14 September 1939: At Stratford, Connecticut, Igor Sikorsky made the first tethered flight of the Vought-Sikorsky VS-300 prototype helicopter. The duration of the flight was just 10 seconds but demonstrated that the helicopter could be controlled.
The Vought-Sikorsky VS-300 was the first successful single main rotor, single tail rotor helicopter.
The three-bladed main rotor had a diameter of 28 feet (8.534 meters) and turned approximately 255 r.p.m. The rotor turned clockwise as seen from above (the advancing blade is on the left). This would later be reversed. A counter-weighted single blade anti-torque rotor with a length of 3 feet, 4 inches (1.016 meters) is mounted on the left side of the monocoque beam tail boom in a pusher configuration and turns counter-clockwise as seen from the helicopter’s left (the advancing blade is above the axis of rotation).
In the initial configuration, the VS-300 was powered by an air-cooled, normally-aspirated, 144.489-cubic-inch-displacement (2.368 liter) Lycoming O-145-C3 horizontally-opposed, four-cylinder, direct-drive engine with a compression ratio of 6.5:1. It was rated at 75 horsepower at 3,100 r.p.m., using 73-octane gasoline. It was equipped with a single Stromberg carburetor and dual Scintilla magnetos. The dry weight of the O-145-C3 was 167 pounds (75.75 kilograms). Later in the VS-300’s development, the Lycoming was replaced by a 90-horsepower Franklin 4AC-199 engine.
On 19 December 1939, the VS-300 was rolled over by a gust of wind and damaged. It was rebuilt, however, and developed through a series of configurations. It made its first free (untethered) flight 13 May 1940.
Test flights continued for several years. After 102 hours, 32 minutes, 26 seconds of flight, the VS-300 was donated to the Henry Ford Museum, Dearborn, Michigan.
18 August 1943: At Bridgeport, Connecticut, Sikorsky chief test pilot Charles Lester (“Les”) Morris made the first flight of the Vought-Sikorsky VS-327, c/n 33. Also known as the Sikorsky Model S-48, the U.S. Army Air Corps designated the helicopter XR-5 and assigned the serial number 43-28236.
The XR-5 was a significant improvement over the earlier R-4. Its narrow fuselage was streamlined and the cockpit had excellent visibility. The R-4’s box-like fuselage interfered with the downward flow of air from the main rotor, and this was a consideration in the shape of the new helicopter.
The Sikorsky XR-5 (Model S-48) was a single-engine, two-place helicopter. The cabin was built of aluminum with plexiglas windows. The fuselage was built of plastic-impregnated plywood and the tail boom was wood monocoque construction. The main rotor consisted of three fully-articulated blades built of wood spars and ribs and covered with fabric. The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left.
There were five XR-5 helicopters, followed by twenty-six YR-5A service test helicopters built between November 1944 and July 1945. There were slight changes from the earlier five XR-5A prototypes. The R-5A went into production in July 1945 and more than 300 had been built by the time production ended in 1951.
The helicopter’s fuselage was 41 feet, 7½ inches (12.687 meters) long. The main rotor had a diameter of 48 feet (14.630 meters) and tail rotor diameter was 8 feet, 5 inches (2.2.565 meters), giving the helicopter an overall length of 57 feet, 1 inch (17.399 meters) with rotors turning. It was 13 feet, 1½ inches (4.001 meters) high. The landing gear tread was 12 feet (3.7 meters). The R-5A had an empty weight of 3,780 pounds (1,714.6 kilograms) and maximum takeoff weight of 4,900 pounds (2,222.6 kilograms). Fuel capacity was 100 gallons (378.5 liters).
The helicopter was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney Wasp Jr. T1B4 (R-985 AN-5) direct-drive, nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.
The R-5 had a maximum speed (Vne) of 107 knots (123.1 miles per hour/198.2 kilometers per hour). Range was 275 miles (442.6 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914.4 meters).
On 13 September 1943, Dimitry D. (“Jimmy”) Viner was hovering out of ground effect at 75 feet (23 meters) when 43-28236 suffered a tail rotor failure. The helicopter made a hard landing and was dignificantly damaged. Neither Viner nor his passenger were injured.
In 1944, while flying to a war bond rally in Nebraska, XR-5 43-28236 suffered an engine failure and crash landed. The helicopter was damaged beyond repair and was stripped for parts.
Thanks to regular This Day in Aviation reader Mike for suggesting this subject.
29 May 1940: Vought-Sikorsky Aircraft Division test pilot Lyman A. Bullard, Jr. took the U.S. Navy’s new prototype fighter, the XF4U-1, Bu. No. 1443, for its first flight at the Bridgeport Municipal Airport, Bridgeport, Connecticut. Designed by Rex B. Beisel, this would be developed into the famous F4U Corsair.
The F4U Corsair is a single-place, single-engine fighter, designed for operation from the U.S. Navy’s aircraft carriers. The XF4U-1 prototype was 30 feet (9.144 meters) long with a wing span of 41 feet (12.497 meters) and overall height of 15 feet, 7 inches (4.750 meters). It had an empty weight of 7,505 pounds (3,404 kilograms) and gross weight of 10,500 pounds (4,763 kilograms).
