Abstract: An unmanned aerial vehicle (UAV) including wing sections and hinge assemblies. Each wing section includes an airfoil and a propulsion unit. The wing sections are arranged side-by-side, pivotably connected by the hinge assemblies to define an airframe module. The airframe module is transitionable between a fixed-wing state and a rotor state. In the fixed-wing state, the airframe module has an elongated shape extending between opposing, first and second ends. In the rotor state, the first end is immediately proximate the second end. With this construction, the UAV provides two distinct modes of flight (fixed-wing for low power flight, and rotor for high maneuverability flight (including hover)). The wing sections can carry solar cells and a battery. A maximum power point tracker (MPPT) can be provided for optimizing the match between the solar array and the battery. The propulsion unit can include a variable pitch propeller.