Chapter 12 - Cleaning and Corrosion - Oral Questions Flashcards Preview

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Flashcards in Chapter 12 - Cleaning and Corrosion - Oral Questions Deck (21):

Is there any requirement for cleaning an aircraft prior to an annual or 100 hour inspection?

It is a legal requirement as specified in FAR Part 43, Appendix D


Discuss the general precautions that should be observed when washing an airplane.

Avoid or protect areas which may be damaged or contaminated such as

Pitot and static ports,


sealed areas, and



What are some of the more common light duty cleaning agents?

Soap or detergents and water


What materials are commonly used as heavy duty cleaners?

Solvents and emulsions


What are the preferred cleaners for plastic surfaces such as windshields

Mild soap and water or a manufacturer approved cleaner


What type of cleaning agents should be used to remove grease, oil or fuel from aircraft tires?

Soap and Water


Give at least three examples of the factors that cause or influence corrosion

1) The environmental conditions

2) The presence of dissimilar metals

3) The type of metal

4) the presence of electrolytes and or contaminants

5) The condition of protective coatings


Name at least three forms of corrosion

1) Surface

2) Intergranular

3) Filliform

4) Dissimilar metal (galvanic)

5) Oxidation

6) Pitting
7) Stress

8) Fretting


Name at least one cause of filliform corrosion

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1) Improper or incomplete curing of a wash primer prior to painting

2) Failure to completely wash off acidic surface contamination


What are the visible signs of filliform corrosion?

Blistered paint surfaces, worm or thread-like tracks under the paint

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What are two primary factors that may cause development of stress corrosion cracks?

A corrosive environment and sustained tensile stress

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What are the visible signs of fretting corrosion?

Corrosion residue has a dark, smoky appearance and often appears around and streaming back from rivet heads

(smoking guns)

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Why are piano-type hinges prime spots for corrosion?

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The steel pin and aluminum hinge material are dissimilar metals and the hinge design tends to trap moisture and contaminants


What is the best way to protect piano hinges from corrosion?

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Keep them clean and properly lubricated


Provide at least four examples of procedures used to prevent corrosion

1) Cleaning

2) Lubrication

3) Treatment

4) Sealing

5) Inspection

6) Installing protective covers

7) Keeping drain holes free and clear


Describe the tools that should be used to remove corrosion from aluminum surfaces

Nylon scrubber pads (scotch brite),

bristle brushes,

aluminum wool or

aluminum wire brushes


Describe the effects of using steel brushes or steel wool to remove corrosion from aluminum surfaces

Steel brushes or steel wool must not be used to clean aluminum because steel particles can become embbedded in the aluminum and cause corrosion


What is the purpose of alodine?

Alodine is a chemical process that deposits a protective film on aluminum alloys. This film improves corrosion reistance and paint adhesion


For what reason should you avoid cleaning anodized aluminum surfaces with aluminum metal polish

The polish removes the protective oxide coating


Why should aircraft fabrics and plastics be cleaned only with recommended cleaners?

They cause the least amount of deterioration or damage


List at least five areas of an aircraft prone to corrosion

1) Battery compartments

2) Exhaust trail areas

3) Bilge areas

4) Vent areas

5) Landing gear and wheel wells

6) Fuel tanks

7) Wing flap recesses

8) Around and below galleys and lavatories

9)Piano Hinges

10) Any area that can trap water