Tag Archives: Wright R-1820-84

12 July 1956

U.S. Army Sikorsky H-34A Chocktaw, 56-4303, MSN 58-671. (Sikorsky Archives)

12 July 1956: Starting at 5:29 a.m., 12 July 1956, a Sikorsky H-34 Chocktaw, the U.S. Army variant of the S-58, flown by Captains Claude E. Hargett and Ellis D. Hill, near Milford, Connecticut, set three Fédération Aéronautique Internationale (FAI) world records for speed: over a 100 kilometers (62.1 statute miles) without payload, 228,39 kilometers per hour (141.92 miles per hour/123.32 knots);¹ 500 kilometers (310.7 statute miles) without payload, 218,89 kilometers per hour (136.01 miles per hour/118.19 knots);² and 1,000 kilometer (621.4 statute miles) circuit without payload, 213,45 kilometers per hour (132.63 miles per hour/115.3 knots).³ Captain Hargett was awarded a bronze oak leak cluster in lieu of a second award of the Distinguished Flying Cross. Captain Hill was awarded the Legion of Merit.

Captains Claude E. Hargett and Ellis D. Hill, U.S. Army, with a Sikorsky H-34A Chocktaw. (FAI)

The Dothan Eagle reported:

“RECORD HOLDERS—Captain Claude E. Hargett (left) of New Bern, N. C., and Ellis De. Hill of Birmingham [Alabama], both stationed at Fort Rucker are shown in the cockpit of an Army H-54 Sikorsky helicopter which they piloted to break three world speed records last month in a closed-circuit course at Milford, Conn. Both pilots, assigned to the Continental Army Command’s Board No. Six, reside at Enterprise.” (The Dothan Eagle)

Rucker Pilots Set 3 World Records

     FORT RUCKER — The establishment of three new world helicopter records by Fort Rucker Army pilots was announced yesterday by the Department of the Army. Flying an Army H-34 Sikorsky helicopter on July 12, over a course bordering a section of the southern Connecticut shore, Army aviators set a new closed-circuit record for 100, 500 and 1,000 kilometers. The old record had stood for a period of 10 years.

     The H-34, assigned to the Army Board Six of the Continental Army Command at Fort Rucker and piloted by Capt. Claude E. Hargett of New Bern, N. C., and Capt. Ellis D. Hill, Birmingham, set marks of 141.9 miles per hour for the 100 kilometer course, 136 for the 500 kilometers course, and 132.5 for the 1,000 kilometer course.

     Previous records for the same distances are 122.7, set in 1949 by a Sikorsky S-55; 66.6 mph set by a French SE 3-120 in 1950 and 66.6 mph in a Sikorsky R-5 in 1946.

     The special speed run was conducted by the Army under the supervision of Charles S. Logsdon, of the National Aeronautics Association in Washington, D.C.

     The records are subject to confirmation and acceptance by the Federation Aeronautique Internationale which is represented in the U. S. by the NAA.

     Recent reports indicate that Russia flew the 500-kilometer course at a speed of 116.2 miles an hour, approximately 20 miles an hour slower than the U. S. Army achieved.

     The USSR claim for the “hound helicopter” has been authenticated by the FAI in Paris, the world wide governing body for sporting aviation. The stock production model, the record H-34, is known commercially as the Sikorsky S-58.

     Capt. Hargett and Hill are presently stationed at Fort Rucker and both reside in Enterprise.

     The two record holders said they started the run at 5:20 a.m. near Milford, Conn. They flew about five hours at a height of 50 feet, with ninety per cent of the run made over water. An additional 3,000 pounds of gas was aboard the craft during the run.

     Both captains praise the Coast Guard which provided an auxiliary craft which followed the helicopter in the water as an added safety measure.

     Both are veterans of World War II and Korea. Hill has logged approximately 3,500 hours of flying time, Hargett, approximately 3,000 hours.

The Dothan Eagle, Vol. 48, No. 276, Tuesday, 7 August 1956, Page 8, Column 5

A U.S. Army Sikorsky H-34A Cocktaw, s/n 54-2873, landing at Fitzsimons Army Hospital, Aurora, Colorado. (Vertipedia)

The H-34A Chocktaw is a U.S. Army variant of the Sikorsky Model S-58, which had been developed as an internal project by Sikorsky, using the company’s own money. It was a major improvement of the earlier Model S-55 (H-19 Chickasaw/HO4S). The S-58 (a U.S. Navy XHSS-1 Seabat) first flew 8 March 1954.

