MAINTENANCE Maintenance of the type CRU-79/P regulator is limited to inspection, testing, adjustment of the pressure   breathing   aneroid,   and   tightening   of loose  screws.  Ensure  that  antiseize  tape  is  used on   pipe   threads.   This   section   contains   only   the procedural   steps   necessary   to   meet   these requirements. NOTE:   Upon   completion   of   any maintenance action (for example, inspec- tion, adjustment, modifications, etc.), be sure to complete the required maintenance data collection system forms. If the regulator fails any inspection or testing requirements,  it  must  be  disposed  of  in  accordance with any local directives and replaced with a ready for  issue  (RFI)  component. The  miniature  regulator  will  remain  in  service as  long  as  it  continues  to  function  correctly  and does  not  require  other  than  authorized adjustment. Procedural  steps  outlined  in  this  section  are listed  under  the  inspection  cycle  in  which  they  are required,   and   in   the   sequence   in   which   they normally   occur. DAILY/PREFLIGHT    INSPECTION The daily/preflight inspection is a visual type inspection  performed  by  the  aircrew  member  to whom the regulator is issued, either daily or before each  flight.  To  perform  this  inspection,  visually inspect  the  following: WARNING WHEN   WORKING   WITH   OXYGEN, MAKE  CERTAIN  THAT  CLOTHING, TUBING   FITTINGS,   AND   EQUIP- MENT  ARE  FREE  OF  OIL,  GREASE, FUEL,  HYDRAULIC  FLUID,  OR  ANY COMBUSTIBLE  MATERIALS.  FIRE OR EXPLOSION MAY RESULT WHEN EVEN   SLIGHT   TRACES   OF   COM- BUSTIBLE   MATERIAL   COME   IN CONTACT   WITH   OXYGEN   UNDER PRESSURE. 1. Inlet and outlet connections for security of attachment. Make sure that all clamps, locknuts, fittings  and  screws  are  tight. 2.  The  regulator  body  for  dents,  scratches, corrosion,  cracks,  condition  of  the  nameplate,  or any  other  damage. 3. Perform a functional test as outlined in the next  inspection  (special  inspections). If  discrepancies  are  found  or  suspected,  the regulator should be taken to the Aviator’s Equip- ment   Branch   for   the   required   corrective maintenance. SPECIAL  INSPECTIONS Special  inspections  are  required  at  specified intervals   in   addition   to   the   daily/preflight   or calendar  inspections.  The  interval  for  miniature oxygen  regulators  is  30  days.  This  inspection consists  of  a  visual  inspection  and  a  functional test, both performed by personnel of the Aviator’s Equipment   Branch.   To   perform   the   special inspection,  proceed  as  follows: 1. Visually inspect the regulator as outlined in  the  previous  section  (daily/preflight). 2.  Functionally  test  the  regulator  by  attaching the mask, regulator, and delivery tube to a suitable oxygen  supply  source.  Use  a  regulator-to-seat  hose for  an  attachment. 3.  Turn  on  the  supply  source.  There  should be  a  flow  of  oxygen  through  the  mask. 4.  Don  the  mask  and  breathe.  There  should be a slight resistance on exhalation. This resistance is  due  to  the  positive  pressure  feature  of  the regulator. When you finish the special inspection, record the date and place of inspection in the’ ‘NOTES” section of the Aircrew Personal Protective Equip- ment  History  Card. CALENDAR   INSPECTION The  calendar  inspection  is  performed  on  all miniature  regulators  upon  issue  prior  to  being installed   in   an   in-service   personal   oxygen configuration  and  must  be  performed  on  all miniature regulators in service at least every 90 days. The  calendar  inspection  consists  of  a  visual inspection  and  a  bench  test.  All  work  must  be done  in  a  clean,  dust-free  and  oil-free  area. VISUAL  INSPECTION To  visually  inspect  the  miniature  regulator, proceed  as  follows: 1. Disconnect the communication connectors. 2.  Loosen  the  hose  clamp  that  holds  the regulator  outlet  to  the  mask  delivery  hose,  and remove  the  regulator  from  the  hose.  Retain  the hose  clamp. 12-2