FAA rules for replacing aircraft parts and appliances on single engine planes

FAA Rules for Single-Engine Aircraft Part Replacement: What You Need to Know

Maintaining the airworthiness of your single-engine aircraft is paramount to safe and compliant operation. The Federal Aviation Administration (FAA) establishes comprehensive regulations to ensure that every component installed on your plane meets rigorous safety and performance standards.1 Understanding these rules is not just a matter of compliance; it’s a commitment to the safety of every flight. This article delves into the essential FAA regulations governing aircraft part and appliance replacement on single-engine piston aircraft, offering clarity and practical guidance for owners and operators in California, Arizona, and Nevada.

AIRWORTHINESS: THE FOUNDATION OF FLIGHT

At the core of all FAA maintenance regulations is the concept of airworthiness. An aircraft is deemed airworthy when it conforms to its type design and is in a condition for safe operation.2 Simply being able to fly doesn’t mean an aircraft is airworthy. 14 CFR Part 91.7 clearly states that no person may operate an aircraft that is not in an airworthy condition.3 This responsibility extends beyond the mechanic; the pilot in command is ultimately responsible for determining that the aircraft is in a safe condition for flight.4 This principle underscores the gravity of proper part replacement.

WHO CAN PERFORM MAINTENANCE AND REPLACE PARTS?

The FAA carefully defines who is authorized to perform maintenance, preventive maintenance, rebuilding, and alterations on aircraft.5 For single-engine piston aircraft, this primarily involves certificated mechanics holding an Airframe and Powerplant (A&P) rating, often with an Inspection Authorization (IA). Part 43.3 outlines these authorizations.6 While an owner or operator can perform certain preventive maintenance tasks as defined in Appendix A of Part 43, most part replacements, especially those deemed “major repairs” or “major alterations,” require the expertise and certification of an A&P mechanic. This ensures that the work is performed by qualified individuals who understand the intricate systems of your aircraft.

APPROVED PARTS: THE CORNERSTONE OF SAFETY

When it comes to replacing parts and appliances, the type of part used is critical. The FAA requires that all parts installed on a type-certificated aircraft be “approved.”7 This approval can come from several sources, as detailed in 14 CFR Part 21:

PRODUCTION APPROVAL:

  • Production Certificate (PC): Parts manufactured by the original aircraft manufacturer under their FAA-approved production system. These are typically new parts from the aircraft’s original equipment manufacturer (OEM).
  • Parts Manufacturer Approval (PMA): Parts produced by a manufacturer other than the original design holder, but approved by the FAA to be eligible for installation on a specific type-certificated product. PMA parts undergo a rigorous approval process to ensure they meet the same design and production standards as OEM parts.8 This often involves demonstrating equivalence in design, material, and manufacturing processes.
  • Technical Standard Order (TSO): Articles (including parts and appliances like avionics, seat belts, or ELTs) that conform to minimum performance standards defined by the FAA. A TSO approval means the part itself meets certain performance criteria, but it doesn’t automatically mean it’s approved for installation on every aircraft; the installation itself must also be approved.9

OTHER ACCEPTABLE PARTS:

  • Standard Parts: Common components such as nuts, bolts, washers, and rivets that conform to established industry or U.S. specifications (e.g., AN, NAS standards).10 These do not require direct FAA approval as long as they meet the defined technical and manufacturing standards.
  • Owner-Produced Parts: In some cases, an owner or operator may produce a part for installation on their own aircraft.11 However, this is a highly scrutinized area and is permissible only if the owner participates in the design and manufacture of the part, and the part meets airworthiness standards. These parts are not for resale.
  • Salvaged Parts: Parts from salvaged aircraft can be reused, but only after they have been thoroughly inspected, tested, and certified as airworthy by a certificated repair station or FAA-authorized individual.12 The documentation for such parts must clearly demonstrate their airworthy condition.

