ARMY TM 9-2815-257-24 AIR FORCE TO 38G1-128-2 MARINE CORPS TM 10155A/2815-24/3 B-1 APPENDIX B MAINTENANCE ALLOCATION CHART (MAC) Section I.  INTRODUCTION B-1.  General. a.    This  section  provides  a  general  explanation  of  all  maintenance  and  repair  functions  authorized  at various maintenance categories. 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 in 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: 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.