If the instructive content is invalid, you send a invalidation message. But if there's a violation of constraints, modern practice (both in and outside crypto p

If the instructive content is invalid, you send a invalidation message. But if there's a violation of constraints, modern practice (both in and outside crypto projects) can do a pretty good job of precluding it, with test cases, wide review, multiple implementations, formal verification, and so forth. And when something slips by, many eyes & many implementations make a consensus fix very fast. No one has 'fat-fingered' the major blockchains in a long time! Some proprietary/permissioned chains have had problems. And stuff as complicated as smart contracts can go awry in subtle ways. But NOTAM seems to be just a simple text log! Distributed consensus inherently achieves one-source-of-truth without single-point-of-failure. As the notices relevant to individual flight-paths are inherently geo-local, with many independent submitters (like airports), any routing "through the FAA in DC" introduces risks – even if the FAA has final authority over who (which keys) can add entries. Yes, Bitcoin's consensus state is relatively simple – but also far more compicated than NOTAM's even-simpler message. And continually redundantly verified & replicated by many independent actors & codebases, very successfully, for 10+ years.