Sikorsky X-2

Sikorsky developed the X2 helicopter on a $50 million budget. The design includes expertise gathered from several earlier design projects. The S-69/XH-59A Advancing Blade Concept Demonstrator had shown that high speed was possible with a coaxial helicopter with auxiliary propulsion supplied using two jet engines, but that vibration and fuel consumption was excessive; the Cypher UAV expanded the company’s knowledge of the unique aspects of coaxial flight control laws with a fly-by-wire aircraft; and the RAH-66 Comanche developed expertise in composite rotors and advanced transmission design.

Other features include slowed “de-swirling” rigid rotors two feet apart, active force counter-vibration inspired by the Black Hawk, and using most of the power in forward flight for the pusher propeller rather than the rotor. Unusually for helicopters, the power required for high speed is more than the hover power. The pilot controls the independent propeller power with a thumb wheel on the collective.

Test flights and flight simulations were combined to improve test procedure. The fly-by-wire system is provided by Honeywell, the rotor by Eagle Aviation Technologies, anti-vibration technology from Moog Inc, and propeller by Aero Composites The rotor hub can have 10-20 times the drag of the blade. Sikorsky intended to test hub fairings to reduce drag by 40%, and test flew fairings on the hubs themselves but not the central hub fairing (“aero sail”) in between the hubs. Sikorsky has since patented a “Standpipe” (fixed tube between rotating rotor axes) suitable for a central hub fairing.

The X2 first flew on 27 August 2008 from Schweizer Aircraft, a division of Sikorsky Aircraft Corporation’s facility at Horseheads, New York. The flight lasted 30 minutes. This began a four-phase flight test program, to culminate with reaching a planned 250-knot top speed. The X2 completed flights with its propeller fully engaged in July 2009. Sikorsky completed phase three of the testing with the X2 reaching 181 knots in test flight in late May 2010.

On 26 July 2010, Sikorsky announced that the X2 exceeded 225 knots (259 mph; 417 km/h) during flight testing in West Palm Beach Florida, unofficially surpassing the current FAI rotorcraft world speed record of 216 knots (249 mph; 400 km/h) set by a modified Westland Lynx in 1986.

On 15 September 2010, test pilot Kevin Bredenbeck achieved Sikorsky’s design goal for the X2 when he flew it at a speed of 250 knots (290 mph; 460 km/h) in level flight, an unofficial speed record for a helicopter. The demonstrator then reached a new record speed of 260 knots (300 mph; 480 km/h) in a shallow 2˚ to 3˚ dive, which was just short of the 303 mph achieved by the Sikorsky S-69 technology demonstrator helicopter. Sikorsky states that the X2 has the same noise level at 200 knots that a regular helicopter has at 100 knots. Above 200 knots, the rotor speed is reduced from 446 to 360 RPM to keep tip speed below Mach 0.9, the rotor disc is slightly nose-up, and the lift-to-drag ratio is about twice that of a conventional helicopter. Hands-off flying was also successfully performed during flight tests.

On 14 July 2011, the X2 completed its final flight and was officially retired after accumulating 22 hours over 23 test flights. With the end of development, the X2 will be followed by its first application, the S-97 Raider high-speed scout and attack helicopter. It was donated to the National Air and Space Museum in October 2016 and is on display in the Steven F. Udvar-Hazy Center in Chantilly, Virginia.

Powerplant: 1 × LHTEC T800-LHT-801 turboshaft, 1,800 shp (1,300 kW)
Main rotor diameter: 2 × 26 ft 5 in (8.05 m)
Main rotor area: 548 sq ft (50.9 m2) contra-rotating four-bladed coaxial.
Propellers: 6-bladed pusher
Aspect ratio: 9.5
Empty weight: 5,300 lb (2,404 kg)
Gross weight: 6,000 lb (2,722 kg)
Max takeoff weight: 5,300 lb (2,404 kg)–6,000 lb (2,700 kg)
Maximum speed: 290 mph (460 km/h, 250 kn)
Range: 35 mi (56 km, 30 nmi)
Wing loading: 0.44 lb/sq ft (2.1 kg/sq.m)
Power/mass: 3.66 hp/lb
Crew: Two

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

Sibnia / Chaplygin TVS-2

TVS-2-DT RA-2519G at MAKS, Zhukovsky, Moscow, Russia, August 26, 2015

Another organization working on a “better” An-2 is SibNIA (Siberian Aeronautical Research Institute) in Novosibirsk, Russia. In this version, the An-2MS (An-2MC in Russian) and later usually referred to as the TVS-2MS), the radial engine was replaced by a 1,100 hp Honeywell TPE331-12UHR turbine, driving a five-bladed Hartzell propeller. The first An-2MS/TVS-2MS was first flown on September 5, 2011 and by 2015 well over fifteen examples had been delivered by SibNIA and Rusaviaprom JSC, all built, from existing An-2 airframes retaining the An-2 wings and tail feathers.

