{"id":"S2003001445","label":"National Airspace System (U.S.)","description":"","source_url":"https://id.loc.gov/authorities/subjects/sh2003001445","normalized_label":"national airspace system (u.s.)","broader":["http://id.loc.gov/authorities/subjects/sh2003006650"],"aliases":["NAS (U.S.)"],"source_identifier":"http://id.loc.gov/authorities/subjects/sh2003001445","provider":"lcsh","revision":"c78f15685c3f8698","taxonomy_revision":"f050b5d4780b1289","title":"National Airspace System (U.S.)","url":"/topics/S2003001445","kind":"topic-directory","aeo_cohort":"topic-directory","catalogue_revision":"f050b5d4780b1289","numeric_address":"13837393445393670662","address_version":"morton4x16-v1","coordinates":[0,477,36225,37888],"answer_status":"Directory metadata; local answer requires separate source review","truth_status":"Subject descriptor, not a factual answer or a demonstrated knowledge gap","reviewed_answer":null}