Piston and rotary engines using spark ignition—such as those powering general aviation aircraft, light sport aircraft, and certain unmanned aerial systems—occupy a tightly defined classification that separates them from both jet engines and automotive piston engines. FAA type-certificate status and airworthiness documentation are central to the commercial transaction, and CBP classification depends on demonstrating the engine's design and certification for aircraft use. Importers should note that aircraft engines and their components may also be subject to FAA import requirements and bilateral airworthiness agreements that govern the acceptability of foreign-manufactured engines for US-registered aircraft.

AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.