DO-178C

DO-178C, Software Considerations in Airborne Systems and Equipment Certification is the primary document by which the certification authorities such as FAA, EASA and Transport Canada approve all commercial software-based aerospace systems. The document is published by RTCA, Incorporated, in a joint effort with EUROCAE and replaces DO-178B. The new document is called DO-178C/ED-12C and was completed in November 2011 and approved by the RTCA in December 2011. It became available for sale and use in January 2012. Except for FAR 33/JAR E, the Federal Aviation Regulations do not directly reference software airworthiness. On 21 Jul 2017, the FAA approved AC 20-115D, designating DO-178C a recognized "acceptable means, but not the only means, for showing compliance with the applicable FAR airworthiness regulations for the software aspects of airborne systems and equipment certification." Since the release of DO-178B, there had been strong calls by FAA Designated Engineering Representatives (DERs) for clarification/refinement of the definitions and boundaries between the key DO-178B concepts of high-level requirements, low-level requirements, and derived requirements and a better definition of the exit/entry criteria between systems requirements and system design (see ARP4754) and that of software requirements and software design (which is the domain of DO-178B). Other concerns included the meaning of verification in a model-based development paradigm and considerations for replacing some or all software testing activities with model simulation or formal methods. The release of DO-178C and the companion documents DO-278A (Ground Systems), DO-248C (Additional information with rationale for each DO-178C objective), DO-330 (Tool Qualification), DO-331 (Modeling), DO-332 (Object Oriented), and DO-333 (Formal Methods) were created to address the issues noted. The SC-205 members worked with the SAE S-18 committee to ensure that ARP4754A and the above noted DO-xxx documents provide a unified and linked process with complementary criteria.