New Aerospace Standard Supplement
You are using COTS Software in your aerospace development?
This article is for you!
Introduction to New RTCA Supplement
An RTCA and EUROCAE joint committee (SC-240/WG-117) entitled Aviation Software Standards is creating a new RTCA supplement to the software assurance standards DO-178C/DO-278A and ED-12C/ED-109A. Initial issuance is for COTS Software and Open Source Software (OSS) for assurance levels at DAL-C and below. The motivation for this supplement has come from UAS and lower risk applications.
COTS in Communication, Navigation, and Surveillance
Within the current Communication, Navigation and Surveillance/Air Traffic Management (CNS/ATM) ground standards, COTS is addressed within chapter 12 “Additional Considerations” as CNS/ATM systems often include COTS. The new supplement is currently identified as RTCA DO-395 “Incorporation of COTS and/or OSS as supplement to DO-178C/ED-12C and DO-278A/ED-109A”.
Document Review and Finalization
Expectations are for the document to enter Final Review and Comment (FRAC) in summer 2024. FRAC is required prior to issuance and eventual recognition by certifying agencies as a Means of Compliance (MoC). A follow-on revision is planned to include Product Service History and to address levels DAL-A and DAL-B systems.
Challenges with COTS Software in Aerospace
Aerospace software utilizing COTS Software and/or OSS have challenges that are unique from in-house development. For instance, it is common that COTS Software does not include source code, but a user community may exist providing usage confidence. For OSS, it may have unknown development pedigree but provides the user with the ability to customize for user needs. Utilizing these types of software with core aerospace standards may make it difficult to satisfy objectives.
CS Group is engaged with this joint committee for the development of this new supplement as we believe it is of interest to and can potentially be leveraged by our customers.
New Terminology: Off the Shelf Software (OTSS)
Terminology is being developed for this standard such as Off the Shelf Software (OTSS) to capture the scope of applicable software. OTSS examples could include operating systems, hardware interface libraries, cybersecurity libraries, symbology libraries, etc
