Ambassador memories:
We planespotter kids who lived near Heathrow noted that the Lizzie's Centaurus engines made a distinct not-unpleasant low-pitched whine during the approach - due to the sleeve valve operating mechanism perhaps?
Flew as a pax DUS-LTN in one of Autair's machines, September 1966. During the cruise there was an almighty crash and everyone froze. One of the stewardesses had dropped a tray of cutlery. Took a few mins for the tension to ease.