The XF4U-1 was first powered by an experimental air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liters) Pratt & Whitney Double Wasp A2-G (R-2800 X-2), and then an SSA5-G (R-2800 X-4), both twin-row 18-cylinder radial engines. The R-2800 X-4 was an X-2 with a A5-G supercharger. It was rated at 1,600 horsepower at 2,400 r.p.m. at 3,500 feet (1,067 meters); 1,540 horsepower at 2,400 r.p.m. at 13,500 feet (4,115 meters); 1,460 horsepower at 2,400 r.p.m. at 21,500 feet (6,553 meters); and 1,850 horsepower at 2,600 r.p.m for takeoff. The engine drove a 13 foot, 4 inch (4.064 meter) diameter, three-bladed, Hamilton Standard Hydromatic constant-speed propeller through a 2:1 gear reduction. The X-4 had a compression ratio of 6.66:1 and used a two-speed, two-stage supercharger. This was the most powerful engine and largest propeller used on any single engine fighter up to that time. The R-2800 X-4 was 4 feet, 4.50 inches (1.334 meters) in diameter and 7 feet, 4.81 inches (2.256 meters) long. It weighed 2,500 pounds (1,134 kilograms).
The size of the propeller was responsible for the Corsair’s most distinctive feature: the inverted gull wing. The width of the wing (chord) limited the length of the main landing gear struts. By placing the gear at the bend, the necessary propeller clearance was gained. The angle at which the wing met the fuselage was also aerodynamically cleaner.
The XF4U-1 prototype had a maximum speed of 378 miles per hour (608 kilometers per hour) at 23,500 feet (7,163 meters). Although it has been widely reported that it was the first U.S. single-engine fighter to exceed 400 miles per hour (643.7 kilometers per hour) in level flight, this is actually not the case. During a flight between Stratford and Hartford, Connecticut, the prototype averaged a ground speed 405 miles per hour (652 kilometers per hour). This was not a record flight, and did not meet the requirements of any official speed record.
Several changes were made before the design was finalized for production. Fuel tanks were removed from the wings to make room for six Browning AN-M2 .50-caliber machine guns and ammunition. A new tank was placed in the fuselage ahead of the cockpit. This moved the cockpit rearward and lengthened the nose.
The production F4U-1 Corsair had a length of 33 feet, 4.125 inches (10.163 meters), wingspan of 40 feet, 11.726 inches (12.490 meters) and overall height (to top of propeller arc) of 15 feet, 0.21 inches (4.577 meters). The outer wing had a dihedral of 8.5°, and the leading edges were swept back 4°10′. With its wings folded, the width of the F4U-1 was 17 feet, 0.61 inches (5.197 meters), and gave it a maximum height of 16 feet, 2.3 inches (4.935 meters). When parked, the Corsair’s 13 foot, 4 inch (4.064 meter) propeller had 2 feet, 1.93 inches (65.862 centimeters) ground clearance, but with the fighter’s thrust line level, this decreased to just 9.1 inches (23.1 centimeters).
During fight testing of a production F4U-1 Corsair with a Pratt & Whitney Double Wasp SSB2-G (R-2800-8) engine installed, armed with machine guns with 360 rounds of ammunition per gun, the fighter reached a maximum speed of 395 miles per hour (635.7 kilometers per hour) in level flight at 22,800 feet (6,949 meters), using Military Power. The service ceiling was 38,400 feet (11,704 meters).
A total of 12,571 Corsairs were manufactured by Chance Vought Aircraft Division (F4U-1), Goodyear Aircraft Corporation (FG-1D) and Brewster Aeronautical Corporation (F3A-1). The Corsair served the U.S. Navy and Marine Corps in World War II and the Korean War. Corsairs also served in other countries’ armed forces. Its last known use in combat was in Central America in 1969.
25 May 1889: И́горь Ива́нович Сико́рский (Igor Ivanovich Sikorsky) was born at Kiev, 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 SS 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.
21 April 1944: The first military helicopter combat rescue began with Lieutenant Carter Harman, 1st Air Commando Group, being ordered to proceed from Lalaghat, India with his Vought-Sikorsky YR-4B, 43-28247, 600 miles (965 kilometers) to Taro in northern Burma.
Technical Sergeant Ed “Murphy” Hladovcak, pilot of a Stinson L-1A Vigilant liaison airplane, had crashed in the jungle behind Japanese lines while transporting three wounded British soldiers. Lieutenant Harman was assigned to attempt to rescue the four men. It would be a marathon operation.
It took Harman and his Sikorsky 24 hours to arrive at Taro. After a brief rest and dip in the river to cool off, he continued for another 125 miles (202 kilometers) to an airstrip in the jungle called “Aberdeen” which was well behind the enemy lines. It was from here that Sgt. Hladovcak had been operating, flying out wounded soldiers. From Aberdeen, Harman was led to the location of the downed men by another liaison airplane. The survivors were surrounded by Japanese soldiers who had found the crashed airplane and were trying to locate the four men.
