ASTM F3269-21 PDF

SIGNIFICANCE AND USE 4.1 This practice provides an architectural framework for developing an RTA system, which provides run-time assurance as an alternative to design-time assurance to fulfill safety requirements for an unassured or complex function. The standard provides best practices and guidelines to assist in the RTA system’s development. Further, it describes the architectural components and requirements for designing the RTA system. Compliance to this practice is achieved by deriving RTA System requirements from the standard and capturing them in the Larger System Specification. The system design requirements can then be validated and verified using acceptable engineering practices. It is anticipated that this practice will provide a means to accept complex automation/autonomy aircraft functions that have been difficult to certify using traditional methods. 4.2 The following three-step process is used to derive verifiable design requirements using this architecture standard: 4.2.1 Create RTA System requirements using the guidance provided by this architecture standard. 4.2.2 Capture RTA System requirements in the Larger System Specification. 4.2.3 Perform verification and validation on the RTA System requirements in the Larger System Specification. 4.3 The RTA architecture can be applied to all sizes, levels, and classes of UAS. Using run-time assurance can provide systems with the following benefits: 4.3.1 The ability to mitigate hazards related to nondeterministic or unexpected behavior from unassured functions that employ advanced software methods or algorithmic complexity that cannot be certified using traditional certification practices. 4.3.2 The ability to use functions for which it may not be possible to obtain artifacts of conventional DO-178 or DO-254 assurance processes. 4.3.3 The ability to use COTS hardware or software, or both, for the unassured function. 4.3.3.1 For example, automotive components, thereby leveraging mature software with ex... SCOPE 1.1 The scope of this practice includes the following: 1.1.1 A set of components that comprise an RTA system. 1.1.2 Requirements and best practices to determine safe boundaries and RTA system coverage. 1.1.3 Requirements and best practices for an RTA system and RTA components, as applicable. 1.1.4 Appendixes with examples that demonstrate key RTA system concepts. 1.2 RTA components are required to meet the design assurance level dictated by a safety assessment process. Guidance for the safety assessment process may be found in references appropriate for the intended operations (ARP4754A, ARP4761, Practice F3178, etc.). 1.3 This practice was developed with UAS in mind. It may be applicable for aspects of manned aircraft certification/approval, as well as aviation ground systems. The scope of this practice is also envisioned to allow a variety of aircraft implementations where a human may perform the role of either the Complex Function or a Recovery Function. 1.4 The scope of this practice does not cover aspects of hardware/software integration. These should be considered separately during the development process. Note 1: This practice does not suggest a one-size-fits-all strategy knowing that not all use cases may fit well into this architecture. There may exist additional components required to satisfy specific applications to the practice. 1.5 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 Table of Contents: Title Section Introduction Background Scope 1 Referenced Documents 2 ASTM Standards 2.1 FAA Advisory Circular 2.2 RTCA Standards 2.3 SAE Standards 2.4 Terminology 3 Unique and Common Terminology 3.3 Definitions of Terms Specific to This Standard 3.4 Abbreviations 3.5 ...