Daily FAA registry snapshots can show what public registration state was observed and what changed between observations. They do not automatically prove the exact legal effective time of a change.
N-numbers and Mode S / ICAO24 addresses identify related parts of a U.S. aircraft registration, but they are not interchangeable and neither should be treated as permanent physical-aircraft identity.
The FAA makes the registry downloadable. Turning seven public files into a reliable developer API still requires validation, normalization, identity rules, atomic publication, provenance, history, and privacy controls.