The S-58 followed the single main rotor/tail (anti-torque) rotor configuration pioneered by Sikorsky with the Vought-Sikorsky VS-300 in 1939. The helicopter was designed to be flown by two pilots in a cockpit above the main cabin. Like the S-55, the engine was placed in the nose, installed at a 35° angle, and driving the transmission located behind the cockpit. For maintenance the engine could be accessed through two large clam shell doors in the nose. The wheeled landing gear was conventional, with two main wheels forward, and a tail wheel.

The S-58 fuselage had been designed using wind tunnel testing. The helicopter was built primarily of aluminum but the fuselage incorporated magnesium skin panels. The helicopter would be equipped with Automatic Stabilization Equipment (ASE), an autopilot system specifically for helicopters.

Sikorsky S-58 three-view illustration with dimensions. (Sikorsky)

The production H-34A was powered by an air-cooled, supercharged, Wright R-1820-84 nine-cylinder radial engine with a compression ratio of 6.80:1. It was rated at 1,525 horsepower at 2,800 r.p.m. for takeoff; 1,425 horsepower at 2,700 r.p.m., 30-minute limit; and 1,275 horsepower at 2,500 r.p.m., continuous. The R-1820-84 was 4 feet, 4.00 inches (1.321 meters) long, 4 feet, 7.74 inches (1.416 meters) in diameter and weighed 1,405 pounds (627 kilograms). The engine required 115/145 octane aviation gasoline.

The R-1820-84 drove the transmission through a 0.5625:1 gear reduction. The transmission had a gear reduction ratio of 11.293:1. Maximum main rotor speed was 258 r.p.m. (2,914 engine r.p.m.)

A U.S. Army Sikorsky H-34A Chocktaw, s/n 54-3033, MSN 58386.

The H-34 had an empty weight of 8,400 pounds (3,810 kilograms), and maximum takeoff weight of 13,300 pounds (6,032 kilograms). Its fuel capacity was 307 U.S. gallons (1,162 liters).

The helicopter had a cruise speed of 84 knots (97 miles per hour/156 kilometers per hour), and a maximum speed of 126 knots (145 miles per hour/233 kilometers per hour) at Sea Level. Its service ceiling was 17,600 feet (5,364 meters), and the hovering ceiling, out of ground effect, was 9,900 feet (3,018 meters) at takeoff power. The range was 227 nautical miles (261 statute miles/420 kilometers).

In transport configuration the S-58 could carry 16 troops or 6 litters and medical attendant.

The S-58 was built in a number of military and civil variants. Sikorsky built more than 1,800 S-58 series helicopters. Another 600 were produced by licensed manufacturers.

U.S. Army Sikorsky H-34A Chocktaw, s/n 57-1687.

¹ FAI Record File Number 13068

² FAI Record File Number 2155

³ FAI Record File Number 2154

© 2023, Bryan R. Swopes

8 March 1954

U.S. Navy Sikorsky XHSS-1 Seabat, Bu. No. 134668. (Sikorsky Historical Archives)

8 March 1954: A prototype for a new anti-submarine helicopter for the United States Navy, the Sikorsky XSSH-1, made its first flight at the Sikorsky factory in Bridgeport, Connecticut. The helicopter, the Model S-58, had been developed as an internal project by Sikorsky, using the company’s own money. It was a major improvement of the earlier Model S-55 (H-19 Chickasaw/HO4S).

The S-58 followed the single main rotor/tail (anti-torque) rotor configuration pioneered by Sikorsky with the Vought-Sikorsky VS-300 in 1939. The helicopter was designed to be flown by two pilots in a cockpit above the main cabin. Like the S-55, the engine was placed in the nose, installed at a 35° angle, and driving the transmission located behind the cockpit. For maintenance the engine could be accessed through two large clam shell doors in the nose. The wheeled landing gear was conventional, with two main wheels forward, and a tail wheel.

