What maintenance can an aircraft owner legally do?

Short answer: A pilot-owner of a standard-category aircraft may perform "preventive maintenance," the specific list of simple tasks in 14 CFR Part 43, Appendix A, paragraph (c), on an aircraft they own or operate (14 CFR 43.3(g)). With at least a private pilot certificate, they can also approve that work for return to service and must log it (14 CFR 43.7(f) and 43.9). Anything beyond that list, including annual and 100-hour inspections, requires a certificated mechanic.

Who qualifies?

Under 14 CFR 43.3(g), the holder of a pilot certificate issued under Part 61 may perform preventive maintenance on an aircraft they own or operate, as long as it is not used under Part 121, 129, or 135. Sport pilot certificate holders are excluded from this privilege for type-certificated aircraft. To approve the work for return to service, you need at least a private pilot certificate (14 CFR 43.7(f)).

Experimental and light-sport aircraft follow different rules; this answer covers standard-category airplanes like Cessnas, Pipers, Beechcraft, and Cirrus.

What is on the preventive maintenance list?

Appendix A, paragraph (c) says preventive maintenance "is limited to" the listed work, and the work must not involve complex assembly operations. A 2009 FAA Chief Counsel letter reads the list as examples rather than all-inclusive, but the safe practice is to treat it as the boundary. Highlights relevant to typical piston owners include:

• Removing, installing, and repairing landing gear tires
• Servicing landing gear shock struts with oil, air, or both
• Servicing wheel bearings (cleaning and greasing)
• Replacing defective safety wire or cotter keys
• Lubrication not requiring disassembly beyond nonstructural items like cover plates, cowlings, and fairings
• Replacing safety belts
• Replacing bulbs, reflectors, and lenses of position and landing lights
• Replacing any cowling not requiring removal of the propeller or disconnection of flight controls
• Replacing or cleaning spark plugs and setting plug gap
• Replacing any hose connection except hydraulic connections
• Replacing prefabricated fuel lines
• Cleaning or replacing fuel and oil strainers or filter elements
• Replacing and servicing batteries
• Updating databases in self-contained, panel-mounted navigation units (excluding autopilots, transponders, and DME)
• Removing and replacing self-contained, panel-mounted nav and comm units with tray-mounted connectors (same exclusions)

If a task is not on the list, or doing it requires something that is not on the list, ask a mechanic before treating it as preventive maintenance.

What can an owner NOT do?

• Required inspections. Annual inspections need an IA (14 CFR 65.95); 100-hour inspections need an A&P. An owner cannot sign either.
• Repairs and alterations beyond the Appendix A list, including any major repair or major alteration.
• AD compliance, unless the specific AD expressly allows the owner or pilot to perform and record it.
• Transponder and altimeter checks required by 14 CFR 91.413 and 91.411, which must be done by an appropriately rated repair station or other authorized person.

Can I help with my own annual?

Yes, with limits. Under 14 CFR 43.3(d), a person working under the supervision of a certificated mechanic may perform maintenance that the supervisor is authorized to perform, if the supervisor personally observes the work to the extent necessary and is readily available in person. This is the basis for "owner-assisted" annuals, where the owner removes panels, cleans, and helps with routine work. It does not let the owner perform the inspection itself; that remains the IA's job.

How must owner work be recorded?

Every preventive maintenance task must be entered in the maintenance records under 14 CFR 43.9, including:

• A description of the work (or reference to acceptable data)
• The date the work was completed
• Your name, signature, certificate number, and kind of certificate

The work must also be done to the standards in 14 CFR 43.13, using methods, tools, and data acceptable to the FAA, such as the manufacturer's maintenance manual. An unlogged oil filter change is, legally, maintenance that never happened.

A practical rule of thumb

If you would hesitate to explain the task to an FAA inspector, or if it touches flight controls, fuel system plumbing beyond prefabricated lines, structure, or the engine internals, stop and call a mechanic. Preventive maintenance done well saves money; done outside the list, it can make the aircraft unairworthy.

How Wingman handles it

Wingman AeroCare is happy to work with hands-on owners. If you are not sure whether a task falls under Appendix A, call (970) 292-0719 and ask before you start. When you bring your aircraft to KFNL for an annual or 100-hour, an annual is performed and signed off by an A&P with Inspection Authorization (a 100-hour by a certificated A&P), and every finding comes to you on an online estimate with photos, labeled Airworthy, Recommended, or Optional, so you decide what we do. See annual inspections or contact us.