The HX280 is a next generation high cruise speed helicopter concept. Idea was to create a heli with coaxial main rotor and  variable-pitch pusher propeller. I was inspired by the great Sikorsky’s S97 Raider. The HX280 is a single-engine, 10m rotor diameter, 2.1m diameter propeller aircraft with a crew of two and room for six passengers. It can also be equipped with a standard pallet-sized cargo door.