . 7-15

7.21.1 Treatment of EMI Seals and

Gaskets. . . . . . . . . . . . . . . . . . 7-15

8 EMERGENCY PROCEDURES . . . . . . . . . . 8-1

8.1 PURPOSE. . . . . . . . . . . . . . . . . . 8-1

8.2 RESPONSIBILITY. . . . . . . . . . . . 8-1

8.3 EMERGENCY

PREPARATIONS . . . . . . . . . . . 8-1

8.3.1 Priority Removal List of Equipment

and/or Components. . . . . . . . . . 8-1

8.3.2 Emergency Reclamation Team . . . . 8-2

8.3.3 Emergency Reclamation

Equipment. . . . . . . . . . . . . . . . 8-2

8.3.4 Production Planning . . . . . . . . . . . 8-2

8.4 GENERAL PROCEDURES . . . . . . 8-2

8.4.1 Removal of Contaminated Installed

Equipment. . . . . . . . . . . . . . . . 8-8

8.4.2 Disassembly/Removal of

Components . . . . . . . . . . . . . . 8-8

8.4.2.1 Aircraft Involved in Water

Crashes. . . . . . . . . . . . . . . . . . 8-8

8.4.3 Clean . . . . . . . . . . . . . . . . . . . . . 8-8

8.4.4 Tagging . . . . . . . . . . . . . . . . . . . 8-8

TO 1-1-691

vii

8.5 GENERAL CLEANING

PROCEDURES . . . . . . . . . . . . 8-8

8.5.1 Primary Method . . . . . . . . . . . . . . 8-9

8.5.2 Alternate Methods . . . . . . . . . . . . 8-9

8.5.2.1 Method One (Preferred) . . . . . . . . 8-9

8.5.2.2 Method Two (Alternate) . . . . . . . . 8-9

8.5.3 Removing Fire Extinguishing Pow-

der (O-D-1407 Potassium Bicar-bonate [Purple K{PKP}], Sodium Bicarbonate, Ammonium Phos-phate Monobasic) and/or Other Dry Chemical Agents . . . . . . . . 8-10

8.5.4 Removing MIL-F-24385 Aqueous

Film Forming Foam (AFFF) Fire Extinguishing Agent and Other Synthetic Based Foaming Agents Including High-Expansion (Hi- Ex) Foams . . . . . . . . . . . . . . . 8-10

8.5.5 Removal of Carbon Dioxide (CO2), HFC-125, or Halon Fire Extin-guishing Agents . . . . . . . . . . . . 8-11

8.5.6 Removal of Protein Type Foam and

Soda-Acid Fire Extinguishing Agents . . . . . . . . . . . . . . . . . . 8-11

8.5.7 Treatment After Landing on a

Foamed Runway . . . . . . . . . . . 8-11

8.5.8 Treatment After Exposure to Volca-

nic Ash. . . . . . . . . . . . . . . . . . 8-11

8.6 SPECIFIC INTERNAL

AREAS . . . . . . . . . . . . . . . . . 8-12

8.6.1 Aircraft Cockpit Area . . . . . . . . . . 8-12

8.6.2 Aircraft Ejection Seats . . . . . . . . . 8-12

8.6.3 Avionic, Electronic, and Electrical

Equipment. . . . . . . . . . . . . . . . 8-13

8.6.4 Photographic Equipment . . . . . . . . 8-13

8.6.5 Graphite or Carbon Fiber/Epoxy, Boron Fiber/Epoxy, and Tungsten Fiber/Epoxy Composite Materials. . . . . . . . . . . . . . . . . 8-13

8.6.5.1 Cleanup . . . . . . . . . . . . . . . . . . . 8-13

8.7 SPECIFIC EXTERNAL AREAS OF

AIRCRAFT. . . . . . . . . . . . . . . 8-14

8.7.1 Airframes . . . . . . . . . . . . . . . . . . 8-14

8.7.2 Antennas. . . . . . . . . . . . . . . . . . . 8-14

8.7.3 Reciprocating Engines. . . . . . . . . . 8-14

8.7.4 Turbine Engines . . . . . . . . . . . . . . 8-15

8.7.5 Treatment for Engines Which Have

Ingested Fire Extinguishing Pow-der (Potassium Bicarbonate [Purple K{PKP}], Sodium Bicar-bonate, Ammonium Phosphate Monobasic) and/or Synthetic Foaming Agents (AFFF, Hi-Ex, AR) . . . . . . . . . . . . . . . . . . . . 8-15

