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Inspection, Prevention, Control, and Repair of Corrosion on Avionics Equipment

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Inspection, Prevention, Control, and Repair of Corrosion on Avionics Equipment AC 43-206 DATE: 05/30/01 INSPECTION, PREVENTION, CONTROL, AND REPAIR OF CORROSION ON AVIONICS EQUIPMENT Initiated by: AFS-300 Subject: INSPECTION, PREVENTION, Date: 05-30-01 AC 43-206 CONTROL, AND REPAIR OF Initiated By: AFS-300 CORROSION ON AVIONICS EQUIPMENT 1. PURPOSE. This advisory circular (AC) contains methods, techniques, and practices acceptable to the Administrator for inspection, prevention, control, and repair of corrosion on avionics systems and equipment. The procedures in this AC are an acceptable means, but not the only means, of inspecting, preventing, controlling, and repairing avionics corrosion. This AC is intended to supplement the original equipment manufacturer’s (OEM) published recommendations, or for use when there are no OEM repair or maintenance instructions. Operators having their own FAA-approved maintenance program may also include the guidance contained in this AC in the development of such programs. 2. BACKGROUND. Today’s avionics systems assume a major responsibility for the performance, safety, and success of commercial and general aviation. These avionics systems control the operation of flight-critical and flight-essential equipment, including navigation, communications, power distribution, flight and engine controls, displays, and wiring. The reliability of these complex and often interrelated systems in any environment is critical for safe operation. Nicholas A. Sabatini Director, Flight Standards Service 05/30/01 AC 43-206 CONTENTS Section Page CHAPTER 1. GENERAL...............................................................................................................1 1. Purpose..................................................................................................................................1 2. Background ...........................................................................................................................1 3. Military Specifications..........................................................................................................1 4. Scope and Arrangement........................................................................................................2 5. Environmental Concerns.......................................................................................................3 6. Safety ....................................................................................................................................3 7. thru 200. RESERVED ..........................................................................................................4 CHAPTER 2. CORROSION PRINCIPLES AND DESCRIPTION...............................................5 201. Overview...........................................................................................................................5 202. Corrosion Theory..............................................................................................................5 203. Factors Influencing Corrosion...........................................................................................6 204. Environmental Conditions ..............................................................................................10 205. Corrosive Conditions ......................................................................................................10 206. Types of Corrosion..........................................................................................................14 207. thru 300. RESERVED ....................................................................................................17 CHAPTER 3. CORROSION CONTROL PROGRAM AND INSPECTION..............................19 301. General............................................................................................................................19 302. Preventive Maintenance Program ...................................................................................19 303. Corrosion-Prone Areas....................................................................................................20 304. Inspection Process...........................................................................................................25 305. Recognizing Avionics Corrosion....................................................................................28 306. Corrosion Effects on Nonmetals.....................................................................................31 307. Corrosion Effects of Solder Flux ....................................................................................32 308. Effects of Microbial Attack.............................................................................................33 309. Effects of Insect and Animal Attack ...............................................................................33 310. Effects of Dust/Lint Accumulation.................................................................................38 311. thru 400. RESERVED ....................................................................................................38 CHAPTER 4. CLEANING AND PRESERVATION ..................................................................39 401. General............................................................................................................................39 402. Avionics Corrosion Cleaning Facility.............................................................................39 403. Materials and Support Equipment Requirements ...........................................................39 404. Avionics Cleaning Equipment ........................................................................................43 405. Avionics Cleaning Procedures........................................................................................46 Page i AC 43-206 05/30/01 Section Page 406. Drying Equipment and Procedures .................................................................................52 407. Preservation.....................................................................................................................55 408. Lubricants........................................................................................................................59 409. Packaging, Handling, and Storage ..................................................................................59 410. thru 500. RESERVED ....................................................................................................62 CHAPTER 5. CORROSION REMOVAL, SURFACE TREATMENT, PAINTING, AND SEALING ...............................................................................63 501. General............................................................................................................................63 502. Corrosion Removal Materials and Equipment................................................................63 503. Surface Treatment...........................................................................................................64 504. Protective Coatings .........................................................................................................67 505. Encapsulates....................................................................................................................72 506. thru 600. RESERVED ....................................................................................................85 CHAPTER 6. TREATMENT OF SPECIFIC AVIONICS EQUIPMENT ...................................87 601. General............................................................................................................................87 602. Repair of Avionics Equipment Housings, Mounting Racks, and Storage Hardware.....................................................................................................87 603. Repair of Avionics Systems, Equipment, and Components ...........................................98 604. thru 700. RESERVED ..................................................................................................128 CHAPTER 7. CORROSION CONTROL MEASURES FOR ELECTRICAL BONDING/GROUNDING..................................................................................129 701. Electrical Bonding/Ground Connections ......................................................................129 702. Bonding/Grounding Surface Preparation......................................................................130 703. thru 800. RESERVED ..................................................................................................138 CHAPTER 8. EFFECT AND TREATMENT OF CORROSION ON ELECTROMAGNETIC INTERFERENCE SHIELDING DEVICES.............................................................................................................139 801. Definition/Description of EMI......................................................................................139 802. EMI Standards, Test Requirements, and Documents ...................................................139 803. Aircraft System EMI Protection Requirements ............................................................140 804. Types of EMI Protection...............................................................................................142 805. EMI Protection Maintenance ........................................................................................147 806. thru 900. RESERVED ..................................................................................................150 Page ii 05/30/01 AC 43-206 Section Page CHAPTER 9. EFFECT AND TREATMENT OF CORROSION ON ELECTROSTATIC
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