JF Ptak Science Books Post 2642
The OED identifies the first usage of "anti-aircraft" 1914, which to me sounds about right--and pre-war, of course. That said there were many opportunities to talk about something like anti-aircraft, as bombs had been dropped from balloons by 1849, and airplanes had been dropping grenades/bombs on soldiers and civilians since at least 1911--so the need for combating aircraft was there even though it took the English language a few years to catch up to expressing this idea in a hyphenated term. By (July 23) 1927, when this short picture-article appeared in the Illustrated London News, there was enormous evidence and experience in anti-aircraft weaponry, and it seems that the Soviet Union was in a full-bore status to acquire a competent system, or at least they were talking about some aspects of it.
And thank goodness for the artist who provided us with the right stuff to discern the "bomb falling", dropped from one of the "attacking Bomber Squadron" able to elude the anti-aircraft defenses. The changes proposed were somewhat large in regards to the AA emplacements--on the other hand, the reassignment of space in a city, spreading stuff out so that dropped and exploded bombs would destroy less given the proximity of structures to one another, is an absolutely monumental undertaking. The city rebuilding is also predicated on a problem, as the bomb used in the scenario is only 1000-kilograms. This sort of thinking extends into the nuclear age when think tanks proposed Atomurbias, spreading out the population of the U.S. to basically everywhere, as well as evenly distributing industrial centers throughout the country (sometimes underground). There are problems enough relieving Flint of its water supply problems--it would be terrifying to think of redistributing the majority of the population of the U.S. and providing entirely new urban-ish areas for everyone to move into. Of course there wouldn't be enough material to do this, or workers, or more, or will, but that didn't stop people from undertaking some federally-funded planning for it.
The other part of this scenario is the protection from poison gas. And I guess we can just stop right there, with that small tank "neutralizer" that is supposed to absorb poison fumes and release "purified air", because that sort of protection just will not happen...especially back in 1927.