T M     5 - 4 5 2 0 - 2 0 8 - 2 5P SECTION I INTRODUCTION 1 .    S c o pe This  manual  contains  a  list  of  reparts  parts required  for  the  performance of  organizational, direct  support, general support and depot main- tenance of the heater. 2.   General This  repair  parts  list  is  divided  into  four principal  sections  and  a  Federal  stock  number index. a. Section  II,  Prescribed  Load  Allowance List (PLA), is a consolidated listing of repair parts quantitatively elloatad for initial stock- age  at  the  organizational  level.  This  is  a  man- datory  minimum  stockage  allowance. b. Section  III,  Repair  Parts  List,  is  a  list of  repair  parts  authorized  for  the  performance of  maintenance  at  the  organizational  level. No special tools required for this end item. c. Section IV, Repair Parts List, is a list of repair  parts  authorized  for  the  performance  of maintenance at the direct support general sup- port,  and  depot  level. d. Section  V,  Federal  stock  number  and Manufacturer’s  Part  Number  Index,  is  an  index of Federal stock numbers and manufacturer’s part  numbers  to  page  and  manufacturer’s  codes. e. Refer  to  TM  5-2805-208-14,  for  Repair Parts applicable to engine assembly. f. Parts   applicable   to   specific   models   of this end item are indicated by a letter symbol in the “description”   column,   following   the nomenclature. Parts not indicated by a letter symbol  apply  to  all  models.  The  symbols  apply as  follow: (A)-applies   to   model   BT   400-40 (B)-applies   to model  BT 400-40-1. only only 3. Explanation of Columns The  following  provides  an  explanation  of columns in the tabular lists. a. Source, Maintenance, and Recoverability Codes. (1) Code P M A Xl X2 Source  Code  indicates  the  selection status  and  source  for  the  listed  item. Source codes used are: Applied   to   repairs   parts   which   are   stocked in   or   supplied   from   DSA/GSA   or   Army supply   system   and   authorized   for   use   at indicated   maintenance   categories. Applied   in   repair   parts   which   are   not   pro- cured    or    stocked    but    are    to    be    manu- factured  at  indicated  maintenance cate- gories. Applied  to  assemblies  which   are  not  pro- cured   or   stocked   as   such   but   made   up   of two   or   more   units,   each   of   which   carry individual   stock   numbers   and   dcscrip tions   and   procured   and   stocked   and can    be    assembled    by    units    at    indicated maintenance    categories. Applied   to   repair   parts   which   are   not   pro- cured   or   stocked   the   requirement   for which   will   be   supplied   by   use   of   the   next higher assemnbly or components. Applied   to   repair   parts   which   are   not stocked.   The   indicated   maintenance   cate- gory   requiring   such   repair   parts   will   at- tempt   to   obtain   them   through   cannibali- zation;   if   not   obtainable   through   canni- balization,  such  repair  parts  will  be  req- uisitioned   with   supporting   justification through    norma1   supply   channels. Note.   Source  code  is  not  shown  on  com- mon   hardware   items   known   to   be   readily available    in    Army    supply    channels    and through  local  procurement. (2) Maintenance Code indicates the lowest category  of  maintenance  authorized  to iii