Aircraft Corrosion Oral Examination Prep

Vocabulary terms and definitions covering typical oral examination questions on aircraft corrosion types, susceptible areas, treatment, and prevention.

Aircraft areas prone to corrosion

Locations including the battery compartment, exhaust system and exhaust trails, wheel wells, bilge (lower belly), piano hinges, dissimilar metal contact points, welded areas, inside of fuel tanks (especially integral tanks), high-stress metal fittings, lavatories, and foodservice areas.

Filiform corrosion

A form of corrosion caused by improperly cured primer that is most likely to occur under a dense coating of topcoat enamel such as polyurethane.

Fretting corrosion

Corrosion that occurs in locations where there is a slight amount of relative movement between two components and no way for the corrosive residue to be removed as it forms.

Intergranular corrosion

Corrosion occurring along the grain boundaries of aluminum alloys that have been improperly heat-treated, to which extruded aluminum alloy is particularly susceptible.

Dissimilar metal corrosion

Corrosion that develops anywhere different types of metal come in contact with each other, especially where moisture is present.

Stress corrosion

Corrosion occurring in any metal component continually under tensile stress, such as the metal around holes in castings fitted with pressed-in bushings.

Aluminum alloy surface corrosion removal and treatment

A procedure consisting of removing corrosion residue with a bristle brush or nylon scrubber, neutralizing the surface with chromic acid or a conversion coating, and protecting it with a coat of paint.

Oxide coating or aluminum cladding

Protective barriers used to keep corrosion from forming on structural aluminum alloy.

Highly stressed metal part rust removal

The removal of rust accomplished by glass bead blasting, careful polishing with mild abrasive paper, or using fine buffing compound on a cloth buffing wheel.

Piano hinge corrosion prevention

Minimizing corrosion by keeping the hinges as clean and dry as practicable and lubricating them with a low viscosity moisture dispersing agent.