Version of the S-51 for the U.S. Navy. 90 were manufactured.
A video of the aircraft in flight can be seen in the link below,
Source: "Sikorsky HO3S-1 Rescue, 1951", VFS YouTube site, Published on 4 Mar 2012
VTOL type: Helicopter
Lift devices: 1 Single main rotor
Dedicated control device: 1 Tail rotor
Crew required: 1-2 in Tandem arrangement
Landing gear: Wheels (non-retractable)