Sikorsky designed the HOS-1(R-6) as a follow on to his fabric covered HNS-1 (R-4). While retaining the R-4’s rotor and transmission system, the R-6 had an all-metal fuselage. In October 1944 the first of three XHOS-1 were delivered to the US Navy and transferred to the US Coast Guard Air Station Floyd Bennett Field for test and evaluation. One of these crashed.
The Navy then acquired 36 HOS-1 (R-6A) from the Army Air Force which were purchased by the Coast Guard between January 1945 and January 1946. Of these, two were destroyed in crashes (no fatalities), and the majority of the remaining helicopters were returned to the Navy or disposed of with the closing of the helicopter training school
On 18 June 1946 CDR Erickson was moved to the Coast Guard Elizabeth City air station. His downsized Helicopter Test and Development Unit consisted of a small group of dedicated personnel, one hangar, one HNS and two HOS helicopters. This was the thread that kept the Coast Guard helicopter program alive.