Chapter Page

8.7.6 Helicopter Transmission, Rotor

Head, and Rotor Hub . . . . . . . . 8-16

8.7.6.1 External Surface

Contamination . . . . . . . . . . . . . 8-16

8.7.6.2 Internal Surface Contamination. . . . 8-16

8.7.7 Helicopter Main and Tail Rotor

Blades . . . . . . . . . . . . . . . . . . 8-16

8.7.8 Armament . . . . . . . . . . . . . . . . . . 8-16

8.7.8.1 Safety Precautions . . . . . . . . . . . . 8-16.1

8.7.8.2 Cleaning Procedure. . . . . . . . . . . . 8-16.1

8.7.9 Aircraft Fuel Systems . . . . . . . . . . 8-17

9 SOUTHWEST ASIA ENVIRONMENTS . . . . 9-1

9.1 INTRODUCTION . . . . . . . . . . . . 9-1

9.1.1 Climatic Conditions . . . . . . . . . . . 9-1

9.1.2 Aircraft Wash . . . . . . . . . . . . . . . 9-1

9.1.3 Aircraft Clear Water Rinse

(CWR) . . . . . . . . . . . . . . . . . . 9-1

9.1.4 Effects of Desert Environment . . . . 9-1

9.2 PRE-DEPLOYMENT

RECOMMENDATIONS . . . . . . 9-1

9.3 RECOMMENDED ACTIONS

WHILE DEPLOYED . . . . . . . . 9-2

9.3.1 High Efficiency Particulate Air

(HEPA) Filtration . . . . . . . . . . . 9-2

9.3.1.1 Pneumatic Wheeled Units . . . . . . . 9-2

9.3.1.2 Pneumatic Backpack. . . . . . . . . . . 9-2

9.3.2 Areas to be Checked and

Cleaned . . . . . . . . . . . . . . . . . 9-2

9.4 POST DEPLOYMENT . . . . . . . . . 9-3

9.5 CORROSION PREVENTIVE

COMPOUNDS (CPC’s) . . . . . . 9-3

9.5.1 Recommended CPC’s . . . . . . . . . . 9-3

10 REMOTELY PILOTED AIRCRAFT CORRO-

SION PREVENTION . . . . . . . . . . . . . . . 10-1

10.1 REMOTELY PILOTED AIRCRAFT

(RPA). . . . . . . . . . . . . . . . . . . 10-1

10.1.1 Definition . . . . . . . . . . . . . . . . . . 10-1

10.2 CORROSION CONTROL

PROGRAM. . . . . . . . . . . . . . . 10-1

10.3 CARBON FIBER COMPOSITES

AND CORROSION . . . . . . . . . 10-1

10.3.1 Corrosion Concerns . . . . . . . . . . . 10-1

10.3.2 Moisture Absorption . . . . . . . . . . . 10-2

10.4 CORROSIVE

ENVIRONMENTS. . . . . . . . . . 10-2

10.5 APPROVED CLEANING

COMPOUNDS . . . . . . . . . . . . 10-2

10.5.1 MIL-PRF-87937, Type IV and MIL-

PRF-85570, Type II . . . . . . . . . 10-2

TO 1-1-691

viii Change 4

10.5.2 MIL-PRF-87937, Type III and MIL-

PRF-85570, Type V . . . . . . . . . 10-2

10.5.3 MIL-C-43616, Class 1A Emulsion

Cleaner. . . . . . . . . . . . . . . . . . 10-2

10.6 AIRCRAFT CLEANING. . . . . . . . 10-2

10.6.1 Frequency of Cleaning . . . . . . . . . 10-3

10.6.1.1 Assembled RPA . . . . . . . . . . . . . . 10-3

10.6.1.2 Disassembled and Container Stored

RPAs . . . . . . . . . . . . . . . . . . . 10-3

10.6.2 Wipe Down or Spot Cleaning. . . . . 10-3

10.6.2.1 Wipe Down or Spot Cleaning

Method. . . . . . . . . . . . . . . . . . 10-3

APPENDIX A CONSUMABLE MATERIALS. A-1

A.1 INTRODUCTION . . . . . . . . . . . . A-1

A.1.1 Shelf Life . . . . . . . . . . . . . . . . . . A-1 A.1.2 Consumable Materials

