What is only inspected on a C-130?

The correct answer pertains specifically to the PIP-pin and the door locks needing to be seated properly on the C-130. In the context of pre-flight inspections for the C-130 aircraft, certain components are prioritized to ensure safety and functionality. The PIP-pin and door locks are critical because they maintain the integrity of the troop doors during flight. If these components are not secured, the risk of an in-flight door malfunction increases, which can be catastrophic during a jump operation.

While other components like the troop door up-lock, fuel line integrity, and propeller conditions are important for overall aircraft safety and performance, they are not exclusive to the C-130 and can be part of checks on other aircraft as well. The specific attention to the PIP-pin and door locks emphasizes that these features are unique to this aircraft model and are vital for the operational safety of paratroopers being transported.