Sikorsky S-35

The S-35 was designed as a twin-engined transport with a range of about 1600km.

In the spring of 1926 Capt. Rene Fonck, a French First World War fighter ace, persuaded Sikorsky to redesign it in an attempt to win the $25,000 Orteig prize for the first non-stop New York-Paris flight. It became a very different aircraft, with three 400hp Gnome-Rhone Jupiter engines and vastly increased fuel load. The first test flight, by Fonck and Igor Sikorsky, was made on 23 August 1926. Later, pilot Frank LaVista of the Department of Commerce reported that the aircraft handled very well, could climb on two engines, and lost only 15m of height while flying at 132km/h for 35 seconds on one engine.

Jettisonable auxiliary landing gear was fitted to the S-35 for take-off on its transatlantic attempt, at an overload weight of 8400kg, on 20 September 1926. Fonck insisted on having a radio operator, Charles Clavier, and veteran Sikorsky mechanic Jacob Islamoff, in addition to his co-pilot Lt Lawrence Curtin of the US Navy. Watched by a huge crowd, part of the auxiliary landing gear broke away as the aircraft gathered speed. It plunged down a steep slope beyond the runway and burst into flames. Only the two pilots escaped. The S-35, which had cost $100,000 to build, was destroyed.

The original wingspan, before extra bays were added, was 76’0″. This was increased to 101’0″.

Gallery

Sikorsky S-35
Engines: three 420hp Gnôme-Rhône Jupiter
Wingspan (upper): 101’0″
Wingspan (lower): 76’0″
Original load: 6600 lb
Load: 15,710 lb
Ceiling: 16,800 ft
Seats: 4

Sikorsky S-34

Sikorsky’s first attempt to build an amphibian, the six-seat S-34 NX883, flew in 1926. During a test flight in November 1927, piloted by Capt. Collier and with Igor Sikorsky as observer, it developed engine trouble while flying low over water and sank after forced landing. The two men were rescued and taken ashore by motor boat.

Sikorsky S-34 NX883

Engines: two 200hp Wright J-4
Wingspan: 50’5″
Sponsons width: 12’0″
Length: 34’0″
Useful load: 1600 lb
Max speed: 111 mph
Cruise: 90 mph
Stall: 52 mph
Range: 360 mi
Ceiling: 15,000′
Seats: 7

Sikorsky S-33

Two S-33 Messengers were built, the first in 1926 as a racing aircraft with a 60hp Wright Gale aircooled engine, the second in 1927 as a two-seat utility aircraft with a 60hp Lawrence. The racer was flown by Al Krapish, one of the company’s earliest employees and a passenger on the first unhappy flight of the S-29A. It spanned 9.75m and had a speed of 165km/h.

S-33 Messenger
Engine: 60hp Anzani
Wingspan (upper): 32’0″
Wingspan (lower): 20’0″
Useful load: 500 lb
Max speed: 115 mph
Stall: 35 mph
Ceiling: 15,000′
Seats: 1

Sikorsky S-32

The 1925 one-off S-32 was a large fabric-covered metal biplane, with a 400hp Liberty engine, built for the Andean National Corporation, a subsidiary of Standard Oil Company, for extra-heavy duties in Colombia.

It carried the pilot in the rear cockpit and two pairs of passengers in the forward cockpits. In landplane form it had a top speed of 215km/h and endurance of more than four hours, but was flown mainly on floats.

Sikorsky S-32 on floats

Engine: 400hp Liberty 12
Wingspan: (upper) 58’4″ / 17.78m
Wingspan (lower): 38’0″
Length: 36’0″
Maximum weight: 2450 kg
Useful load: 2100 lb
Max speed: 133 mph
Stall: 40 mph
Ceiling: 16,000′
Seats: 5

Sikorsky S-31

The 1925 five-seat S-31, with a 200hp Wright J-4 Whirlwind engine, was used by the Fairchild Company for aerial photo-mapping work in South America.

Up to four passengers, or photographic equipment, could be carried in the semi-closed centre cabin.

During flight testing, the S-31 climbed to 4680m in 47 minutes with a pilot, two passengers and fuel for four hours of flying.

