I have often wondered at the feasibility of constructing airliners with the passenger section as a complete 'pallet' which gets loaded into the aircraft...
It could be cleaned, catered, baggage packed, boarded, all off the apron, then simply loaded into the aircraft Galaxy-style. In an emergency, it could be ejected out of the back, and descend under canopies, Apollo-style...
An advantage would be, unload one pallet and load the next, and you´re off....the pax and bags and catering and loo's etc ...all taken off your hands in one fell swoop..
Pallets could be pax or cargo..the idea is, they are all prepacked & self contained.