Containers. . . . . . . . . . . . . . . . A-1

Chapter Page

A.1.3 Local Purchase . . . . . . . . . . . . . . A-1 A.1.4 Local Environmental Laws and

Regulations . . . . . . . . . . . . . . . A-1 A.1.5 Unit of Issue Codes . . . . . . . . . . . A-1

APPENDIX B EQUIPMENT FOR CLEAN-

ING AND CORROSION PREVENTION

AND CONTROL. . . . . . . . . . . . . . . . . . . . B-1

B.1 INTRODUCTION . . . . . . . . . . . . B-1

B.1.1 Unit of Issue Codes . . . . . . . . . . . B-1

GLOSSARY . . . . . . . . . . . . . . . . . . . . . Glossary 1

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . Index 1

TO 1-1-691

Change 4 ix

LIST OF ILLUSTRATIONS

Number PageTitle

2-1 Simplified Corrosion Cell . . . . . . . . . . . 2-2 2-2 Elimination of Corrosion by Application of an Organic Film to a Metal Surface . . . . . . . . . . . . . . . . . . . . . . 2-3

2-3 Effect of Sea Water on Galvanic Corrosion . . . . . . . . . . . . . . . . . . . . 2-3

2-4 Galvanic Corrosion in a Flashlight Battery . . . . . . . . . . . . . . . . . . . . . . 2-4

2-5 Effect of Area Relationship in Dissimilar Metal Contacts . . . . . . . . . . . . . . . . . 2-4

2-6 Galvanic Corrosion of Magnesium Adja-cent to a Steel Fastener . . . . . . . . . . . 2-5

2-7 Pitting of an Aluminum Wing Assembly . . . . . . . . . . . . . . . . . . . . 2-6

2-8 Cross-Section of Corrosion Pits . . . . . . . 2-6 2-9 Cross-Section of 7075-T6 Aluminum

Alloy . . . . . . . . . . . . . . . . . . . . . . . 2-7 2-10 Grain Structure of a Corroding Aluminum

Surface . . . . . . . . . . . . . . . . . . . . . . 2-7 2-11 Intergranular Corrosion of 7075-T6 Alumi-num Adjacent to Steel Fastener. . . . . . 2-7 2-12 Example of Exfoliation . . . . . . . . . . . . . 2-7 2-13 Another Example of Exfoliation . . . . . . . 2-7 2-14 Concentration Cell Corrosion . . . . . . . . . 2-9 2-15 Stress Corrosion Cracking . . . . . . . . . . . 2-9 2-16 Galvanic Series of Metals and Alloys in

Sea Water . . . . . . . . . . . . . . . . . . . . 2-10 2-17 Filiform Corrosion Found Under Paint

Coating on a Magnesium Panel. . . . . . 2-11 2-18 Schematic of the Development of Filiform

Corrosion on an Aluminum Alloy . . . . 2-11 2-19 Magnesium Corrosion Products. . . . . . . . 2-12 2-20 Steel Corrosion Products (Rust) . . . . . . . 2-13 2-21 Aluminum Surface Corrosion

Products . . . . . . . . . . . . . . . . . . . . . 2-14 2-22 Cadmium Plated Surface Conditions . . . . 2-15 2-23 Failed Chromium Plating . . . . . . . . . . . . 2-17 3-1 Foam Generating Cleaning Unit (15

Gallons) . . . . . . . . . . . . . . . . . . . . . 3-30 3-2 Foam Generating Cleaning Unit (45

