American Sportscopter Ultrasport 331
The American Sportscopter Ultrasport 331 is an American helicopter that was designed and produced by American Sportscopter of Newport News, Virginia. Now out of production, when it was available the aircraft was supplied as a kit for amateur construction. Design and development. The Ultrasport 331 is a development of the Ultrasport 254 and, like that model, is named for its empty weight in pounds. The aircraft was designed to comply with the US "Experimental - Amateur-built" aircraft rules. It features a single main rotor, a single-seat enclosed cockpit with doors, skid-type landing gear and  a twin cylinder, air-cooled, two-stroke, dual-ignition Hirth 2706 engine. The aircraft fuselage is made from composites. Its diameter two-bladed rotor has a chord of and employs an ATI 012 (VR-7 mod) airfoil at the blade root, transitioning to an ATI 008 (VR-7 mod) airfoil at the tip. The ring-mounted tail rotor has a diameter and a chord of . The cyclic control is mounted from the cockpit ceiling, but otherwise is conventional. The horizontal tailplane mounts end-fins for directional stability. The aircraft has an empty weight of and a gross weight of , giving a useful  load of . With full fuel of the payload is . The manufacturer estimated the construction time from the supplied kit as 60 hours. Operational history. By June 2014 three examples had been registered in the United States with the Federal Aviation Administration, although a total of six had been registered at one time.