Interesting to see some additional "X" designations in Eurocopter's naming system. Especially seeing that a few were given to production lines that I honestly never knew carried them!
I know. I just meant to clarify the description of X4, because Stingray's description is rather vague and can be confused with the original Dauphin lines.
I think now the X4 entry can be split into two sections, one for the original X3 successor and another for the H160.
As I said before the X4 and its relationship with th US patent drawing is yet to be confirmed. It could've been an early X3 design study for all we know.
You might be right about it being an early design study. If you look at the patent for the supposed X4, it was filed in 2011, while there appears to be another patent filed domestically the next year, bearing closer similarity with the X3.
Patent filing dates shouldnt be references for desgn chronology. Let's just agree that until we get more facts from the source itself nothing is certain yet. :P