HO2S / H-5 Dragon Fly
The Sikorsky (model S-48) R-5 (British name Dragonfly) was first flown on August 18, 1943. The first XR-5, in 1944, was a tandem rotor model, the VS-272; all others, VS-327s, were single rotor. The R-5, developed concurrently with the R-6, with a crew of two seated in tandem, had an all-metal fuselage. It was designed to have a greater useful load, range, speed, and service ceiling than the R-4.
Sikorsky designed what would become the two-seat R-5 helicopter in response to a USAAF specification for a large observation helicopter. The USAAF interest was in part a response to the success of Sikorsky's R-4, which was designated by the military as the HNS-1 and was tested extensively by the Coast Guard under the expert guidance of Coast Guard helicopter pioneer CDR Frank Erickson--the Coast Guard's first helicopter pilot.
The two-passenger R-5 (H02S-1) was further redesigned to meet civilian and military requirements and became, in August 1946, the first helicopter to be sold to a commercial operator. This three-passenger version of the R-5, while retaining its 450-horsepower engine, was designated by Sikorsky as the S-51 and by the Navy in 1946 as the HO3S-1.
The R-5, produced in 11 models through 1951, could be rigged to carry four external litters, two per side, in the MedEvac role. It had provisions for cameras and a radio. The R-5D model added a third seat, nosewheel, external hoist, and an external fuel tank.
The H-5, originally designated the R-5 (H for Helicopter; R for Rotorcraft), was designed to provide a helicopter having greater useful load, endurance, speed, and service ceiling than the R-4. The first XR-5 of four ordered made its initial flight on August 18, 1943. In March 1944, the AAF ordered 26 YR-5As for service testing, and in February 1945, the first YR-5A was delivered. The S51 Dragon Fly, was placed in production in 1946.
The R-5 (H-5D) served with the U.S. Army Air Force, U.S. Navy (as the HO2S-1), and U.S. Marine Corps. The R-5/H-5D was build under license to Great Britain as the Dragonfly. The Westland Dragonfly served with the Royal Navy and a few saw service with the Royal Air Force. The R5-A was powered by a 450 hp Pratt & Whitney R-985-AN-5 Wasp Junior engine.
In 1947 was delivered to the United States Army upgraded by incorporating a 600 horsepower 1340 Pratt and Whitney engine and an increased rotor diameter from 48 to 53 feet. Licence-produced by Westland, the British service designation of the S.51 was Dragonfly.
The R-5D was the basis for the four-seat Sikorsky (model S-51) which gained fame in Korea with the U.S. Naval Air Rescue Service. The Sikorsky S-51 commercial helicopter, a development of the USAF Sikorsky R5 of 1943, first flew on 16 February 1946. In USAF service the S-51 became the R-5F until June 1948, when "R" designations were recategorized as "H". Consequently, the commercial S51 then became the military H-5F. This early helicopter was called the HO3S-1 Hoverfly in US Navy service.
A later Westland development was the Widgeon, which had a larger fuselage with a distinct nose. This version set the stage for ongoing development work in 1949 which evolved into the S-55 HO4S-3 helicopter.
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 Conflict when it was called upon repeatedly to rescue United Nations' pilots shot down behind enemy lines and to evacuate wounded personnel from frontline areas. More than 300 H-5s had been built by the time production was halted in 1951.
Three American helicopters saw duty in Korea: the Sikorsky H-5 Dragon Fly, the Bell H-13 Sioux, and the Sikorsky H-19 Chickasaw. They participated in air evacuation of combat casualties and search and rescue missions to locate downed pilots behind enemy lines. At the beginning of the war, FEAF had five H-5Hs, a type that first flew in 1943, and AMC authorized the shipment of 15 more in August 1950. These had to be disassembled and shipped by aircraft from the San Antonio and Sacramento AMAs. By 1952, the H-5 was being phased out of the Air Force inventory.
Sikorsky Aircraft built about 65 R-5s, of various versions, for the USAAF, Navy, and Coast Guard. The first two examples tested by the Navy were designated HO2S-1, while the remainder of the Navy/Coast Guard R-5 derivations were designated the HO3S-1. The prototype first flew in August of 1943 while the first HO3Ss were delivered to the Coast Guard in August of 1946.
LT Stewart R. Graham of the Coast Guard Rotary Wing Development Unit was a pioneer in the development of the helicopter for the Coast Guard and Navy. He flew the Coast Guard's HO2S-1 (BuNo 75690) during tests for the Navy of the Hayes XCF "dipping" sonar in March of 1946. These tests proved the worth of "dipping" sonars mounted on helicopters. The test also involved the captured U-2513--which proved to be significantly more quiet than the U.S. fleet submarine used during the tests--leading the Navy to order the removal of all deck-mounted weaponry and material from every fleet submarine still in commission.
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