The noise of the Rotodyne is often raised as the reason it was eventually cancelled.
Which is fundamentally false!
Yes, the original prototype was noisy when in helicopter mode with the tip jets operating, but the progress made by Fairey with regard to tip jet silencers was such that the only comments raised when it flew to Battersea Heliport came from people who were hoping to see it and hadn't heard it arriving!
The usual tale of British dithering over size and specification is the real reason why this promising high speed point-to-point airliner never made it into commercial service.