Preventive maintenance

Preventive maintenance is a narrow privilege: a defined list of simple tasks on aircraft you own or operate, logged and signed off by you. Step outside that list and you've crossed into unauthorized maintenance.

What counts as preventive maintenance

Preventive maintenance is "simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations" §1.1. The exact qualifying tasks are listed item-by-item §43-app-a-c.

Anything not on that list is regular maintenance, a major repair, or a major alteration — all of which require an A&P (or an A&P with IA for majors), not a pilot.

Who can perform it

The holder of a pilot certificate issued under Part 61 may perform preventive maintenance §43.3, subject to two limits:

• The pilot must own or operate the aircraft
• The aircraft must not be used under Part 121, 129, or 135 operations

A renter at a flight school does not qualify — the flight school is the operator §91.403. A co-owner in a partnership or LLC does qualify for their share of the aircraft. Sport pilots have a narrower authority limited to aircraft with a light-sport special airworthiness certificate.

Preventive maintenance vs. inspections

Easy to conflate, completely different in practice.

Preventive maintenance

• Narrow Part 43 Appendix A(c) list — tires, bulbs, spark plug cleaning, oil servicing
• Pilot owner may perform and sign the return-to-service themselves

Annual and 100-hour inspections

• Full regulatory inspections per Part 43 Appendix D §91.409
• Annual must be signed off by an Inspection Authorization (IA) holder
• 100-hour can be signed off by any A&P mechanic
• A pilot cannot sign off either inspection, regardless of certificate level

The trap: a pilot owner who just replaced the battery thinks "I just did maintenance." They did — specifically, preventive maintenance. That authority does not extend to signing the annual.

Common items

A sampling from the Part 43 Appendix A(c) list:

• Replace landing gear tires; service wheel bearings and shock struts
• Replace safety belts and seats (approved parts, no structural disassembly)
• Replace bulbs, reflectors, and lenses of position and landing lights
• Replace or clean spark plugs and set the gap
• Replenish hydraulic fluid
• Refinish decorative coatings (not on control surfaces)
• Replace the battery
• Replace prefabricated fuel lines

The list is enumerative, not illustrative — if it's not there, it's not preventive maintenance.

Logging and return to service

The maintenance record entry must contain §43.9:

• A description of the work (or reference to acceptable data)
• The date completed
• The name of the person who performed the work
• Signature, certificate number, and kind of certificate of the person approving the aircraft for return to service

For pilot-performed preventive maintenance, your pilot certificate number and level go in that final block. That signature is the return-to-service approval §43.5 §43.7 — without it, the work isn't formally approved back into service.

Worked examples:

• Oil change on a Cessna 172 — Owner-pilot drains the oil per the POH service procedure, installs a new filter, refills, makes the maintenance record entry, and signs the return-to-service block §43.7 §43.9. This task is on the Part 43 Appendix A(c) list — a private pilot or higher may do it on their own aircraft.
• Magneto timing — Not on the Part 43 Appendix A(c) list. Requires an A&P mechanic; the owner's signature won't satisfy the return-to-service rule. Even though it's a "small" tweak to the existing ignition system, the work falls outside preventive maintenance.