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.
25 May 1889: Ігор Іванович Сікорський (Igor Ivanovich Sikorsky) was born at Kiev, Ukraine, Russian Empire, the fifth of five children of Professor Ivan Alexeevich Sikorsky and Doctor Mariya Stefanovich Sikorskaya.
He studied at the Imperial Naval Academy, St. Petersburg, from 1903 until 1906, when he left to study engineering, first in Paris, and then at the Kiev Polytechnic Institute.
Flying an airplane of his own design, the S-5, on 18 April 1911, he received a Fédération Aéronautique Internationale pilot’s license from L’Aéro-Club Imperial de Russie (Imperial Russian Aero Club).
He was chief aircraft engineer for Russko-Baltiisky Vagonny Zavod at St. Petersburg and continued to develop airplanes. In 1913, he flew the twin engine S-21 Le Grand, to which he added two more engines, and it became the Russky Vityaz.
Igor Sikorsky married Olga Fyodorovna Simkovich. They had a daughter, Tania. The couple soon divorced, however.
Following the October Revolution, Sikorsky emigrated to the United States. Departing Le Havre, France, aboard S.S. La Lorraine, he arrived at New York on 31 March 1919. With financial backing from composer and conductor Sergei Vasilievich Rachmaninoff, he founded the Sikorsky Aero Engineering Company at Long Island, New York, in 1924, and continued designing and building airplanes.
In 1924, Sikorsky married Elisabeth Semion, who was also born in Russia, in 1903. They would have four children. In 1928, he became a citizen of the United States of America.
Beginning in 1934, Sikorsky Aircraft produced the S-42 flying boat for Pan American Airways at a new plant at Stratford, Connecticut.
Interested in helicopters since the age of 9, he directed his creative effort toward the development of a practical “direct-lift” aircraft. The first successful design was the Vought-Sikorsky VS-300. Using a single main rotor, the VS-300 went through a series of configurations before arriving at the single anti-torque tail rotor design, the VS-316A. This was put into production for the U.S. military as the Sikorsky R-4.
The company which Igor Sikorsky founded has continued as one of the world’s biggest helicopter manufacturers. Recently acquired by Lockheed Martin, Sikorsky continues to produce the UH-60-series of Blackhawk medium helicopters, the large CH-53K King Stallion, and the civil S-76D and S-92. A variant of the S-92 has been selected as the next helicopter for the U.S. presidential air fleet, the VH-92A. This helicopter is planned to be operational by 2020.
Igor Ivanovich Sikorsky died at Easton, Connecticut, 26 October 1972 at the age of 83 years.
6 May 1941: At Stratford, Connecticut, Igor Sikorsky piloted his Vought-Sikorsky VS-300 helicopter to a new world’s record for endurance. He flew for 1 hour, 32 minutes, 26 seconds. ¹ The previous record—1 hour, 20 minutes, 49 seconds—had been set by Ewald Rohlfs with the Focke-Wulf Fw 61 tandem-rotor helicopter, 25 June 1937. ²
During its development, the VS-300 went through at least 18 changes in its rotor configuration. This photograph, taken after the record-setting flight, shows an intermediate version, with one main rotor for lift and three auxiliary rotors for anti-torque and directional control.
In the final configuration, Sikorsky arrived at what we now recognize as a helicopter, with the main rotor providing lift, thrust and roll control through variable collective and cyclic pitch, and a single tail rotor for anti-torque and yaw control.
The VS-300 had a welded tubular steel airframe and used a 28-foot (5.34 meters) diameter, fully-articulated, three-bladed main rotor, which turned clockwise (as seen from above) at 260 r.p.m. (The advancing blade was on the left. This would later be reversed.) The main rotor had collective pitch control for vertical control, but cyclic pitch (Sikorsky referred to this as “sectional control”) for directional control would not be developed for another several months.
The tail “propellers” (what we now consider to be rotors—one vertical and two horizontal) each had two blades with a diameter of 7 feet, 8 inches (2.337 meters) and turned approximately 1,300 r.p.m. The vertical rotor provided “torque compensation” (anti-torque) and the blade pitch was fully reversible. The horizontal rotors were mounted on 10-foot (3.048 meters) outriggers at the aft end of the fuselage. For lateral control, the pitch on one rotor was increased and the other decreased. For longitudinal control, the pitch of both rotors was increased or decreased together.
The VS-300 was originally equipped with an air-cooled, normally-aspirated 144.489-cubic-inch-displacement (2.368 liter) Lycoming O-145C-3 four-cylinder horizontally-opposed engine which was rated at 75 horsepower at 3,100 r.p.m. According to Mr. Sikorsky, “early in 1941,” the Lycoming engine was replaced by an air-cooled, normally-aspirated 198.608 cubic inch (3.255 liter) Franklin 4AC-199-E, a four-cylinder horizontally-opposed overhead valve (OHV) direct-drive engine with a compression ratio of 7:1, rated at 90 horsepower at 2,500 r.p.m. It is not known if this change was made prior to 6 May.
¹ During World War II, only a very few ballooning and gliding world records were certified by the Fédération Aéronautique Internationale. Although Sikorsky’s flight duration exceeded that of Rohlfs, it is not listed as an official world record.