DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

Subject:  PREVENTIVE MAINTENANCE

Date:  10/28/83

Advisory Circular No:  43-12A

Initiated by:  AWS-340

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 repairman 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 preventative maintenance. In addition to those persons listed in paragrapn 4a or 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 accomplish.

   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 same 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