"Do you mean the self-loading cargo?"
Yes.
The downside of such cargo is that it places a minimum size on the whole vehicle, and with that form factor it's going to be biiiig.
Concorde, at 100 seats, was finally accepted by the French as the minimum size for an SST. Most people who've looked at this since have said you need at least 300 passengers (plus baggage) to make this viable. You also need a minimum range from day one of roughly Frankfurt to New York.
One interesting idea is that the maximum use temperature of plastics has been gradually rising. In principle CFC would be viable up to about 250C today. Likewise stainless steel could be an option up to 300c with laser welding or diffusion bonding.
Biting the hand that feeds IT
