What basic method helps prevent corrosion on aluminum airframes?

• A. Applying protective coatings and keeping surfaces clean.
• B. Expose metal to air without coating.
• C. Keep surfaces wet.
• D. Use bare metal without sealant.

Answer: (A)

Preventing corrosion on aluminum airframes relies on creating a protective barrier and keeping the surface free of contaminants. Protective coatings—such as primers, paints, and sealants—form a continuous film that blocks moisture, salts, and other corrosive agents from reaching the metal, while also providing corrosion-inhibiting protection. Keeping surfaces clean removes dirt, salt, and moisture that can trap corrosive substances and accelerate oxidation, making any flaws in the coating easier to spot and repair. Together, these practices minimize electrochemical reactions that drive corrosion.

Exposing metal to air without a coating invites oxidation, as there’s nothing to keep moisture and contaminants from contacting the aluminum. Keeping surfaces wet promotes ongoing corrosion, supplying the water needed for electrochemical reactions. Using bare metal without sealant leaves no protective barrier at all, making corrosion highly likely.