Tag Archives: Vought-Sikorsky Aircraft Division

24 June 1942

Vought-Sikorsky F4U-1 Corsair, Bu. No. 02170, with test pilot Willard Bartlett Boothby, 24 October 1942. This is the twenty-fifth production F4U-1. (Rudy Arnold/National Air and Space Museum NASM-XRA-1294)

24 June 1942: The first production Vought-Sikorsky F4U-1 Corsair, Bu. No. 02155, made its first flight at Stratford, Connecticut. (Some sources state 25 June.)

The Corsair was designed by Rex Buren Beisel, and is best known for its distinctive inverted “gull wing,” which allowed sufficient ground clearance for its 13 foot, 4 inch (4.064 meter) diameter propeller, without using excessively long landing gear struts. The prototype XF4U-1, Bu. No. 1443, had first flown 29 May 1940, with test pilot Lyman A. Bullard in the cockpit.

The F4U-1 was 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 wings’ angle of incidence was 2°. The outer wing had 8.5° dihedral 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). The F4U-1 had an empty weight of 8,982 pounds (4,074.2 kilograms) and gross weight of 12,162 pounds (5,516.6 kilograms).

Vought-Sikorsky F4U-1 Corsair, Bu. No. 02170, with test pilot Willard Bartlett Boothby, 24 October 1942. (Rudy Arnold/National Air and Space Museum NASM-XRA-1301)

The F4U-1 variant of the Corsair was powered by an air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liter) Pratt & Whitney Double Wasp SSB2-G (R-2800-8) two-row, 18-cylinder radial engine, with a compression ratio of 6.65:1. The R-2800-8 had a normal power rating of 1,675 horsepower at 2,550 r.p.m. and 44.0 inches of manifold pressure (1.490 bar) at 5,500 feet (1,676 meters); 1,550 horsepower at 21,500 feet (6,553 meters); and 2,000 horsepower at 2,700 r.p.m. with 54.0 inches of manifold pressure (1.829 bar) for takeoff. The engine turned a three-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 13 feet, 4 inches (4.064 meters) through a 2:1 gear reduction. The R-2800-8 was 7 feet, 4.47 inches (2.247 meters) long, 4 feet, 4.50 inches (1.334 meters) in diameter and weighed 2,480 pounds (1,125 kilograms).

Vought-Sikorsky F4U-1 Corsair, circa 1942. (Rudy Arnold)

The F4U-1 had a cruise speed of 186 miles per hour (299 kilometers per hour) at Sea Level. Its maximum speed at Sea Level was 365 miles per hour (587 kilometers per hour). During flight testing, an F4U-1 reached 431 miles per hour (694 kilometers per hour) at 20,300 feet (6,187 meters) with War Emergency Power. The service ceiling was 38,200 feet (11,643 meters) and its maximum range was 1,510 miles (2,430 kilometers) with full main and outer wing tanks.

The Corsair was armed with six air-cooled Browning AN-M2 .50-caliber machine guns, three in each wing, with 400 rounds of ammunition per gun.

Three Browning AN-M2 .50-caliber machine guns and belted ammunition installed in the left wing of a Vought-Sikorsky F4U-1 Corsair, 11 August 1942. (Vought-Sikorsky VS-6015)

A total of 12,571 Corsairs were manufactured by the Vought-Sikorsky 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.

Vought-Sikorsky F4U-1 Corsair, circa 1942. (Rudy Arnold/National Air and Space Museum NASM-XRA-1329)

© 2019, Bryan R. Swopes

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29 May 1940

Vought-Sikorsky Aircraft Division XF4U-1 Corsair prototype, Bu. No. 1443, in flight. (Rudy Arnold Collection/NASM)

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 Buren Beisel, the prototype would be developed into the famous F4U Corsair.¹

Rex Buren Beisel, designer of the F4U-1 Corsair, at left, with Corsair pilot Major Gregory Boyington, USMCR, circa 1942. (Unattributed)

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 7,576 pounds (3,436 kilograms) and gross weight of 9,374 pounds (4,252 kilograms).

