Utility observation helicopter for US Army, 4 built. Two modofied into S-59 / XH-39 turbine powered prototypes. 
List of Operators of Sikorsky YH-18 | |
| From | Organisation with model YH-18 | |||||
| Construction Numbers on database of YH-18 | ||||||
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Construction Numbers | Help Us | |
| C/N | Year | History | |
| 52-005 | 1951 |  49-2888 : Sikorsky S-52-2, c/n 52-005, ff:?; acc 29Mar51; del US + | |
| 52-006 | 1951 | 49-2889 : Sikorsky S-52-2, c/n 52-006, ff:?; acc 29Mar51; del US + N54066 :  S-52-2 wfu & reg US as S-52-2, N54066, unk. | |
 | 52-007 | 1951 | 49-2890 : Sikorsky S-52-2, c/n 52-007, ff:?; acc 29Mar51; del US + s-59 modified to S-52-5, YH-18B configuration, unk; modified+ 26aug54 XH-39 set a world speed record for a helicopter+ |
| 52-008 | 1951 | 49-2891 : Sikorsky S-52-2, c/n 52-008, ff:?; acc 17Apr51; del US + s-59 modified to S-59/XH-39A prototype, c/n 59-002, 49-2891,+ rtnd to YH-18A configuration, unk. N7741 : S-52-2 wfu & reg US as S-52-2, N7741, unk. |