The sole example built was shown in a publicity photo shows it with a machine-gunner in the rear cockpit, suggesting plans for a military export version.

S-31
Engine: 200hp Wright J-4
Wingspan (upper): 45’0″
Wingspan (lower): 32’0″
Length: 26’0″
Useful load: 1200 lb
Max speed: 124 mph
Cruise: 110 mph
Stall: 35 mph
Range: 500 mi
Ceiling: 15,000′
Seats: 3

Sikorsky S-29-A

S-29-A 2756

In New York, Sikorsky formed a small company and started to build the S-29-A, a twin-engined 14 passenger and freight carrier. With $5,000 finance from the great pianist and composer Sergei Rachmaninoff the S-29-A was completed. The suffix “-A” denoted “Made in America,” as 28 previous S-numbers were all built and utilized in Russia. First Sikorsky built in the US, originally had 220hp Hispano-Suizas

With Hisso engines

Rachmaninoff accepted the position of first vice-president of the struggling corporation. The engines were old, some of the parts from junkyards. On 4 May 1924 a take-off was attempted. With too many loyal passengers the aircraft flew, but crashed. The aircraft was rebuilt repowered with Liberty 12 engines.

With Liberty Engines

It was owned by Roscoe Turner and made many long-distance flights in the East and Midwest 1925-27, was even used to deliver two grand pianos.

In 1928, Howard Hughes bought the S-29A for use in his epic film “Hell’s Angels”. To simulate a First World War German Gotha bomber, he painted it black, with Maltese cross insignia and with machine-guns above the mid-fuselage cockpit, at side hatches and above and below the nose. In the film, the aircraft is seen to spin down and crash. Few of the viewers realized that the pilot had parachuted to safety, but that the man releasing the smoke trail from the rear fuselage had not known that the S-29A was out of control and died when it slammed into the ground.

S-29-A
Engines two 400hp Liberty 12
Wingspan: 69’0″
Length: 49’10”
Useful load: 4225 lb
Max speed: 115 mph
Cruise: 100 mph
Stall: 56 mph
Ceiling: 12,300 ft
Seats: 16

Sikorsky

Igor Sikorsky
Sikorsky Aero Engineering Corporation

lgor Ivan Sikorsky was born in Kiev, Ukraine, on May 25, 1889. His father was a graduate physician and professor of psychology. His mother also was a physician but never practiced professionally. Her interest in art and in the life and work of Leonardo da Vinci stimulated her son’s early interest in model flying machines; when he was 12 years old he made a small rubber-powered helicopter that could rise in the air.

Sikorsky Article

In 1903 Sikorsky entered the Naval Academy in St. Petersburg, with the intention of becoming a career officer, but his interest in engineering led to his resignation from the service in 1906. After a brief period of engineering study in Paris, he returned to Kiev and entered the Kiev Polytechnic Institute. Following a reasonably successful academic year, however, he concluded that the abstract sciences and higher mathematics as then taught had little relationship to the solution of practical problems, and he left the school, preferring to spend his time in his own shop and laboratory.

A trip through Europe in the summer of 1908 brought him into contact with the accomplishments of the Wright brothers and the group of European inventors who were trying to match their progress in flight. Returning to Kiev, Sikorsky came to the conclusion that the way to fly was “straight up,” as Leonardo da Vinci had proposed, a concept that called for a horizontal rotor. Assisted financially by his sister Olga, he returned to Paris in January 1909 for further study and to purchase a light-weight engine.

Back in Kiev in May of 1909 he began construction of a helicopter, the H-1. Its failure revealed some of the practical obstacles. Powered by a three-cylinder, 25-hp Anzani engine that drove coaxial, twin blade rotors, the H-1 shook wildly but did not have enough power to lift itself off of the ground. A second machine with a larger engine was tested in 1910, but also failed to fly. He then made a major decision: “I had learned enough to recognize that with the existing state of the art, engines, materials, and-most of all-the shortage of money and lack of experience … I would not be able to produce a successful helicopter at that time.” In fact, he had to wait 30 years before all conditions could be met.

