COH—Complex Overhaul. COMCARGRU—Commander Carrier Group. COME-ALONG—Ratchet hoist. COMFAIRMED—Commander   Fleet   Air,   Mediter- ranean. COMFAIRWESTPAC—Commander Fleet Air, Western Pacific. COMNAVAIRLANT—Commander Naval Air Force, U.S. Atlantic Fleet. COMNAVAIRPAC—Commander   Naval   Air   Force, U.S. Pacific Fleet. COMNAVAIRSYSCOM—Commander    Naval    Air Systems Command. COMNAVSEASYSCOM—Commander   Naval   Sea Systems Command. COMNAVSURFLANT—Commander  Naval  Surface Force, U.S. Atlantic Fleet. COMNAVSURFPAC—Commander    Naval    Surface Force, U.S. Pacific Fleet. COMPONENT—A   part   of   an   assembly   or   sub- assembly. CONCENTRICITY—Having   a   common   axis   or center.  Usually refers to the closeness of tolerances between the common center of two or more circles (bore  and  outside  diameter,  bore  and  bolt  circle diameters, and so forth). CONDENSATE—The liquid that forms when a gas or vapor, such as steam, is cooled. CONTINUITY—The  completeness  of  an  electrical circuit. CORROSION—Deterioration   of   a   metal   surface, usually caused by moist, salty air. COSAL—Coordinated Shipboard Allowance List. CROV—Constant Run Out Valve. CSMP—Current Ship's Maintenance Project. CSV—Capacity Selector Valve. CV—Multi-purpose aircraft carrier. CVN—Nuclear-powered   multi-purpose   aircraft   car- rier. DLA—Defense Logistics Agency. D-LEVEL—Depot level. DEAD LOAD—A wheeled vehicle used instead of an aircraft during catapult testing. DEENERGIZE—To   remove   from   operation   elec- trically. DEFORMATION—A    change    in    the    shape    or dimensions   of   a   body,   due   to   overstressing   or repeated usage. DEPRESSURIZE—To  remove  air  or  hydraulic  fluid from a system. DIAMETER—The width or thickness of a part. DIAMETRAL CLEARANCE—The difference between  the  inside  diameter  (ID)  of  one  part  and the  outside  diameter  (OD)  of  another  part  when both parts have the same axis. DOD—Department of Defense. DON—Department of the Navy. DSCC—Defense Supply Center Columbus. DSCP—Defense Supply Center Philadelphia. DYNAMOMETER—A device used to measure force. EI—Engineering Investigation. EIC—Equipment Identification Code. ELONGATION—An   increase   in   the   length   of   a material  due  to  heating,  stretching,  hammering, and so forth. EM—Electrician's Mate. ENERGIZE—To put into operation electrically. EROSION—Pitting or eating away of metal due to the action of steam, chemicals, water, or atmosphere. ERRATIC—Operating in an unusual manner that may result in possible breakdown or failure. FATIGUE—A major breakdown of the surface metal over  a  large  area,  resulting  in  the  surface  metal's becoming   loose   and   detached   from   the   base material. FBR—Feedback Report. FED LOG—Federal Logistic. FLOLS—Fresnel Lens Optical Landing System. FMSO—Fleet Material Support Office. FOD—Foreign Object Damage. FREEZING—Stopping    of    motion    between    two contacting surfaces because of lack of lubrication. AI-2