Which of the following is NOT part of a visual inspection?

The process of visual inspection in aircraft armament systems primarily focuses on identifying physical conditions and defects that can be observed without the aid of tools. Checking for overheating of electronic components, inspecting for loose or missing mechanical hardware, and examining wires for fraying, burning, or breakage all involve directly observing the physical condition of the components and hardware. These elements are crucial in ensuring the system's operational readiness and safety.

In contrast, checking for software updates is not considered part of a visual inspection because it involves accessing software interfaces, performing updates or checks that cannot be done visually. This activity requires tools and software management practices, rather than direct observations of hardware. Therefore, this choice correctly identifies an action outside the scope of a visual inspection.