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Proposed Advisory Circular (AC) 20-DO-254, RTCA, INC., Document No. (RTCA/DO)-254, Design Assurance Guidance For Airborne Electronic Hardware.

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Federal Aviation Administration (DOT).


Notice of availability and request for public comment.


This notice announces the availability of and requests comments on a proposed Advisory Circular (AC) 20-DO-254, Design Assurance Guidance for Airborne Electronic Hardware. This proposed AC provides guidance for manufacturers of aircraft products appliances incorporating custom micro-coded components in the design of their aircraft systems and equipment. In it, we recommend how you get design and airworthiness approval for your equipment.


Comments must be received on or before August 2, 2004.


Send all comments on the proposed AC to: Federal Aviation Administration (FAA), Aircraft Certification Service, Aircraft Engineering Division, Technical Programs and Continued Airworthiness Branch, AIR-120, 800 Independence Avenue, SW., Washington, DC 20591. ATTN: Mr. John Lewis. Or deliver comments to: Federal Aviation Administration, Room 815, 800 Independence Avenue, SW., Washington, DC 20591.

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Mr. John Lewis, AIR-120, Room 815, Federal Aviation Administration, Aircraft Certification Service, Aircraft Engineering Division, 800 Independence Avenue, SW., Washington, DC 20591. Telephone (202) 493-4841, FAX: (202) 267-5340. Or, via e-mail at:

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Comments Invited

Interested persons are invited to comment on the proposed AC listed in this notice by submitting such written data, views, or arguments as they desire to the above specified address. Start Printed Page 40711Comments received on the proposed AC may be examined, before and after the comment closing date, in Room 815, FAA Headquarters Building, 800 Independence Avenue, SW., Washington, DC 20591, weekdays except Federal holidays, between 8:30 a.m. and 4:30 p.m. All communications received on or before the closing date will be considered by the Director of the Aircraft Certification Service before issuing the final Advisory Circular.


When following the guidance and procedures outlined in RTCA/DO-254, Design Assurance Guidance For Airborne Electronic Hardware, dated April 19, 2000, you are assured that the hardware design will perform its intended functions in its specified environment, and will meet its airworthiness requirements. RTCA.D)-254 distinguishes between complex and simple electronic hardware; recognizes five levels of failure effects ranging from catastrophic to no effect; and provides guidance for each hardware design assurance level. Although the guidance in RTCA/DO-254 is applicable to five categories of hardware items (e.g., Line Replaceable Units (LRUs), Circuit Board Assemblies, etc.), this AC recognizes the guidance in RTCA/DO-254 is applying specifically to custom micro-coded components, rather than LRUs and other types of electronic hardware items described in RTCA/DO-254.

How to Obtain Copies

You may get a copy of the proposed AC form the Internet at:​rgl. Once on the RGL Web site, select “Advisory Circular”, then select the document by number. See section entitled For Further Information Contact for the complete address if requesting a copy by mail. You may inspect the RTCA document at the FAA office location listed under Addresses. Note however, RTCA documents are copyrighted and may not be reproduced without the written consent of RTCA, Inc. You may purchase copies of RTCA, Inc. documents from: RTCA, Inc., 1828 L Street, NW., Suite 815, Washington, DC 20036, or directly from their Web site:

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Dated: Issued in Washington, DC, on June 29, 2004.

Susan J. M. Cabler,

Assistant Manager, Aircraft Engineering Division, Aircraft Certification Service.

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[FR Doc. 04-15251 Filed 7-2-04; 8:45 am]