Gallons) . . . . . . . . . . . . . . . . . . . . . 3-31 3-3 Universal Wash Unit . . . . . . . . . . . . . . . 3-32 3-4 Top Loading Type . . . . . . . . . . . . . . . . 3-36 3-5 Front Loading Type . . . . . . . . . . . . . . . 3-36 3-6 Use of Aircraft Washing Applicator . . . . . 3-40 3-7 Aircraft Cleaning Procedure . . . . . . . . . . 3-41 3-8 Automatic Water Spray Nozzle . . . . . . . . 3-44 4-1 Depth Dimension of Corrosion Pits . . . . . 4-3 4-2 Fiber Optic Borescope. . . . . . . . . . . . . . 4-4 4-3 Optical Depth Micrometer (Analog Me-chanical Read Out Type) . . . . . . . . . . 4-7

Number PageTitle

4-4 Optical Depth Micrometer (Digital Read Out Type) . . . . . . . . . . . . . . . . . . . . 4-8

4-5 Typical Use of a Straight Edge to Deter-mine if Suspect Areas Have Been Pre-viously Reworked . . . . . . . . . . . . . . . 4-9

4-6 Corrosion Around Fasteners . . . . . . . . . . 4-10 4-7 Galvanic Corrosion of Aluminum Adjacent to Steel Fasteners . . . . . . . . . . . . . . . 4-10 4-8 Spot Weld Corrosion . . . . . . . . . . . . . . . 4-11 4-9 Spot Welded Skin Corrosion

Mechanism . . . . . . . . . . . . . . . . . . . 4-11 4-10 Gun Blast Area Corrosion Points. . . . . . . 4-12 4-11 Exhaust Trail Area Corrosion Points . . . . 4-12 4-12 F-15 Nose Landing Gear Wheel Well . . . 4-12 4-13 Flaps Lowered to Expose Recess

Areas . . . . . . . . . . . . . . . . . . . . . . . 4-12 4-14 Reciprocating Engine Frontal Area Corro-sion Points. . . . . . . . . . . . . . . . . . . . 4-13 4-15 Jet Engine Frontal Area Corrosion

Points . . . . . . . . . . . . . . . . . . . . . . . 4-13 4-16 Corrosion Prone Point of Air Inlet. . . . . . 4-13 4-17 Corrosion in Air Intake Duct . . . . . . . . . 4-14 4-18 Wing Fold Joint . . . . . . . . . . . . . . . . . . 4-15 4-19 Hinge Corrosion Points . . . . . . . . . . . . . 4-16 4-20 Piano Hinge Lugs . . . . . . . . . . . . . . . . . 4-16 4-21 Control Cables . . . . . . . . . . . . . . . . . . . 4-16 4-22 Personnel Relief Tube Vent . . . . . . . . . . 4-16 4-23 Common Water Entrapment Areas. . . . . . 4-17 4-24 Bilge Areas . . . . . . . . . . . . . . . . . . . . . 4-17 4-25 Battery Compartment . . . . . . . . . . . . . . 4-18 5-1 3M Co. Scotch-BriteTM Flap Brush and

Mandrel . . . . . . . . . . . . . . . . . . . . . 5-4 5-2 Abrasive Flap Wheels with Spindle

Mount. . . . . . . . . . . . . . . . . . . . . . . 5-4 5-3 3M Co. Radial Bristle Disc . . . . . . . . . . 5-5 5-4 3M Co. Roloc Discs . . . . . . . . . . . . . . . 5-6 5-5 3M Co. Inline Bristle Disc . . . . . . . . . . . 5-7 5-6 Abrasive Blasting Equipment . . . . . . . . . 5-10 5-7 Shaping Reworked Areas . . . . . . . . . . . . 5-13 5-8 Acceptable Clean-Up of Pitting Corrosion on Critical Structure . . . . . . . . . . . . . 5-13 5-9 Limited Clearance. . . . . . . . . . . . . . . . . 5-14 5-10 A Water-Break Free Surface Compared with One with Breaks . . . . . . . . . . . . 5-40 5-11 Magnetic Almen Strip Holder . . . . . . . . . 5-46 5-12 “A” Test Strip Magnetic to SAE J442

Stripholder Arc Height Conversion Graph . . . . . . . . . . . . . . . . . . . . . . . 5-47

