Which appendix of 14 CFR Part 43 specifies alterations that are considered major?

The appendix of 14 CFR Part 43 that specifies alterations considered major is Appendix A. This appendix provides a clear definition and list of alterations that the Federal Aviation Administration (FAA) classifies as major. Major alterations pertain to changes that could substantially affect the aircraft's performance, characteristics, or safety. Understanding what constitutes a major alteration is crucial for aircraft maintenance professionals, as they must follow specific procedures, including obtaining proper approvals and documenting these changes in the aircraft's maintenance records.

The knowledge of major and minor alterations is essential in ensuring compliance with regulation standards and maintaining the safety and airworthiness of aircraft. This classification assists technicians in determining when a Form 337 (Report of Major Repair or Alteration) is required to be filed with the FAA.