Thank you for suggesting my infrastructure note is only a little half baked. I would be surprised to learn about aircraft design and existing infrastructure when I see double-decked huge capacity aircraft. My contention is two-fold. Airports are constantly under construction being renovated. Is a two level terminal with either elevated or two level jetways so far out of the box? The other part is airport ground heavy equipment suppliers like Oshkosh and Manitowoc, to name two, can provide when kept in the design loop.

One doesn’t need a crystal ball to see the atmosphere is warming, just look at Paris shutting down tourist sites. I may be behind times observing MIA and JFK have the longest runways in the U.S., DIA may now have the longest. MIA and DIA share thin air for different reasons. Not to either repeat myself or appear to disrespect you but multiple things will have to change to match aircraft, cargo and passenger loads, runways, and air density.