Vought-Sikorsky XF4U-1 Corsair, Bu. No. 1443
Vought-Sikorsky XF4U-1 Corsair, Bu. No. 1443. The airplane’s wings are painted yellow. (Vought-Sikorsky Aircraft Division)

The XF4U-1 was first powered by an experimental air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liters) Pratt & Whitney R-2800 X-2 (Double Wasp A2-G), and then an R-2800 X-4 (Double Wasp SSA5-G), both two-row 18-cylinder radial engines. The R-2800 X-4 was an X-2 with an A5-G supercharger. The R-2800 X-2 had a compression ratio of 6.65:1 and was rated at 1,500 horsepower at 2,400 r.p.m. at 7,500 feet (2,286 meters). The X-4 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.

Vought Aircraft Division XF4U-1, front. (Vought Sikorsky VS-2612)
Vought-Sikorsky XF4U-1 Corsair, front, 19 April 1941. (Vought-Sikorsky VS-2612)
Vought Aircraft Division XF4U-1, right front quarter view. (Vought-Sikorsky VS-2618)
Vought-Sikorsky XF4U-1 Corsair, right front quarter view, 19 April 1941. (Vought-Sikorsky VS-2618)
Vought Aircraft Division XF4U-1, right profile (Vought-Sikorsky VS-2619)
Vought-Sikorsky XF4U-1 Corsair, right profile, 19 April 1941. (Vought-Sikorsky VS-2619)
Vought-Sikorsky XF4U-1, right rear quarter, 26 May 1940. (Vought-Sikorsky VS-1414/ cropped image from Connecticut Air & Space Center)
Vought Aircraft Division XF4U-1, rear, 26 May 1940. (Vought-Sikorsky VS-1407)
Vought-Sikorsky XF4U-1 Corsair, rear, 26 May 1940. (Vought-Sikorsky VS-1407)
Vought Aircraft Division XF4U-1, left side, wings folded, 26 May 1940. (Vought-Sikorsky VS-1416)
Vought-Sikorsky XF4U-1, left side, wings folded, 26 May 1940. (Vought-Sikorsky VS-1416)

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.

On 11 July 1940, the XF4U-1 was low on fuel. Rather than returning to Bridgeport, test pilot Boone Tarleton Guyton made a precautionary landing on a golf course at Norwich, Connecticut. The grass was wet from rain and the prototype ran into the surrounding trees. Guyton was not injured, but 1443 was seriously damaged. Vought-Sikorsky repaired it and it returned to flight testing about two months later.

Vought-Sikorsky F4U-1 Corsair, Bu. No. 2170, with test pilot Willard Bartlett Boothby, 24 October 1942. (Rudy Arnold Collection/National Air and Space Museum NASM-XRA-1294)

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 wing had 2° incidence at the root. 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).

Vought-Sikorsky F4U-1 Corsair, 1942. (U.S. Navy)

During fight testing of a production F4U-1 Corsair with a Pratt & Whitney R-2800-8 (Double Wasp SSB2-G) 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 the Vought-Sikorsky 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.

Vought-Sikorsky F4U-1 Corsair, 1942. (U.S. Navy)

¹ corsair: noun, cor-sair. A pirate, or privateer (especially along the Barbary Coast of the Mediterranean Sea); a fast ship used for piracy.

© 2018, Bryan R. Swopes

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Igor Ivanovich Sikorsky (25 May 1889–26 October 1972)

Igor Ivanovich Sikorsky, 1914. (Karl Karlovich Bulla)
Igor Ivanovich Sikorsky, 1914. Sikorsky is wearing the cross of the Imperial Order of St. Vladimir. (Karl Karlovich Bulla)

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.

15 year-old Midshipman Igor Ivanovich Sikorksky, at lower right, with his sisters Olga, Lydia and Elena, and brother Sergei, 1904. (Sikorsky, a Lockheed Martin Company)
15 year-old Midshipman Igor Ivanovich Sikorksky, Imperial Naval Academy, at lower right, with his sisters Olga, Lydia and Elena, and brother Sergei, 1904. (Sikorsky, a Lockheed Martin Company)

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.

Airplane pilot Igor Sikorsky with a passenger. (RIA Novosti)
Pilot Igor Ivanovich Sikorsky with a passenger, circa 1914. (RIA Novosti)

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).

Igor I. Sikorsky's FAI pilot's license. (Sikorsky Historical Archives)
Igor I. Sikorsky’s FAI pilot’s license. (Sikorsky Historical Archives)

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 with one of his early biplanes.
Igor Sikorsky with one of his early biplanes.
Sikorsky S-21 in flight
Sikorsky’s S-21 in flight, 1913

Igor Sikorsky married Olga Fyodorovna Simkovich. They had a daughter, Tania. The couple soon divorced, however.

