JF Ptak Science Books Quick Post
I've seen a number of plans from the 1925-1935 period calling for skyscraper-topped airports, and airports built over a largely cover-ed themes, and over a covered-up Central Park, and floating in NYC harbor, and so on. I have not seen too many future visions of underground airports. This plan appears in Popular Mechanics for June 1941 and advocates a very tightly controlled underground environment for airports. The war in Europe was nearly two years old at this point, and the bombing war from the air was very advanced. There is little doubt that all sorts of plans were being considered to protect air force complexes from bombing, though something of this scale, dealing with so few number of plans, could hardly have made it further than this public outing.)
[Image is expandable]
An earlier and peace-time example of underground tech is found at the great Modern Mechanix blog, and features an April 1935 article in the journal of the same name an effort to remove the airport underground. Dr. William Christmas is the chief major domo in the piece and he is depicted with his visions of flight of the future, holding a model of his 400' 25,000hp plane with 75' propellers set to cruise at 200 mph. The monster could not be accommodated by the plans for an underground airport at right, which frankly looks like a hard drive, and which seems like a positively enormous amount of engineering for a spinning platter underground airport with room for eight planes.
[Source: Modern Mechanix, https://blog.modernmechanix.com/mags/ModernMechanix/4-1935/under_air.jpg]