Because of the high heat, elevation and humidity increased the Density Altitude, the YR-4B’s air-cooled radial engine was unable to produce its full rated power. Also, the helicopter’s rotor blades were not as effective as they would be at lower density altitudes.
Harman planned to lift one of the survivors out of the clearing in the jungle and fly a short distance to a sand bank where other L-1 or L-5 liaison airplanes could fly them back to Aberdeen. He would repeat the operation until all four men had been rescued. However, it took the rest of the day to airlift just the first two wounded and very sick soldiers.
On the second flight, the helicopter’s engine was overheating and on landing it seized and could not be restarted. Sergeant Hladovcak and the remaining soldier were still in the jungle, Lieutenant Harman was stuck by the river bank and Japanese soldiers were everywhere.
On the morning of 25 April Lieutenant Harman was able to get the helicopter’s engine to start, and again, one at a time, he rescued the two remaining survivors. A liaison plane flew out the wounded soldier while Hladovcak rode along with Harman back to Aberdeen. He had never seen a helicopter before.
For his actions, Lieutenant Carter Harman was awarded the Distinguished Flying Cross.
Sikorsky YR-4B 43-28247 was condemned 31 December 1944.
The Sikorsky YR-4B was a two-place, single-engine helicopter with a single main rotor and an anti-torque tail rotor. The fuselage was 35 feet, 8.375 inches (10.881 meters) long with a main rotor diameter of 38 feet, 0 inches (11.582 meters). The tail rotor was 8 feet, 2.25 inches (2.496 meters) in diameter. Its overall length, with rotors turning, was 48 feet, 3.375 inches (4.716 meters). The helicopter had an overall height of 12 feet, 5 inches (3.785 meters). The empty weight was 2,020 pounds (916 kilograms) and maximum takeoff weight of 2,540 pounds (1,152 kilograms). The helicopter’s fuel capacity was 30 gallons (113.6 liters)
The main rotor consisted of three tapered, fully-articulated blades built of chrome-molybdenum steel spars and spruce plywood ribs, with laminated spruce, balsa and mahogany forming the leading edge and a flexible cable forming the trailing edge. The blades were covered with two layers of doped fabric. The three-bladed semi-articulated tail rotor was built with a spruce spar and alternating laminations of maple and mahogany, covered with fabric. Both the main and tail rotors had a thin brass abrasion strip covering the leading edges. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted on the helicopter’s right side in a tractor configuration. It turned clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)
The YR-4B was powered by an air-cooled, direct-drive 555.298-cubic-inch-displacement (9.100 liter) Warner Super Scarab SS185 (R-550-3) seven-cylinder radial engine with a compression ration of 6.20:1. The R-550-3 was rated at 185 horsepower at 2,175 r.p.m. at Sea Level, and 200 horsepower at 2,475 r.p.m (five minute limit) for takeoff. The engine was placed backwards in the aircraft with the propeller shaft driving a short driveshaft through a clutch to a 90° gear box and the transmission. The R-550-3 weighed 344 pounds (156 kilograms).
The R-4B had a cruise speed of 65 miles per hour (105 kilometers per hour) and maximum speed of 82 miles per hour (132 kilometers per hour). The service ceiling was 12,000 feet (3,658 meters) and range was 157 miles (253 kilometers).
The YR-4B was equipped with bomb racks. It could carry three 125 pound (56.7 kilogram) demolition bombs or one 325 pound (147 kilogram) depth bomb. The equipment was deleted for the R-4B.
Sikorsky built 27 YR-4Bs and 100 R-4B helicopters. Of these, 40 were assigned to the Army Air Corps, 19 to the Navy and Coast Guard, and 41 were sent to the Royal Air Force and Royal Navy.
Carter Harman was born at Brooklyn, New York, 14 June 1918, the son of Steven Palmer Harman, a newspaper editor, and Helen F. Doremus Harman.
Before the war, Harman had been a musician and author. He assisted Duke Ellington write an autobiography. Harman earned a bachelor’s degree in music composition from Princeton University, Princeton, New Jersey, in 1940.
Harman enlisted as a private in the Army of the United States Army on 1 April 1942, assigned to the Air Corps. Enlistment records indicate that he was 5 feet, 7 inches (170.2 centimeters) tall and weighed 125 pounds (57 kilograms)
After World War II ended, Harman returned to his musical studies at Columbia University, New York City, receiving a master’s degree in 1949.
Harman worked as a music critic for The New York Times and Time Magazine, and also continued writing books, as well as composing for ballet and opera. He was also a music producer and became executive vice president of CRI Records (Composers Recordings, Inc.).
Harman was married three times. He married Miss Nancy Hallinan, 5 February 1946, however they later divorced. His second wife was Helen Scott. They had four children together. His third wife was Wanda Maximilien.
Carter Harman died at Berlin, Vermont, 23 January 2007 at the age of 88 years.