SAS/Vert
V-22 is to XV-3 (1955) as XH59 is to Hiller X-2-235 (1945!)
The high hinge offset rigid rotor is a dinosaur in and of itself
A better ancestor comparison for the V22 is the XV-15, which flew for 3 decades with nary a hiccup. It's even the only display at Udvar-Hazy to self-deliver!
The lack of civil certification to this point is largely a result of no certification agency thus far being capable of determining preceisely just how to determine actual cert
requirements of a tiltrotor; not the machine itself.