Regulations last checked for updates: Jun 02, 2024

Title 14 - Aeronautics and Space last revised: May 28, 2024
§ 171.21 - Scope.

(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.

(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.

[Doc. No. 5034, 29 FR 11337, Aug. 6, 1964, as amended by Amdt. 171-2, 31 FR 5408, Apr. 6, 1966; Amdt. 171-7, 35 FR 12711, Aug. 11, 1970]
authority: 49 U.S.C. 106(g), 40103-40107, 40109, 40113, 44502, 44701-44702, 44708-44709, 44711, 44719-44721, 45303, 46308
source: Docket No. 5034, 29 FR 11337, Aug. 6, 1964, unless otherwise noted.
cite as: 14 CFR 171.21