Sikorsky S-67 Blackhawk Sikorsky S-67 Blackhawk The Sikorsky S-67 Blackhawk was a private-venture, prototype attack helicopter built in 1970 with Sikorsky Aircraft research and development (R&D) funds. A tandem, two-seat aircraft designed around the dynamic drive and rotor systems of the Sikorsky S-61, it was designed to serve as an attack helicopter or to transport up to eight troops into combat. The US Army issued a request for proposals (RFP) for its Advanced Aerial Fire Support System (AAFSS) program on 1 August 1964. Lockheed offered its CL-840 design, a rigid-rotor compound helicopter. Sikorsky submitted the S-66, which featured a "Rotorprop" serving as a
Sikorsky S-11 Sikorsky S-11 The Sikorsky S-11 " Polukroogly " (Half Round) was a Russian single engine prototype reconnaissance aircraft completed in July 1913 by the Russian Baltic Railroad Car Works while Igor Sikorsky was the chief engineer of the aircraft manufacturing division. The S-11 was a two seat mid-wing monoplane with wire-braced wings powered by a Gnome Monosoupape air-cooled rotary engine rated at . It was smaller and lighter than the S-7 on which it was based, and had a conventional wooden fuselage. The cockpit featured side-by-side seating with controls for the pilot only on the left. Originally built with ailerons