1. (a) Except as provided in paragraphs (b) and (d) of this section, this part prescribes rules governing the maintenance, preventive maintenance, rebuilding, and alteration of any—

   1. (1) Aircraft having a U.S. airworthiness certificate;
   2. (2) Foreign-registered civil aircraft used in common carriage or carriage of mail under the provisions of Part 121 or 135 of this chapter; and
   3. (3) Airframe, aircraft engines, propellers, appliances, and component parts of such aircraft.

2. (b) This part does not apply to—

   1. (1) Any aircraft for which the FAA has issued an experimental airworthiness certificate, unless the FAA has previously issued a different kind of airworthiness certificate for that aircraft;
   2. (2) Any aircraft for which the FAA has issued an experimental airworthiness certificate under the provisions of § 21.191(i)(3) or (l) of this chapter, and the aircraft was previously issued a special airworthiness certificate in the light-sport category under the provisions of § 21.190 of this chapter; or
   3. (3) Any aircraft that is operated under part 107 of this chapter, except as described in § 107.140(d).
3. (c) This part applies to all life-limited parts that are removed from a type certificated product, segregated, or controlled as provided in § 43.10.

4. (d) This part applies to any aircraft issued a special airworthiness certificate in the light-sport category except:

   1. (1) The repair or alteration form specified in §§ 43.5(b) and 43.9(d) is not required to be completed for products not produced under an FAA approval;
   2. (2) Major repairs and major alterations for products not produced under an FAA approval are not required to be recorded in accordance with appendix B of this part; and
   3. (3) The listing of major alterations and major repairs specified in paragraphs (a) and (b) of appendix A of this part is not applicable to products not produced under an FAA approval.
5. (e) Additional applicability of maintenance provisions for powered-lift is set forth in part 194 of this chapter.

[Doc. No. 1993, 29 FR 5451, Apr. 23, 1964, as amended by Amdt. 43-23, 47 FR 41084, Sept. 16, 1982; Amdt. 43-37, 66 FR 21066, Apr. 27, 2001; Amdt. 43-38, 67 FR 2109, Jan. 15, 2002; Amdt. 43-39, 69 FR 44863, July 27, 2004; Amdt. 43-44, 75 FR 5219, Feb. 1, 2010; Docket FAA-2015-0150, Amdt. 43-48, 81 FR 42208, June 28, 2016; Docket FAA-2018-1087, Amdt. 43-51, 86 FR 4381, Jan. 15, 2021; FAA-2023-1275, Amdt. No. 43-62, 89 FR 92483, Nov. 21, 2024; Amdt. 43-63, 90 FR 35211, July 24, 2025]