Owner Maintenance, Who Can Do What?

I subscribe to several email distribution lists that discuss maintenance and aircraft ownership. I've noticed that there are many people out there that don't fully understand the Federal Aviation Regulations (FAR's) in regards to maintenance. In particular, there is a lot of confusion on what an owner can legally do to their airplanes. I thought I'd write a bit on the subject.

Federal Aviation Regulations
The FAR's that govern maintenance and returning an aircraft to service are referenced in FAR PART 43—MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION. This is where the feds specify who can do what to USA certificated (N-Numbered) airplanes.

FAR PART 43.3 describes who can do what:

• (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.

Most owners that are not licensed mechanics fall into subsection (d) and (g). So what does this mean exactly? In a nutshell, it means an aircraft owner can do anything that a licensed mechanic can do as long as they follow the rules governing this maintenance. If it falls into section g (preventative maintenance) they can do the work on their own and legally return the aircraft to service on their own. An owner can also do anything a licensed mechanic can do as long as a mechanic that can legally do the maintenance being performed is supervising their work. Yep, an owner could even change out an engine or recover a fabric airplane if a licensed mechanic is supervising them.

NOTE: One thing to note about supervised maintenance is that the mechanic supervising the work does not need to hover over you. It is up to the mechanic to decide how much oversight you need and when they need to inspect what you've done. It is best to work this out up front before starting anything so there is no confusion.

Preventative Maintenance
Ok, we all know we can change the oil, but what else can an owner legally do on their own without being supervised by a mechanic? FAR Part 43 Appendix A is where we find the answer to that question:

(c) Preventive maintenance. Preventive maintenance is limited to the following work, provided it does not involve complex assembly operations:

