INTERIM CHANGE—A change having an action classification of immediate or urgent and issued by message. INVENTORY CONTROL—The phase of military logistics that includes management, cataloging, requirements determination, procurement, dis- tribution, overhaul, and disposal of material. Synonymous with material control, material management, inventory management, and supply management. INVESTIGATION—Inquiry into a condition or situation systematically for the purpose of developing and providing factual information to cognizant authorities. IPB—Illustrated Parts Breakdown—A manual con- taining illustrations and part numbers for all parts of the aircraft or equipment on which it is issued. The IPB contains information required for ordering parts, including part numbers, and for identifying parts and arrangements of parts in assemblies. IRAC—Interim Rapid Action Change. ITEM—Any level of hardware assembly; for example, segment of a system, subsystem, equipment, or component part. ITEMS PROCESSED (ITEMS/P)—This  term identifies the total number of times an AT code is applied toward a WUC. JCN—Job Control Number—The JCN is a 9-, 10-, or 11-digit alphanumeric code that identifies each individual maintenance action. JOAP—Joint Oil Analysis Program. JULIAN DATE—The year and numerical day of the year identified by four numeric characters. The first character indicates the year and the remaining three characters specify the day of the year; for example, 9209 indicates the 209th day of 1999 or 28 July 1999. LAMS—Local Asset Management System—An automated management information system, provides for standardized local management of IMRL assets through the use of bar code technology. It provides for an accurate wall-to-wall inventory, which can be accomplished by unit personnel, resulting in significant reductions of manpower expenditures and operational disruptions. LANDING—The controlled return of an aircraft in flight to the surface. It includes touch and go (carrier or field) providing the landing gear touches the surface. A bolter is an attempted arrested landing on a carrier in which the landing gear or hook touches the deck but the arresting gear is not engaged and the aircraft continues in flight. LCF—Low Cycle Fatigue—A fatigue cracking failure mode that is defined by the frequency and characteristics of a loading that causes a crack. LCF is caused by stresses built up by mechanical/ thermal cycles which occur only a few times per flight. The four most significant LCF events are: stop/start/stop cycles, rapid major changes in operating temperature, rapid major changes in rotational speed, and significant increases in aerodynamic loading of the blades/ disks. LIFE CYCLES—The total life span of an aeronautical system beginning with the concept formulation phase and extending through the operational phase up to retirement from the inventory. LIQUID PENETRANT—Methods used for the detection of surface cracks or discontinuities, where the inspection surfaces are sprayed with or immersed in liquid. The excess liquid is removed, and the defect is indicated visually by color or fluorescence. LOAN—Aircraft loaned to non-Navy organizations for non-Navy purposes. A lease may or may not be required to cover the loan. NOTE: Aircraft that are in the Navy inventory but not in the physical custody of the Navy are either on bailment or on loan. Bailment indicates usage by the bailee for the Navy, while loan indicates usage by the lessee for the lessee. LOGISTICS—The science of planning and carrying out the movement and maintenance of forces. For its most comprehensive sense, those aspects of military operations that deal with design and development, acquisition, storage, movement, dis- tribution, maintenance, evaluation, and disposition of material; movement, evaluation, and hospital inspection of personnel; acquisition or construc- tion, maintenance, operation, and disposition of facilities; and acquisition or furnishing of services. LOOK PHASE—The portion of an inspection that includes the basic requirements outlined by the PMICs, excluding repair of discrepancies, that cannot be completed within the time allotted on MRCs. AI-12