Table  4-1.-Constrained  Turn-Around  Time .   The   item   is   locally   repairable   at   the organizational or intermediate level of maintenance. l Constrained TAT is used in the computation (see Table 4-1). The TAT is the number of calendar days between removal of the item for processing through repair cycle until it is available for reinstallation. In computing the total average TAT for each NIIN, use  the  lower  figure  of  the  actual  experience  or maximum  allowed  time  for  each  repair  element.  After summing  the  individual  elements,  the  total  NIIN average  will  be  constrained  to  20  days.  The  constrained average daily NIIN TAT is used in the calculation of LRCR  values. To   determine   the   LRCR   quantity,   use   the computation formula and Poisson distribution table (part   of   enclosures)   in   FASOINST   4441.15   or FASOINST  4441.16. SUMMARY In  this  chapter,  we  discussed  the  Navy  Supply System  echelons  and  their  functions  for  managing aeronautical  materials  in  the  Navy.  Aeronautical material is composed of consumable and repairable items.  We  discussed  the  difference  between  these categories  of  material  and  the  procedures  used  to determine   the   activity’s   stocking   levels   for   each category. The primary inventory manager of aeronautical materials  in  the  Navy  is  the  Naval  Inventory  Control Point-Philadelphia. The   repairable   items   are categorized as field level repairable (FLR) and aviation depot level repairable (AVDLR). The AVDLR items represent the most significant dollar investment in the aeronautical   inventory. Therefore, strict inventory control is required to manage these items. The  activities  that  are  required  to  provide  supply support to aircraft and aeronautical equipment will be outfitted  with  items  for  stock.  The  designated  activity is outfitted through the AVCAL/SHORCAL process. After  the  AVCAL/SHORCAL  process,  any  increase  or decrease to the allowance quantity must be submitted to   the   NAVICP   on   the   Allowance   Change Request-Fixed   (ACR-F)   form.   The   FLRs   may   be carried in purpose code W or L of an activity’s fixed allowance. The FLRs that are excess to the authorized allowance are carried in A purpose code. Ships carry FLRs under stores account 51000 pending issue to the customer. The ownership of AVDLR items relate to the stores account they are carried under. These stores accounts   could   be   the   DBOF,   APA,   contractor supported,  and  end-use  ashore  or  afloat. We  discussed  the  different  Navy  management programs  for  AVDLR  items.  These  programs  provide specific   procedures   in   inventory   management, scheduling,  repair,  carcass  tracking,  reclamation,  and support  of  AVDLRs. Managing repairable material has become more significant in today’s Navy. The activities must ensure that  procedures  for  processing  transactions  are  being followed. Since the number of AVDLR items in the Navy  has  increased,  intensive  management  procedures are  required.  The  inventory  management  and  carcass tracking programs provide the necessary procedures in support of the AVDLR. We  discussed  the  carcass  tracking  and  the Advanced  Traceability  and  Control  (ATAC)  programs. The carcass tracking program includes shipment of retrograde,   maintaining   carcass   tracking   records (CTRs),   carcass   tracking   follow-up   inquiry   from NAVICPs,  replies  from  shipping  activities,  and  billings. The follow-up inquiry documents must be processed within the prescribed time frame to prevent additional billing from the NAVICPs. To  prevent  the  duplication  of  effort  and  to  ensure currency of information, certain paragraphs in this chapter  refer  you  to  the  reference(s)  that  describe  the subject  in  detail. 4-27