FAA Aviation Mechanic General (AMG)Materials, Hardware and ProcessesEasy
A technician is performing a visual inspection of a steel aircraft component. Which type of corrosion is characterized by a general roughening of the surface and a red, flaky deposit?
- AFiliform corrosion
- BUniform etch corrosion
- CPitting corrosion
- DFretting corrosion
Show answer & explanationAnswer & explanation
Correct answer: B. Uniform etch corrosion
Uniform etch corrosion, also known as surface corrosion, is characterized by a general roughening of the metal surface and often appears as a red, flaky deposit on steel.
Why the other options are wrong
- A. Filiform corrosion appears as worm-like tracks under the paint film.
- C. Pitting corrosion appears as small, localized holes or pits on the surface.
- D. Fretting corrosion occurs at contact areas between two surfaces under slight relative motion, often appearing as dark streaks.
Uniform Etch Corrosion
A type of corrosion characterized by a general roughening of the metal surface, often appearing as a red, flaky deposit on steel or a white powdery deposit on aluminum.
- Attacks the entire exposed surface relatively evenly.
- Commonly called surface corrosion.
- On steel, it manifests as red rust; on aluminum, as a white powder.
Memory trick: Corrosion's many forms, know their tell-tale signs.