Sikorsky H-5

Infobox Aircraft
name= H-5


caption= Sikorsky YH-5A at National Museum of the United States Air Force
type=Helicopter
manufacturer=Sikorsky
designer=
first flight= 18 August, 1943
introduced= February 1945
retired=
status=
primary user=
more users=
produced= 1944-1951
number built= over 300
unit cost=
developed from =
variants with their own articles = Westland DragonflyThe Sikorsky H-5 ("R-5" until 1948; company designation "VS-327")Fitzsimons, Bernard, general editor. "Illustrated Encyclopedia of 20th Century Weapons and Warfare" (London: Phoebus, 1978), Volume 20, p.2173, "R-5, Sikorsky".] is a helicopter built by Sikorsky Aircraft Corporation, formerly used by the United States Air Force, and its predecessor, the United States Army Air Forces, as well as the United States Navy and United States Coast Guard (with the designations HO2S and HO3S). It was also used by the United States Post Office Department. [ [http://blog.modernmechanix.com/2007/01/28/what-happens-when-you-mail-a-letter/?Qwd=./PopularScience/12-1951/when_mail_letter&Qif=when_mail_letter_5.jpg&Qiv=thumbs&Qis=XL#qdig "What Happens When You Mail a Letter" article in "Popular Science" magazine (December 1951)] ]

Design and development

The H-5 was designed to provide a helicopter having greater useful load, endurance, speed, and service ceiling than the Sikorsky R-4. It differed from the R-4 in having a new, longer fuselage for two in tandem and a much greater rotor diameter. The first XR-5 of four ordered made its initial flight on August 18, 1943. In March 1944, the United States Army Air Force ordered 26 YR-5As for service testing, and in February 1945, the first YR-5A was delivered. This order was followed by a production contract for 100, outfitted with racks for two litters (stretchers); only 34 were actually delivered.

Twenty-one YR-5As were fitted with third seat, rescue hoist, auxiliary external fuel tank , and nosewheel; the United States Navy evaluated three, as the HO2S-1. Five more were converted as dual-control YR-5Es.

A civil version, the S-51, featured four seats and even greater rotor diameter and gross weight, first flew on February 16, 1946. Eleven of these became USAF R-5Fs; while ninety went to the Navy as HO3S-1s. In December 1946 an agreement was signed between Westland and Sikorsky to all and anglicized version of the S-51 to be manufactured under license in Britain as the Westland-Sikorsky WS-51 Dragonfly, all of which were powered by a 500hp Alvis Leonides engine. More than 300 H-5s had been built by the time production was halted in 1951. A considerably modified version was also developed by Westland as the Westland Widgeon.

Thirty-nine additional specialized rescue helicopters were built, as the H-5G, in 1948, while sixteen were fitted with pontoons as the H-5H amphibian in 1949.

The R-5 was designated under the United States Army Air Force system, a series starting with R-1 and proceeded up to about R-16. In 1947 with the start of the United States Air Force, there was a new system, and many aircraft, but not all, were redesignated. The R-6 became the H-6. The United States Army broke off with its own designation system in the 1950s, resulting in new designations for its helicopter projects (such as the HO-6). [Polmar, Norman, & Kennedy, Floyd D., Jr. "Military Helicopters of the World" (Annapolis, Maryland: Naval Institute Press, 1981), p.227] In 1962 under the new tri-service system (see 1962 United States Tri-Service aircraft designation system), many Navy and Army aircraft were given the low numbers. Under the 1962 system, the low H numbers were given to new aircraft. For example, H-6 was given to the HO-6, which entered service as the "Cayuse".

Operational history

During its service life, the H-5 was used for rescue and mercy missions throughout the world. It gained its greatest fame, however, during the Korean War when it was called upon repeatedly to rescue United Nations' pilots shot down behind enemy lines and to evacuate wounded personnel from frontline areas before being replaced in most roles by the H-19 Chickasaw.

