AC No:  43-12A





         Date:  10/28/83





      Initiated



           by:  AWS-340





       Change:





      Subject:  PREVENTIVE MAINTENANCE.





      1.  PURPOSE.  This advisory circular (AC) provides information 

      concerning preventive maintenance, who may perform it, the 

      standards of performance applicable to it, authority for 

      approving aircraft for return to service, and the applicable 

      recording requirements.  This AC also clarifies those areas most 

      frequently misunderstood in the past, and explains the recent 

      changes in the rules concerning preventive maintenance. 



      2.  CANCELLATION.  AC 43-12, Preventive Maintenance, dated July 

      16, 1976, is canceled.





      3.  RELATED FEDERAL AVIATION REGULATIONS (FAR).  Part 1, 

      Definitions and Abbreviations, Section 1.1; Part 43, Maintenance, 

      Preventive Maintenance, Rebuilding, and Alteration; Part 61, 

      Certification:  Pilots and Flight Instructors; and Part 145, 

      Repair Stations.





      4.  PREVENTIVE MAINTENANCE.





          a.  The holders of mechanic and repairmen certificates, 

      persons working under the supervision of these mechanics and 

      repairmen, repair stations certificated under Part 145, and air 

      carriers certificated under Parts 121, 127, and 135, are 

      authorized to perform preventive maintenance.  These persons are 

      also authorized to perform other maintenance.  Therefore, it is 

      of little consequence to them how a particular function is 

      classified, since they are authorized to perform the function as 

      either preventive maintenance or as other maintenance.  Further, 

      the procedures used in approving for return to service and 

      recording are identical.  This AC will, therefore, consider 

      preventive maintenance from the owners/operators point of view. 



          b.  FAR Part 1, Section 1.1, defines preventive maintenance 

      as ". . . simple or minor preservation operations and the 

      replacement of small standard parts not involving complex 

      assembly operations."



              (1)  FAR Part 43, Appendix A, paragraph (c) contains the 

      list of those functions determined by the FAA to meet this 

      definition.  If a function does not appear in this list, it is 

      not preventive maintenance.  Further, because of differences in 

      aircraft, a function may be preventive maintenance on one 

      aircraft and not on another.  To provide for this, paragraph (c) 

      contains the limitation, "provided it does not involve complex 

      assembly operations" on the aircraft involved.  Owners and pilots 

      must use good judgment in determining that a specific function 

      may appropriately be classified as preventive maintenance. 



              (2)  A Pilot may not perform preventive maintenance on 

      aircraft used under Parts 121, 127, or 135, even when the pilot 

      owns the aircraft.





          c.  Persons authorized to perform preventive maintenance.  In 

      addition to those persons listed in paragraph 4a of this AC, 

      Section 43.3(g) authorizes the holder of a pilot certificate 

      issued under Part 61 to perform preventive maintenance.  Section 

      43.7 limits the privilege to persons holding at least a private 

      pilot certificate and Section 43.5 prohibits operation of the 

      aircraft unless approved for return to service.  Further, pilots 

      may only approve for return to service preventive maintenance 

      which they themselves have accomplished.





          d.  Applicable performance standards.





              (1)  FAR 43.13 requires preventive maintenance to be 

      done using methods, techniques, and practices acceptable to the 

      Administrator.  These are normally set forth in the



      manufacturer's maintenance manuals; however, some may be found in 

      AC's published by the FAA.





              (2)  FAR 43.13 requires the use of the tools, equipment, 

      and test apparatus necessary to assure completion of the work in 

      accordance with accepted industry practices.  This means that the 

      proper tools and test apparatus must be used.  Normally, these 

      are listed as part of any FAA-approved manufacturer's maintenance 

      literature.





              (3)  FAR 43.13 also requires that any special equipment 

      recommended by the manufacturer or its equivalent must be used in 

      a manner acceptable to the Administrator.  This provision is more 

      directly applicable to maintenance than preventive maintenance. 

      However, it may come into play.  Therefore, owners and pilots 

      should be aware of it.





