The avionics industry is currently undergoing a transition to multi-core processor architectures. This transition provides the potential for increased functionality on a common computing platform, while reducing size, weight and power (SWaP). The advent of multi-core processor architectures also presents new challenges in the design, implementation and safety-certification of real-time operating systems (RTOS). In this paper, the impact of multi-core architecture on RTOS design, the ARINC 653 software standard, and safety-certification under RTCA DO-178C and EUROCAE ED-12C will be considered. Additionally Wind River’s experiences of the DO-178C DAL A safety certification of VxWorks 653 Multi-core Edition on the NXP QorIQ T2080 multi-core processor will be presented.