The MPUAS RX-4 design was based on well-established aircraft design textbooks and methodologies. In-house sizing tools and routines were used to facilitate the layout, aerodynamics, and stability calculations. These tools were adjusted to the needs of UAVs and tuned to incorporate the unique characteristics of the novel VTOL platform. They have also been validated through the design of the HCUAV RX-1, the first large-scale Hellenic Civil UAV for surveillance missions, which has successfully undergone several flight tests.
The layout design and sizing procedure is in compliance with FAA pt. 23 regulations and supported by high-fidelity aerodynamic analysis (CFD) and structural analysis (FEM) tools. The geometry used for the analyses was generated using existing parametric 3D CAD tools, which allow changes at the aerial vehicle configuration to be executed swiftly and accurately during design. The results were imported in a dedicated flight simulator software, for the evaluation of the key performance, aerodynamic and stability specifications of the RX-4.