Demonstration of Radio Altimeter Tolerant Aircraft

Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Department of Transportation Federal Aviation Administration 14 CFR Part 21 [Docket No. FAA-2023-0938] AGENCY: Federal Aviation Administration, DOT ACTION: Notice of availability; final policy and disposition of comments. SUMMARY: The Federal Aviation Administration (FAA) announces Policy Statement PS-AIR-600-39-01 for demonstrating an aircraft is a “radio altimeter tolerant airplane” or a “radio altimeter tolerant rotorcraft” using a method approved by the FAA. DATES: This policy is effective July 19, 2023. FOR FURTHER INFORMATION CONTACT: For technical questions concerning this policy statement, contact Barbara Clark, Supervisory Aviation Safety Specialist, Avionics Navigation & Flight Deck Unit (AIR-626B), 800 Independence Ave. SW, Washington, DC 20591; telephone: 202-267-8569; email: barbara.clark@faa.gov . SUPPLEMENTARY INFORMATION: Background The current performance standards for radio altimeters (also known as radar altimeters) are based on the presumption that no occupancy of an adjacent radio frequency spectrum would cause interference with radio altimeters. During 2021, the radio frequency (RF) operating environment surrounding radio altimeters substantially changed when wireless telecommunication service providers began offering 5G C-Band services near the 4.2-4.4 GHz band. In both the U.S. and internationally, this band is allocated on a primary basis for aeronautical radionavigation service, which is used by aviation radio altimeters. …