14 CFR § 171.321 - DME and marker beacon performance requirements.

---
identifier: "/us/cfr/t14/s171.321"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 171.321 - DME and marker beacon performance requirements."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "171.321"
section_name: "DME and marker beacon performance requirements."
chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "J"
subchapter_name: "NAVIGATIONAL FACILITIES"
part_number: "171"
part_name: "NON-FEDERAL NAVIGATION FACILITIES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 106(g), 40103-40107, 40109, 40113, 44502, 44701-44702, 44708-44709, 44711, 44719-44721, 45303, 46308."
regulatory_source: "Docket 5034, 29 FR 11337, Aug. 6, 1964, unless otherwise noted."
cfr_part: "171"
---


# 171.321 DME and marker beacon performance requirements.

(a) The DME equipment must meet the performance requirements prescribed in subpart G of the part. This subpart imposes requirements that performance features must comply with International Standards and Recommended Practices, Aeronautical Telecommunications, Vol. I of Annex 10 to ICAO. It is available from ICAO, Aviation Building, 1080 University Street, Montreal 101, Quebec, Canada, Attention: Distribution Officer and also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: *http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.*

(b) MLS marker beacon equipment must meet the performance requirements prescribed in subpart H of this part. This subpart imposes requirements that performance features must comply with International Standards and Recommended Practices, Aeronautical Telecommuncations, Vol. I of Annex 10 to ICAO.

[Docket 5034, 29 FR 11337, Aug. 6, 1964, as amended at 69 FR 18803, Apr. 9, 2004]