Open Design of a Multi-Mission Medium-Altitude-Long-Endurance UAV Using COTS Components

This paper presents a systematic preliminary design methodology for a multi-mission medium altitude-long-endurance (MALE) unmanned aerial vehicle (UAV) capable of executing intelligence, surveillance, reconnaissance (ISR), search and rescue (SAR), and combat missions with minimal configuration changes. An open-design architecture utilizing commercial off-the-shelf (COTS) components enables rapid mission reconfiguration while maintaining design flexibility and cost-effectiveness. The initial sizing methodology employs constraint analysis and matching chart techniques to establish design parameters, resulting in a platform with maximum take-off mass (MTOM) of 1450 kg, wing area of 14 m2 , and 112 kWatt power requirement. The selected configuration features a Rotax 916 engine with high-aspect-ratio tapered wing (AR = 18.21) using NLF-0215 and NACA 0009 airfoils, achieving 38 hour endurance, 1250 km range, and 7000 m service ceiling. Modular payload integration accommodates up to 400 kg of mission specific equipment including electro-optical/infrared sensors, synthetic aperture radar, satellite communication systems, and warfare payloads. Stability analysis confirms adequate longitudinal and lateral-directional characteristics across operational mass range from 675 kg to 1816 kg, with the X-tail configuration providing satisfactory damping in short-period and Dutch roll modes. Performance calculations using Breguet equations demonstrate missionspecific capabilities: ISR baseline configuration achieves 5908 km optimum range and 30.37 hours endurance, while combat configuration maintains 2037 km range with full weapons payload. The methodology demonstrates that systematic application of classical aircraft design principles combined with COTS integration can accelerate preliminary design phases for multi-mission MALE platforms.