characters  identify  a  particular  TM  and  are  divided into three groups. The first group (TM acronym) consists of three letters or numbers that identify the type of manual; for example,  in  figure  2-17,  the  TM  acronym  NFM identifies the manual as a NATOPS flight manual supplement.  Numerically,  they  can  identify  the  first three digits of a particular Work Unit Code; for example, 520 is an autopilot. In some instances of Work Unit Codes, such as support equipment (SE), a combination of a letter and two numbers are used for the TM acronym; for example, S14 is an air compressor. The second group of the TM identifier (TM serial number) is made up of two numbers. It is used to identify different volumes, parts, and changes to specific TMs. For NAVAIR TMs, these numbers range from 00 through 99. In the example shown in figure 2-17, the TM serial number is 50. This stands for a  Pilots Pocket Checklist. The third group of the TM identifier is the TM issue, and is either a number (0 to 9) or a single letter. The number 0 indicates the TM is a basic issue or superseding revision. The letters A through Z (except I and 0) designate (in alphabetical sequence) permanent changes or rapid action changes (RACs). PI  SUFFIX  COMPOSITION.—The  PI  suffix has a variable composition, depending upon whether or  not  the  TM  has  a  security  classification.  For classified TMs, the PI suffix is always used, and the security   classification   indicator   forms   the   first component  of  the  suffix.  The  security  classification indicator is always three characters (a letter enclosed in parentheses). The entire suffix can contain up to 17 characters, if required. In figure 2-17, you can see that the PI suffix is not required. Therefore, the TMINS number A1-F18AC-NFM-500 stands for the initial or revised edition of a Pilots Pocket Checklist supplement to the NATOPS  manual  of  an  F/A-18  aircraft.  In-depth information can be found in the OPNAV N0000-00-IDX-000/TMINS   publication. Q16. Q17. Q18. How many numbering systems are currently in use by NAVAIR and what are they? What part of the NAVAIR numbering system can the category of the publication be found? The standard TMINS number is made up of how many distinct parts and what are they? Q19. The two-digit subject serial number is what group of the PI? Q20. What are the last six positions in the publication identifier  (PI)  called? USING TECHNICAL MANUALS LEARNING  OBJECTIVE:  Recognize  the procedures  for  using  maintenance  instruction manuals  (MIMs)  and  illustrated  parts breakdowns (IPBs). Technical  manuals  help  ensure  proper maintenance.  In  today’s  Navy,  the  equipment  is complex  and  you  must  use  technical  manuals  at  all levels of servicing and repair. The purpose of this section is to introduce you, the worker, to the content of technical manuals. MAINTENANCE INSTRUCTION MANUAL (MIM) As discussed earlier, the Maintenance Instruction Manual (MIM) is identified by the number 2 in part III of the NAVAIR publication number. For example, the first  numeral  2  in  NAVAIR  01-75PAA-2-2.3 identifies the MIM for the P-3A aircraft. The MIM is made  up  from  a  number  of  individual  publications. Each  publication  deals  with  some  portion  of  the maintenance  for  the  applicable  model  aircraft.  It contains   essential   information   that   aircraft maintenance personnel require to service and maintain the complete aircraft. Before you attempt any task on an aircraft, consult the MIM for that particular model of aircraft. By using the MIM properly, you may prevent possible aircraft damage and save time. The recommended  maintenance  methods  provide procedures  that  can  be  accomplished  by  the appropriate maintenance level activity. NOTE:  Different  aircraft  manufacturers  may group the material in the various volumes of the MIMs under different titles. For example, the “Survival and Environmental Systems” volume for the older aircraft covers  the  ejection  seat,  canopy,  liquid  oxygen, heating,  air  conditioning,  ventilation,  and  anti-g systems.  Two  volumes  titled  “Personnel Environmental  Systems”  and  “Canopy  and  Survival Systems” are prepared to cover the same subjects for newer  aircraft. The “General Information and Servicing” volume is  designed  primarily  for  the  plane  captain.  This 2-17