Variants

;XR-5:Prototype based on the VS.372 with two seats and tailwheel landing gear and powered by a 450hp R-985-AN-5, five built.;YR-5A:As the XR-5 with minor modifications, 26 built including two to the United States Navy as the H02S-1.;R-5A:Production rescue model with provision for two external stretchers, 34 built later re-designated H-5A.;R-5B:Modified R-5A, not built.;YR-5C:Modifiec R-5A, not built.;R-5D:Modified R-5As with nose-wheel landing gear, rescue hoist, twenty conversion later re-designated H-5D.;YR-5E:Modified YR-5As with dual controls, five conversions later re-designated YH-5E.;R-5F:Civil model S-51 four-seaters bought in 1947, 11 built later re-designated H-5F.;H-5A:R-5A redesignated.;H-5D:R-5D redesignated.;YH-5E:YR-5E redesignated.;H-5F:R-5F redesignated.;H-5G:Four-seater as H-5F with rescue equipment, 39 bought.;H-5H:As H-5G with updated equipment, 16 built.;H02S-1:Two YR-5As to the United States Navy later passed to the United States Coast Guard, order for 34 cancelled.;H03S-1:Four-seat version for the USN similar to the H-5F, 88 built.;H03S-1G:H03S-1 for the United States Coast Guard, nine built.;H03S-2:Was a naval version of the H-5H, not built.;H03S-3:One H03S-1 modified in 1950 with a redesigned rotor.;S-51:Civil four-seat transport version.

Operators

ikorsky S-51

;BRA;FRA
* French Navy ;flag|Canada|1921;JPN;PHI;flag|South Africa|1928
* South African Air Force - Used for DDT spraying to combat Malaria in Zululand in the 1950's.;THA;UK
*Royal Navy;USA
* Los Angeles Airways
* United States Army
* United States Air Force
* United States Navy

urvivors

* National Museum of the United States Air Force at Wright-Patterson AFB near Dayton, Ohio
* National Museum of Naval Aviation in Pensacola, Florida
* Aviodrome in Lelystad,Netherlands
* South African Air Force Museum at AFB Swartkop outside Pretoria

pecifications

aircraft specifications
plane or copter?= copter
jet or prop?= prop
ref=
crew=
capacity=
length main= 41 ft 2 in
length alt= 12.5 m
span main= 48 ft
span alt= 14.6 m
height main= 12 ft 11 in
height alt= 3.9 m
area main=
area alt=
airfoil=
empty weight main=
empty weight alt=
loaded weight main= 4,815 lb
loaded weight alt= 2,184 kg
useful load main=
useful load alt=
max takeoff weight main=
max takeoff weight alt=
more general=
* Tail rotor diameter: 8 ft 5 in (2.5 m)

engine (prop)=Pratt & Whitney R-985
type of prop=
number of props=1
power main=450 hp
power alt=335 kW
power original=

max speed main= 78 knots
max speed alt= 90 mph, 145 km/h
cruise speed main= 61 knots
cruise speed alt= 70 mph, 113 km/h
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main= 244 nm
range alt= 280 mi, 451 km
ceiling main= 10,000 ft
ceiling alt= 3,000 m
climb rate main=
climb rate alt=
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=None
avionics=

References

External links

* [http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=280 Sikorsky H-5 page at the National Museum of the United States Air Force]
* [http://www.dna.gov.ar/DIVULGAC/HELO.HTM Sikorsky S-51 First Helicopter in Antarctica. Civil Aeronautics Direction page - Argentinian Government. Link in Spanish]
* [http://blog.modernmechanix.com/2007/01/28/what-happens-when-you-mail-a-letter/?Qwd=./PopularScience/12-1951/when_mail_letter&Qif=when_mail_letter_5.jpg&Qiv=thumbs&Qis=XL#qdig 1951 Popular Science article showing a Sikorsky S-51 delivering mail]

ee also

aircontent
related=
* Sikorsky R-4
* Westland Widgeon

similar aircraft=

lists=
* List of helicopter models
see also=