Aviation is the most thoroughly federalized corner of American transportation law, and almost every hard question in it is a question about where federal authority stops. This guide traces the architecture from the top: the United States' exclusive sovereignty over navigable airspace under 49 U.S.C. § 40103, the FAA's certification of aircraft, airmen, and operators, and the operating regimes of Parts 91, 121, and 135. It then works through the three distinct preemption doctrines that lawyers routinely confuse — implied field preemption of aviation safety standards (contested, with the circuits genuinely split), the Airline Deregulation Act's express preemption of state laws related to price, route, or service (Morales, Wolens, Ginsberg), and the Montreal Convention's treaty exclusivity for international carriage (Tseng). Along the way it covers FAA enforcement and the NTSB certificate appeal, aircraft title and the Oklahoma City registry after Philko, Cape Town Convention financing and Bankruptcy Code § 1110, airport proprietor liability and noise, aviation product liability and the General Aviation Revitalization Act's 18-year repose, the inadmissibility of NTSB probable-cause findings under 49 U.S.C. § 1154(b), aviation insurance warranties, and the fast-moving law of unmanned aircraft. Drone rules in particular change constantly, and Part 107 does not displace state privacy, trespass, or nuisance law — verify before you rely on anything in this space.