Par 1005 Page 186
(c) For all avionics components and electrical connectors, apply (by spraying) a coating of Water-Displacing Corrosion Preventive Compound, Ultra-Thin Film, conforming to MIL-PRF-81309, Type III.
1006. OPERATOR LEVEL EMERGENCY CLEANING PROCEDURES.
WARNING: Ensure that all electrical power internal and external to the aircraft or equipment is disconnected. Disconnect all batteries. Ensure that all safety devices are installed.
a. Removable Avionics Equipment. Equipment or components that are removed at the operator’s facility should be inspected for smoke, heat, fire damage, or damaged seals.
Equipment and components that are forwarded to the operator’s facility should have their background researched to determine the extent, cause of damage, and previous cleaning and preservation procedures that may have been accomplished. Most avionics equipment contain dissimilar metals and particular attention should be paid to these areas for evidence of corrosion during the inspection. If contaminated avionics equipment can be forwarded immediately and inducted into an avionics repair station for expeditious cleaning, inspection, and repair of damage, then the drying and preservation identified in paragraph 1005 is not necessary. When immediate induction into the avionics repair station is not possible, proceed with the drying and preservation procedures of paragraph 1005. When the aircraft or equipment has been exposed to saltwater intrusion, fire extinguishing agents, or water immersion, the aircraft or equipment should be cleaned, dried, and preserved as follows:
(1) Electrically ground the aircraft or equipment.
WARNING: Ensure that all electrical power sources, including batteries, are disconnected from the aircraft or equipment and all other powered systems (hydraulic, pneumatic, and mechanical) are deactivated.
(2) Ensure all external electrical power and batteries are disconnected. Remove hydraulic and pneumatic power and install safety struts in hydraulic, pneumatic, and mechanic actuated devices.
(3) Remove installed avionics equipment. Removal priority should be determined from the developed priority list for emergency reclamation of equipment or as directed by the emergency reclamation team leader. See paragraph 1003 and Table 10-1.
(4) Remove all covers, modules, and components authorized at this level.
(5) Tilt the equipment back and forth to allow accumulated water or other liquids to drain off.
(6) Examine the individual items thoroughly for evidence of saltwater, fire extinguishing agents, smoke, oily films, corrosion, etc.
(7) Items that are contaminated should be cleaned using the primary cleaning method described in subparagraph 1004b.
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(8) If the primary method cannot be performed for lack of available fresh water, use one of the alternate cleaning methods described in subparagraph 1004c.
(9) Tag all components, identifying date, cleaning and drying method, and type of preservation applied.
b. Removal and Cleaning of Identification and Modification Plates. Identification and modification plates can trap contaminants, allowing corrosion to start. The following procedures are applicable for the cleaning of identification and modification plates:
(1) Visually examine for the presence and the condition of a fillet seal along the edge of the identification and modification plates. Identification and modification plates with sealed edges that appear intact and undamaged do not have to be removed at this maintenance level.
Identification and modification plates with missing or damaged edge seals should be removed.
(2) Remove the affected identification and modification plate as required.
(3) Thoroughly clean both sides of the identification and modification plate and the adjacent mounting areas on the equipment using the primary cleaning method described in subparagraph 1004b.
(4) Installation of the identification and modification plates will depend on any additional processing of the avionics component at another level of maintenance. To maintain correct identity and configuration control, reinstall the identification and modification plates. If the avionics component will be repaired at the operator level and returned to service, proceed as follows:
(a) Visually examine the identification and modification plate and the adjacent mounting areas for evidence of corrosion. Clean, treat, and reapply any protective finish in accordance with Chapter 4, paragraph 405, and Chapter 5, paragraphs 502, 503, and 504, as required.
(b) After cleaning and surface treatment, lightly coat the seal by applying a coating of Sealing Compound to the underside of the identification and modification plate and the adjacent mounting areas, conforming to SAE-AMS-S-8802. Install identification and modification plate within the working time of the sealant. Ensure sealant squeezes out around the periphery of the plate.
c. Hermetically Sealed Avionics Equipment. When removing hermetically sealed units, pay particular attention to cable clamp areas, bindings securing wire harnesses, and cable connectors. These are areas where salt and fire extinguishing agents can become entrapped.
