Siemens Digital Industries Software has collaborated with Dovetail Electric Aviation, a sustainable aviation company based in Australia with operations in Spain, to design zero emission, battery, and hydrogen-electric propulsion systems for commercial aircraft. Dovetail's approach, rooted in circular economy principles, involves retrofitting legacy airplanes used by regional airlines and cargo flights to reduce operating costs by up to 40% and decarbonize air transportation. The company is known for converting Cessna 208s into zero emission battery electric planes and designing a hydrogen-electric retrofit for the Beechcraft King Air. By utilizing Siemens' NX X software for cloud-enabled computer-aided design (CAD), Dovetail aims to streamline collaboration between its teams in Spain and Australia, enabling quicker prototyping and design iterations. The software also helps in developing digital twin design concepts, saving time in design processes. Siemens' software supports Dovetail in creating efficient hydrogen-electric propulsion systems, including fuel cells and hydrogen storage, to address climate change challenges. This collaboration highlights the importance of innovation, sustainability, and the use of digital twins in achieving zero emissions in the aviation industry.