Linux Is Not Suitable as the Kernel Foundation for an ARINC 653 Platform

In response to the emerging practice of attempting to use the general-purpose open-source Linux system as a replacement for high–safety-assurance avionics kernels, this paper presents eight core arguments, rooted in architectural principles, demonstrating that Linux is fundamentally unsuitable for civil aviation operating systems. These arguments address Linux’s limitations in scheduling determinism, memory architecture, kernel fault isolation, trusted computing base (TCB) size, static configuration and semantic freezing, fault-handling behavior, version stability, and ecosystem-driven certification burden. By contrasting Linux with the avionics application software standard interface (ARINC 653), the paper elucidates the structural reasons why Linux cannot meet the airworthiness and high-integrity operational requirements of avionics systems. Furthermore, engineering-practical and standards-aligned technical pathways are proposed, offering guidance for avionics software development in the context of the low-altitude economy and civil aviation applications.