5-13 “A” Test Strip Arc Height Magnetic to SAE J442 Stripholder Conversion Chart, 0.001 Inch . . . . . . . . . . . . . . . 5-48 x Change 4

5-14 “N” Arc Height Magnetic to SAE J442 Stripholder Conversion Graph. . . . . . . 5-49

5-15 “N” Arc Height Magnetic to SAE J442 Stripholder Conversion Chart, 0.001 Inch . . . . . . . . . . . . . . . . . . . . . . . . 5-50

5-16 First Trial Estimate of Intensity for “A” Test Strip . . . . . . . . . . . . . . . . . . . . 5-51

5-17 Example of Coverage . . . . . . . . . . . . . . 5-52 6-1 Pneumatic Sealant Gun . . . . . . . . . . . . . 6-6 6-2 Sealant Application Nozzles . . . . . . . . . . 6-7 6-3 Countersink Application Nozzles. . . . . . . 6-8 6-4 Rivet Application Nozzles . . . . . . . . . . . 6-9 6-5 Sealant and Adhesive Smoothing

Tools . . . . . . . . . . . . . . . . . . . . . . . 6-10 6-6 Sealant Injection Guns. . . . . . . . . . . . . . 6-11 6-7 Injection Style Semkit®. . . . . . . . . . . . . 6-12 6-8 Non-Metallic Spatula . . . . . . . . . . . . . . 6-26 6-9 Faying Surface Sealing . . . . . . . . . . . . . 6-28 6-10 Typical Fillet Seal. . . . . . . . . . . . . . . . . 6-29 6-11 Typical Injection Seal . . . . . . . . . . . . . . 6-30 6-12 Typical Methods of Sealing Fasteners . . . 6-31

Number PageTitle

6-13 Typical Lap Skin Sealing . . . . . . . . . . . . 6-33 6-14 Sealing Procedures for Typical Aircraft

Fitting. . . . . . . . . . . . . . . . . . . . . . . 6-34 6-15 Typical Spar Cap Sealing. . . . . . . . . . . . 6-35 6-16 Sealing of Access Doors . . . . . . . . . . . . 6-36 7-1 Beryllium-Copper Spiral Contact with En-vironmental Fluorosilicone Seal . . . . . 7-16 7-2 Dorsal Longeron EMI Seal . . . . . . . . . . 7-17 7-3 Stainless Steel (CRES) EMI Screen. . . . . 7-17 7-4 Bonding Cable from Airframe to Graphite/

Epoxy Avionics Bay Door . . . . . . . . . 7-18 7-5 EMI Bonding Washers in an Avionics

Bay . . . . . . . . . . . . . . . . . . . . . . . . 7-19 9-1 Soil Makeup in the SWA Area . . . . . . . . 9-2 9-2 Global Dust Producing Regions . . . . . . . 9-2 9-3 Open Circuit Board. . . . . . . . . . . . . . . . 9-3 B-1 Back Mounted Full Facepiece

Respirator . . . . . . . . . . . . . . . . . . . . B-43 B-2 Front Mounted Full Facepiece

Respirator . . . . . . . . . . . . . . . . . . . . B-44 B-3 Hooded Air Respirator System . . . . . . . . B-45

LIST OF TABLES

Number PageTitle

2-1 Corrosion of Metals - Type of Attack and Appearance of Corrosion Products . . . 2-15

3-1 Aircraft Wash Intervals . . . . . . . . . . . . . 3-2 3-2 Cleaning of Specific Areas and

Components. . . . . . . . . . . . . . . . . . . 3-12 3-3 Deicing/Anti-Icing Fluid Residue Inspec-tion and Cleaning Procedures . . . . . . . 3-28 3-4 Recommended Dilution of Low Tempera-ture Cleaner . . . . . . . . . . . . . . . . . . . 3-45 3-4.1 Fungus Growth Removal from Organic

Materials . . . . . . . . . . . . . . . . . . . . . 3-47 3-5 Common Military Greases and Their

Uses . . . . . . . . . . . . . . . . . . . . . . . . 3-55 3-6 Time Limitations for CPC’s . . . . . . . . . . 3-57 3-7 Corrosion Preventive Compounds . . . . . . 3-57 3-8 Preservation of Specific Areas and

