14 CFR Part 43 · Maintenance, Preventive Maintenance, Rebuilding, and Alteration

14 CFR 43.3: Who may perform maintenance

Maintenance may be done by certificated mechanics and repairmen, repair stations, air carriers and manufacturers, and by people working under a mechanic's direct supervision. A pilot may do preventive maintenance on an aircraft they own or operate, as long as it is not used under Parts 121, 129 or 135.

Section last amended December 30, 2016 · Text current as of October 15, 2026 · Also cited as FAR 43.3 · Read it on eCFR

14 CFR 43.3 in plain English

  • The work that counts as a major alteration, a major repair or preventive maintenance is listed in Appendix A. (a)
  • Certificated mechanics and repairmen work under the privileges of Part 65. (b)
  • Someone without a certificate may work under a mechanic's supervision if the mechanic watches closely enough and is readily available in person. That never covers the required inspections. (d)
  • Repair stations, air carriers and manufacturers each work under their own rules. (e)
  • A pilot certificate holder, other than sport pilot, may do preventive maintenance on an aircraft they own or operate that is not used under Parts 121, 129 or 135. (g)
  • Avionics database updates loaded from the flight deck without tools or disassembly are not maintenance, and pilots may do them. (k)

Common questions

Can a renter or student do preventive maintenance on a school airplane?
Paragraph (g) requires the pilot to own or operate the aircraft. A renter is usually not the operator of a school's aircraft, so most schools leave preventive maintenance to their mechanic.
Can my friend help me with an oil change under my A&P's supervision?
Under (d), yes, if the mechanic personally observes enough to be sure it is done properly and is readily available in person. The mechanic then signs for it.
Who signs off preventive maintenance a pilot does?
The pilot, under 43.7(f), with a logbook entry that meets 43.9.

Official text of 14 CFR 43.3

§ 43.3 Persons authorized to perform maintenance, preventive maintenance, rebuilding, and alterations. Verbatim from the eCFR, current as of October 15, 2026.

(a)Except as provided in this section and § 43.17, no person may maintain, rebuild, alter, or perform preventive maintenance on an aircraft, airframe, aircraft engine, propeller, appliance, or component part to which this part applies. Those items, the performance of which is a major alteration, a major repair, or preventive maintenance, are listed in appendix A.

(b)The holder of a mechanic certificate may perform maintenance, preventive maintenance, and alterations as provided in Part 65 of this chapter.

(c)The holder of a repairman certificate may perform maintenance, preventive maintenance, and alterations as provided in part 65 of this chapter.

(d)A person working under the supervision of a holder of a mechanic or repairman certificate may perform the maintenance, preventive maintenance, and alterations that his supervisor is authorized to perform, if the supervisor personally observes the work being done to the extent necessary to ensure that it is being done properly and if the supervisor is readily available, in person, for consultation. However, this paragraph does not authorize the performance of any inspection required by Part 91 or Part 125 of this chapter or any inspection performed after a major repair or alteration.

(e)The holder of a repair station certificate may perform maintenance, preventive maintenance, and alterations as provided in Part 145 of this chapter.

(f)The holder of an air carrier operating certificate or an operating certificate issued under Part 121 or 135, may perform maintenance, preventive maintenance, and alterations as provided in Part 121 or 135.

(g)Except for holders of a sport pilot certificate, 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, 129, or 135 of this chapter. The holder of a sport pilot certificate may perform preventive maintenance on an aircraft owned or operated by that pilot and issued a special airworthiness certificate in the light-sport category.

(h)Notwithstanding the provisions of paragraph (g) of this section, the Administrator may approve a certificate holder under Part 135 of this chapter, operating rotorcraft in a remote area, to allow a pilot to perform specific preventive maintenance items provided:

(1)The items of preventive maintenance are a result of a known or suspected mechanical difficulty or malfunction that occurred en route to or in a remote area;

(2)The pilot has satisfactorily completed an approved training program and is authorized in writing by the certificate holder for each item of preventive maintenance that the pilot is authorized to perform;

(3)There is no certificated mechanic available to perform preventive maintenance;

(4)The certificate holder has procedures to evaluate the accomplishment of a preventive maintenance item that requires a decision concerning the airworthiness of the rotorcraft; and

(5)The items of preventive maintenance authorized by this section are those listed in paragraph (c) of appendix A of this part.

(i)Notwithstanding the provisions of paragraph (g) of this section, in accordance with an approval issued to the holder of a certificate issued under part 135 of this chapter, a pilot of an aircraft type-certificated for 9 or fewer passenger seats, excluding any pilot seat, may perform the removal and reinstallation of approved aircraft cabin seats, approved cabin-mounted stretchers, and when no tools are required, approved cabin-mounted medical oxygen bottles, provided:

(1)The pilot has satisfactorily completed an approved training program and is authorized in writing by the certificate holder to perform each task; and

(2)The certificate holder has written procedures available to the pilot to evaluate the accomplishment of the task.

(j)A manufacturer may:

(1)Rebuild or alter any aircraft, aircraft engine, propeller, or appliance manufactured by him under a type or production certificate;

(2)Rebuild or alter any appliance or part of aircraft, aircraft engines, propellers, or appliances manufactured by him under a Technical Standard Order Authorization, an FAA-Parts Manufacturer Approval, or Product and Process Specification issued by the Administrator; and

(3)Perform any inspection required by part 91 or part 125 of this chapter on aircraft it manufactured under a type certificate, or currently manufactures under a production certificate.

(k)Updates of databases in installed avionics meeting the conditions of this paragraph are not considered maintenance and may be performed by pilots provided:

(1)The database upload is:

(i)Initiated from the flight deck;

(ii)Performed without disassembling the avionics unit; and

(iii)Performed without the use of tools and/or special equipment.

(2)The pilot must comply with the certificate holder's procedures or the manufacturer's instructions.

(3)The holder of operating certificates must make available written procedures consistent with manufacturer's instructions to the pilot that describe how to:

(i)Perform the database update; and

(ii)Determine the status of the data upload.

AerScheduler keeps inspections, squawks and work orders on each aircraft. It tracks the status; the signed logbook stays the record. See how