Aviation Maintenance Terms beginning with C

Chord

The distance from the blade leading edge to the trailing edge.

Chord line

A straight line drawn between the leading and trailing edges of the blade.

Corrosion

Deterioration of a metal because of reaction with its environment. For further references see AC 43-4, Corrosion Control for Aircraft.

Corrosion, intergranular

Intergranular corrosion occurs in the grain boundaries of some alloys of aluminum. The presence of intergranular corrosion may be the result of fatigue, stress, or the continued presence of moisture such as under a decal, or in a fastener hole. Sometimes called exfoliation corrosion, when it occurs in forgings, extrusions or rolled sheets.

Corrosion, pitting

Visible cavities extending inward from the metal surface due to chemical or electro-chemical action.

Corrosion, surface

Surface loss of metal due to chemical or electro-chemical action. On polished surfaces begins as a dulling of surface, soon becoming frosted, followed by widespread pitting.

Crack

A physical opening or fissure within the body of a material. May be either internal within the material or at the surface (surface breaking). On a propeller, cracks can be started by cuts, nicks, or corrosion.

Cut

A deep, long, narrow fissure usually caused by a sharp object.