Size matters, even when it comes to planes: the more voluminous the aircraft the better they fly, with more stability and efficiency (think of the recent, huge Airbus A380). Nothing prevents us from imagining, therefore, a timeline in which we will aim to create ever larger aircraft, to the point of launching real flying airports, able to host and make other planes land on us.
This is the underlying reason for the 'Airborne Metro' concept: it is, in fact, a system similar to that of a bus. You could take a plane, land on a flying airport and leave for another destination: a net cut in emissions, a net cut in noise in airports, a net cut in overcrowding. 3000 passengers at a time is no joke.
The obvious problem in the management of similar aircraft is still represented by the unthinkable expense of making them land or take off: it is clear that something similar to nuclear propulsion would be needed to allow them to fly without ever stopping, or almost without stopping. Fleets of giant airports could cover precise circular 'routes', Africa-South America, or Europe-North America: the speculation, developed by a group of aviation experts and technicians, the ACARE (Advisory Council for Aeronautics Research in Europe) also makes two bills in the pocket of these giants of the sky, imagining fuel savings for the carrier planes that should reach the flying airports from time to time ranging from 40% to 80% in the case of ocean flights.
Needless to say, we are decades away from a technology capable of developing a similar scenario: perhaps other more intelligent and feasible ones will emerge, the fact is that if we managed to manage a similar situation, civil aviation as we know it would be totally revolutionized.
Advisory Council for Aeronautics Research in Europe (ACARE)
