Which areas are primarily focused on in corrosion control for aircraft?

Corrosion control in aircraft primarily focuses on aircraft structures and avionics because these areas are critical for maintaining the integrity and functionality of the aircraft.

Aircraft structures, such as the fuselage and wings, are exposed to various environmental factors, including moisture, salt, and contaminants, which can lead to corrosion. Protecting these components helps ensure the strength and safety of the aircraft during operation.

Similarly, avionics, which include the electrical systems and equipment essential for navigation and communication, can also suffer from corrosion. Any deterioration due to corrosion can lead to failure in these systems, potentially compromising flight safety.

While the other options address important systems and components on an aircraft, they do not encapsulate the primary focus of corrosion control. For instance, propulsion and fuel systems are vital for operation, but corrosion management in these areas is more specialized and secondary compared to the overarching structural considerations.