The FAA allows pilots to accomplish some maintenance on aircraft, the maintenance allowed is considered preventative maintenance and outlined in CFR Title 14, Part 43, Appendix A(c). Preventive maintenance can be best described as simple or minor operations and the replacement of small standard parts not involving complex assembly operations. These operations can be performed by the holder of a private pilot certificate or greater as outlined in CFR Title 14, 43.3(g) if the aircraft is not used under part 121, 129, or 135.
There are numerous specific items the FAA allows pilots to maintain. On landing gear you may remove, install and repair landing gear tires, service landing gear shock struts by adding oil, air, or both; and service landing gear wheel bearings, such as cleaning and greasing. You may replace defective safety wiring or cotter keys and replenish hydraulic fluid in the hydraulic reservoir.
When you move into the cabin you may repair upholstery and decorative furnishings of the cabin or cockpit when it does not require disassembly of any primary structure or operating system, interfere with an operating system, or affect the primary structure of the aircraft; replace side windows where that work does not interfere with the structure or any operating system such as controls, electrical equipment; and replace safety belts and seats or seat parts with replacement parts approved for the aircraft, not involving disassembly of any primary structure or operating system.
In the electrical system you may troubleshoot and repair broken circuits in landing light wiring circuits, replace bulbs, reflectors, and lenses of position and landing lights, replace and service batteries.
On the engine you may replace or clean spark plugs, set spark plug gap clearance, replace prefabricated fuel lines, remove, check and replace magnetic chip detectors, and clean or replace fuel and oil strainers or filter elements. When it comes to your panel mounted avionics you may update self-contained, front instrument panel-mounted air traffic control navigational software data bases 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.
Now that you know what you can work on you should collect some reference material to assure that you correctly perform each task. You should at least have the approved maintenance manuals. Both aircraft manufacturers and component manufacturers usually have guidance to explain the proper methods to correctly perform maintenance on the products they produce. Remember, after you perform a task you need to assure that the aircraft will still operate within the requirements that were originally outlined in its certification to remain airworthy. If you don’t have any information on how to quantify the operation of the system, as is found in maintenance manuals, you cannot positively state that the repair is airworthy.
As an example, you can replace your battery, but if you don’t have the appropriate knowledge on removal and installation significant damage can be done to the aircraft. Another example may be replacing fuel lines. If you don’t have the maintenance manual that explains how to verify that there is proper fuel flow after the maintenance is complete, you are just experimenting at that point. A situation like that would be frowned upon by the FAA not to mention your insurance company.
After the maintenance is complete you need to properly return the aircraft to service. Logbook entries are required any time maintenance is accomplished to document the work. The logbook entry should include the date, aircraft make, model, serial number, total time, a reference to the instructions used to perform the work, the name of the person that did the work and their pilot certificate number. You can usually reference a previous maintenance entry completed by an airframe and powerplant mechanic to see the proper details and format.
One word of caution, I’ve seen more than one case where an owner comes to me with a significant problem that started out as a very minor issue that they felt they could fix themselves. They used an improper method or material and it quickly became a dangerous and expensive event. The take away lesson is to only do the approved preventative maintenance items if you have a high level of knowledge and ability to perform the task. If you are not one hundred percent sure that you have knowledge and ability, either seek out the information you need or take it to the shop.