Immerse the unit in a container of fresh water to test for airtight integrity of the seal. The presence of air bubbles will indicate a faulty seal. Clean hermetically sealed avionics equipment as follows:
Par 1006 Page 188
(1) Clean the equipment in accordance with subparagraph 1004b or c.
(2) Dry and preserve the equipment in accordance with one of the methods described in subparagraph 1005b.
(3) Units that indicate a faulty seal should be forwarded to an avionics repair station for disposition.
d. Electric Motors and Generators. Cleaning is an essential preliminary procedure in salvaging electric motors, generators, inverters, and miniature synchro transmitters and receivers.
(1) Clean the equipment in accordance with subparagraph 1004b or c.
(2) Dry and preserve the equipment in accordance with one of the methods described in subparagraph 1005b.
(3) Thoroughly inspect the equipment to determine whether it may be returned to serviceable condition or must be forwarded to an avionics repair station. Equipment with sealed bearings should be forwarded to an avionics repair station for replacement.
(4) Equipment that is determined serviceable should have the Corrosion Preventive Compound removed using Dry Cleaning Solvent, MIL-PRF-680, Type II.
(5) Blow off excess liquid from component with not more than 10 psi dry air pressure or dry nitrogen. Deflect the jet of air off interior, back and sides of enclosure to disuse.
e. Cockpit Area Components. The cockpit area contains various types of components.
Non-removable components and equipment should be cleaned, dried, and preserved in accordance with subparagraphs 1006i through 1006k. Removable components should be cleaned and preserved as follows:
(1) Remove all removable components, control boxes, equipment, relay boxes, indicators, etc., in accordance with the OEM maintenance instructions.
(2) Visually examine all removed components for evidence of saltwater, fire extinguishing agents, smoke, oily films, etc.
(3) Clean contaminated equipment in accordance with subparagraph 1004b.
(4) Dry and preserved the equipment in accordance with subparagraph 1005b.
(5) Special attention should be given to cockpit electrical connectors. Clean and preserve in accordance with subparagraph 1006m.
(6) Cockpit circuit breakers, toggle, rotary, interlock, and push-button switches should be cleaned and preserved in accordance with subparagraph 1006f.
f. Switches and Circuit Breakers. Most aircraft and aircraft-related test equipment switches are enclosed in a sealed case. Cleaning of internal parts is generally not possible.
Par 1006 Page 189 Exposed areas such as terminal posts, toggles, push buttons, or rotary switches should be cleaned and preserved as follows:
(1) Remove contamination with fresh water while scrubbing with an acid brush.
Thoroughly rinse with fresh water.
(2) Blow off excess liquid from component with not more than 10 psi dry air pressure or dry nitrogen. Wipe with a clean cloth to help reduce drying time.
(3) Use Dry Cleaning Solvent, MIL-PRF-680, Type II, applied with an acid brush, to remove stubborn oil and grease stains and clean sliding contacts, contact points, and circuit breaker points. Rinse with Dry Cleaning Solvent, MIL-PRF-680, Type II. Ensure removal of any contamination from sliding contacts, contact points, and circuit breaker points. Wipe with a clean cloth.
(4) Dry in accordance with one of the methods described in subparagraph 1005b. Do not apply Water-Displacing Corrosion Preventive Compounds as directed in that paragraph.
(5) If required, preserve exterior of switch in accordance with Chapter 4, paragraph 407.
g. Antennas. Antennas should be cleaned and preserved as follows:
(1) Remove the antenna in accordance with OEM maintenance instructions.
(2) Visually examine antennas, insulators, and electrical connectors for damage. Repair or replace as required.