• (1) Removal, installation, and repair of landing gear tires.
• (2) Replacing elastic shock absorber cords on landing gear.
• (3) Servicing landing gear shock struts by adding oil, air, or both.
• (4) Servicing landing gear wheel bearings, such as cleaning and greasing.
• (5) Replacing defective safety wiring or cotter keys.
• (6) Lubrication not requiring disassembly other than removal of nonstructural items such as cover plates, cowlings, and fairings.
• (7) Making simple fabric patches not requiring rib stitching or the removal of structural parts or control surfaces. In the case of balloons, the making of small fabric repairs to envelopes (as defined in, and in accordance with, the balloon manufacturers’ instructions) not requiring load tape repair or replacement.
• (8) Replenishing hydraulic fluid in the hydraulic reservoir.
• (9) Refinishing decorative coating of fuselage, balloon baskets, wings tail group surfaces (excluding balanced control surfaces), fairings, cowlings, landing gear, cabin, or cockpit interior when removal or disassembly of any primary structure or operating system is not required.
• (10) Applying preservative or protective material to components where no disassembly of any primary structure or operating system is involved and where such coating is not prohibited or is not contrary to good practices.
• (11) Repairing upholstery and decorative furnishings of the cabin, cockpit, or balloon basket interior when the repairing does not require disassembly of any primary structure or operating system or interfere with an operating system or affect the primary structure of the aircraft.
• (12) Making small simple repairs to fairings, nonstructural cover plates, cowlings, and small patches and reinforcements not changing the contour so as to interfere with proper air flow.
• (13) Replacing side windows where that work does not interfere with the structure or any operating system such as controls, electrical equipment, etc.
• (14) Replacing safety belts.
• (15) Replacing seats or seat parts with replacement parts approved for the aircraft, not involving disassembly of any primary structure or operating system.
• (16) Trouble shooting and repairing broken circuits in landing light wiring circuits.
• (17) Replacing bulbs, reflectors, and lenses of position and landing lights.
• (18) Replacing wheels and skis where no weight and balance computation is involved.
• (19) Replacing any cowling not requiring removal of the propeller or disconnection of flight controls.
• (20) Replacing or cleaning spark plugs and setting of spark plug gap clearance.
• (21) Replacing any hose connection except hydraulic connections.
• (22) Replacing prefabricated fuel lines.
• (23) Cleaning or replacing fuel and oil strainers or filter elements.
• (24) Replacing and servicing batteries.
• (25) Cleaning of balloon burner pilot and main nozzles in accordance with the balloon manufacturer’s instructions.
• (26) Replacement or adjustment of nonstructural standard fasteners incidental to operations.
• (27) The interchange of balloon baskets and burners on envelopes when the basket or burner is designated as interchangeable in the balloon type certificate data and the baskets and burners are specifically designed for quick removal and installation.
• (28) The installations of anti-misfueling devices to reduce the diameter of fuel tank filler openings provided the specific device has been made a part of the aircraft type certificiate data by the aircraft manufacturer, the aircraft manufacturer has provided FAA-approved instructions for installation of the specific device, and installation does not involve the disassembly of the existing tank filler opening.
• (29) Removing, checking, and replacing magnetic chip detectors.
• (30) The inspection and maintenance tasks prescribed and specifically identified as preventive maintenance in a primary category aircraft type certificate or supplemental type certificate holder’s approved special inspection and preventive maintenance program when accomplished on a primary category aircraft provided:
• (i) They are performed by the holder of at least a private pilot certificate issued under part 61 who is the registered owner (including co-owners) of the affected aircraft and who holds a certificate of competency for the affected aircraft (1) issued by a school approved under §147.21(e) of this chapter; (2) issued by the holder of the production certificate for that primary category aircraft that has a special training program approved under §21.24 of this subchapter; or (3) issued by another entity that has a course approved by the Administrator; and
• (ii) The inspections and maintenance tasks are performed in accordance with instructions contained by the special inspection and preventive maintenance program approved as part of the aircraft’s type design or supplemental type design.
• (31) Removing and replacing self-contained, front instrument panel-mounted navigation and communication devices that employ tray-mounted connectors that connect the unit when the unit is installed into the instrument panel, (excluding automatic flight control systems, transponders, and microwave frequency distance measuring equipment (DME)). The approved unit must be designed to be readily and repeatedly removed and replaced, and pertinent instructions must be provided. Prior to the unit’s intended use, and operational check must be performed in accordance with the applicable sections of part 91 of this chapter.
• (32) Updating self-contained, front instrument panel-mounted Air Traffic Control (ATC) navigational software data bases (excluding those of automatic flight control systems, transponders, and microwave frequency distance measuring equipment (DME)) provided no disassembly of the unit is required and pertinent instructions are provided. Prior to the unit’s intended use, an operational check must be performed in accordance with applicable sections of part 91 of this chapter.

Many owners are surprised at how many things they can legally do. It is indeed quite a list. Where this can really pay off is in interior refurbishment. An owner can replace their seats, carpet, etc. inside the cabin as long as major structural/complex disassembly is not required. They can even replace the side windows.

NOTE: I am referencing Owner performed maintenance here. Sub-section 30 (i) above specifically states only an owner or co-owner can do preventative maintenance. A private pilot, for example, cannot perform preventative maintenance if they are not listed as an owner of the airplane in FAA records or are a shareholder of the corporation the aircraft title is held in. This limitation holds true even if the private pilot is the only person flying the aircraft in question (e.g. Son changing oil on Dad's plane).

Parts Suppliers Geared Toward Owners
There are many places to buy parts online. I've found that Aircraft Spruce is one of the best for general parts needed such as tires, breaks, oil lines, etc. They have an easy website to use, their prices are competitive and they have thousands of parts in stock that are shipped form two huge distribution warehouses.

AirTex Aircraft Interiors has established a darn good business out of selling easy to install replacement interior panels and parts. These inexpensive kits can turn an out-dated cabin into one that looks like new. They sell seat belts, hardware and everything needed to do a professional install.

