On display at the Museo Nacional Aeronáutico y del Espacio is this S-55C.

Delivered to the Royal Navy as XK943 in 1958. To Lee-on-Solent for use as ground trainer A2653 in 1975. Moved to Abingdon for Battle Damage training as 8796M later in 1983. Scrapped in 1992.

Delivered to the Royal Navy as XN261 in 1959. To Lee-on-Solent for use as ground trainer A2652 in 1975. Burnt on the fire dump there in 1985.

Delivered to the RAF as XP328 in 1961. Sold and registered as G-BKHC in 1982. Remained in its RAF markings. Damaged beyond repair in an accident in 1988 and stored at Tattershall Thorpe, Lincs. Moved to a private location at North Somercotes, Lincs by 2021.

A new and deadly strain of flu emerges in China, and a pandemic spreads... in 1957. A vaccine was developed in the United States by the summer, and here the first doses are being rushed to LGA airport by helicopter from the Lederle Labs in Pearl River. Photo by: Walter Sanders / Life

Delivered to the Royal Navy as XM685 in 1959. Sold to Autair Helicopters in 1971. Registered as G-AYZJ but not applied and stored at Luton. Moved to Elstree then to Panshanger. To the Newark Air Museum in 1980.

This was the first S-55 delivered to the US Marines, on 27 April 1951. The US Navy had received construction numbers 55006 through 55015 as HO4S-1 helicopters for evaluation in the anti-submarine warfare role. 127783 to NACA at Langley in March 1953.

Delivered in May 1952. Crashed in the Camp Pendleton area, California and written off on 14 October of the same year.

Performing an engine run at the RAF Northolt Nightshoot XXVIIa.

Delivered as an HO4S-2(G) in December 1951. Marked here as an HO4S-3G, although by 1963 it was officially an HH-19G. Photo from: SFO Museum

Scrapped at Otterburn in 1985.

Delivered to the RAF as XP360 in 1962. Sold in 1976 and moved to Fawkham Green, Kent. To the Second World War Aircraft Preservation Society at Lasham in 1980. Moved to NEAM Sunderland in 1991 then to Upper Hill, Herefordshire in 1992 and to a paintball park at Bicton, Herefordshire in 2005. Still there in 2021.

Delivered to the Royal Navy as XN309 in 1960. Used as ground trainer A2663 at Culdrose from 1977. Moved to Faygate in 1980 then to the Second World War Aircraft Preservation Society at Lasham in 1981. Moved to Thatcham in 1989 then to Baldonnel, Ireland in 1990 and later scrapped.

During the 1955 flood in Yuba City, California, this particular HO4S rescued 138 people in twelve hours. Photo date and location unknown to me. This airframe served in the US Coast Guard from 1953 until 1967, although it should have been marked as an HH-19G after 1962. It is marked as an HO4S-3, without its G suffix for the USCG model. To civil as N17378.

Loomis Dean apparently took this snapshot while he was at Edwards to photograph a Douglas X-3 Stiletto flight, which must have been between August 1954 and May 1956. The helo was delivered earlier in 1954. It was still with AFFTC in 1959 but its fate is unknown. Photo by: Loomis Dean / Life

Written off on 17 december 1969 when operating from HMS Endurance. It ran out of fuel after carrying external loads (barrels of jet fuel) between Port Salvador, East Falklands and Foam Creek for two hours. It ditched and the floatation gear was deployed but it rolled to port. The four crew swam 80 yards to shore. After 12 hours floating inverted it beached at Sheila Creek, Port Salvador. It was then towed to the settlement where it became a children's plaything. During the Falklands War, Argentine pilots reported its presence to higher authorities who thought it had been used to insert the SAS.

Written off on 31 Aug 2002 at Lythe Creek, California, following loss of control while fire-fighting.

The first prototype of the S-55, first flown on 10 November 1949. The S-55 was the first successful single-rotor helicopter capable of transporting significant loads. The key was to put the big piston engine in the nose, and the changeable payload and fuel in the centre of gravity. Initially 49-2012 had a half horizontal tailplane with endplate on this side instead of the two canted fins seen here. Print stamped June 1952.