The consistent use of FAA-approved parts is a fundamental aspect of maintaining your aircraft’s airworthiness. Relying on unapproved or questionable parts can lead to serious safety issues and regulatory violations.13

MAJOR VS. MINOR REPAIRS AND ALTERATIONS

The FAA distinguishes between “major” and “minor” repairs and alterations, which dictates the level of approval and documentation required.14 Appendix A to Part 43 provides detailed lists of what constitutes a major repair or major alteration.15

  • Minor Repair/Alteration: This is work that does not appreciably affect the aircraft’s weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other airworthiness qualities, and is not a major repair or alteration.16 Minor repairs and alterations can typically be approved for return to service by an A&P mechanic.
  • Major Repair/Alteration: These are repairs or alterations that substantially affect the airworthiness of the aircraft. Examples include changes to the basic design of fuel systems, wing structure, or engine mounts, or the replacement of primary structural members by fabrication methods like riveting or welding. Major repairs and alterations require approved data and must be recorded on an FAA Form 337, which is then submitted to the FAA.17 The work must be approved for return to service by an IA or a certificated repair station.

Understanding this distinction is vital, as it determines the required procedures and the level of authorized personnel needed to sign off on the work.

DOCUMENTATION AND RETURN TO SERVICE

Accurate and thorough record-keeping is a cornerstone of FAA regulations. After any maintenance, preventive maintenance, rebuilding, or alteration, the aircraft cannot be returned to service until it has been approved by a person authorized under Part 43.7.18 This approval involves a proper entry in the aircraft’s maintenance records, including:

  • A description of the work performed.
  • The date the work was completed.
  • The total time in service of the aircraft.
  • The signature, certificate number, and type of certificate of the person approving the aircraft for return to service.

For major repairs or alterations, the FAA Form 337 serves as the official record and must be completed and submitted to the FAA.19 This documentation is crucial for demonstrating compliance and maintaining the aircraft’s airworthiness history.

ADVISORY CIRCULARS 43.13-1B AND 43.13-2B

While the regulations in 14 CFR Parts 21, 43, and 91 provide the legal framework, Advisory Circulars (ACs) offer acceptable methods, techniques, and practices for complying with these regulations. AC 43.13-1B, “Acceptable Methods, Techniques, and Practices – Aircraft Inspection and Repair,” and AC 43.13-2B, “Acceptable Methods, Techniques, and Practices – Aircraft Alterations,” are invaluable resources. These ACs provide detailed guidance on a vast array of common repairs and alterations for aircraft weighing 12,500 pounds or less, which includes most single-engine piston aircraft. They can be used as approved data for many minor repairs and as a basis for FAA approval for major repairs when referenced correctly on a Form 337.

CHOOSING YOUR MAINTENANCE PROVIDER

When selecting a maintenance provider for your single-engine aircraft, authority and social proof are key indicators of reliability. Look for facilities with a proven track record, certified mechanics, and a deep understanding of FAA regulations. A strong reputation within the aviation community speaks volumes about the quality of service.

The Aero Center prides itself on upholding the highest FAA standards in all our maintenance operations. As the only 24/7 maintenance center in California, Arizona, and Nevada, we are committed to dramatically reducing your airplane downtime. Our team of experienced and FAA-certificated mechanics ensures every part replacement adheres strictly to regulatory requirements, providing you with peace of mind and an airworthy aircraft.

Footnotes:

  1. Federal Aviation Administration. (Current Edition). 14 CFR Part 91, General Operating and Flight Rules.
  2. Federal Aviation Administration. (Current Edition). 14 CFR Part 43, Maintenance, Preventive Maintenance, Rebuilding, and Alteration.
  3. Federal Aviation Administration. (Current Edition). 14 CFR Part 21, Certification Procedures for Products and Articles.
  4. Federal Aviation Administration. (1998). Advisory Circular 43.13-1B, Acceptable Methods, Techniques, and Practices – Aircraft Inspection and Repair.

The Aero Center is located at William J. Fox Airfield KWJF | Lancaster, CA. Contact us at 209.885.6950 for questions or appointments.

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