Vantage Plane Plastics sells replacement plastic interior parts for many airplanes. This is the place to go if you have a specialized plastic part that is cracked and you want to replace it.

LP Aero Plastics sells side windows and other Lucite parts. They manufacturer high quality components and can often build specialized parts to order if you can send them a part to replicate.

Logbook Entries
The key to performing maintenance on an aircraft, however, is that all work done to an airplane MUST have a logbook entry and be performed in accordance with some applicable data. This is where many owners fall short. They are afraid to put their name in the logbook or are not sure how to do it. If they don't, the aircraft is not legally airworthy even if the work performed was legit. Further, a pilot caught flying an airplane without proper records would likely loose their license. Insurance could also refuse to pay a claim if an airplane is deemed not airworthy.

FAR 43.9 describes what is legally required to be included in a logbook entry:

(a) Maintenance record entries. Except as provided in paragraphs (b) and (c) of this section, each person who maintains, performs preventive maintenance, rebuilds, or alters an aircraft, airframe, aircraft engine, propeller, appliance, or component part shall make an entry in the maintenance record of that equipment containing the following information:

• (1) A description (or reference to data acceptable to the Administrator) of work performed.
• (2) The date of completion of the work performed.
• (3) The name of the person performing the work if other than the person specified in paragraph (a)(4) of this section.
• (4) If the work performed on the aircraft, airframe, aircraft engine, propeller, appliance, or component part has been performed satisfactorily, the signature, certificate number, and kind of certificate held by the person approving the work. The signature constitutes the approval for return to service only for the work performed.

A logbook entry for carpet replacement would look something like this.

"Date, total Time. Removed aircraft cabin carpet from floor and sidewalls. Installed Airtex Navy Blue Nylon carpet part number xxx in accordance with AC 43-13-1B, Section 4. Materials used exceeds FAR 23.853(a) specifications. Burn tests results described in FAR part 23 Appendix F have been included in the aircraft records. Your signature, your pilots license number, your certification level (e.g. private pilot) ."

There are two key logbook requirements that owners tend to omit.

The first is referencing the applicable data that is "acceptable by the administrator." No one can perform work on an airplane unless they have something that tells them how to do it. Routine maintenance procedures like changing carpet or fixing broken wires are not generally referenced in an aircraft maintenance manual, so we need other applicable data to reference in order to make the installation legal. The FAA has published an Advisory Circular 43.13 that covers standard aircraft maintenance practices and procedures. Part 1B section 4 describes interior standards and requirements. You cannot be too specific when referencing applicable data. Many mechanics reference the exact paragraphs they used as well.

The second section that many owners omit when replacing fabrics and materials is references to FAR 23. Technically if you do the work IAW with AC43.13 then you would have done so using materials that meet the burn tests; however, IA's and mechanics tend want to have it specifically spelled out in the logbook entry. NOTE: This covers them from a legal perspective since they are signing off the airworthiness of the airplane for annuals and 100 hour inspections.

Another thing to note in my sample entry above is that I stated the FAR 23 Appendix F test results are included with the aircraft records. These documents will provide you with all of the information you need to prove you legally installed the materials. Skip this step and rest assured a mechanic some day will question the work. NOTE: AirTex has these documents, but they do not send them automatically. You must specifically request the test results of the materials that they are using when you place an order.

If you are being supervised by a licensed mechanic they will help you with creating the logbook entry. In general, however, to legally return an aircraft to service after supervised maintenance is by actually creating two logbook entires. The person (e.g. owner) performing the work would sign it off similar to my sample above. Then directly under that entry, the mechanic would sign indicating that they supervised the work, that it was done in accordance with whatever and the aircraft is ok to return to service. If the mechanic supervising did not actually perform the work, it is NOT legal for them to create a logbook entry stating they did the work. Many do, but this falls into FAR Part 43.12 -- Maintenance records: Falsification, reproduction, or alteration. A mechanic and pilot would likely loose their licenses if an overzealous fed caught them falsifying records like this.