The Russian inventor Igor Sikorsky flew the self-designed Russky Vityaz, the world's first four-engine fixed-wing aircraft.

Igor Ivanovich Sikorsky was a Russian-American aviation pioneer in both helicopters and fixed-wing aircraft. His first success came with the Sikorsky S-2, the second aircraft of his design and construction. His fifth airplane, the S-5, won him national recognition and F.A.I. pilot's license number 64. His S-6-A received the highest award at the 1912 Moscow Aviation Exhibition, and in the fall of that year the aircraft won first prize for its young designer, builder and pilot in the military competition at Saint Petersburg. In 1913, the Sikorsky-designed Russky Vityaz (S-21) became the first successful four-engine aircraft to take flight. He also designed and built the Ilya Muromets family of four-engine aircraft, an airliner which he redesigned to be the world's first four-engine bomber when World War I broke out.

The Sikorsky Russky Vityaz, or Russian Knight (S-21), previously known as the Bolshoi Baltisky (The Great Baltic) in its first four-engined version, was the first four-engine aircraft in the world, designed by Igor Sikorsky and built at the Russian Baltic Railroad Car Works in Saint Petersburg in early 1913.

A fixed-wing aircraft is a heavier-than-air aircraft, such as an airplane, which is capable of flight using aerodynamic lift. Fixed-wing aircraft are distinct from rotary-wing aircraft, and ornithopters. The wings of a fixed-wing aircraft are not necessarily rigid; kites, hang gliders, variable-sweep wing aircraft, and airplanes that use wing morphing are all classified as fixed wing.