              (4)  Additionally, Section 43.13 requires that the work 

      performed and the materials used are to be such as to ensure 

      that, when the work is finished, the item worked on is at least 

      equal to its original condition.  Caution must be exercised 

      because some functions which appear to be simple tasks may, in 

      fact, be quite complicated.  Care should be taken to ensure that 

      the manufacturer's instructions are understood, the function is 

      within the individual's capability, within the definition of 

      preventive maintenance, and that it is listed in paragraph (c) of 

      Appendix A of Part 43.





          e.  Recording preventive maintenance.  Preventive maintenance 

      must be recorded in accordance with Section 43.9 of FAR Part 43. 

      This is done by entering in the maintenance record, of the item 

      worked on, the following:





              (1)  "A description (or reference to data acceptable to 

      the Administrator) of the work performed."  This should indicate 

      what was done and how it was done.  This is normally quite simple 

      for preventive maintenance; however, if the description is 

      extensive, reference to documents containing that description is 

      acceptable.  These may be manufacturer's manuals, AC's, or other 

      documents or references containing data acceptable to the 

      Administrator.  If documents other than types which are in common 

      use are referenced, the document should be made a part of the 

      maintenance record, as required by Section 43.9(a)(1). 



              (2)  "The date of completion of the work performed." 

      This is self explanatory and is the date on which the entry is 

      made, as required by Section 43.9(a)(2).





              (3)  The kind of airman certificate exercised.  When 

      preventive maintenance is performed as authorized in Section 

      43.3(g), the certificate may be indicated in any manner which 

      would be clear to the reader.  For example:  PP, CP, or ATP might 

      be used to indicate private, commercial, or airline transport 

      pilot, respectively.  The certificate number is that number 

      displayed on the certificate being exercised.  Affixing a 

      signature to the entry, which describes the work accomplished, 

      constitutes approval for return to service, as required by 

      Section 43.9(a)(4).





           NOTE:  Since owners/pilots are not authorized to approve 

           work accomplished by others, Section 43.9(a)(3) is not 

           applicable when preventive maintenance is performed by the 

           holder of a pilot's certificate.  The holder of the pilot's 

           certificate doing the work is the only person who can sign 

           the approval for return to service.



          f.  The changes to Section 43.9 which require preventive 

      maintenance to be recorded became effective October 15, 1982 

      (Amendment 43-23, 47 FR 41076; September 16, 1982).  On this same 

      date, the list of items considered to be preventive maintenance 

      in Appendix A of Part 43 was expanded.  Two of the items warrant 

      discussion.





              (1)  Item 25 (Part 43, Appendix A, paragraph (c)).  This 

      item deals with the assembly of gliders and has been on the list 

      of preventive maintenance for some time.  The new recording 

      requirements, however, significantly affects this item.  The 

      recording requirements are intended to provide continuity in the 

      maintenance record and to ensure that the person performing 

      preventive maintenance assumes responsibility for the work 

      performed.  An entry for the assembly after required inspection 

      ensures this assumption of responsibility.  Repeated entries are 

      required each time a person assembles the aircraft for operation. 

      The assembly must be recorded and the aircraft approved for 

      return to service in accordance with Section 43.9 by a person 

      authorized in Section 43.7.





              (2)  Item 28 (Part 43, Appendix A, paragraph (c)).  This 

      item deals with the installation of balloon baskets and burners 

      specifically designed for quick removal and installation.  Such 

      disassembly and assembly is necessary to facilitate transporting 

      the balloon either to the launch site or after a flight is 

      terminated.  The assembly operation is preventive maintenance and 

      subject to the provisions of Sections 43.3, 43.7, and 43.9.  As 

      required by Section 43.1(b), entries are required for assembly 

      operations on all balloons except those certificated in the 

      experimental category which have not been previously certificated 

      in another category.





          g.  Items 6 and 23 (Part 43, Appendix A, paragraph (c)). 

      These items permit the draining and reservicing of oil, and the 

      removal, cleaning and reinstallation of oil screens, filters, and 

      strainers in an aircraft oil system to be done as preventive 

      maintenance, and are subject to the provisions of Sections 

      43.13(a) and (b).







      /s/ Joseph A. Pontecorvo



          Acting Director of Airworthiness