Compagnie Générale Transatlantique liner, SS La Lorraine, 11,146 gross tons.
Compagnie Générale Transatlantique liner, S.S. La Lorraine, 11,146 gross tons.

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.

Sikorsky S-39 amphibian NC54V (Civil Air Patrol)
Sikorsky S-39 amphibian NC54V (Civil Air Patrol)

Beginning in 1934, Sikorsky Aircraft produced the S-42 flying boat for Pan American Airways at a new plant at Stratford, Connecticut.

U.S. Navy RS-1 (Sikorsky S-41) (National Museum of Naval Aviation)
U.S. Navy RS-1 (Sikorsky S-41) (National Museum of Naval Aviation)
A Pan American Airways Sikorsky S-42, NC16742, moored at Honolulu, Territory of the Hawaiian Islands. (hawaii.gov/hawaiiaviation)
Pan American Airways Sikorsky S-42, NC16734, moored at Honolulu, Territory of the Hawaiian Islands. (hawaii.gov/hawaiiaviation)

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 prototype VS-300 helicopter clears the ground for the first time, 14 September 1939. Igor Sikorsky is at the controls. His right foot rests on the anti-torque pedal. (Sikorsky Historical Archives)
The prototype VS-300 helicopter clears the ground for the first time, 14 September 1939. Igor Sikorsky is at the controls. His right foot rests on the anti-torque pedal. (Sikorsky Historical Archives)
Igor Sikorsky hovers the Vought-Sikorsky VS-300. (Sikorsky, a Lockheed Martin Company)
Igor Sikorsky hovers the Vought-Sikorsky VS-300A. (Sikorsky, a Lockheed Martin Company)
On behalf of the Fédération Aéronautique Internationale, the National Aeronautic Association of the United States issued Helicopter Pilot Certificate No. 1 to Igor I. Sikorsky, 10 December 1940. (Sikorsky Historical Archives)
On behalf of the Fédération Aéronautique Internationale, the National Aeronautic Association of the United States issued Helicopter Pilot Certificate No. 1 to Igor I. Sikorsky, 10 December 1940. (Sikorsky Historical Archives)
Igor Sikorsky in the cockpit of a production R-5 helicopter. (Sikorsky, a Lockheed Martin Company)
Igor Sikorsky in the cockpit of a Sikorsky S-48 (R-5) helicopter. (Sikorsky, a Lockheed Martin Company)

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.

