The maintenance regulations in Part 91 are something that you will be tested on for all certificates. They are especially important if you are the owner/operator of an aircraft. Part 43 governs maintenance and preventive maintenance.
The owner or operator of an aircraft is primarily responsible for maintaining that aircraft in an airworthy condition, including compliance with Airworthiness Directives.
No person may perform maintenance, preventive maintenance, or alterations on an aircraft other than as prescribed in this subpart and other applicable regulations, including part 43 of this chapter.
Each owner or operator of an aircraft shall have that aircraft inspected; have discrepancies repaired; shall ensure that maintenance personnel make appropriate entries in the aircraft maintenance records indicating the aircraft has been approved for return to service; and shall have any inoperative instrument or item of equipment, permitted to be inoperative repaired, replaced, removed, or inspected at the next required inspection.
Operation After Maintenance
No person may carry any person (other than crewmembers) in an aircraft that has been maintained, rebuilt, or altered in a manner that may have appreciably changed its flight characteristics or substantially affected its operation in flight until an appropriately rated pilot with at least a private pilot certificate flies the aircraft, makes an operational check of the maintenance performed or alteration made, and logs the flight in the aircraft records.
The aircraft does not have to be flown as required above if, prior to flight, ground tests, inspection, or both show conclusively that the maintenance, preventive maintenance, rebuilding, or alteration has not appreciably changed the flight characteristics or substantially affected the flight operation of the aircraft.
No person may operate an aircraft unless, within the preceding 12 calendar months, it has had an annual inspection in accordance with part 43 and approved for return to service. An annual inspection must be conducted by an IA.
100 Hour Inspections
No person may operate an aircraft carrying any person (other than a crewmember) for hire, and no person may give flight instruction for hire in an aircraft which that person provides, unless within the preceding 100 hours of time in service the aircraft has received an annual or 100-hour inspection and been approved for return to service in accordance with part 43. A 100 hour inspection may be conducted by an A&P or IA.
The 100-hour limitation may be exceeded by not more than 10 hours while en route to reach a place where the inspection can be done. The excess time used to reach a place where the inspection can be done must be included in computing the next 100 hours of time in service.
There are lots of exceptions that do not generally apply to light aircraft. Experimental certificate and light-sport require an annual condition inspection performed once every 12 calendar months.
Light sport can be conducted by a certificated repairman (light-sport aircraft) with a maintenance rating, an appropriately rated mechanic, or an appropriately rated repair station.
The operating limitations on your homebuilt will include the following (or something similar):
No person shall operate this aircraft unless within the preceding 12 calendar months it has had a condition inspection performed in accordance with the scope and detail of appendix D to part 43, or other FAA-approved programs, and found to be in a condition for safe operation. The inspection can be performed by any licensed A&P mechanic, an FAA Approved Repair Station, or by the builder of the airplane provided the builder obtains a “Repairman’s Certificate” from the FAA.
No person may operate an airplane, or helicopter, in controlled airspace under IFR unless within the preceding 24 calendar months, each static pressure system, each altimeter instrument, and each automatic pressure altitude reporting system has been tested and inspected.
No persons may use an ATC transponder unless, within the preceding 24 calendar months, the ATC transponder has been tested and inspected and found to comply with regulations.
Except for work performed in accordance with the regulations governing Altimeters and Transponders, each registered owner or operator shall keep the following records until the work is repeated or superseded by other work or for 1 year after the work is performed.
Records of the maintenance, preventive maintenance, and alteration and records of the 100-hour, annual, progressive, and other required or approved inspections, as appropriate, for each aircraft (including the airframe) and each engine, propeller, rotor, and appliance of an aircraft must include—
• A description (or reference to data acceptable to the Administrator) of the work performed; and
• The date of completion of the work performed; and
• The signature, and certificate number of the person approving the aircraft for return to service.
• The total time in service of the airframe, each engine, each propeller, and each rotor.
• The current status of life-limited parts of each airframe, engine, propeller, rotor, and appliance.
• The time since last overhaul of all items installed on the aircraft which are required to be overhauled on a specified time basis.
• The current inspection status of the aircraft, including the time since the last inspection required by the inspection program under which the aircraft and its appliances are maintained.
• The current status of applicable airworthiness directives (AD) and safety directives including, for each, the method of compliance, the AD or safety directive number and revision date. If the AD or safety directive involves recurring action, the time and date when the next action is required.
• Copies of the forms prescribed by §43.9(d) of this chapter for each major alteration to the airframe and currently installed engines, rotors, propellers, and appliances.
The records specified in of this section shall be retained and transferred with the aircraft at the time the aircraft is sold.