FAR-AMT Practice Test 2026 – The Comprehensive All-in-One Guide to Exam Success!

Part 121 governs airline-style operations by air carriers, spelling out the operating requirements for flights conducted domestically within the U.S., as well as flag (international) and supplemental (charter) services. That scope is captured in the term “domestic and flag operations,” which is why this option is the best fit. The other categories—small general aviation, experimental aircraft, and rotorcraft operations—are governed by different parts of the regulations (for example, general aviation largely falls under Part 91, with separate rules for experimental and rotorcraft operations), so they do not fall under Part 121. The key idea is that Part 121 applies to the airline, large-aircraft, carrier operations that occur domestically and on international services.