23 June 1913: While parked at St. Petersberg, Igor Ivanovich Sikorsky’s S-21, Русский Витязь (Russky Vityaz or “Russian Knight”), the world’s first four-engine airplane, and, at the time, the world’s largest airplane, was crushed by an engine that had fallen off of a single-engine Morane-Saulnier airplane that was flying overhead.

Igor Sikorsky began work on the S-21 in 1911, while chief engineer for Russko-Baltiisky Vagonny Zavod at St. Petersburg, and it first flew 10 May 1913. It was a four-engine biplane operated by a crew of three and could carry up to seven passengers in two enclosed cabins. These cabins were large enough that the passengers could stand and move  around.

The S-21 was 20 meters (65.6 feet) long. The upper wing had a span of 27 meters (88.6 feet) and the lower wing, 20 meters (65.6 feet). Overall height of the airplane was 4 meters (13.1 feet). Its empty weight was 3,400 kilograms (7,496 pounds) and the gross weight was 4,000 kilograms (8,818 pounds).

Russky Vityaz was powered by four water-cooled Argus Motoren G.m.b.H. As 1 inline four-cylinder engines in a tractor configuration. These produced 100 horsepower, each, and turned two-bladed fixed-pitch propellers. The biplane had a maximum speed of 90 kilometers per hour (56 miles per hour), service ceiling of just 600 meters (1,969 feet) and range of 170 kilometers (106 miles).

Rather than try to repair the wrecked S-21, Sikorsky decided to build something even bigger: the Sikorsky S-22 Ilya Muromets.

Igor Sikorsky emigrated to the United States of America in 1919, where he designed and built large seaplanes for airline use before focusing on the development of the helicopter, beginning with the Vought-Sikorsky VS-300. His company remains in operation today and produces some of the most widely used military and commercial helicopters.

© 2020, Bryan R. Swopes