| S-55 || 1949 || Commercial version with 600HP P&W R-1340 Wasp engine. |
| YH-19 || 1949 || The first of the five YH-19 prototypes capable of carrying ten passengers in addition to a crew of two first flew on 10 November 1949 and was cha ... |
| H-19A Chickasaw || 1950 || USAF version of the YH-19 powered by a 600hp P&W R-1340-57 Wasp engine. Some converted to SH-19A SAR helicopter. Redesignated HH/UH-19A in 1962, ... |
| HO4S-1 || 1950 || US Navy version of the S-55 powered by a 600hp P&W R-1340-57 Wasp engine. Redesignated UH-19F in 1962, 10 built under contract: NOa(s) 12024. |
| S-55A || 1950 || Commercial version with 800HP Wright R-1300-3 Cyclone engine. |
| HO4S-2 || 1951 || Navalized SAR version of the H-19B powered by a 700hp Wright R-1300-3 Cyclone engine. Redesignated UH-19G in 1962, 10 built: 7 for USCG & 3 for R ... |
| HRS-1 || 1951 || USMC version of the HO4S-1 with P&W R-1340-57 Wasp engine for eight troops, 60 built, plus one static airframe used for testing. |
| S-55B || 1951 || Improved commercial version with 800HP Wright R-1300-3 Cyclone engine. |
| H-19C Chickasaw || 1952 || US Army version of the H-19A with 600HP P&W R-1340-57 Wasp engine for troop transport duties. Redesignated UH-19C in 1962, 72 built. |
| HO4S-3 || 1952 || Re-engined US Navy & Canadian version with 700HP Wright R-1300 Cyclone engine. Redesignated UH-19F (American variant) & HO4S-3 (Canadian & Dutch ... |
HO4S-3: 133844 - 133853, contract NOa(s) 42-471 (MDAP) cancelled, airframes not built.
HO4S-3: 138432 - 138459, contract cancelled, airframes not built.
| HRS-2 || 1952 || USN/USMC HRS-1 with equipment changes, 101 built. [Includes 10 supplied to UK RN as Whirlwind HAR.21 under MAP.] |
| westland whirlwind || 1952 || During 1950, the Royal Navy had received 10 rescue (HAR.21) and 15 anti-submarine (HAS.22) versions of the Sikorsky-built S-55 airframes for eval ... |
The main driver for the S-55 evaluation was the frustration of the Admiralty over the difficulties experienced in development and sea tests by th ...
Westland had acquired some familiarity with the US built Sikorsky S-55. In November 1950, it negotiated a licence from Sikorsky to build and deve ...
The first British Whirlwind flew at Yeovil on 15 Aug 1953 for the Royal Navy with a 3 man crew and three more versions of the Series 1, two for t ...
The Whirlwind HAR.5 (a prototype development of the naval HAR.3) was the first British engined version, to be powered by the 14 cylinder, 882hp, ...
Westland judged that turbine engines were powerful and reliable enough to incorporate the Gnome into the HAR.9, which needed a redesigned no ...
A number of versions were built for civil commercial passenger and freight users, both for the UK and export market. More than 400 Whirlwind ...
| Whirlwind HAR.21 || 1952 || Ten Sikorsky HRS-2 for UK Royal Navy as Whirlwind HAR.21. |
| Whirlwind HAS.22 || 1952 || Fifteen Sikorsky HO4S-3 for UK Royal Navy as Whirlwind HAS.22. |
| H-19B Chickasaw || 1953 || USAF version of the H-19A powered by a 700hp Wright R-1300-3 Cyclone engine. Many converted to SH-19B SAR helicopters. Redesignated HH/UH-19B in ... |
| H-19D Chickasaw || 1953 || US Army version of the H-19B powered by 700HP Wright R-1300 Cyclone engine. Redesignated UH-19D in 1962, 268 built. |
H-19D: 57-2553 - 57-2558, contract cancelled, airframes not built.
H-19D: 59-0492 - 59-0521, contract cancelled, airframes not built.
| HRS-3 || 1953 || Improved HRS-2 with a 700HP Wright R-1300-3 Cyclone engine. Redesignated CH-19E in 1962. 91 built and conversions from HRS-2. |
| S-55C || 1953 || Improved commercial version with 800HP Wright R-1300-3 cyclone engine. |
| H-19D-3 || 1956 || US Army improved version of the H-19D. Redesignated UH-19D-3 in 1962, 25 built: 14 for US Army, 11 for France. |
| HRS-3Z || 1956 || VIP version of HRS-3 for France. [5 built on contract 56-4123.] |
| H-19D-4 || 1957 || H-19D-3 with equipment changes for France. 1 built. |
| HO4S-3G || 1957 || Specialized SAR version of HO4S-3 for USCG. 9 built. |
| mitsubishi S-55 || 1958 |
| S-55T || 1969 || Designation applied to aircraft modified with a 650 shp Garrett AirResearch turboshaft and other updated equipment. |
Aircraft modified by Aviation Specialties and produced and marketed by Helitec with a 650SHP Garrett AiResearch TPE-331-3U-303 turboshaft and upd ...