(3) Brush or spray a mixture of one part Aircraft Cleaning Compound conforming to MIL-PRF-85570, Type I, to nine parts of fresh water. Clean surfaces with a clean cloth dampened with cleaning solution.
(4) Rinse with clean fresh water. Wipe excess water with a dry, clean cloth.
(5) Preserve antenna in accordance with Chapter 4, paragraph 407.
h. Mounting Racks and Shock Mounts. Mounting racks and shock mounts should be cleaned and preserved as follows:
(1) Remove the mounting racks, shock mounts, and associated hardware in accordance with the OEM maintenance instructions.
(2) Clean the detailed parts or components in accordance with subparagraph 1004b.
(3) Dry the mounting racks, shock mounts, and associated hardware in accordance with one of the methods described in subparagraph 1005b.
Par 1006 Page 190
(4) Tag the equipment to be forwarded to the avionics repair station. The tag should indicate date, cleaning and drying method, and preservation type applied. Include any additional notes that may be helpful.
i. Non-removable Avionics Equipment. Non-removable avionics equipment exposed to saltwater or fire extinguishing agents should be cleaned and preserved as follows:
(1) Ensure aircraft or equipment is electrically grounded.
WARNING: Ensure that all electrical power sources, including batteries, are disconnected from the aircraft or equipment and all other powered systems (hydraulic, pneumatic, and mechanical) are deactivated.
(2) Ensure all external electrical power and batteries are disconnected. Remove hydraulic and pneumatic power and install safety struts in hydraulic, pneumatic, and mechanic actuated devices.
(3) Open all equipment bay doors.
(4) After all removable components have been removed in accordance with the OEM maintenance instructions and in the order determined by the priority established in the emergency reclamation list or Table 10-1, examine all non-removable components for evidence of saltwater, fire extinguishing agents, smoke, oily films, etc.
(5) Contaminated items should be cleaned in accordance with subparagraph 1004b whenever possible. Ensure that areas behind and under mounting structure and components are thoroughly cleaned. When the primary cleaning method cannot be accomplished, use one of the alternate cleaning methods described in subparagraph 1004c.
(6) For all non-removable avionics components and electrical connectors, dry and preserve in accordance with subparagraph 1006k.
j. In-place Cleaning. Where access is limited, use a backpack hand pump for one of the cleaning methods described in subparagraph 1004c, except the solvent method described in subparagraph 1004c(1). Dry and preserve limited-access components in accordance with subparagraph 1006k.
k. Drying and Preservation of Non-removable Avionics Equipment. Dry and preserve non-removable avionics components as follows:
(1) Blow off excess liquid from component with not more than 10 psi dry air pressure or dry nitrogen. Deflect the jet of air off interior, back, and sides of enclosure to diffuse.
(2) Where authorized, dry the equipment with a hot air gun. Where the hot air gun is not authorized, wipe the area with a dry, clean cloth and allow to air dry.
Par 1006 Page 191
(3) For all avionics components and electrical connectors, apply (by spraying) a coat of Water-Displacing Corrosion Preventive Compound, Ultra-Thin Film, conforming to MIL-PRF-81309, Type III. Wipe off excess preservative with a dry, clean cloth.
l. Terminal Boards, Junction Boxes, Relay Boxes, and Circuit Breaker Panels.
Terminal boards, junction boxes, relay boxes, and circuit breaker panels not normally removed from the aircraft or equipment should be cleaned as follows:
(1) Ensure aircraft or equipment is electrically grounded.
WARNING: Ensure that all electrical power sources, including batteries, are disconnected from the aircraft or equipment and all other powered systems (hydraulic, pneumatic, and mechanical) are deactivated.
(2) Ensure all external electrical power and batteries are disconnected. Remove hydraulic and pneumatic power, and install safety struts in hydraulic, pneumatic, and mechanic actuated devices.
(3) Remove covers and access panels.
(4) Examine all components for evidence of saltwater, fire extinguishing agents, smoke, oily films, etc.
