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Universal Access Transceiver Equipment

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Federal Aviation Administration (FAA), DOT.


Notice of availability and requests for public comment.


This notice announces the availability of, and requests comments on, proposed Technical Standard Order (TSO)-C154a, Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz. In this TSO, we (the Federal Aviation Administration, or FAA) refer to a revised minimum performance standard (MPS)—RTCA Inc., Document (RTCA/DO)-282A, Minimum Operational Performance Standards for Universal Access Transceiver (UAT) Automatic Dependent Surveillance Broadcast (ADS-B), dated July 29, 2004. We also add Appendix 1, which lists corrections to RTCA/DO-282A since its date of issuance. The TSO also supports an optional frequency Diplexer. The Diplexer allows the ATCRBS/Mode S Transponder and the UAT equipment developed under this TSO to share antennas. This TSO is for manufacturers of Universal Access Transceiver ADS-B equipment or UAT Diplexer seeking a TSO authorization or letter of design approval. In it, we tell them what MPS their UAT equipment must meet for approval and identification with the TSO-C154a marking.


Comments must be received on or before March 28, 2005.


Send all comments on this proposed TSO to: Ms. Bobbie Smith, AIR-103, ATTN: File No. TSO-C154a, Federal Aviation Administration, Aircraft Certification Service, Aircraft Engineering Division, Room 815, 800 Independence Avenue, SW., Washington, DC 20591. You may deliver comments to: Federal Aviation Administration, Room 815, 800 Independence Avenue, SW., Washington, DC 20591.

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Mr. Richard Jennings, AIR-130, Federal Start Printed Page 9440Aviation Administration, 1895 Phoenix Blvd., Suite 450, Atlanta, GA 30349. Telephone (770) 703-6090, fax (770) 703-6055. E-mail

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Comments Invited

Submit written data, views, or arguments on the proposed TSO to the above address. Before and after the comment closing date, you can examine comments received in Room 815, FAA Headquarters Building (FOB-10A), 800 Independence Avenue, SW., Washington, DC 20591, weekdays except Federal holidays, between 8:30 a.m. and 4:30 p.m. Before issuing the final TSO, the director of the Aircraft Certification Service will consider all comments received on or before the closing date for comments.


This proposed TSO prescribes the minimum standards for airborne equipment. It supports ADS-B using UAT equipment operating on the frequency of 978 MHz. ADS-B is a system by which aircraft and certain equipped surface vehicles can share position, velocity, and other information with one another (and with ground-based facilities such as air traffic services) via radio broadcast techniques. UAT is a multipurpose aeronautical datalink system to support not only ADS-B, but also Flight Information Service-Broadcast (FIS-B), Traffic Information Service-Broadcast (TIS-B), and supplementary ranging and positioning capabilities. This TSO supports two major classes of UAT equipment: Class A and Class B equipment. Class A equipment combines a broadcast and receive subsystem. Class B equipment supports broadcast only.

How To Obtain Copies

You can download a copy of proposed TSO-C154a from the FAA Web site at:​rgl. At the Web page, select “Technical Standard Orders (TSO) and Index.” At the TSO page, select “Proposed TSOs.” For a paper copy of the proposed TSO, or for further assistance, contact the person listed in FOR FURTHER INFORMATION CONTACT.

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Issued in Washington, DC, on February 17, 2005.

Susan J.M. Cabler,

Acting Manager, Aircraft Engineering Division, Aircraft Certification Service.

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[FR Doc. 05-3609 Filed 2-24-05; 8:45 am]