TM 55-1680-358-12&P SECTION III.  ILLUSTRATED PARTS BREAKDOWN 3-12.  General.  This Illustrated Parts Breakdown (IPB) lists,  illustrates,  and  describes  the  items  necessary  to support   and   maintain   the   Helicopter   Internal   Cargo Handling System, Part No.  18049 J 100, for the CH47 Helicopter.        The    purpose    of    this    IPB    is    to    assist personnel with identification and for establishing relationships between parts. 3-13.      Scope.      The   scope   of   the   Illustrated   Parts Breakdown is as follows: a. General.    This  paragraph  contains  descriptive and user information.  It provides an overview on how to use the Illustrated Parts Breakdown. b. Maintenance Parts List.  This section contains a breakdown  of  assemblies  and  parts.    It  also  includes keyed    illustrations    of    the    end    items    that    can    be disassembled,    repaired,    obtained    from    reclamation, supply channels, reinstalled, replaced, and reassembled.          The     listings     for     specific     systems, components,   groups,   etc.,   are,   when   practical,   in   a sequence    compatible    to    the    order    in    which    such systems, components, groups, etc., are discussed in the maintenance sections.  The Maintenance Parts List does not contain: (1) Parts and assemblies that are not repairable or replaceable. (2) Parts   which   lose   their   identity   by   being welded, sealed, or joined to other pieces as a permanent assembly. (3) Parts  made  of  bulk  stock,  such  as  lock wire,   bonding   braid,   upholstery,   cloth,   friction   tape, electrical wire, insulation, etc. (4) Support equipment, such as tools and test equipment. c. Numerical Index.   This section contains the part numbers of all parts listed in the Maintenance Parts List. 3-14.  Abbreviations and Symbols.   The abbreviations used     in     this     Illustrated     Parts     Breakdown     are     in accordance with Military Standard MII,STD-12. 3-15.    Operation  and  Maintenance  Data.    Refer   to Chapter  2  and  Chapter  3,  Section  II  for  operation  and maintenance instructions. 3-16.  Indention.    The  items  listed  in  the  Maintenance Parts  List  are  indented  to  indicate  item  relationship  or next  higher  assembly  (NHA).    The  description  of  each assembly  is  followed  immediately  (except  for  attaching parts)  by  the  description  of  the  detailed  parts  indented one  column  to  the  right.    This  indention  indicates  the relationship  of  the  part  to  the  assembly.    To  determine the next higher assembly of a part or assembly, note the column in which the first word of the description begins. The first item directly above, which appears one column to  the  left  (except  attaching  parts)  is  the  next  higher assembly. 3-17.  Figure Cross-Reference Notes.    The  continuity of the parts listed, and their relationship to the complete assemblies or subassemblies covered by the Maintenance Parts List, are maintained by a parenthetical  figure  cross-reference  note  following  the description  of  the  part  being  referenced.    These  notes are as follows: a. (See  figure  ...  for  breakdown.)  This  statement indicates    that    the    complete    or    continued    detailed breakdown of the part being referenced may be found in the figure reference. b. (See    figure    ...    for    NHA.)    This    statement indicates that the part being referenced may be found in the figure reference, with requirements and relationships to    its    next    higher    assembly    indicated    by    column indention. 3-18.    Parts  Listed.    In  general,  the  assemblies  and parts installed at the time the end item was manufactured are listed and identified in this manual. 3-19.    Attaching  Parts.    Screws,  bolts,  washers,  nuts and other items which serve as attaching parts are listed immediately  following,  and  with  the  same  indention  as the  components  they  attach.    Attaching  parts  are  not listed  in  disassembly  sequence  and  are  not  part  of  the components   they   attach   unless   so   indicated.      The caption (AP) appears in the description column following these attaching parts. 3-3