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Semi-Airborne Airport

Put the airport where the airplanes are
  [vote for,

Airplanes approaching an airport for landing usually approach at some shallow angle (3° if using ILS). This results in excessive aircraft noise experienced on the ground in the surrounding area, as well as a large area around the airport having to be controlled airspace, which is inconvenient for applications of drones within cities. Past proposals have suggested increasing the glideslope to mitigate this (i.e. delaying the start of the landing approach until closer to the airport, and descending more steeply).

I propose the opposite: Descend at a shallower angle— possibly even don't descend at all (well, maybe a couple of meters to go from above the runway to on the runway). Move the airport upward to meet the planes at some higher altitude instead.

It would be difficult to build a conventional building several thousand feet tall (and as wide as an airport plus all of the runways). I suggest supporting the airport buildings and runways on top of several fountain towers instead. The bases for these can be smaller in footprint, too, enabling use of the land between them for other purposes. (Also, at times of low usage, or if (part of) the airport is to be shut down for a while, it can be lowered to just above ground level and rest on top of the bases.) Guywires or similar may be necessary to keep the airport from being blown off station by the wind.

Additional benefits of detaching the runways from the ground are that they a) are repositionable, and b) don't have to be horizontal. Repositionable runways are obviously useful to enable increased utilization of runways with changing wind conditions (so you can have most of your runways aimed into the wind, regardless of the wind direction). Sloped runways would help with STOL and crosswinds. (To address the concerns at [3]: These runways would be capable of coordinating their motions with those of the airplanes, and if you need to do a go-around, there's no mountain in the way.)

To accomplish these features, the fountain base stations would need to be able to aim their pellet streams somewhat (and the vacuum tubes would need to be movable, and somehow accommodate a curved stream while the angle is changing, but that's doable). As well, there would need to be a horizontal component to actually move the runways around. I think that would be easiliest accomplished by winches on the guywires.

Passengers, cargo, employees, etc. are transported up and down between the ground and the airport by fountain elevators climbing the same fountains that support the airport buildings (fountains which will remain vertical at all times), possibly with additional angled fountains or guywires for stabilization. [1] Security, customs, etc. can be in a terrestrial building still, with only the terminal/runways being an airborne building.


notexactly, Oct 24 2016

[1] Fountain elevator
Mentioned in idea. Prior art (which turns out to not be my own) [notexactly, Oct 24 2016, last modified Oct 27 2016]

[2] Vertical airport
Prior art [notexactly, Oct 24 2016]

[3] Sloped runway
Prior art and concerns [notexactly, Oct 24 2016]

Fulton recovery system https://en.wikipedi...air_recovery_system
A "kick in the pants", apparently... [neutrinos_shadow, Oct 25 2016]


       " It'll never fly ... "
normzone, Oct 25 2016

       Ummm ...   

       Landing weight of a typical LCA, maybe 100,000 kg.   

       Now, you can't just "fly" a big plane onto a runway. You have to dump speed, and activate drag-inducing high-lift devices, or you'll burst the tyres. The glideslope's a function of sink rate and airspeed, not that amenable to tinkering, because if you go too low or too slow there's no quick way of recovering with a turbofan.   

       How much noise will the fountains make ?   

       How much energy will they use ?   

       How fast can the control system react to an extra 100 tons of load dropping down on it ?
8th of 7, Oct 25 2016

       I know that technology was developed to allow a person to be picked up by a passing aircraft, without its having to land. Presumably the same technology could be used to drop passengers off, as well, while the plane stays safely away from the ground.   

       In fact... OK, I've got the disembarkation figured out. You just need a tail-ramp on the plane, a large pod in which the passengers can stand, and a drogue chute. For picking passengers up, you could do exactly the same thing, only in reverse and using a different system.
MaxwellBuchanan, Oct 25 2016

       [MaxwellBuchanan]; I believe you are thinking of the Fulton recovery system (linky).   

       The problem with an airborne airport is you need some way, prehaps an aircraft, to get to it. Then that aircraft would need an airport. Before long, you end up with a stairway of airports...
neutrinos_shadow, Oct 25 2016

       [+] only because of so much half-baked prior art ...
ixnaum, Oct 27 2016


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