For the time being Sikorsky decided to enter the field of fixed-wing design and began construction of his first airplane. His S-1 biplane was tested early in 1910, and, although its 15-horsepower engine proved inadequate, a redesigned airframe with a larger engine (S-2) carried him on his first short flight. The S-3, S-4, and S-5 followed in quick succession, each a refinement of its predecessor, and each adding to his piloting experience. Finally, by the summer of 1911, in an S-5 with a 50-horsepower engine, he was able to remain in the air for more than an hour, attain altitudes of 1,500 feet (450 metres), and make short cross-country flights. This success earned him International Pilot’s License Number 64.

The subsequent S-6 series established Sikorsky as a serious competitor for supplying aircraft to the Russian Army. Characteristically, he soon took a giant step: the first four-engined airplane, called “Le Grand,” the precursor of many modern bombers and commercial transports, which he built and flew successfully by 1913. Among its innovative features, not adopted elsewhere until the middle 1920s, was a completely enclosed cabin for pilots and passengers.

Although he was now an internationally known aircraft designer and pilot, Sikorsky decided to leave Russia for France in 1918 following the Bolshevik Revolution. On Mar. 30, 1919, Sikorsky came to New York City to begin his career anew. Initially unable to land a job with a U.S. airplane manufacturer, Sikorsky supported himself by teaching mathematics to Russian emigees in New York and giving lectures on aviation and astronomy until Mar. 5, 1923, when he received enough financing to launch the Sikorsky Aero Engineering Corp.

They set up shop in an old barn on a farm near Roosevelt Field on Long Island. Sikorsky became a U.S. citizen in 1928. From 1925 to 1926, the company produced one-of-a-kind, fixed-wing designs built to customer needs. In 1924, using junkyard parts and war-surplus materials, Sikorsky constructed his first S-29A, a twin-engine, 14 passenger design. By 1929 the company, having become a division of United Aircraft Corporation, occupied a large modern plant at Bridgeport, Connecticut, and was producing S-38 twin-engined amphibians in considerable numbers. In 1931 the first S-40, the “American Clipper,” pioneered Pan American World Airways mail and passenger routes around the Caribbean and to South America. By the summer of 1937 Pan American began transpacific and transatlantic service with the first four-engined S-42 “Clipper III” the last of the Sikorsky series, the ancestor of which had been “Le Grand” of 1913.

As the era of flying boats faded, lgor Sikorsky revived the idea of developing the helicopter. Once again he was involved in “advanced pioneering work . . . where extremely little reliable information and no piloting experience whatever were available.” By the late 1930s changing requirements for military and commercial air transport forecast the termination of the large flying boat, and Sikorsky returned to his first love, the helicopter. The essential aerodynamic theory and construction techniques that had been lacking in 1910, however, were now available. In a memo to the general manager of Vought-Sikorsky (the new name of the company) dated Aug. 10, 1938, he wrote:

“Besides having considerable possibilities as a privately owned aircraft, the direct-lift ship [helicopter] will be a very important service type for the army and navy. For the army, this type of ship would render excellent services for communication, fire control, short-range reconnoitering and bombing operations. For the navy, the ship would be extremely useful as the only aircraft that could take off and land without catapulting from any surface vessel….”

Even though an official manufacturing order had not been issued to begin work on a “new” type of aircraft, helicopter development continued throughout the fall of 1938. lgor Sikorsky and a handful of engineers and production personnel spent lunch breaks and off hours sketching, designing, fabricating and testing various components and systems for what would become known as the VS-300 (“V’ for Vought, “S” for Sikorsky and “300” for Sikorsky’s third helicopter design).

Rotor tests were encouraging enough for Sikorsky to request a meeting with Eugene Wilson, a senior vice president of United Aircraft, at which he received the go-ahead to construct a prototype helicopter. Sikorsky’s argument for building the rotorcraft had been compelling.

