I mentioned a long time ago how I had a fascination for “megaliners”, “superjumbos”, or aircraft designed to hold more passengers than a 747. Leaving aside the impracticality of them, most were/are pretty conventional. They just took an existing jumbo and either added or stretched the upper deck.

But not the Tu-404. This not-found Tupolev design was a flying wing for maximum passenger space.

Some variants stretched capacity into the four digits, and it would have been driven by six propfans.