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Sikorsky S-55 Helicopter and its Variants

Overview

Sikorsky Aircraft developed the Sikorsky S-55 with its own funds. The Air Force put in an order for five prototypes, designated the YH-19. Igor Sikorsky nephew and Sikorsky Aircraft’s chief test pilot, Dimitry D. Viner piloted the first YH-19 on its maiden flight on November 10, 1949.[i] The U.S. Air Force (USAF) received its first YH-19, on April 16, 1950. A total of 1,728 S-55s were built by Sikorsky and three foreign companies.[ii] This total far exceeded any previous helicopter type. It served in all branches of the U.S. military, the U.S. Coast Guard, and 26 foreign countries.[iii]


[i] This Day in Aviation, Sikorsky S-55 Archives - This Day in Aviation, last accessed 9/5/22.

[ii] “S-55/H-19/HO4S/HRS Helicopter”, Sikorsky Product History, Igor Sikorsky Historical Archives by Vinny Devine, November 2012.

[iii] Arsenal of Democracy by Tom Gervasi © 1977 by Tom Gervasi and Bob Adelman. The U.S. Space Force didn’t exist when the Department of Defense retired the S-55.

The Korean War

The U.S. Navy received its first S-55, designated the HO4S-1 on August 31, 1950. In March 1951 the USAF sent a lone YH-19 to Korea for service trials. It went through a five-week trial period. It carried out rescues of downed aircrew, medical evacuation, and front-line cargo support for the army troops. It also carried out clandestine missions. It participated in a mission behind enemy lines to recover components from a crashed MiG-15.[i]

The U.S. Marine Corps (USMC) received its first S-55, designated HRS-1, on April 27. HRS-1 equipped Marine Helicopter Transport Squadron 161 (HMR-161) deployed to Korea in August 1951. On September 21 HMR-161 flew history’s first tactical helicopter troop lift. HMR-161 flew the first night troop lift on the 28th.[ii] Marine HMR-161 duties included airlifting USMC patrols behind enemy lines and bringing them back.

A second (USAF) YH-19 arrived in Korea in September.[iii] The USAF ordered 50 H-19As. The H-19 was the primary rescue and medical evacuation helicopter during the Korean War.[iv] The USAF resistance to the Army getting heavy helicopters delayed U.S. Army H-19 helicopters getting deployed to Korea until March 1953. On March 20 floods cut off elements of the 3rd Infantry Division. Army H-19s flew 30 missions to resupply these troops. H-19s delivered 33,925 pounds (15,390 kilos) of supplies and ammunition, including coal, to a landing zone within 300 yards (100 meters) behind the main line of resistance.[v] In June a joint Army-Marine helicopter mission used 45 H-19/S-55 helicopters to transport 300 Republic of Korea troops.[vi]

In April 1953 a USAF 3rd Air Rescue Squadron H-19 rescued Captain Joseph McConnel from the Yellow Sea. He was an ace with six air victories.[vii] He finished the war as the top American jet ace with 16 air victories.

H-19s of the 3rd Rescue Squadron transported CIA agents in and out of places behind enemy lines. The squadron also transported United Nations officers to and from the peace talks at Kaesong with H-19s. H-19s also participated the prisoner exchanges.[viii]


[i] Global Security.org, H-19 Chickasaw / HO4S / HRS, H-19 Chickasaw / HO4S / HRS (globalsecurity.org), last accessed 8/17/22.

[ii] Marines.mil, VMM-161 History, VMM-161 History (marines.mil), last accessed 8/15/22.

[iii] NHA Historical Society, HO4S/H-19 (Sikorsky S-55) Helicopter, HO4S/H-19 (Sikorsky S-55) Helicopter | Naval Helicopter Association Historical Society (nhahistoricalsociety.org), last accessed 9/5/22.

[iv] National Museum of the Air Force, Sikrsky UH-19B Chickasaw, Sikorsky UH-19B Chickasaw > National Museum of the United States Air Force™ > Display (af.mil), last accessed 8/17/22.

[v] Sikorsky Archives, Sikorsky Product History, Sikorsky Archives | S-55, last accessed 9/5/22.

[vi] Sikorsky Archives, Sikorsky Product History, Sikorsky Archives | S-55, last accessed 9/5/22.

[vii] Air War over Korea by Larry Davis, © 1982 Squadron/Signal Publications, Inc.

[viii] Global Security.org, H-19 Chickasaw / HO4S / HRS, H-19 Chickasaw / HO4S / HRS (globalsecurity.org), last accessed 8/17/22.

