Beags,
It all came down to funding of course .
Westlands simply weren't prepared to risk their own development money for the Tyne "Z" Rotodyne for BEA ( they had already had 4 million development from t 'guv'ment). The beast was on growth cost spiral with no really firm support from potential customers, including the RAF.
The Yeovil originated Westminster ( with largely a Sikorsky S-56 rotor system ) would also have been a potential competitor and of course the Rotodyne was not a home grown product.
The Groen Brothers in Utah are great Rotodyne fans and point out that with modern materials and engines the concept still has relevance. They went so far as proposing a chopped C-130 with a rotor pylon as a concept.
As a P.S. I think that the enormous development effort poured in to the American tilt rotor programmes would also count against a Rotodyne concept resurgence politically. You will recall the tandem wing 4 rotor "C130 esque" concepts floated some years ago - on paper probably more attractive in the U.S.A. , although there are some very clever smaller gyroplane concepts around offloading and/or slowing rotors in fast forward flight - such as the Cartercopter project.
Last edited by Haraka; 2nd Jul 2015 at 10:21.