Made - at least initially - for small aircraft, the airport's main service is to provide takeoff and landing assist via electric drones : those with enough power and energy to pick up an aircraft and take it up to a decent altitude and speed before releasing ; likewise catching an incoming aircraft and landing it, vertically. No need for a runway.
Once a network of these airports can be established, small aircraft can be designed without flaps or landing gear, engine/motor and aerodynamic surfaces optimized for cruising speed.
Of course, you'd still need a hardpoint on top for the drone to hook onto, and one beneath as a pedestal mount.-- FlyingToaster, Jul 18 2019 Parasite aircraft https://en.wikipedi...site_aircraft#1950sExisting technology [8th of 7, Jul 18 2019] Semi-Airborne Airport Mentioned in my anno. My idea that's vaguely related to this [notexactly, Jul 20 2019] I have considered this too. I think the lower top speed of a rotorcraft vs. a fixed wing is the main problem. You might have to do some clever geometry-shifting (like a V-22, but with the rotors part of the "drone" instead of attached to the plane proper) or drop them nose first... which would also mean catching the plane from a dive to land.-- neutrinos_shadow, Jul 18 2019 We just need to make indefinitely suspended airports but this is good too.-- 2 fries shy of a happy meal, Jul 18 2019 In the 1920's and '30's there were experiments with "parasite" fighters deployed from airships; and post-WW2, a similar scheme was devised to launch and recover a fighter from a jet bomber. So mid-air capture and launch can be done, but required immense skill.
// without flaps or landing gear //
If something goes wrong mid-flight, you still need the hardware to let you land on a convenient bit of flat ground, at low speed.-- 8th of 7, Jul 18 2019 what [shadow] said-- pertinax, Jul 18 2019 Common sense says a BRS, probably attached to the top hardpoint, given the CG requirement. Also - perhaps - an internal belly skid, like modern cars with the bumper inside plastic fascia.
The hex/quad/whatever-copters would have their own BRS.-- FlyingToaster, Jul 19 2019 // which would also mean catching the plane from a dive to land. //
From a climb.
// indefinitely suspended airports //
I don't know what those are—are they like my [linked] idea?
// If something goes wrong mid-flight, you still need the hardware to let you land on a convenient bit of flat ground, at low speed. //
Whole-airplane parachutes are available. Is that what "BRS" refers to?-- notexactly, Jul 20 2019 BRS = Ballistic Recovery System.
Useful, but not particularly steerable.-- 8th of 7, Jul 20 2019 That's exactly what I was guessing it stood for. Probably a guess based on a vague memory, not just being that smart (not that I'm not, of course :P).
But I only know of such systems for small GA planes, not airliners, yet.-- notexactly, Jul 21 2019 That's because the big civil stuff doesn't have the margin of strength in the airframe to take a BRS; they would come apart, in a spectacular and deeply unpleasant way.-- 8th of 7, Jul 21 2019 What about that plane whose roof came off but still landed safely in Hawaii?
Couldn't the harness distribute the forces, too?-- notexactly, Jul 21 2019 Ah yes, Aloha Airlines famous "Verandah" service ...
The problems with a BRS for a civil jet are numerous, but amongst them are:
1. Ideally, the chute should be coupled through to the mainspar, which runs across the centre of the cabin floor in most designs; a pylon at that point, colocated with the overwing exits, might be a little inconvenient.
2. The speed at which the chute needs to deploy; in fact, a staged system is needed to get the airspeed down to 150kt or less, which takes time (= altitude ) on a big jet.
3. The extra mass & bulk of the chute & harness.
4. The psychological factor of "expecting failure". On a single -engine puddle jumper, failure is always an option - on a scheduled service, maybe not so much.-- 8th of 7, Jul 21 2019 [notexactly]: from a climb That makes much more sense.-- neutrinos_shadow, Jul 21 2019 random, halfbakery