The S-58 fuselage had been designed using wind tunnel testing. The helicopter was built primarily of aluminum but the fuselage incorporated magnesium skin panels. The helicopter would be equipped with Automatic Stabilization Equipment (ASE), an autopilot system specifically for helicopters.

The S-58 has and overall length of 65.7 feet (20.03 meters) with rotors turning. The fully articulated four-blade main rotor diameter is 56.0 feet (17.07 meters), and the tail rotor, also with four blades, is 9.5 feet (2.90 meters) in diameter. The fuselage is 46.6 feet (14.20 meters) long. The helicopter has an overall height of 15.9 feet (4.85 meters). To minimize storage space on ships, the main rotor blades and the tail rotor pylon can be folded.

The four-blade main rotor allows the helicopter to reach higher speeds before encountering retreating-blade stall than the three-blade system used on previous Sikorsky models.

Sikorsky S-58 three-view illustration with dimensions. (Sikorsky)

The production HSS-1 was powered by an air-cooled, supercharged, Wright R-1820-84 nine-cylinder radial engine with a compression ratio of 6.80:1. It was rated at 1,525 horsepower at 2,800 r.p.m. for takeoff; 1,425 horsepower at 2,700 r.p.m., 30-minute limit; and 1,275 horsepower at 2,500 r.p.m., continuous. The R-1820-84 was 4 feet, 4.00 inches (1.321 meters) long, 4 feet, 7.74 inches (1.416 meters) in diameter and weighed 1,405 pounds (627 kilograms). The engine required 115/145 octane aviation gasoline.

The R-1820-84 drove the transmission through a 0.5625:1 gear reduction. The transmission had a gear reduction ratio of 11.293:1. Maximum main rotor speed was 258 r.p.m. (2,914 engine r.p.m.)

The HSS-1 had an empty weight of 8,400 pounds (3,810 kilograms), and maximum takeoff weight of 13,300 pounds (6,032 kilograms). Its fuel capacity was 307 U.S. gallons (1,162 liters).

The helicopter had a cruise speed of 84 knots (97 miles per hour/156 kilometers per hour), and a maximum speed of 126 knots (145 miles per hour/233 kilometers per hour) at Sea Level. Its service ceiling was 17,600 feet (5,364 meters), and the hovering ceiling, out of ground effect, was 9,900 feet (3,018 meters) at takeoff power. The range was 227 nautical miles (261 statute miles/420 kilometers).

In an anti-submarine warfare configuration, the helicopter was equipped with a dipping sonar system and armed with two Mark 43 torpedoes. The Mark 43 was an electrically driven homing torpedo, 91.5 inches (2.324 meters) long, 10 inches in diameter (0.254 meters), weighing 265 pounds (120 kilograms). It had a 54 pound (25 kilogram) explosive warhead. In transport configuration (HUS-1 Seahorse and UH-34 Choctaw) the S-58 could carry 16 troops or 6 litters and medical attendant.

U.S. Army Sikorsky H-34A Chocktaw, 56-4303. (Sikorsky Historical Archives)

Starting at 5:29 a.m., 12 July 1956, a Sikorsky H-34 Chocktaw, the U.S. Army variant of the S-58, flown by Captains Claude E. Hargett and Ellis D. Hill, near Milford, Connecticut, set three Fédération Aéronautique Internationale (FAI) world records for speed: over a 1,000 kilometer (621.4 statute miles) circuit without payload, 213,45 kilometers per hour (132.63 miles per hour/115.3 knots);¹ 500 kilometers (310.7 statute miles) without payload, 218,89 kilometers per hour (136.01 miles per hour/118.19 knots);² and 100 kilometers (62.1 statute miles) without payload, 228,39 kilometers per hour (141.92 miles per hour/123.32 knots).³ Captain Hargett was awarded a bronze oak leak cluster in lieu of a second award of the Distinguished Flying Cross. Captain Hill was awarded the Legion of Merit.

Captains Claude E. Hargett and Ellis D. Hill, U.S. Army. (FAI)

The S-58 was built in a number of military and civil variants. Sikorsky built more than 1,800 S-58 series helicopters. Another 600 were produced by licensed manufacturers.

¹ FAI Record File Number 2154

² FAI Record File Number 2155

³ FAI Record File Number 13068

© 2023, Bryan R. Swopes