Igor Sikorsky piloting his pontoon-equipped VS-300, 17 April 1941. (Sikorsky Historical Archives)
Igor Sikorsky piloting his pontoon-equipped VS-300, 17 April 1941. (Sikorsky Historical Archives)
s-47-4
Les Morris at the controls of the Vought-Sikorsky XR-4, 41-18874 (VS-316A), on its first flight at Stratford, Connecticut, 14 January 1942. (Sikorsky Historical Archives)
Lt. Carter Harman hovering in ground effect with Sikorsky YR-4B Hoverfly 43-28247 at Lalaghat, India, March 1944. This is the helicopter with which he made the first combat rescue, 21-25 April 1944. (U.S. Air Force)
Lt. Carter Harman hovering in ground effect with Sikorsky YR-4B Hoverfly 43-28247 at Lalaghat, India, March 1944. This is the helicopter with which he made the first combat rescue, 21-25 April 1944. (U.S. Air Force)
A Sikorsky R-5 flown by Jimmy Viner with Captain Jack Beighle, lifts a crewman from Texaco Barge No. 397, aground on Penfield Reef, 29 November 1945. (Sikorsky Historical Archive)
U.S. Army R-5 (Sikorsky S-48) flown by Jimmy Viner with Captain Jack Beighle, lifts a crewman from Texaco Barge No. 397, aground on Penfield Reef, 29 November 1945. (Sikorsky Historical Archive)
Sikorsky R-5 medevac, Korean War
U.S. Air Force H-5 (Sikorsky S-51) lifts off during the Korean War. (U.S. Air Force)
U.S. Coast Guard HOS-1 (Sikorsky S-49), with Igor Sikorsky as a passenger, over the Kill Devil Hills, North Carolina, 17 December 1947—the 44th annivesary of teh Wright Brothers first controlled, powered airplane flight. (Sikorsky Historical Archives)
U.S. Coast Guard HOS-1 (Sikorsky S-49), with Igor Sikorsky as a passenger, over the Kill Devil Hills, North Carolina, 17 December 1947—the 44th annivesary of the Wright Brothers first controlled, powered airplane flight. (Sikorsky Historical Archives)
U.S. Army YH-18A 49-2889 (Sikorsky S-52-2) (Ed Coates Collection)
U.S. Army YH-18A 49-2889 (Sikorsky S-52-2) (Ed Coates Collection)
SH-19A Air Rescue Sqd. AR.1999.026
U.S. Air Force SH-19A Chickasaw 51-3850 (Sikorsky S-55), Air Rescue Service. (U.S. Air Force)
Sikorsky H-34A-SI Choctaw (S-58) 57-1743 hovers in ground effect. Later registered as a civilian aircraft, N47246). (U.S. Army)
U.S. Army H-34A-SI Choctaw (Sikorsky S-58) 57-1743 hovers in ground effect. Later registered as a civilian aircraft, N47246). (U.S. Army)
Sikorsky CH-37 Mojave heavy-lift helicopter
U.S. Marine Corps CH-37 Mojave (Sikorsky S-56) heavy-lift helicopter
A U.S. Navy Sikorsky SH-3A Sea King (S-61), Bu. No. 149867, near Oahu, Hawaiian Islands, 5 April 1976. (PH2 (AC) Westhusing, U.S. Navy)
U.S. Navy SH-3A Sea King (Sikorsky S-61), Bu. No. 149867, near Oahu, Hawaiian Islands, 5 April 1976. (PH2 (AC) Westhusing, U.S. Navy)
A Sikorsky HH-3E Jolly Green Giant (66-13290) ot the 37th ARRS, hovering in ground effect at Da Nang, 1968. (U.S. Air Force)
U.S. Air Force HH-3E Jolly Green Giant (Sikorsky S-61R), 66-13290, of the 37th ARRS, hovering in ground effect at Da Nang, 1968. (U.S. Air Force)
A U.S. Air Force Sikorsky HH-53C Super Jolly Green Giant hovers to hoist a pararescueman with one downed pilot, while a second waits on the ground, 16 June 1967. The blade tip vortices are visible because of the high humidity. (National Archives at College Park)
Sikorsky CH-54A Tarhe 68-18448, Nevada National Guard, 16 Nober 1989. (Mike Freer/Wikipedia)
U.S. Army CH-54A Tarhe 68-18448 (Sikorsky S-64) heavy-lift helicopter, Nevada National Guard, 16 November 1989. (Mike Freer/Wikipedia)
Sikorsky MH-53M Pave Low IV, 68-8424, prepares for its last combat mission, Iraq, 27 September 2008. (A1C Jason Epley, U.S. Air Force)
U.S. Air Force MH-53M Pave Low IV 68-8424 (Sikorsky S-65), prepares for its last combat mission, Iraq, 27 September 2008. (A1C Jason Epley, U.S. Air Force)
U.S. Army Special Forces soldiers dismount a Sikorsky UH-60 Blackhawk, Zabul Province, Afghanistan, 21 January 2010. (Detail from photograph by Staff Sergeant Aubree Clute, U.S. Army)
Sikorsky HH-60G Pave Hawk 89-26212. (U.S. Air Force)
U.S. Air Force HH-60G Pave Hawk (Sikorsky S-70) 89-26212, Kunar Province, Afghanistan. (Captain Erick Saks, U.S. Air Force)
British Airways' Sikorsky S-61N G-BEON, 1982. ( )
British Airways’ Sikorsky S-61N Sea King G-BEON, 1982.
An Erickson Air-Crane, Inc. Sikorsky S-64 Skycrane drops water on a forest fire. (Sikorsky Archives)
An Erickson Air-Crane, Inc., Sikorsky S-64 Skycrane drops water on a forest fire. (Sikorsky Archives)
1280px-040327-pb-firehawk-17-16
A Los Angeles County Fire Department Sikorsky S-70A Firehawk, N160LA, during a rescue near Palmdale, California, 27 March 2004. (Alan Radecki/Wikipedia)
A Queen's Helicopter Flight Sikorsky S-76C, s/n 760753, G-XXEB (Russell Lee/Wikipedia)
A Queen’s Helicopter Flight Sikorsky S-76C, s/n 760753, G-XXEB (Russell Lee/Wikipedia)
Cougar Helicopters' Sikorsky S-92A C-GKKN landing at Ilulissat Airport, Greenland, 5 August 2010. (Algkalv/Wikipedia)
Cougar Helicopters’ Sikorsky S-92A C-GKKN landing at Ilulissat Airport, Greenland, 5 August 2010. (Algkalv/Wikipedia)
Sikorsky CH-53K King Stallion (Sikorsky, A Lockheed Martin Company)
The prototype Sikorsky CH-53K King Stallion (Sikorsky, A Lockheed Martin Company)

