ASTM F3269 - An Industry Standard on Run Time Assurance for Aircraft Systems

Abstract

This paper discusses the philosophy and editorial considerations behind the ongoing second revision of the ASTM F38 Committee standard on run time assurance for aircraft systems - ASTM F3269, titled "Standard Practice for Methods to Safely Bound Flight Behavior of Unmanned Aircraft Systems Containing Complex Functions". It describes the key aspects of the Run Time Assurance (RTA) architecture as depicted in the current revision of the standard and provides some insights on the design best practices suggested in the standard. RTA is a certification strategy for unmanned aircraft systems that contain complex functions, which may not be certifiable using traditional design assurance practices. This challenge may arise in part due to the inherent algorithmic complexity of these functions. It may also be due to the inability to produce design assurance artifacts according to industry standards such as RTCA DO-178C (software) or DO-254 (hardware) for commercial off-the-shelf components used on-board the aircraft. RTA adds value not only to unmanned applications, but also to manned aviation - particularly in General Aviation (GA) and Advanced Air Mobility (AAM). It has the potential to enable technologies for autonomous aircraft systems and simplified vehicle operations. The strategy will also play a role in the design assurance and certification of adaptive controllers and functions using artificial intelligence and machine learning algorithms.