What Pilots Can Legally Do Themselves: Preventive Maintenance Under FAR Part 43

Every GA owner-operator eventually asks the same question. The tires are getting tired. The spark plugs are due to come out and get cleaned. The battery isn’t holding charge like it used to. Do you really need to pay shop rates for any of this, or can you handle some of it yourself?

The honest answer is: yes, you can do a meaningful amount of it — if you have the right pilot certificate, the aircraft is eligible, the task falls into a specific category the FAA has defined, and you log the work correctly.

That category is called preventive maintenance, and the rules live in 14 CFR Part 43.

What “preventive maintenance” means in regulation

The FAA draws a clear line between three things: maintenance, preventive maintenance, and major repairs/alterations. Preventive maintenance is the narrowest of the three. It’s defined in 14 CFR Part 43 as “simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations.” The specific tasks that qualify are listed in Appendix A to Part 43.

Under 14 CFR 43.3(g), the holder of a pilot certificate issued under Part 61 may perform preventive maintenance on any aircraft owned or operated by that pilot — provided the aircraft is not used under Parts 121, 129, or 135. In plain language: if you own (or operate) the airplane and you fly it under Part 91, the regulation lets you do certain limited work yourself.

Key boundaries: Preventive maintenance is not the same as inspections, major repairs, or major alterations. You cannot perform an annual or 100-hour inspection. You cannot sign off return-to-service after major work. And your certificate authority does not extend to aircraft you don’t own or operate, or to aircraft flown under Part 121, 129, or 135. When in doubt, ask your A&P or IA before turning a wrench.

What’s actually on the list

FAR Part 43 Appendix A(c) enumerates the specific tasks that qualify as preventive maintenance. The list is long, but the items cluster into a handful of recognizable categories. Rather than reproducing the regulation verbatim (you should read it for yourself), here’s the practical shape of what’s allowed:

Tires, wheels, and landing gear servicing

Removing, installing, and repairing tires. Replacing landing gear shock cords. Servicing landing gear wheel bearings (cleaning, repacking with grease). Servicing landing gear shock struts by adding air, oil, or both. Replacing wheels and skis where no weight-and-balance computation is involved.

Lubrication and basic servicing

Lubrication that does not require disassembly other than removal of nonstructural items such as cover plates, cowlings, and fairings. Replenishing hydraulic fluid in the hydraulic reservoir. Replacing defective safety wiring or cotter keys.

Spark plugs, batteries, and filters

Replacing or cleaning spark plugs and setting spark plug gap clearance. Replacing and servicing batteries. Cleaning or replacing fuel and oil strainers or filter elements. Replacing prefabricated fuel lines. Replacing any hose connection except hydraulic connections.

Lights, fuses, and simple electrical work

Troubleshooting and repairing broken circuits in landing light wiring circuits. Replacing bulbs, reflectors, and lenses of position and landing lights.

Cabin and interior items

Replacing safety belts. Replacing seats or seat parts with replacement parts approved for the aircraft, when the work does not involve disassembly of any primary structure or operating system. Repairing upholstery and decorative furnishings in the cabin or cockpit interior. Replacing side windows when the work does not interfere with structure or any operating system.

Cowlings, fairings, and cosmetic work

Replacing any cowling that does not require removal of the propeller or disconnection of flight controls. Making small simple repairs to fairings, nonstructural cover plates, cowlings, and small patches and reinforcements that do not change the contour so as to interfere with proper airflow. Refinishing decorative coating on fuselage, wings, tail surfaces (except balanced control surfaces), fairings, cowlings, landing gear, and the cabin or cockpit interior — as long as removal or disassembly of any primary structure or operating system is not required.

Chip detectors, fasteners, and panel-mount avionics

Removing, checking, and replacing magnetic chip detectors. Replacement or adjustment of nonstructural standard fasteners incidental to operations. Removing and replacing self-contained, front instrument panel-mounted navigation and communication devices that connect via tray-mounted connectors when the unit is installed into the panel.

This is not the complete list, and the regulation contains qualifying language for nearly every item — conditions like “where no weight and balance computation is involved” or “not involving disassembly of any primary structure or operating system.” Before performing any task, read the actual text of Appendix A(c) on ecfr.gov and confirm your task fits the listed condition.

The logbook entry is not optional

This is where pilot-performed preventive maintenance most commonly goes sideways. Under 14 CFR 43.9, anyone who performs maintenance, preventive maintenance, rebuilding, or alteration must make an entry in the aircraft’s maintenance record. That includes you.

A compliant maintenance record entry for preventive maintenance generally includes:

What FAR 43.9 requires in the entry

Description of work performed. Specific enough that someone reading it later can tell what was done and what was used. “Replaced battery” is thin. “Replaced battery, P/N XYZ, S/N 12345, at tach 1,247.6” is much better.