(5) Contaminated components should be cleaned in accordance with the primary cleaning method described in subparagraph 1004b whenever possible. Ensure that all areas behind and under mounting structure and components are thoroughly cleaned. When the primary cleaning method cannot be accomplished, use one of the alternate cleaning methods described in subparagraph 1004c.
(6) For all non-removable avionics components and electrical connectors, dry and preserve in accordance with subparagraph 1006k.
m. Electrical Connectors and Receptacles. Electrical connectors and receptacles require special procedures for cleaning and preserving. Connectors and receptacles that cannot be opened and separated for cleaning should be cleaned, inspected, and preserved in place as follows:
(1) Disconnect and disassemble connector and receptacles to the extent possible to release entrapped contaminants.
(2) Thoroughly rinse connector and receptacles with fresh water.
(3) Blow off excess liquid from connector and receptacles with not more than 10 psi dry air pressure or dry nitrogen. Wipe with a clean cloth to help reduce drying time.
(4) To remove stubborn oil and grease contaminants, use Dry Cleaning Solvent, MIL-PRF-680, Type II, applied with an acid brush, followed by wiping with a solvent-dampened cleaning cloth.
Par 1006 Page 192
(5) Apply (by spraying) a light coating of Water-Displacing Corrosion Preventive Compound, Ultra-Thin Film, conforming to MIL-PRF-81309, Type III, to remove any trapped liquid. Wipe off excess preservative with a dry, clean cloth.
(6) Dry and preserve in accordance with one of the methods described in subparagraphs 1005b(1) through (5). Whenever these drying methods are not applicable, allow connector to air dry.
n. Wire Harnesses and Cables. Wire harnesses and cables exposed to saltwater, fire extinguishing agents, smoke, etc., should be cleaned and preserved as follows:
(1) Remove cable clamps, straps, hangers, wire ties, etc., to allow wire harness and cable wiring to be separated.
(2) Separate wiring, open and separate connectors. Rinse with fresh water to wash away entrapped contaminants. If the wire harness, cables, or connectors are encased, the exteriors should be rinsed with fresh water.
(3) Blow excess water from wiring and connectors with not more than 10 psi dry air pressure or dry nitrogen. Wipe with a clean cloth to help reduce drying time.
(4) Wire harnesses and cables that can be readily removed from the aircraft or equipment should be dried by one of the methods in subparagraph 1005b.
(5) Wire harnesses and cables that cannot be readily removed from the aircraft or equipment should be dried using a hot air gun.
(6) Apply (by spraying) to metal components a light coating of Water-Displacing Corrosion Preventive Compound, Ultra-Thin Film, conforming to MIL-PRF-81309, Type III.
1007. AVIONICS REPAIR STATION EMERGENCY CLEANING PROCEDURES.
a. General. The initial emergency salvage and reclamation steps taken by the operator or unit level are designed to prevent further corrosion damage. Immediate induction of avionics equipment into an avionics repair station for cleaning, drying, inspection, preservation, repair, and functional testing after an accident can be delayed for many reasons. These can include the delayed access due to an ongoing accident investigation, field disassembly problems, shipping distance, and work contracts. It is, therefore, essential that the avionics repair station be ready to provide services when the equipment does arrive.
b. Emergency Reclamation Team. Each avionics repair station that operates, stores, maintains, or repairs avionics equipment should have a team identified to handle emergency reclamation situations. The team should be composed of a team leader and the necessary number of avionics technicians required to accomplish the assigned task. The primary goal of the emergency reclamation team is to accomplish those tasks that are necessary to salvage the affected equipment and perform appropriate corrosion control efforts to minimize damage and, where possible, return the equipment to usable service. Repairable equipment damaged beyond the capability of the avionics repair station may be returned to the OEM for disposition.
