TM 10-3930-671-24 APPENDIX B MAINTENANCE ALLOCATION CHART (MAC) Section I.  INTRODUCTION B-1. GENERAL. a. This introduction (Section I) provides a general explanation of all maintenance and repair functions authorized at various maintenance levels under the standard Army Maintenance System concept. b. The  Maintenance  Allocation  Chart  (MAC)  in  Section  II  designates  overall  authority  and  responsibility  for  the performance  of  maintenance  functions  on  the  identified  end  item  or  component.    The  application  of  the  maintenance functions   to   the   end   item   or   component   will   be   consistent   with   the   capacities   and   capabilities   of   the   designated maintenance levels which are shown on the MAC in column (4) as: Unit includes two sub-columns, C (operator crew) and 0 (unit) maintenance; Direct Support includes an F sub-column; General Support includes an H sub-column; Depot includes a D sub-column. c. Section   III   lists   the   tools   and   test   equipment   (both   special   tools   and   common   tool   sets)   required   for   each maintenance function as referenced from column (5) in section II. d. Section IV lists any special explanation remarks required for each maintenance function as referred from column (6) in section II. B-2. MAINTENANCE FUNCTIONS. Maintenance functions will be limited to and defined as follows: a. Inspect.    To  determine  the  serviceability  of  an  item  by  comparing  its  physical,  mechanical,  and/or  electrical characteristics with established standards through examination (e.g., by sight, sound, or feel). b. Test.  To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical characteristics of an item and comparing those characteristics with prescribed standards. c. Service.  Operations required periodically to keep an item in proper operating condition; e.g.,  to  clean  (includes decontaminate, when required), to preserve, to drain, to paint, or to replenish fuel, lubricants, chemical fluids, or gases. d. Adjust.    To  maintain  or  regulate,  within  prescribed  limits,  by  bringing  into  proper  position,  or  by  setting  the operating characteristics to specified parameters. e Align.  To adjust specified variable elements of an item to bring about optimum or desired performance. 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. B-1