What maintenance level is performed by designated maintenance activities supporting operating units?

The correct answer is I-level. This level of maintenance is performed by designated maintenance activities that support operating units and typically focuses on intermediate repairs, which are not feasible at the operational level. I-level maintenance includes tasks such as inspections, service, and component replacements to ensure that equipment and aircraft remain operational and in a ready state.

In contrast, O-level maintenance refers to organizational level maintenance, which is performed by the operating units themselves and includes routine servicing and minor repairs. D-level, or depot level maintenance, is more extensive and involves major overhaul and repair work usually conducted at a centralized facility, while field level maintenance can sometimes refer to actions taken in the field, but it is not a recognized standard level like O-level, I-level, and D-level.

Understanding the distinctions between these maintenance levels is crucial for the effective management of aircraft readiness and reliability within aviation operations.