area, at a particular base or station, or aboard aviation ships. The mission of I-level maintenance activities is to sustain the combat readiness of supported activities (squadrons) by providing quality and timely material support at the nearest location with the lowest practical resource expenditure. I-level maintenance includes: Shop-type repair and test work on aircraft, com- ponents, and equipment from supported units Technical assistance to supported units Manufacture of selected aeronautical compo- nents, liquids, and gases Performance of on-aircraft maintenance when required Permanently assigned Sailors and Sailors that are temporarily assigned from tenant squadrons man inter- mediate maintenance activities. When these squadrons deploy, their intermediate maintenance Sailors accompany the squadron and are temporarily assigned to the aircraft intermediate maintenance department (AIMD) onboard the ship or at the new station. Depot Maintenance (D-Level) Depot-level maintenance supports O- and I-levels of maintenance by providing engineering assistance and performing maintenance that is beyond the capabi- lity of O- and I-level activities. Depot maintenance is work that must be done in an industrial-type facility. Such a facility may either be civilian, military, or both. If the work is contracted out to a civilian facility, the type of work is still depot maintenance. Standard depot-level maintenance (SDLM) includes overhaul, repair, and modification of aircraft, components, and equipment. Depot maintenance also includes the manu- facture of aeronautical parts for spares, the manufacture of kits for aircraft, and the modification of equipment. The depot level or a lower level of maintenance installs the spare parts and incorporates modification kits. For the most part; civilians man naval aviation depots (NADEPs), which are Navy depot-level maintenance facilities. Military personnel at a NADEP help perform the intermediate and organizational maintenance work that is related to the depot facility. MAINTENANCE TYPES Maintenance technicians perform two types of aircraft maintenance within the Navy—rework and upkeep. Rework may be performed on any aircraft or equipment. Industrial-type facilities that provide maintenance program support perform rework. Rework is the restorative and additive work that NADEPs, contractor facilities, or other industrial-type facilities perform on aircraft or equipment. There are two categories of rework—SDLM and special. Upkeep is the preventive, restorative, or additive maintenance for aircraft and equipment. Activities (squadrons) that have aircraft or equipment or have the responsibility of providing direct support to activities that have aircraft or equipment perform upkeep. Upkeep includes periodic inspections, servicing, preservation, modification, replacement, and repair. There are also two categories of upkeep—SDLM and special. Shore Stations Navy shore activities that have intermediate maintenance responsibilities have an AIMD to perform the maintenance. Those shore activities with aircraft have an OMD within the operations department to perform organizational maintenance on assigned aircraft and transient aircraft. A naval air reserve unit performs organizational and intermediate maintenance on its aircraft; however, the supporting station provides logistic support. A naval air reserve squadron that is on active duty or is assigned to a fleet unit provides organizational maintenance on its aircraft. Ships Multipurpose aircraft carriers and amphibious assault ships perform organizational and intermediate maintenance on assigned aircraft. These ships also provide organizational and intermediate material, facilities, and support equipment to embarked air wings, squadrons, and other units. Squadrons A squadron performs organizational maintenance on its aircraft. While shore based, designated squadron maintenance technicians are assigned to the AIMD of the supporting station for training and augmentation of the support effort. When the squadron is afloat, designated squadron maintenance personnel are assigned, as required, to the AIMD of the supporting ship. 1-3