Par 1007 Page 193 NOTE: Units or components that will be returned to the OEM for cleaning, inspection, and repair should be tagged to indicate date of cleaning, cleaning method and materials used, and type of preservation applied.
c. Initial Screening Procedure. Avionics equipment that is damaged beyond the capability of the operator or operating unit to clean, inspect, repair, test, and preserve will normally be forwarded to an avionics repair station for disposition. Upon receipt, the avionics repair station should screen the affected equipment and records to determine the following:
(1) Extent of damage (reported or observed),
(2) Local repair capability,
(3) Cleaning methods used at operator/unit activity,
(4) Drying methods used at operator/unit activity, and
(5) Preservation methods used at operator/unit activity.
d. Cleaning Priority. After initial screening, the cleaning priority needs to be established by the emergency reclamation team leader. Table 10-1 will aid in determining the cleaning priority.
e. Disassembly Inspection Procedures. The extent of damage from saltwater, fire extinguishing agents, smoke, fire, heat, etc., must be determined. Most avionics equipment contains dissimilar metals and particular attention should be given to those dissimilar metal couples. Avionics equipment exposed to saltwater, fire extinguishing agents, smoke, fire, heat, etc., should be cleaned, disassembled, and visually examined as follows:
(1) Remove Corrosion Preventive Compounds, dirt, and grime with Dry Cleaning Solvent, MIL-PRF-680, Type II, to facilitate inspection.
(2) Remove all covers, access panels, modules, and normally removed components.
(3) Visually examine the individual items thoroughly for evidence of saltwater intrusion, fire extinguishing agents, smoke, fire, heat damage, etc.
(4) Visually examine the individual items for evidence of corrosion. Particular attention should be focused on areas of dissimilar metal couples.
(5) Visually examine encapsulated and conformal-coated laminated circuit boards for damage caused by saltwater intrusion, fire extinguishing agents, and cleaning solvents. Pay particular attention to conformal coatings and circuit board laminates that are discolored, softened, or deformed.
(6) Visually examine electrical cables, wires, and harnesses for signs of damage and deterioration from cleaning solvents. Pay particular attention to any signs of discoloration, softening, or cracked wire coating.
Par 1007 Page 194
(7) Disassemble and inspect electrical connectors and receptacles for damage and signs of corrosion. Pay particular attention to seals and gaskets.
(8) Visually examine hermetically sealed components for signs of broken seals and corrosion damage. Units with broken seals should be disassembled for further inspection or forwarded to the OEM for disposition.
(9) Visually examine electrical motors, generators, inverters, miniature synchro transmitters, and receivers for damage. Pay particular attention to lubricated fittings and sealed bearings.
(10) Visually examine control boxes and instruments for damage and corrosion. Pay particular attention to areas around switch toggles and knobs, hardware, interior components, and under faceplates, rubber boots, and mounting areas.
(11) Visually examine component identification and modification plates for evidence of corrosion. Pay particular attention to the condition of the fillet seal around the periphery of the plates.
(12) Visually examine shock mounts, mounting racks, cases, chassis, and cover plates for corrosion. Pay particular attention to evidence of buckling and heat damage. Check painted surfaces for cracks, nicks, and peeling. Pay particular attention to the condition of rubber shock mounts.
f. Undamaged Items. Avionics components that show no visual signs of damage should be functionally checked in accordance with the OEM maintenance instructions. The avionics component may be returned to the operator level in accordance with established procedures.
g. Damaged Items. Avionics components that show signs of damage should be repaired and functionally checked per the OEM maintenance instructions in accordance with established procedures.
h. Emergency Cleaning and Preservation Procedures. Cleaning and preservation procedures are as follows:
(1) Avionics equipment exposed to saltwater, fire extinguishing agents, smoke, fire, heat, field-applied cleaning solutions, etc., and cleaned and decontaminated at the operator or unit level should be inspected for damage in accordance with subparagraph 1007e. Corrosion removal, treatment, restoration of protective finishes, and preservation should be in accordance with Chapters 4 and 5.
(2) Avionics equipment exposed to saltwater, fire extinguishing agents, smoke, fire, heat, etc., that were not cleaned and decontaminated at the operator or unit level should be cleaned, inspected, repaired, and preserved as follows:
(a) Clean using the primary cleaning method detailed in subparagraph 1004b.