SibNIA went a step further and also developed an upgraded An-2 with an entirely new composite construction high-lift, high-aspect-ratio wing. This new wing was first tested on an An-2MS which flew as a high wing monoplane. The aircraft, designated TVS-2-DT, first flew in December 2014 and had the TPE331 engine and old style tail. It then received curved wingtips on the upper wing and a new lower wing with wingtips acting as interconnecting struts. In this guise it flew on June 10, 2015, initially also with the old tail, but this was soon replaced by a new design larger and squared vertical tail as shown in the photo.

Sherpa K-650T

The Sherpa K-650T 8 place is turbine powered and capable of operating on wheels, skis, or floats.

I don’t like it. For me the worst aircraft of all bush planes.
The plane is hard to land correctly and difficult to control.
I regret the purchase.
ry.ma@gmx.net

Engine: Honeywell TPE331-5, 840 hp
Optional engine: Honeywell TPE331-10, 1000 hp
Prop: 116 in 3-blade
Wingspan: 47 ft 4 in
Wing chord: 6 ft 8 in
Aspect ratio: 7.1
Length: 34 ft 1 in
Height: 9 ft 9 in
Empty weight: 3500 lb
MTOW: 6500 lb
Max wing loading: 20.63 lb/sq.ft
Max power loading: 8.66 lb/hp
Fuel capacity: 346 USG
Tailplane span: 18 ft 3 in
Wheel track: 8 ft 10 in
Prop ground clearance 3 pt: 3 ft 1 in
Prop ground clearance level: 1 ft 7 in
Cabin door height: 3 ft 7 in
Cargo door width: 5 ft 1 in
Baggage door height; 1 ft 8 in
Baggage door width: 2 ft 6 in
Cruise 18,000 ft: 188 mph
Econ cruise 18,000 ft: 174 mph
Stall clean: 58 mph
Stall flaps down: 34 mph
ROC SL: 1400 fpm
Service ceiling: 25,000 ft
TO run gross: 336 ft
Landing run gross; 240 ft
Range max cruise (42USG/hr) + res: 1256 sm
Range econ cruise (36USG/hr) + res: 1500 sm
Cabin volume: 220 cu.ft
Baggage volume: 7.5 cu.ft
Useful load: 3000 lb
Wing area: 315 sq.ft
Aileron area – total: 26.4 sq.ft
Spoileron area – total: 4.6 sq.ft
Flap area: 67.9 sq.ft
Fin area: 32.6 sq.ft
Rudder area: 15.7 sq.ft
Horiz. Stab. Area: 77.6 sq.ft
Elevator area: 36.8 sq.ft
Seats: 8
Tires: 29x11x10 (35in opt.)

Sherpa K-300

Sherpa N711SA

The K-300 can carry up to eight people. They are convertible for freight or passengers, also as two-litter medivac ambulance.

Tires can be up to 42 inch.

Engine: Lycoming O-720, 400 hp
Stall: 41 mph
Seats: 6
Max payload: 2200 lb

Engine: Lycoming TIO-720 twin-turbo, 450hp
Wingspan: 44’10”
Useful load: 2504 lb
Max speed: 166 mph
Stall: 42 mph
Ceiling: 12,000′
Seats: 8

Shenyang J-31

The second product of the J-XX program to be revealed to the public was the J-31. Revealed to the public in 2012, it clearly incorporates some stealth aspects, especially towards the front of the aircraft.

Testing began in October 2012, and in late 2014, the J-31 was displayed publicly at an airshow for the first time. The prototype mounts two Russian-designed RD-93 turbofans (the same engines as the MiG-29). The mockup shown at that same event seems to show that several changes to the design are in store. While the intended role of the J-31 within China is unclear, it does seem to be slated for export, with Pakistan reportedly planning to purchase up to 40 J-31s.

Shenyang J-16

In 2000, China purchased an Su-30MKK from Russia, which formed the basis for development of two-seat J-11 variants. The Chinese developed the two-seat J-11BS into a dedicated strike fighter under the designation J-16.

Just as its predecessor, it extensively employs composites to lower airframe weight, while new materials and design elements were used to lower RCS. The J-16 first took flight in 2011 and was accepted into service two years later.

A small production of only 25 aircraft built. While still in production, priority seems to be placed on development and production of the fifth-generation J-20 and J-31 fighters.

Shenyang J-15

Soon after development of the J-11B began, Shenyang began to develop a navalized version of the aircraft to operate from the recently purchased carrier Varyag. In 2001, China purchased an unfinished Su-33 prototype from the Ukraine, allowing Shenyang to work with the design to develop a carrier aircraft. Meanwhile, the Chinese government made repeated attempts to acquire Su-33s directly from Russia. Negotiations fell apart in 2006 when the J-11B was revealed, and thus Shenyang was forced to develop a domestic solution. The resulting aircraft was almost identical in appearance to the Su-33, but is considerably lighter and more capable thanks to extensive use of composites and newer onboard systems.

The J-15 first flew in 2009, powered by the same AL-31F turbofans that powered the Su-33. Carrier trials began in late 2012, and as of late 2013 the J-15 has began operational testing.