--- schema_version: '1.0' id: government-20260731-86f4ce content_kind: government-document url: https://www.federalregister.gov/documents/2026/07/31/2026-15585/requirements-for-interference-tolerant-radio-altimeter-systems url_hash: 86f4ce27c932e768ae02e1b042aea753a2de153de17268f8b638e044ec02c007 canonical_url: https://www.federalregister.gov/documents/2026/07/31/2026-15585/requirements-for-interference-tolerant-radio-altimeter-systems source: us-federal-register category: government/us category_raw: Rule country: us region: us tags: - Air carriers - Air taxis - Aircraft - Aviation safety - Safety lang: en published_at: '2026-07-31T00:00:00Z' fetched_at: '2026-07-31T15:01:41.688234Z' updated_at: '2026-07-31T15:09:29Z' status: published content_hash: 2ef7f38d9b8a897573f8a9c47e27b35567e6c61983b1b845a7c1c13f32468b96 content_changed_at: null license_note: full license_basis: public-domain-17usc105 body_available: false attribution: 'Source: Office of the Federal Register, National Archives and Records Administration' license_rule: source:us-federal-register summary: In July 2025, President Trump signed the One Big Beautiful Bill Act. Section 40002 of that law re-institutes the Federal Communications Commission's general auction authority and specifically directs the Commission to complete a system of competitive bidding for not less than 100 megahertz in the 3.98-4.2 gigahertz band (Upper C- band). This final rule supports the Federal Communications Commission's July 2026 Report and Order that makes 160 megahertz of the Upper C-band available for terrestrial wireless flexible use via a system of competitive bidding. To ensure safe, efficient, and reliable aviation operations in the presence of wireless signals in the C-band, the Federal Aviation Administration is issuing new regulations that require all radio altimeters to meet specific minimum performance requirements. These new radio altimeters must withstand interference from wireless signals in neighboring spectrum bands and continue to provide accurate altitude readings to both pilots and integrated aircraft safety systems. These regulations require all aircraft equipped with radio altimeters operating under part 121 and those aircraft with radio altimeters operating under part 129 with 30 or more passenger seats or a payload capacity of more than 7,500 pounds to comply with the minimum performance requirements by December 30, 2030, which is prior to the date the Federal Communications Commission authorizes the use of the Upper C-band for new wireless services, as stated in its Report and Order. All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034. summary_source: official summary_en: In July 2025, President Trump signed the One Big Beautiful Bill Act. Section 40002 of that law re-institutes the Federal Communications Commission's general auction authority and specifically directs the Commission to complete a system of competitive bidding for not less than 100 megahertz in the 3.98-4.2 gigahertz band (Upper C- band). This final rule supports the Federal Communications Commission's July 2026 Report and Order that makes 160 megahertz of the Upper C-band available for terrestrial wireless flexible use via a system of competitive bidding. To ensure safe, efficient, and reliable aviation operations in the presence of wireless signals in the C-band, the Federal Aviation Administration is issuing new regulations that require all radio altimeters to meet specific minimum performance requirements. These new radio altimeters must withstand interference from wireless signals in neighboring spectrum bands and continue to provide accurate altitude readings to both pilots and integrated aircraft safety systems. These regulations require all aircraft equipped with radio altimeters operating under part 121 and those aircraft with radio altimeters operating under part 129 with 30 or more passenger seats or a payload capacity of more than 7,500 pounds to comply with the minimum performance requirements by December 30, 2030, which is prior to the date the Federal Communications Commission authorizes the use of the Upper C-band for new wireless services, as stated in its Report and Order. All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034. provenance: doc_id: 2026-15585 doc_id_scheme: fr_docnum issuer: - Transportation Department - Federal Aviation Administration doc_type: Rule subtype: null action: Final rule. significant: null entities: - name: AI Safety Act type: event - name: Ethics Rules type: concept - name: Forbes type: organization key_facts: [] related: [] related_auto: - name: 米議会 type: organization weight: 1.0 - name: AI type: concept weight: 1.0 - name: Legal Framework type: organization weight: 1.0 - name: Ulrich Boser type: person weight: 1.0 title: Requirements for Interference-Tolerant Radio Altimeter Systems --- # Requirements for Interference-Tolerant Radio Altimeter Systems ## TL;DR In July 2025, President Trump signed the One Big Beautiful Bill Act. Section 40002 of that law re-institutes the Federal Communications Commission's general auction authority and specifically directs the Commission to complete a system of competitive bidding for not less than 100 megahertz in the 3.98-4.2 gigahertz band (Upper C- band). This final rule supports the Federal Communications Commission's July 2026 Report and Order that makes 160 megahertz of the Upper C-band available for terrestrial wireless flexible use via a system of competitive bidding. To ensure safe, efficient, and reliable aviation operations in the presence of wireless signals in the C-band, the Federal Aviation Administration is issuing new regulations that require all radio altimeters to meet specific minimum performance requirements. These new radio altimeters must withstand interference from wireless signals in neighboring spectrum bands and continue to provide accurate altitude readings to both pilots and integrated aircraft safety systems. These regulations require all aircraft equipped with radio altimeters operating under part 121 and those aircraft with radio altimeters operating under part 129 with 30 or more passenger seats or a payload capacity of more than 7,500 pounds to comply with the minimum performance requirements by December 30, 2030, which is prior to the date the Federal Communications Commission authorizes the use of the Upper C-band for new wireless services, as stated in its Report and Order. All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034. ## Key Points - Air carriers / Air taxis / Aircraft / Aviation safety / Safety ## Details (本文なし。リンク先参照) ## Source 元記事: [Requirements for Interference-Tolerant Radio Altimeter Systems](https://www.federalregister.gov/documents/2026/07/31/2026-15585/requirements-for-interference-tolerant-radio-altimeter-systems) — published 2026-07-31T00:00:00Z