Components. . . . . . . . . . . . . . . . . . . 3-60 4-1 NDI Inspection Tools for Various Types of

Corrosion . . . . . . . . . . . . . . . . . . . . 4-2 5-1 Grades of Abrasive Mats . . . . . . . . . . . . 5-3 5-2 Grades of Steel Wool . . . . . . . . . . . . . . 5-3 5-3 Recommended Powered Abrasives for

Corrosion Removal . . . . . . . . . . . . . . 5-8 5-4 Recommended Non-Powered Abrasives for

Corrosion Removal . . . . . . . . . . . . . . 5-10 5-5 Typical Chemical Corrosion Removal Pro-cedures for Aluminum Alloy Parts and Assemblies . . . . . . . . . . . . . . . . . . . 5-18

Number PageTitle

5-6 Typical Chemical Corrosion Removal Pro-cedures for Magnesium Alloys . . . . . . 5-22

5-7 Typical Chemical Corrosion Removal Pro-cedures for Ferrous Metals Other Than Stainless Steel (CRES) . . . . . . . . . . . 5-26

5-8 Typical Chemical Corrosion Removal Pro-cedures for Stainless Steel (CRES) and Nickel Based Alloys . . . . . . . . . . . . . 5-28

5-9 Control of Corrosion Removal/Pickling Action of Nitric-Acid-Hydrofluoric Solutions . . . . . . . . . . . . . . . . . . . . . 5-30

5-10 Typical Chemical Corrosion Removal Pro-cedures for Copper and Copper Alloys. . . . . . . . . . . . . . . . . . . . . . . 5-32

5-11 Typical Chemical Corrosion Removal of Titanium and Titanium Base Alloys. . . . . . . . . . . . . . . . . . . . . . . 5-34

5-12 Typical Chemical Corrosion Removal Pro-cedures for Plated and Phosphated Surfaces . . . . . . . . . . . . . . . . . . . . . 5-36

5-13 Prepaint Treatments for Metal Surfaces . . . . . . . . . . . . . . . . . . . . . 5-41

5-14 Tool Speed Operation Requirements . . . . 5-44 6-1 Sealing Compounds . . . . . . . . . . . . . . . 6-13 6-2 Time Requirements for Sealants When

Used at 75° F (24° C) and 50%

RH. . . . . . . . . . . . . . . . . . . . . . . . . 6-22

TO 1-1-691

LIST OF ILLUSTRATIONS - CONTINUED

Change 4 xi

8-1 Priority Guide for Emergency Treatment of Aircraft, Missiles, and Equipment . . . . . . . . . . . . . . . . . . . . 8-3

8-2 Suggested List of Emergency Reclamation Items . . . . . . . . . . . . . . . . . . . . . . . 8-3

10-1 Air Force RPA Tiers . . . . . . . . . . . . . . . 10-1

Number PageTitle

A-1 Unit of Issue Codes . . . . . . . . . . . . . . . A-1 A-2 Consumable Materials . . . . . . . . . . . . . . A-2 B-1 Unit of Issue Codes . . . . . . . . . . . . . . . B-1 B-2 Equipment for Cleaning and Corrosion

Prevention and Control . . . . . . . . . . . B-2

TO 1-1-691

LIST OF TABLES - CONTINUED

xii Change 4

FOREWORD

1 PURPOSE.

The purpose of this manual is to provide information on materials and procedures for the prevention and repair of corrosion damage to aircraft and missile weapon systems and related equipment. Supervisory and maintenance personnel shall use this manual as a guide for all corrosion control and maintenance efforts. Contractors who maintain and repair corrosion of aircraft, missiles, and related equipment shall also use this manual. Use this manual in conjunction with and in support of the appropriate systems specific aircraft, missile, or equipment technical orders (TO’s). In the case of a conflict between this manual and a systems specific air-craft, missile, or equipment manual, the system specific manual shall take precedence over this manual. Paragraph 6 lists related technical publications used by personnel in-volved in cleaning and corrosion control.

2 SCOPE.

The material in this manual provides basic cleaning, corro-sion prevention and control, and corrective maintenance…