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Meanwhile

In the summer of 1952 two H-19As made the first transatlantic helicopter flight, Massachusetts to Scotland. The H-19s made the flight in five stages.[i] The longest leg, 850 miles (1,360 kilometers), was from Keflavik, Iceland to Prestwick, Scotland.[ii]

An S-55 crashed on landing during a demonstration flight on November 11, 1952 at Issy-les-Moulineaux, France. None of the seven people on board were injured.[iii] New York Airways began America’s first scheduled helicopter passenger service with S-55As on July 8, 1953. The first flight carried eight passengers and a mail shipment.[iv] The service was initially between the three New York area airports.

The Westland version, the Whirlwind, made its first flight on August 15.[v] On September 1, 1953 SABENA[vi] made is inaugural flight with an S-55. This marked the first commercial helicopter service in Europe.[vii]

From 1953 France used S-55s in Vietnam. After France’s defeat they gave some of the S-55s to the South Vietnamese military. French S-55s also served in North Africa.[viii] In Algeria, French forces and their S-55s ushered in the age of using helicopters, rather than fixed wing aircraft, for airborne and other quick reaction forces.[ix]

Petroleum Helicopters purchased S-55s in 1954 and used them for offshore oil industry support.[x]


[i] National Museum of the Air Force, Sikrsky UH-19B Chickasaw, Sikorsky UH-19B Chickasaw > National Museum of the United States Air Force™ > Display (af.mil), last accessed 8/17/22.

[ii] Sikorsky Archives, Sikorsky Product History, Sikorsky Archives | S-55, last accessed 9/5/22.

[iii] Alamy, Nov. 11, 1952 - Crash of a Sikorsky S.55 helicopter.: A Sikorsky S.55 tranport helicopter recently crashed at a demonstration at Issy-les-Moulineaux during the landing. The pilot and six passengers escaped the injuries. Photo shows the helicopter after the crash Stock Photo - Alamy, last accessed 9/8/22.

[iv] This Day in Aviation, Sikorsky S-55 Archives - This Day in Aviation, last accessed 8/20/22.

[v] Helis.com, Westland Whirlwind (helis.com), last accessed 8/27/22.

[vi] Societé Anonyme Belge d’Exploitation de la Navigation Aérienne.

[vii] “Sikorsky S-55/H-19 – History and technical description by Mario Bazzani © 2011.

[viii] AATLSE.org, Sikorsky H-19, Sikorsky H-19 | Ailes Anciennes Toulouse (aatlse.org), last accessed 8/29/22.

[ix] NHA Historical Society, HO4S/H-19 (Sikorsky S-55) Helicopter, HO4S/H-19 (Sikorsky S-55) Helicopter | Naval Helicopter Association Historical Society (nhahistoricalsociety.org), last accessed 9/5/22.

[x] Sikorsky Archives, SHA News Apr 2005 (sikorskyarchives.com), last accessed 9/8/22.

Later Years

Three U.S. Navy HO4S-3s flew operations in Antarctica for Operation Deep Freeze in 1955 and 1956.[i] On July 1, 1958 the U.S. Coast Guard directed every air station have at HO4S helicopter equipped for towing operations. An HO4S could tow an 800-ton vessel.[ii] A tail rotor pylon attachment failure caused a S-55A crash in Malaysia on April 2, 1964.[iii] The U.S. Navy retired their S-55s on February 26, 1969.

On January 17, 1975 wind conditions caused the crash of an S-55B in Iceland. All seven onboard perished.[iv] It was the worst helicopter accident in Iceland’s history.

A Royal Air Force Westland Whirlwind HAR.10 XJ729 – G-BVGE carried out numerous humanitarian flights in 1978. This included search and rescue, food and fodder drops, and medical transport missions. On February 23 XJ729 made a dog food delivery.[v]


[i] Global Security.org, H-19 Chickasaw / HO4S / HRS, H-19 Chickasaw / HO4S / HRS (globalsecurity.org), last accessed 8/17/22.

[ii] Global Security, H-19 Chickasaw / HO4S / HRS (globalsecurity.org), last accessed 9/5/22.

[iii] This Day in Aviation, Sikorsky S-55 Archives - This Day in Aviation, last accessed 9/5/22.

[iv] 14- 14. Issue (17.01.1975) - Tímarit.is (timarit.is), last accessed 9/8/22.

[v] Historic Helicopters, Whirlwind, Historic Helicopters - Whirlwind, last accessed 9/2/22.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2022 Robert Sacchi

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