In 1938, Congress authorized $2,000,000 to conduct research on rotary-winged aircraft. The Army was designated the lead agency because the Navy initially could see no use for the technology. On 14 September 1939, Igor Sikorsky flew the first rotary-winged aircraft, the VS-300, in a tethered test flight. The first untethered flight came on 20 May 1940. The VS-300 was nothing more than a frame of heavy tubes. It had no skin. It had one seat and no instruments.
In December 1940, the Army expressed an interest in buying a 300, but wanted several modifications. Sikorsky presented the VS-316 on 16 April 1941. The Army offered a contract for one experimental model, designated XR-4, to be delivered in August. Modifications to the tail rotor system delayed delivery until December 1941. The Army took delivery in January 1942 and requested Sikorsky to submit a quotation for 13 additional aircraft to be designated YR-4A. By then the US was at war.
On 20 April 1942, CDR Watson Burton, CO of CGAIRSTA Brooklyn, and CDR William Kossler, Chief of Aviation Engineering at Coast Guard Headquarters, witnessed a demonstration of the VS-316/R-4 at the Sikorsky plant in Stratford, CT. They saw unlimited uses for the helicopter including a way to save survivors of torpedoed ships, patrol harbors against saboteurs, and investigate suspicious activities. They immediately recommended the Coast Guard buy three of the aircraft. CDR Frank Leamy, Chief of Aviation Operations, agreed. RADM Harvey Johnson, Chief of Engineering, and RADM Lloyd Chalker, Assistant Commandant, disagreed. They said the price was too high, and that no one was interested in saving lives, just in killing the enemy. The Commandant, ADM Russell Waesche, had not made a decision on the helicopter yet.
In June 1942, LCDR Frank Ericsson, XO at AIRSTA Brooklyn, pointed out to Waesche that helicopters could be used to fight submarines. It required a smaller landing pad than a blimp, so it could be launched and recovered by almost any ship. It could carry a bomb and radio equipment. It could hover over a u-boat and bomb it more accurately. Waesche was still not convinced. The Navy was still cool to the idea, but in July 1942 they ordered six YR-4Bs under the Army contract and designated the aircraft HNS-1. The Navy upped the order to 27 with eight going to the UK.
Testing of the original XR-4 at Wright Field between May 1942 and January 1943 proved very successful. Coast Guard personnel had witnessed these tests and reported to Waesche, who became a convert.
In January 1943, Waesche briefed ADR Ernest King, the CNO, on the potential value of the helicopter and expressed his concern for the lagging Navy effort to develop the helicopter. On 19 February, King issued a directive which placed the responsibility for the development of Navy helicopters with the Coast Guard. He ordered the Coast Guard to conduct extensive testing to determine the helicopter’s value in convoy defense. The Maritime Commission was to provide merchant ships as needed for the tests. On 24 March 1943, the Army ordered 100 R-4s. Seventeen of these were sent to the Coast Guard. The tests began on 7 May 1943, when USAAF Col. Frank Gregory gave a convincing demonstration aboard the tanker Bunker Hill in Long Island Sound. A series of open ocean tests were scheduled. In July 1943, the coastal passenger ship Governor Cobb was converted to the Coast Guard’s first helicopter carrier to conduct underway testing. Also in July, the merchantman T James Parker conducted successful tests, which were duplicated in November aboard the British Lend-Lease freighter Daghestan. On 19 November 1943, AIRSTA Brooklyn was designated the helicopter training facility. In January 1944, Daghestan joined a convoy bound for Liverpool. Poor weather permitted only two flights to be conducted.
In October 1943, Sikorsky developed an improved version of the VS-316/R-4/HNS-1. Sikorsky designated it the VS-316B and, later, the S-49. The rotor and transmission were the same as the VS-316, but it had an all-metal fuselage. The AAF bought the aircraft as the R-6. The Navy designated it the HOS-1. The Coast Guard started flying them in January 1945.
The helicopter never fulfilled the vision of those who thought it could stem the tide of the u-boat war in the Atlantic. Technology could not be improved fast enough to have any major impact during the war. But the era of the helicopter was just beginning. In a glimpse of things yet to come, on 3 January 1944, a Coast Guard HNS-1 delivered blood plasma to survivors of an explosion aboard USS Turner off Sandy Hook. On 1 April 1944, a Coast Guard HNS-1 rescued a young boy who had gotten stranded on a sand bar in Jamaica Bay. On 2 May 1945, a Coast Guard HNS-1 was airlifted to Goose Bay by R5D to rescue 11 Canadian airmen whose aircraft had crashed in northern Labrador. Other dramatic rescues would follow.
For a complete list of helos used in WWII go to this Link.