Conceptual Design and Aerodynamic Configuration of the Relithia Nova: A 2000kg Hybrid-Electric STOL Aircraft

This paper presents the conceptual design of the Relithia Nova, a hybrid-electric Short Take-Off and Landing (STOL) aircraft engineered to provide essential connectivity to remote regions with limited aviation infrastructure, such as the South Pacific and Caribbean. Designed with a Maximum Take-Off Mass (MTOM) of 2,000 kg, the aircraft accommodates six occupants, including the pilot, and is optimized for operations on short, unprepared airstrips up to 2,000 ft elevation. The Relithia Nova employs a series-hybrid propulsion architecture featuring two wing-mounted turboshaft engines coupled with electric generators that drive propulsive rotors via a high-capacity lithium-ion energy storage system. This configuration ensures sustained power for high-lift generation while reducing emissions. Aerodynamically, the aircraft utilizes a high-aspect-ratio wing (AR=8.67) based on the NACA 23012 airfoil, chosen for its favorable lift-to-drag characteristics in subsonic flow (Mach 0.23 cruise). High-lift performance is achieved through the integration of advanced flap systems—specifically, partial-span slotted flaps—complemented by leading-edge slats to delay stall separation at high angles of attack (up to 0.2095 radians), enabling a stall speed not exceeding 50 knots. The structural design leverages a hybrid airframe composed of a 2024-series aluminum alloy fuselage for durability and carbon-fiber composite internal structures for weight optimization. With a cruise speed of 150 knots and a range of 700 km, the Relithia Nova offers a robust alternative to costly helicopter services. The paper will detail the aerodynamic configuration, including wing planform and high-lift device arrangement, and provide comparative analyses against existing STOL platforms like the Electra eSTOL and Aura Aero ERA to benchmark efficiency and operational versatility.