Corrosion Control and Treatment Flashcards

When performing a corrosion inspection of a floatplane after salt water operation, which areas require the most attention?

Answer: Bilge areas, float attachment fittings, and any crevices that can trap salt water

Salt water accumulates in bilge areas, fittings, and crevices, making these the highest-risk locations for rapid galvanic and crevice corrosion after floatplane operations.

A technician discovers active pitting corrosion on an aluminum spar cap. The first step should be to:

Answer: Consult the aircraft structural repair manual and applicable SRM to determine allowable damage limits

Before any repair action, the technician must consult the SRM to determine if the pitting depth and extent is within allowable limits or requires engineering disposition.

Which protective finish system provides the best corrosion protection for a steel aircraft landing gear component operating in a harsh environment?

Answer: Cadmium plate or zinc-nickel plate followed by a primer and topcoat

Electroplated cadmium or zinc-nickel provides sacrificial corrosion protection on steel, and combined with primer and topcoat, creates a multi-layer system suited to harsh environments.

What is the significance of the 'break-out' condition when using a chemical corrosion remover on aluminum?

Answer: It means the reaction has consumed all the corrosion products and the active metal surface is exposed

Break-out occurs when the chemical remover has dissolved all surface corrosion products and begins reacting with bare aluminum, which must be stopped promptly to avoid metal loss.

According to FAA guidance, which corrosion removal method is preferred for high-strength steel (over 180,000 psi) components?

Answer: Mechanical removal using fine abrasives, avoiding hydrogen-embrittlement risk from acid treatments

High-strength steel is susceptible to hydrogen embrittlement from acid treatments; mechanical removal with fine abrasives is preferred to avoid introducing hydrogen into the metal.

Which of the following conditions is required for corrosion to occur on a metal surface?

Answer: The simultaneous presence of an anode, cathode, metallic path, and electrolyte

Corrosion is an electrochemical process requiring four elements: an anode, a cathode, a metallic electrical path between them, and an electrolyte; removing any one element stops corrosion.

When a technician applies corrosion preventive compound (CPC) to an aircraft interior bilge area, which type of CPC is most appropriate for long-term protection in a water-entry-prone zone?

Answer: Heavy-bodied or wax-based compound (Class III or IV) that provides a durable, water-resistant film

Heavy-bodied CPCs (Class III/IV) form a thick, persistent, water-resistant film suited for bilge areas where water exposure is frequent and long protection intervals are needed.