Utility observation helicopter for US Army, 4 built. Two modofied into S-59 / XH-39 turbine powered prototypes. 
List of Operators of YH-18 |
Global Distribution of YH-18 |
|
Construction Numbers |
| C/N | Year | History | |
|---|---|---|---|
| 52-005 | 1951 |  49-2888 | |
| 52-006 | 1951 | 49-2889,N54066 | |
| 52-007 | 1951 | 49-2890 | |
| 52-008 | 1951 | 49-2891,N7741 |
