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Proposed Advisory Circular-Reusable Software Components

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Information about this document as published in the Federal Register.

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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 Advisor Circular that guides Reusable Software Component (RSC) developers, integrators, and applicants to gain Federal Aviation Administration (FAA) acceptance of software components that may makeup a part of the system's software application. This proposed AC also provides a means of FAA acceptance for obtaining credit to use previously approved RSC in follow-on projects.


Submit comments on or before July 15, 2003.


Send all comments on the proposed Advisory Circular to: Federal Aviation Administration, Aircraft Certification Service, AIR-120, Room 835, 800 Independence Avenue, SW., Washington, DC 20591. You may deliver comments to: Federal Aviation Administration (FAA), 800 Independence Avenue, SW., Room 835, Washington, DC 20591. Your comments must identify the Advisory Circular file number.

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Mr. John Lewis, Federal Aviation Administration, Aircraft Certification Service, AIR-120, Federal Aviation Administration, Room 835, 800 Independence Avenue, SW., Washington, DC 20591; Telephone: (202) 493-4841, FAX: (202) 267-5340; E-mail address:

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Comments Invited

You are invited to comment on the proposed Advisory Circular by submitting written data, views, or arguments to the address listed above. You can examine comments received on the proposed Advisory Circular before and after the comment closing date at the FAA's Headquarters Building, Room 835, 800 Independence Avenue, SW., Washington, DC 20591, weekdays except Federal holidays, between 8:30 a.m. and 4:30 p.m. The Director of the Aircraft Certification Service will consider all communications received on or before the closing date before issuing the final Advisory Circular.


Currently, there are no procedures for Reusable Software Components (RSC) developers to directly transfer their accepted data from one project to the next and across company boundaries. Traditionally, RSC developers provided substantiation in one of two ways. First, by resubmitting the data package and repeating the work for each system's application. Secondly, by providing traceability through the TC, ATC, STC, ASTC, or TSO approval back to the desired data and defending the validity of the original approval basis for each application. This AC builds upon that reuse concept by considering components that are reused company boundaries.

Economic incentives and technical advances in software development have made it desirable to the integrator or applicant to develop a RSC that can be integrated into a number of target computers, environments, or both. In these cases, the RSC developer may partially meet the applicable RTCA/DO-178B objectives, while the integrator, applicant (or both) is responsible for completing the software and certification compliance activities. Examples of potential RSCs include software libraries, input and output data files, operating systems, and communication protocols.

How To Obtain Copies

You may get a copy of the proposed AC from the FAA Web site at:​rgl. You may also request a copy from Mr. John Lewis, see section entitled FOR FURTHER INFORMATION CONTACT for the complete address. You may inspect the RTCA document at the FAA office location listed under ADDRESSES. However, RTCA documents are copyrighted and may not be reproduced without the written consent of RTCA, Inc. You may purchase copies of Document No. RTCA/DO-178B from: RTCA Inc., 1828 L Street, NW., Suite 807, Washington, DC 20036 (Web site:

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Issued in Washington, DC, on June 5, 2003.

Nancy C. Lane,

Acting Manager, Aircraft Engineering Division, Aircraft Certification Service.

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[FR Doc. 03-15001 Filed 6-12-03; 8:45 am]