© 2017, Bryan R. Swopes

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17 May 1942

Sikorsky XR-4 41-18874 at Wright Field, Ohio, 17 May 1942. (Sikorsky Historical Archives)
Vought-Sikorsky XR-4 41-18874 at Wright Field, Ohio, 17 May 1942. (Sikorsky Historical Archives)
The Sikorsky XR-4 41-18874 at Wright Field, 17 May 1942. Left to right: E. Walsh, A. Planefisch, Igor Sikorsky, Orville Wright, R. Alex, Les Morris, B. Labensky. (Sikorsky Archives)

17 May 1942: After a 761 mile (1,224.7 kilometer) flight over five days, test pilot Charles Lester (“Les”) Morris and Igor Sikorsky arrived at Wright Field, Dayton, Ohio, to deliver the U.S. Army’s first helicopter, the Vought-Sikorsky XR-4. Morris hovered directly up to the base administration building and landed there. He and Sikorsky were greeted by a large group of people which included Lieutenant Colonel Hollingsworth Franklin (“Frank”) Gregory, the Army’s designated rotorcraft expert, and pioneer aviator Orville Wright.

From the Sikorsky factory at Stratford, Connecticut, to Wright Field, Ohio, was 761 miles (1,224.7 kilometers), direct. Because of the XR-4’s low speed and short range (weight limitations restricted the quantity of gasoline it could carry) the distance was covered in sixteen separate flights with a total flight time of 16 hours, 10 minutes. The longest single flight lasted 1 hour, 50 minutes, a new world’s record for helicopter flight endurance. Igor Sikorsky joined Les Morris for the final leg of the flight.

Sikorsky test pilot Charles Lester (“Les”) Morris in the cockpit of an earlier version of the Vought-Sikorsky VS-300. (Hans Groenhoff Photographic Collection, Smithsonian Institution National Air and Space Museum NASM-HGC-1408)

The Vought-Sikorsky VS-316A (which was designated XR-4 by the U.S. Army Air Corps and assigned serial number 41-18874), established the single main rotor/anti-torque tail rotor configuration. It was a two-place helicopter with side-by-side seating and dual flight controls. The fabric-covered three-blade main rotor was 38 feet (11.582 meters) in diameter and turned counter-clockwise as seen from above. (The advancing blade is on the helicopter’s right). The three-blade tail rotor was mounted to the right of the tail boom in a tractor configuration, and rotated clockwise when seen from the helicopter’s left side. (The advancing blade was below the axis of rotation.)

The XR-4 was 33 feet, 11.5 inches (10.351 meters) long and 12 feet, 5 inches (3.785 meters) high. It weighed 2,010 pounds (911.7 kilograms) empty and the maximum gross weight was 2,540 pounds (1,152.1 kilograms).

The VS-316A had originally been powered by a 499.8-cubic-inch-displacement (8.19 liter) air-cooled Warner Aircraft Corporation Scarab SS-50 (R-500-1) seven-cylinder radial engine, rated at 145 horsepower at 2,050 r.p.m. In the XR-4 configuration, the engine was upgraded to 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 XR-4 was redesignated XR-4C. This would be the world’s first production helicopter. It is at the Steven F. Udvar-Hazy Center of the Smithsonian National Air and Space Museum.

Vought-Sikorsky XR-4C 41-18874 at the National Air and Space Museum. (NASM)

© 2019, Bryan R. Swopes

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6–7 May 1943

Colonel Frank Gregory lands the Vought-Sikorsky XR-4, 41-18864, aboard SS Bunker Hill, 6-7 May 1943. (Sikorsky Historical Archives)
Colonel Frank Gregory lands the Vought-Sikorsky XR-4, 41-18874, aboard SS Bunker Hill, 6-7 May 1943. (Sikorsky Historical Archives)

6–7 May 1943: To determine the feasibility of operating helicopters from the decks of merchant ships for antisubmarine patrols, Colonel Hollingsworth Franklin (“Frank”) Gregory, U.S. Army Air Corps, made 23 landings and takeoffs from the tanker SS Bunker Hill in Long Island Sound, flying the Army’s Vought-Sikorsky XR-4, 41-18874.

