FAR Reference for Repair Station article

FAR 1.1 General definitions
Preventive Maintenance means simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations.

FAR 91.403 General
(a) The owner or operator of an aircraft is primarily responsible for maintaining that aircraft in an airworthy condition, including compliance with Part 39 of this chapter. (See below).
(b) No person may perform maintenance, preventive maintenance, or alterations on an aircraft other than as prescribed in this subpart and other applicable regulations, including part 43 of this chapter.

FAR 39.3 General
No person may operate a product to which an airworthiness directive applies except in accordance with the requirements of that airworthiness directive.

Airworthiness directives are issued by the FAA or a manufacturer if a hazard is discovered that may endanger the operation of your aircraft. Compliance methods are specified in the airworthiness directive (AD).

FAR 91.407 Operation after maintenance, preventive maintenance, rebuilding, or alteration.
(a) No person may operate any aircraft that has undergone maintenance, preventive maintenance, rebuilding, or alteration unless --
(1) It has been approved for return to service by a person authorized under Part 43.7 of this chapter, and
(2) The maintenance record entry required by Part 43.9 or Part 43.11, as applicable, of this chapter has been made.

FAR 43.3 Persons authorized to perform maintenance, preventive maintenance, rebuilding, and alterations.
(a) Except as provided in this section and Part 43.17, no person may maintain... or perform preventive maintenance on an aircraft... to which this part applies.
(c) The holder of a repairman certificate may perform maintenance and preventive maintenance as provided in Part 65 of this chapter.
(e) The holder of a repair station certificate may perform maintenance, preventive maintenance, and alterations as provided in Part 145 of this chapter.
(g) The holder of a pilot certificate issued under Part 61 may perform preventive maintenance on any aircraft owned or operated by that pilot which is not used under Part 121, 127, 129, or 135.

FAR 43.5 Approval for return to service after maintenance, preventive maintenance, rebuilding, or alteration.
No person may approve for return to service any aircraft... or appliance that has undergone maintenance, preventive maintenance, rebuilding , or alteration unless--
(a) The maintenance record entry required by Part 43.9 or 43.11, as appropriate, has been made;

FAR 43.7 Persons authorized to approve aircraft,... appliances, or component parts for return to service after maintenance, preventive maintenance, rebuilding, or alteration.
(f) A person holding at least a private pilot certificate may approve an aircraft for return to service after performing preventive maintenance under the provisions of Part 43.3 (g).

FAR 43.9 Content, form, and disposition of maintenance, preventive maintenance, rebuilding, and alteration records ...
(a) Maintenance record entries. Except as provided in paragraphs (b) and (c) of this section, each person who maintains, performs preventive maintenance, rebuilds, or alters an aircraft... appliance, or component part shall make an entry in the maintenance record of that equipment containing the following information:
(1) A description (or reference to data acceptable to the Administrator) of work performed.
(2) The date of completion of the work performed.
(3) The name of the person performing the work if other than the person specified in paragraph (a)(4) of this section.
(4) If the work performed on the aircraft... appliance, or component part has been performed satisfactorily, the signature, certificate number, and kind of certificate held by the person approving the work. The signature constitutes the approval for return to service only for the work performed.

Appendix A to Part 43 -- Major Alterations, Major Repairs, and Preventive Maintenance
(c) Preventive maintenance. Preventive maintenance is limited to the following work, provided it does not involve complex assembly operations.
(5) Replacing defective safety wiring or cotter keys.
(6) Lubrication not requiring disassembly other than removal of nonstructural items...
(7) Making simple fabric patches not requiring rib stitching or the removal of structural parts or control surfaces. In the case of balloons, the making of small fabric repairs to envelopes (as defined in, and in accordance with, the balloon manufacturer's instructions) not requiring load tape repair or replacement.
(9) Refinishing decorative coating of ... balloon basket, ... cabin, or cockpit interior when removal of any primary structure or operating system is not required.
(10) Applying preservative or protective material to components where no disassembly of any primary structure or operating system is involved and where such coating is not prohibited or is not contrary to good practices.
(11) Repairing upholstery and decorative furnishings of the cabin, cockpit, or balloon basket interior when the repairing does not require disassembly of any primary structure or operating system or interfere with an operating system or affect the primary structure of the aircraft.
(22) Replacing prefabricated fuel lines.
(24) Replacing or servicing batteries.
(25) Cleaning of balloon burner pilot and main nozzles in accordance with the balloon manufacturer's instructions.
(26) Replacement or adjustment of nonstructural standard fasteners incidental to operations.
(27) The interchange of balloon baskets and burners on envelopes when the basket or burner is designated as interchangeable in the balloon type certificate data and the baskets and burners are specifically designed for quick removal and installation.