“So important is this development to the future of society that it becomes our responsibility to undertake it. While admittedly radical, and possibly ‘impossible,’ the helicopter is wholly rational. Like no other vehicle, it will operate without regard to prepared landing surfaces. Thus, it will free us of the serious handicap to progress imposed by fixed-wing aircraft-airport limitations. It is not competitive with the airplane, but complementary to it. If Sikorsky does not create this craft of the future, another [company] will. By training and expedence, we are best equipped to do it. And finally, unlike the airplane, the helicopter will be used not to destroy but to save lives!”

Early in 1939, with a well trained engineering group at his disposal, he started the construction of the VS-300 helicopter. As he said later, “There was a great satisfaction in knowing that, within a short period of time, good engineering along a novel line produced encouraging results.” On September 14, 1939, the plane lifted off the ground on its first flight. Its designer was at the controls; during his entire career Sikorsky always insisted on making the first trial flight of any new design himself. On May 6, 1941, in an improved machine, he established an international endurance record of 1 hour, 32.4 seconds.

Sikorsky regarded it as a useful tool for industry and air commerce but primarily as an effective device for rescue and relief of human beings caught in natural disasters, such as fire, flood, or famine. He estimated that over 50,000 lives had been saved by helicopters.

lgor Sikorsky only complained that of all his past predictions, those that he lived to regret were on the “too conservative” side.

Sikorsky retired as engineering manager tor his company in 1957 but remained active as a consultant until his death on October 26, 1972, at Easton, Connecticut. In addition to his wife (married in 1924), he left one daughter and four sons, all of whom have professional careers. Sikorsky received many honorary doctorates in science and engineering, honorary fellowships in leading scientific and technical societies in the United States and Europe, and the highest medals and awards in aviation, including the Cross of St. V1adimir from Russia; the Sylvanus Albert Reed Award for 1942 from the Institute of Aeronautical Sciences in New York; the United States Presidential Certificate of Merit in 1948; the Daniel Guggenheim Medal and Certificate for 1951; the Elmer A. Sperry Award for 1964; and the National Defense Award in 1971.

Apparently, when he checked in for a Sabena S-58 flight, Igor Sikorsky was asked if his name was spelt like the helicopter’s.

Dean C. Borgrnan, who took over as president and CEO of Sikorsky Aircraft in October 1998, said: “As we approach a new millennium, a new generation of helicopter pioneers is designing and building aircraft that will revolutionize the industry. The S-92 and the RAH-66 represent two of the most advanced helicopters in the world today. Technical achievements from these two programs are being incorporated on the Black Hawk and its derivatives.”

Sikorsky also was retooling its design and engineering computers. Sikorsky selected IBM and Dassault Systemes to provide the Enovia PM (Product Manager) solution as its enterprise~wide computer system.

1923: (Igor I) Sikorsky Aero Engr Corp.

1925: Sikorsky Mfg Co, Bridgeport CT (company funded in part by composer-pianist Sergei Rachmaninoff).

1926: Leased former L-W-F plant, College Point, Long Island NY.

1928: Sikorsky Aviation Div, United Aircraft & Transport Corp, Bridgeport.

1939: (Chance) Vought-Sikorsky Div, United Aircraft Corp.

1943: Sikorsky Aircraft Div, United Aircraft Corp.

1975: Sikorsky Aircraft Div, United Technologies Corp, Stratford CT.

199?: Sikorsky Aircraft Corp, United Technologies Corp

Sikorsky was sold to Lockheed Martin in 2015

Sierra / Aircraft Industries BLW-1 / BLW-2

Sierra San Franciscan NR7713

Designed by H Sherman Tharpe, two 1929 Sierra were built with ATC 2-151. Priced at $8,000 and designated BLW-1 and BLW-2 registered NX215H and NX/NR7713, the latter as San Franciscan in unsuccessful endurance record attempts June-Aug 1929 at Mills Field, San Francisco (piloted by Jim Warner). It is said to have been sold after WW2 to someone in South America.

The design reappeared in the Hawke Duster.

Engine: 130hp Comet
Wingspan: 36’0″
Length: 25’8″
Useful load: 909 lb
Max speed: 125 mph
Cruise: 100 mph
Stall: 47 mph
Range: 400 mi
Seats: 3