Which type of SE requires the attention of support staffs when inoperative?

Nonredundant equipment is critical because it performs functions that do not have backup systems. When this type of equipment becomes inoperative, it can cause significant disruptions in operations, and immediate attention from support staff is essential to restore functionality. Without redundancy, there is no alternative to take over the tasks, leading to potential delays or failures in missions or operations.

In contrast, operational equipment and training devices may have alternative systems or methods to work around their failures. Maintenance tools, while important for upkeep and repairs, do not typically impact operational continuity directly. Thus, the focus of support staff primarily rests on nonredundant equipment to ensure mission readiness and effective operational capability.