Since 2009 the Directorate of Technical Airworthiness and Engineering Support (DTAES) of the Department of National Defense (DND) has relied upon CSL as a source of system/software safety expertise. DTAES ensures that the Canadian military fleets achieve and maintain an adequate level of safety and effectiveness from a technical perspective and comply with the requirements of the DND/CF Airworthiness Program. As part of these engagements, CSL has provided support to DTAES technical regulators at the system and software level, has contributed to system safety assessment of aircraft design changes, and aircraft fleet upgrades. SAE ARP 4761, SAE ARP 4754, RTCA DO-178B/C and RTCA DO-254 served as the basis of these assessments. CSL has helped to assess tools and software-intensive ground systems used by Canadian Forces, and has provided regular training briefs to Air Force working groups on standards evolution, system safety principles and the application of system safety techniques to military systems.