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Regarding COTS IP used in the development custom electronic devices for critical civil aviation applications, EASA newly published AMC 20-152A departs from previously applicable guidance. While it has been recommended to satisfy ED-80/DO-254 prescriptions, this new guidance proposes alternative objectives based on available COTS IP documentation, supplier processes for verification and user support, and complementary verification.

Guidance provided in industry standards DO-178C and DO-254 for civil aviation airborne software and hardware certification may be perceived as complex and difficult to implement in practice. This complexity result from the inherent flexibility of these standards, which allow for a wide range of architecture and development processes. Using document templates provide development teams, which are new to the civil aviation domain, with a useful help to achieve success of their project.

In the context of airborne system design assurance and of the application of ARP-4754A, the question of the difference between validation and verification is very often raised, especially in the case of how testing can contribute to validation.

Objective of defensive code is to improve the robustness of the software as mentioned in DO-178C. But “defensive code” is sometimes used as a kind of basket for justifying a portion of unreachable code.

This article discusses the degree of freedom in implementation of code versus low level requirements, for compliance with DO-178, and for DALs A, B, C. Some people are talking about “implementation details” but they often have difficulties to know what is behind this wording and what is DO-178 compliant or not.