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