10A TECHICAL UNT AdViSOrY U.S. Department DOT LIBRARY MASS CircUlar MAY 8 1987 or Transportation Federal Aviation Administration Subject: Radio Technical Cammission for Date: 8/12/86 AC No:20-115A Aeronautics Document RICA/DO-178A Initiated by: AWS-120 Change:
1. PURPOSE. This advisory circular calls attention to the Radio Technical Commission for Aeronautics (RICA) Document RICA/DO-178A, 'Software Considerations in Airborne Systems and Equipment Certification," issued March 1985. It discusses how the document may be applied with Federal Aviation Administration technical standard order (50), type certification MC), and supplemental type certification (SIC) authorizations.
CANCELLATION. Advisory Circular 20-115, Radio Technical Commission for Aeronautics (RICA) Document DO-178, dated September 3, 1982, is cancelled.
3. RELATED FEDERAL AVIATION REGULATIONS (FAR). FAR Parts 21, 23, 25, 27, 29, and 33.
BACKGROUND. RICA Document RICA/DO-178A was developed to establish software considerations for developers, installers, and users when the aircraft equipment design is implemented using microcomputer techniques.
It is expected that current and future avionics designs will make extensive use of this technology. The RICA document outlines verification, validation, documentation, and software configuration management and quality assurance disciplines to be used in microcomputer systems.
5. USE OF RICA/DO-178A PROCEDURES. An applicant for a 150, IC or SIC authorization for any electronic equipment or system employing digital computer technology may use the considerations outlined in RICA Document RICA/DO-178A as a means, but not the only means, to secure FAA approval of the digital computer software. The FAA may publish advisory circulars for specific FAR's, outlining the relationship between the criticality of the software-based systems and the appropriate "software level" as defined in RICA/DO-178A. Those may differ from and will take precedence over the application of RICA/DO-178A.
6. AVAILABILITY OF RICA DOCUMENT RICA/DO-178A. Copies may be purchased from the Radio Technical Commission for Aeronautics Secretariat, One McPherson Square, 1425 K Street NW., Suite 500, Washington, DC 20005.
Willion t allor.
William J. Sullivan Deputy Director of Airworthiness