Date the work was completed.

Name of the person performing the work.

Signature, certificate number, and kind of certificate held by the person approving the work for return to service. For preventive maintenance performed under 43.3(g), the pilot performing the work signs and lists their pilot certificate information.

The entry should go in the appropriate logbook (airframe, engine, or propeller, depending on the component). If the work is done on the engine, it belongs in the engine log; on the airframe, the airframe log; and so on.

Why this matters at annual time: Your IA will ask to see records of preventive maintenance you performed during the year. An undocumented battery swap or oil filter change isn’t just a paperwork problem — it can raise questions about other undocumented work and slow your inspection down. Clean records save real time.

What’s NOT preventive maintenance (don’t go here without an A&P)

Just as important as knowing what you can do is knowing what’s off-limits. Common items that pilot-owners sometimes assume are okay but are not preventive maintenance under Part 43 Appendix A include:

Beyond the line:

• Oil changes on most engines (engine oil servicing is not in the Appendix A(c) list)
• Magneto inspections, internal magneto work, or timing adjustments
• Carburetor or fuel injection servicing
• Brake disassembly or relining (beyond simple hydraulic top-off)
• Cylinder compression testing as part of an inspection
• Any work on a balanced control surface
• Any inspection required by Part 91 (annual, 100-hour, ELT, transponder)
• Anything that disassembles primary structure or an operating system

Inside the line:

• Spark plug cleaning, gap setting, and replacement
• Tire replacement, wheel bearing service
• Battery replacement and servicing
• Oil and fuel filter element replacement
• Bulb replacement on position and landing lights
• Hydraulic reservoir fluid replenishment
• Magnetic chip detector inspection and replacement
• Lubrication that doesn’t require structural disassembly

The “oil change” question is the one most commonly asked — and the most commonly misunderstood. Routine engine oil changes are not listed in Part 43 Appendix A(c) as preventive maintenance. Many owners participate in oil changes alongside their A&P (with the A&P signing off), but performing and signing off the work as preventive maintenance under 43.3(g) is not what the regulation contemplates. If you want to do oil changes yourself, talk to your A&P about the appropriate arrangement — including supervision and signoff — before you start.

A practical checklist before you turn a wrench

Before performing any preventive maintenance, run through this five-question check:

1. Do I hold a Part 61 pilot certificate, and do I own or operate this aircraft?

Sport, recreational, private, commercial, or ATP all satisfy the certificate requirement under 43.3(g). Student pilots do not. The aircraft must be owned or operated by you, and not used under Parts 121, 129, or 135.

2. Is the task specifically listed in 14 CFR Part 43 Appendix A(c)?

Read the regulation text, not a summary. Confirm the task and the qualifying language — “where no weight and balance computation is involved,” “not requiring disassembly of any primary structure,” etc.

3. Do I have the correct parts, tools, and manufacturer guidance?

The aircraft and engine manufacturer’s maintenance manual is the technical reference, even for tasks the FAA permits you to perform. Following manufacturer procedures keeps you on solid ground both for safety and for any later questions from an IA or insurance carrier.

4. Am I prepared to make a complete, signed logbook entry under 43.9?

If you’re not going to log it, don’t do it. An undocumented repair is worse than no repair — it leaves an unknown in the aircraft’s history.

5. Is there any doubt? If yes, stop and call your A&P.

The cost of a five-minute phone call to your mechanic is always less than the cost of doing work that turns out to be beyond the preventive maintenance line.

Where TachMinder fits in

One of the reasons owner-performed preventive maintenance gets undercounted in maintenance records is friction. The shop visit naturally produces a logbook entry — the mechanic writes it up. A spark plug rotation you do on a Saturday afternoon often doesn’t, because nobody is standing there with a pen.

That’s part of what we’re building TachMinder for: a clean way to capture preventive maintenance you’ve performed yourself, attach a photo of the work and any parts receipts, and produce a tidy entry that mirrors what 43.9 requires. The legal logbook is still your physical or formal record — but your digital record can prompt you for everything that needs to be in it, and give your IA a clean summary before annual.

A few numbers worth keeping in mind: Part 43 Appendix A(c) lists 31 categories of preventive-maintenance tasks; FAR 43.9 is the section that defines what every maintenance record entry must contain; and Part 61 defines the pilot certificates eligible to perform preventive maintenance.

The bottom line

The regulation gives you real authority — tightly defined, but real. Used well, it can lower your maintenance costs, deepen your understanding of your airplane, and produce cleaner records than the average owner. Used carelessly, it can produce a paperwork mess and, worse, work that wasn’t actually within your authority.

The two habits that separate owners who do this well from owners who get into trouble are simple. They read the actual text of the regulation before doing a task for the first time. And they treat the logbook entry as part of the job, not an optional follow-up.