FIELD LEVEL MAINTENANCE:
Field level maintenance consists of operator and organizational level maintenance tasks.
Operator Maintenance. Operator maintenance is the lowest level of maintenance performed on the GSM. It is normally initiated with operator PMCS. PMCS is conducted before, during, and after operation as well as weekly, monthly, quarterly, and annually in accordance with the appropriate GSM technical manuals. The operator is responsible for initial fault detection and isolation. Since the Block I GSM is designed to facilitate modular replacement of components, the operator is authorized to remove and replace components as stated in the technical manual. To aid the operator in diagnostics, 90 percent of the equipment in the GSM has been designed with built-in-tests (BITs), which facilitate thorough fault isolation.
Organizational Level Maintenance. Organizational and unit level maintenance includes PMCS as discussed above, modular removal and replacement, replacement of line replaceable units (LRUs), and limited "off-equipment" maintenance. The main type of maintenance that is done at unit level is non-system maintenance, maintenance on the prime mover, support vehicles, generators, communications equipment, and COMSEC equipment.
SUSTAINMENT LEVEL MAINTENANCE:
Sustainment level maintenance consists of DS and GS repairs.
Direct Support Maintenance. DS maintenance provides both "on-equipment" and "off-equipment" maintenance. The on-equipment maintenance support will fault isolate the 10 percent of the faults detected but not isolated by the GSM operator. LRU removal and replacement restores the equipment to operational status. Off-equipment maintenance includes limited repair of electro-mechanical and mechanical devices. This also includes screening of GO and NO-GO circuit cards.
General Support Maintenance. GS maintenance performs "off-equipment" maintenance that exceeds the "time to repair" constraints or capability of DS maintenance. It includes further fault diagnosis and isolation of modules to internal shop replaceable unit components. Repairs will include adjustments, alignment, and repair in accordance with the government-furnished equipment (GFE) and GSM allocation charts.
DEPOT LEVEL MAINTENANCE:
Depot level maintenance is in accordance with procedures in the appropriate technical publications. GSM depot level maintenance is performed by the contractor at the contractor factory. The contractor provides common spares parts, replaceable modules, stock depot level GSM unique spares, and unique repair parts, as required.
BATTLE DAMAGE ASSESSMENT AND REPAIR (BDAR):
BDAR is designed to rapidly return disabled electronic equipment to operational status. This is done by repairing, bypassing, or alternating components to restore minimum functions required to support combat missions with the Block I GSM. BDAR is divided into two areas: BDA and battle damage repair. BDA is divided into three types of assessments: extent of damage, repairs needed, and location and method to repair.