STANDARD GROUPS

TM 55-1520-240-23-11 f. Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test, measuring, and diagnostic equipment used in precision measurement. Consists of comparisons of two instruments, one of which is a certified standard of known accuracy, to detect and adjust any discrepancy in the accuracy of the instrument being compared. g. Install. The act of emplacing, seating, or fixing into position an item, part, or module (component or assembly) in a manner to allow the proper functioning of an equipment or system. h. Replace. The act of substituting a serviceable like type part, subassembly, or module (component or assembly) for an unserviceable counterpart. i. Repair. the application of maintenance services or other maintenance actions to restore serviceability to an item by correcting specific damage, fault, malfunction, or failure in a part, subassembly, module (component or assembly), end item, or system. j. Overhaul. That maintenance effort (service/action) necessary to restore an item to a completely serviceable/operational condition as prescribed by maintenance standards in appropriate technical publications (i.e., DMWR). Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul does not normally return an item to like new condition. k. Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to a like new condition in accordance with original manufacturing standards. Rebuild is the highest degree of materiel maintenance applied to Army equipment. The rebuild operation includes the act of returning to zero those age measurements (hours/miles. etc.) considered in classifying Army equipments/components. B-4. STANDARD GROUPS (COLUMNS 1 AND 2). The standard groupings shown in the sample below are used, as applicable, throughout this MAC. Maintenance manuals and RPSTL will reflect these standard groupings as individual chapters, with sections in each chapter relative to the individual complete systems, subsystems, modules, components, assemblies, or specific parts noted. GROUP NUMBER DESCRIPTION 01 Aircraft General 02 Airframe System 03 Alighting Gear 04 Powerplant Installation 05 Blades/Rotor Systems 06 Train Systems 07 Hydraulic Systems 08 Instrument Systems 09 Electrical System 10 Fuel System 11 Flight Controls System 12 Utility System 13 Environmental Control System 14 Hoists and Winches 15 Auxiliary Powerplant System 16 Mission Equipment 17 Emergency Equipment NO BREAK - WORK HARDER NO BREAK - WORK HARDER NO BREAK - WORK HARDER 1. Ser vice - respect test, service adjus t, align c alibrate, or replace 2. Actions - w elding, grinding, riveting, straightening, fac ing, remachining, or resurfacing B-5