First all-metal rotor blades helicopter in US. First flight February 12, 1947. 93 units built serving with the Marines and USCG and after retirement many introduced into the civilian market by Orlando Helicopters who acquired the parts inventory from Sikorsky.
| S-52-1 || 1949 || Civilian 4-place utility helicopter, 3 built. |
| S-52-2 || 1950 || Improved 4-place utility helicopter, 1 built. Later converted to S-59 turbine powered prototype. |
| HO5S-1 || 1952 || Improved 4-place light observation and utiliy helicopter for USMC, 79 built. |
| HO5S-1G || 1952 || Utility version of HO5S-1 for USCG, 8 built. |
| YH-18 || 1952 || Utility observation helicopter for US Army, 4 built. Two modofied into S-59 / XH-39 turbine powered prototypes. |
| S-52-3 || 1954 || Civil designation for 4 place light observation and utiliy helicopter equivalent to military HO5S-1. |
| S-59 XH-39 || 1954 || US Army's first turbine-powered helicopter, developed from the S-52. Rejected in favor of the Bell 204 (UH-1 Iroquois) |