TM 5-2590-512-13&P APPENDIX B MAINTENANCE ALLOCATION CHART (MAC) Section I.  INTRODUCTION B-1.  The Army Maintenance System MAC 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 subcolumns, C (operator/crew) and O (unit) maintenance. Direct Support - includes an F subcolumn. General Support - includes an H subcolumn. Depot - includes a D subcolumn. c. Section  III  lists  the  tools  and  test  equipment  ( both  special  tools  and    common  tool  sets)  required  for each  maintenance  function  as  referenced  from  section II. d. Section   IV   contains   supplemental   instructions and   explanatory   notes   for   a   particular   maintenance function. B-2.      MAINTENANCE   FUNCTIONS.      Maintenance functions  are  limited  to  and  defined  as  follows:    (see 3.2.5.2g for ammunition MAC exception). 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   or   exact position,  or  by  setting  the  operating  characteristics  to specified parameters. e. Align.  To adjust specified variable elements of an     item     to     bring     about     optimum     and     desired performance. f. Calibrate.    To  determine  and  cause  correction 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. Remove/Install.      To   remove   and   install   the same  item  when  required  to  perform  service  or  other maintenance   functions.      Install   may   be   the   act   of emplacing, seating, or fixing into position a spare, repair part, or module ( component or assembly) in a manner to   allow   the   proper   functioning   of   an   equipment   or system. h.    Replace.      To   remove   an   unserviceable   item and    install    a    serviceable    counterpart    in    its    place. "Replace"  is  authorized  by  the  MAC  and  the  assigned maintenance  level  is  show  as  the  3rd  position  code  of the SMR code. B-1