Complex sentence: The "AEREON III" was powered by a single Solar Titan gas turbine of 80 hp, located at the aft end of the central hull and driving a 21 ft diameter, two-bladed propeller (actually a helicopter rotor rotating in the vertical plane).
Split into simpler sentences: The "AEREON III" was powered by a single engine located at the aft end of the central hull. The engine drove a 21 ft diameter, two-bladed propeller (actually a helicopter rotor rotating in the vertical plane).