According to an official U.S. Coast Guard history of the tests,

The tanker BUNKER HILL was made available for the tests and a deck 78 feet [23.8 meters] long, with obstructions at both ends, was put in place. An eight foot [2.4 meters] bullseye in the center of a square was painted in the middle of the platform. Colonel Frank Gregory arrived on 6 May to fly the Army XR-4 provided for the tests. The entire helicopter project rested on the XR-4’s ability to land on a ship. Gregory was concerned at first. His “shipboard” experience was limited to a 20 foot [6.1 meters] platform at Wright Field. He immediately set about getting “additional experience.” Gregory noted with reference to his first attempt:

Igor Sikorsky and Colonel Frank Gregory with the Vought-Sikorsky XR-4. (Sikorsky Historical Archives)
Igor Sikorsky and Colonel Frank Gregory with the Vought-Sikorsky XR-4. (Sikorsky Historical Archives)

“The space on the deck looked even smaller—it didn’t look like the helicopter would fit. The cabin superstructure towered up like a two story building, and the people on it had that “it can’t be done” look on their faces—yet the big white bullseye stuck out like a target—the XR-4 came true to the white marker as though being pulled by a powerful magnet, and a minute later the floats touched the deck.”

He continued to practice landings and takeoffs that afternoon with the ship at anchor, then underway at five, seven and one-half, ten and fifteen knots. As the speed increased the landings became more difficult because of increased turbulence over the superstructure but the helicopter proved to be completely controllable.

The next morning guests were ferried out to the BUNKER HILL . . . A total of 97 names were on the guest list. Gregory put on an impressive and flawless performance as the ship cruised at various speeds up to 15 knots and on various headings with relation to the wind which was blowing at 12 knots. . . .

—”The Helicopter as an Anti-Submarine Weapon,” A History of Coast Guard Aviation, The Growth Years (1939–1956).

SS Bunker Hill, a Type T2 tanker, with a tugboat alongside. (Unattributed)
SS Bunker Hill, a Type T-2 tanker, with a tugboat alongside. (Unattributed)

SS Bunker Hill was a 10,590 gross ton Type T-2 tanker owned by the Keystone Tankship Corporation. It was  504 feet (153.6 meters) long, with a beam of 68.2 feet (20.8 meters) and drawing 39.2 feet (12 meters). Its engine developed 7,000 horsepower.

On 6 March 1964, Bunker Hill was enroute from Tacoma to Anacortes, Washington when it suffered a vapor explosion in the Number 9 cargo tank which broke the ship in half. It sank in Rosario Strait in less than one hour. Five members of the crew of thirty-one, including the captain, chief mate, third mate, quartermaster and steward, were lost.

The Vought-Sikorsky VS-316A (which was designated XR-4 by the U.S. Army Air Corps and assigned serial number 41-18874), established the single main rotor/anti-torque tail rotor configuration. It was a two-place helicopter with side-by-side seating and dual flight controls. The fabric-covered three-blade main rotor was 38 feet (11.582 meters) in diameter and turned counter-clockwise as seen from above. (The advancing blade is on the helicopter’s right). The three-blade tail rotor was mounted to the right of the tail boom in a tractor configuration, and rotated clockwise when seen from the helicopter’s left side. (The advancing blade was below the axis of rotation.)

The XR-4 was 33 feet, 11.5 inches (10.351 meters) long and 12 feet, 5 inches (3.785 meters) high. It weighed 2,010 pounds (911.7 kilograms) empty and the maximum gross weight was 2,540 pounds (1,152.1 kilograms).

The VS-316A had originally been powered by a 499.8-cubic-inch-displacement (8.19 liter) air-cooled Warner Scarab SS-50 (R-500-1) seven-cylinder radial engine, rated at 145 horsepower at 2,050 r.p.m. In the XR-4 configuration, the engine was upgraded to 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 XR-4 was redesignated XR-4C. This would be the world’s first production helicopter. It is at the Steven F. Udvar-Hazy Center of the Smithsonian National Air and Space Museum.

Vought-Sikorsky XR-4 41-18874 during shipboard testing, June 1943. (Sikorsky Historical Archives)
Vought-Sikorsky XR-4 41-18874 during shipboard testing, June 1943. (Sikorsky Historical Archives)

© 2019, Bryan R. Swopes

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