 In the summer of 1956, the Royal Canadian Navy believed that flying a helicopter equipped for anti-submarine warfare could be "married" to an existing anti-submarine platform such as a destroyer or frigate.To prove this, the RCN attached a small landing pad aft to "Buckingham" in October–December 1956 and attempted to land a Sikorsky HO4S-3 on it.The attempts were successful and the pad was removed and tested again on the larger .