FAA Aviation Mechanic General (AMG)Regulations, Records and Human FactorsMedium
A technician installs a different engine model on a certificated aircraft that is not listed as an approved alternate in the Type Certificate Data Sheet, requiring recalculation of the aircraft's weight and balance. This change is classified as a:
- APreventive maintenance item
- BMinor alteration
- CMinor repair
- DMajor alteration
Show answer & explanationAnswer & explanation
Correct answer: D. Major alteration
Per 14 CFR Part 1 and Appendix A of Part 43, a change that could appreciably affect weight, balance, structural strength, or performance and is not listed in the manufacturer's data is a major alteration, requiring FAA-approved data and Form 337 documentation.
Why the other options are wrong
- A. Engine substitution is far beyond preventive maintenance scope.
- B. Minor alterations do not appreciably affect airworthiness factors like this change does.
- C. A repair restores to original condition; this is a change to a different configuration.
Major Alteration
A change to an aircraft not listed in the manufacturer's specifications that could appreciably affect weight, balance, structural strength, performance, or other qualities affecting airworthiness.
- Requires FAA-approved data.
- Documented on FAA Form 337.
- Contrasts with minor alterations, which don't need such approval.
Memory trick: 'Major moves the needle' — big impact = major alteration.