Par 1007 Page 195
(b) Inspect for damage in accordance with subparagraph 1007e, and the OEM maintenance instructions.
(c) Disposition in accordance with established procedures and the OEM maintenance instructions.
(d) Preserve in accordance with Chapter 4, paragraph 407.
(3) Avionics equipment that requires disposition and repair by the OEM should be cleaned, dried, preserved, and tagged in accordance with paragraphs 1004b, 1005, and 1006a(9).
1008. through 1100. RESERVED.
Appendix 1 APPENDIX 1. CONSUMABLE SUPPLIES AND MATERIALS
1-1. INTRODUCTION.
This appendix lists many of the acceptable type consumable supplies and materials available for avionics corrosion control.
1-2. SCOPE.
Table 1-1 provides consumable supplies and materials used for avionics cleaning and corrosion control. The table contains the product nomenclature/specification, application, and manufacturer’s designation. Items in this table are located by function in the following groupings:
Grouping Page(s)
a. Abrasives2
b. Cleaning compounds, solvents, and thinners3-4
c. Corrosion preventive compounds4
d. Lubricating oils and greases4-5
e. Cleaning cloth5-6
f. Sealants6
g. Potting compounds6-7
h. Masking materials and tapes7
i. Conformal coatings7-8
j. Neutralizing agents8
k. Chemical conversion coatings8
l. Paint, primers, and strippers8-9
m. Packaging materials9-10
n. Tracers10
Appendix 1 TABLE 1-1. AVIONICS CLEANING AND CORROSION REMOVAL CONSUMABLE
MATERIALS ITEM NO.
NOMENCLATURE/PRODUCT
SPECIFICATION
APPLICATION
ABRASIVES
1. Abrasive Mat. Aluminum Oxide Abrasive, A-A-58054, Grade A, Class 1 (Very Fine), or A-A-58054, Grade B, Class 1 (Fine) Removal of dirt and corrosion products from external avionics chassis, covers, mountings, hardware, antennas, electrical connector shells, etc.
2. Cleaning and Polishing Pad, Nonabrasive Removal of dirt and contaminants from internal avionics structures, laminated circuit boards, wave-guides, TR tubes, cavities, circuit components, relay contacts, control box face plates, etc.
3. Cloth, Abrasive Aluminum Oxide A-A-1048, 320-Grit, Type 1, Class 1 Removal of heavy corrosion products from steel, iron, aluminum, and magnesium structures, mountings, racks, chassis, covers, etc. Scuff sanding of avionics boxes prior to painting, etc.
CAUTION: Do not use Silicon Carbide Abrasive Cloth, A-A-1048.
4. Eraser, Magic Rub, Plastic, A-A-132-14, 2-1/4 x 7/8 x 7/16", (Block Shape, Beveled Ends) Removal of light tarnish on silver. Removal of light corrosion on copper, zinc, nickel, etc. For brightening of gold.
CAUTION: Use only on components that are sufficiently rigid to resist rubbing motion.
5. Eraser, Ruby Red A-A-132-3, 2-3/4 x 3/4 x 1/4 inch, (Rectangular Shape, Beveled Ends) Removal of light tarnish on silver. Removal of medium corrosion on copper, zinc, nickel, etc. For brightening of gold.
CAUTION: Use only on components that are sufficiently rigid to resist rubbing motion.
6. Eraser, Wood or Paper Encased, A-A-132-13, 6 inch x 3/16 inch diameter, (Pencil Shape) Removal of medium tarnish and corrosion products in tight areas.
CAUTION: Care should be taken not to remove thinly plated surfaces.
7. Eraser, Typewriter A-A-132-9, 7 inch x 3/16 inch diameter, (Pencil Shape) Removal of heavy tarnish on silver. Removal of heavy corrosion on copper, zinc, nickel, etc.
CAUTION: Care should be taken not to remove thinly plated surfaces.