Civil Aircraft Airborne Software Safety and Reliability Study Based on RTCA/DO-178C

Abstract

Airborne software is invisible but it can have a critical impact on the safety of aircraft systems. This paper studies the retroactive relationship between the certification regulations of various countries and the ICAO Convention, then analyzes the source of software-related airworthiness Clause from the Annex 8 of the ICAO Convention. Furthermore, the 1301 and 1309 clauses of Part 25 of the software certification basis and the corresponding compliance method RTCA/DO-178C are studied. The study obtains the airborne software process assurance model from the point of safety. A comparative analysis with software reliability is carried out, and finally it is concluded that the development of civil aircraft based on DO-178C focuses on system safety. The design assurance level of software is determined through the system development and safety assessment process according to SAE ARP4754A and SAE ARP4761, and software cannot be assigned a failure rate like hardware based on DO-178C practice. The methods of avoidance, identification, elimination and reduction of software design errors in DO-178C also contributing to software reliability. Given that software reliability efforts are primarily concerned with providing sufficient quantitative and qualitative evidence, it can enhance the software quality, however, software reliability analysis are not useful for providing confidence to regulators in civil aircraft developing program.