Which of the following is highly susceptible to corrosion, especially in aircraft that use external ram air cooling?

Avionic equipment bays are highly susceptible to corrosion, particularly in aircraft that utilize external ram air cooling. This is primarily because the air that flows through these bays can carry moisture and other corrosive elements, especially during flight and when the aircraft is exposed to varying environmental conditions. The presence of electrical components, wiring, and sensitive instruments in these bays further increases the risk, as moisture can lead to not only corrosion of metal parts but also potential electrical failures.

While wing structures, fuel tanks, and cabin interiors may also experience corrosion, the unique conditions in avionic equipment bays—such as airflow that can introduce contaminants—make them particularly vulnerable. Furthermore, the design and material choices in these areas may not always prioritize corrosion resistance, leading to increased susceptibility over time. Therefore, avionic equipment bays are a critical focus for corrosion control measures in aircraft maintenance practices.