{"data":{"id":"us/14-cfr-171.21","jurisdiction":"us","citation":"14 CFR 171.21","heading":"Scope.","body":"(a) This subpart sets forth minimum requirements for the approval and operation of non-Federal, nondirectional radio beacon facilities that are to be involved in the approval of instrument flight rules and air traffic control procedures related to those facilities.\n(b) A nondirectional radio beacon (“H” facilities domestically—NDB facilities internationally) radiates a continuous carrier of approximately equal intensity at all azimuths. The carrier is modulated at 1020 cycles per second for station identification purposes.","path":["Title 14—Aeronautics and Space","CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER J—NAVIGATIONAL FACILITIES","PART 171—NON-FEDERAL NAVIGATION FACILITIES","Subpart B—Nondirectional Radio Beacon Facilities"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-14.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:20Z","sha256":"99135dcfed6f5dde9ef3b7a26b2d74578b252c1ff0cf204c73a85d133bd874c7","source_id":"us-cfr","stale":true,"prev":"us/14-cfr-171.13","next":"us/14-cfr-171.23"},"notice":"GroundRules: Original legal text. Not legal advice."}