Circular Runways

[Green Baron]

Hi,

apparently no april-joke. It works and has advantages.

http://www.endlessrunway-project.eu/

Aircraft-tyres manufacturers will rub their hands :-)

Whether it'll be realized is another story.

 

Edited March 29, 2017 by Green Baron

[kerbiloid]

All circle segments would be called "roundwind".
With one homing beacon in the midde.

Spoiler

Next step will be:

Spoiler

multi storey spiral runway,

Also the planes will be "left" and "right", depending on which wheel is more intact. "Flight 1234, Land counterclockwise" will be the most common instruction from the command center.

Edited March 29, 2017 by kerbiloid

[IllyrianTheGreat]

1 hour ago, Green Baron said:

Hi,

apparently no april-joke. It works and has advantages.

http://www.endlessrunway-project.eu/

Aircraft-tyres manufacturers will rub their hands :-)

Whether it'll be realized is another story.

 

When do we get one in KSP?

[Green Baron]

Airtraffic is very conservative to innovations. I remember the microwave landing system a few decades ago which would have allowed for curved 3d approaches instead of the 2d localizer/glideslope ILSs. It was only installed on one airport due to political reasons (the manufacturers of ILSs sat in one particular country ;-)).

29 minutes ago, IllyrianTheGreat said:

When do we get one in KSP?

Hehe. You'll actually have to touch down at the touch down point, not anywhere on the strip :-)

In the presentation it's 3.5km long, 140m wide and slightly inclined towards the center. Shouldn't be too big a thing to scale it to ksp proportions ...

Edit: one of the and probably the biggest advantage is that aircraft can always land against the wind. Which will cause youtube to concentrate even more on kitten clips ...

Edited March 29, 2017 by Green Baron

[p1t1o]

Are aircraft expected to steer around the curve on takeoff/landing rollouts? Or is it shallow/wide enough to allow straight runs for sufficient distance?  With a diameter of 3km, it doesnt seem that way. What about emergencies, eg: brake failure/tyre blowout etc? A typical conventional runway gives around 3km of straight-run. Cant say I like the idea. Sure would make airports look pretty though.

[Shpaget]

From the video:

"The circular runway is equivalent in length to 3 straight runways"
"But the team calculate [sic]"
"It can handle the work of 4 normal runways"

I call BS.

They speak of headwind, so in order to get direct headwind, you can only use one (very) small section of the circle. The rest is useless, so it does not help to increase the capacity.
They also speak about wake turbulence as if their concept would help reduce its effect - it would not.
The 3 km diameter their design speaks of is not sufficient. International airports have 3 to 4 km long runways for a reason.

[Green Baron]

Sure, it is not new and still in the state of an idea (and maybe will not leave it), but i wouldn't do away with it so rapidly.

Aircraft will not need more than a section of the circle. Yeah, they would have to steer a curve during takeoff run and landing. Jeb says: So ? In calm conditions several sections could be used (3 - 4, maybe more) simultaneously. Today aircrafts have to divert if it is too crosswindy (though the limits are high).

They don't reduce wake turbulence, that is constructive thing. But wake turbulence spacing can be easier; just give different wt classes a few degrees difference in their approaches. Today careful spacing must be observed which reduces capacity. Also noise is an issue in crowded areas. Since the touchdown point on straight runway is fixed a circular one would allow for more flexibility.

Today all the spacing, patterns, approaches and procedures are designed for straight runways. But in principle the technology has not left the 60s (aside from gps). A lot of changes would be necessary and probably a lot of "intelligence" shifted from ground equipment to the aircraft to allow for the required flexibility. So, I could imagine that technology is not the limiting factor for such a change. Air traffic procedures are a worldwide thing ...

Be it as it may, i found it a nice idea. I like it when things are being questioned :-)

Edited March 29, 2017 by Green Baron

[kerbiloid]

This will be an airport..

Spoiler

 

17 minutes ago, Green Baron said:

Today all the spacing, patterns, approaches and procedures are designed for straight runways

https://en.wikipedia.org/wiki/Newton's_laws_of_motion#Newton.27s_1st_Law

[wumpus]

I think I suggested a circular runway in this forum for Mars*( (seeing just how long a runway would have to be).  I can't imagine wanting to build one on Earth, unless you need a shuttle-length runway for some specific reason and can't pick the Mojave desert for its location.

* I wasn't serious.  There are many reasons you can't fly an airplane over Mars, but presumably the impossibility of a runway can be solved with circular runways.

[p1t1o]

11 minutes ago, Green Baron said:

Yeah, they would have to steer a curve during takeoff run and landing. Jeb says: So ?

Quick calculation via an online calculator give a lateral G-force of 0.6 @200mph on a circular course radius 1.5km.

No thanks.

I'd go so far as to say - thats crazy.

[Matuchkin]

And even if you can somehow land on this runway, if there is a tire blowout you will careen out into the residential area around the airport. Imagine a 747 doing that to your house at 120kph.

[Green Baron]

20 minutes ago, p1t1o said:

Quick calculation via an online calculator give a lateral G-force of 0.6 @200mph on a circular course radius 1.5km.

No thanks.

I'd go so far as to say - thats crazy.

The runway is inclined to reduce that to 0.2g ...

Edit: if you're interested: concept description with discussion of technical and organizational aspects. True, it's unconventional, but not insane or crazy :-)

Edited March 29, 2017 by Green Baron

[Matuchkin]

On 29/03/2017 at 9:35 AM, Green Baron said:

The runway is inclined to reduce that to 0.2g ...

Whoa, that just makes landings and takeoffs more insane. I am certainly not going for this concept. No thanks.

Edited April 6, 2017 by Matuchkin

[p1t1o]

1 minute ago, Green Baron said:

The runway is inclined to reduce that to 0.2g ...

In the wet? Im still a big no thanks. And thinking about emergency scenarios makes my mind boggle.

The idea might be suited to smaller airfields handling light aircraft, but do they even suffer from congestion?

[Green Baron]

1 minute ago, p1t1o said:

... light aircraft, but do they even suffer from congestion?

The aircrafts surely not :-)

It's just a concept and we might never see it but i like the idea.

[p1t1o]

4 minutes ago, Green Baron said:

The aircrafts surely not :-)

It's just a concept and we might never see it but i like the idea.

It would work if they thought bigger, put one around a city!

[softweir]

This sounds like a sure-fire recipe for inducing pilot error - and we have more than enough of that at the moment.

1. Pilot confuses the angle of roll needed to land on the centre-line: one set of wheels takes all the impact, high probability of a tyre burst and subsequent loss of directional control, leading to the plane running off the outside or inside of the curve.
2. Pilot lands slightly too far to one side of the other of the centre line: again, the angle of roll fails to match the banking of the runway, tyres bursts, plane runs off the runway.
3. Pilot fails to line up with a constantly curving centre line and ends up running off the runway.
4. Pilot becomes disoriented by the curve and misjudges his descent slope. He either overshoots, or hits the runway too hard.
5. Pilot becomes disoriented by the curve and misjudges his flare, either overshooting or landing too hard.

6 minutes ago, p1t1o said:

It would work if they thought bigger, put one around a city!

We've got the M25 around London. Maybe some of it could be repurposed!  

[Green Baron]

@softweir: don't drink and fly. That addresses 3-5 :-)

Read the concept paper. Many off the points are discussed. Yes, it is unconventional, but what you describe actually happens every day and the concept is meant to reduce some of that. I don't say it's perfect or better or even realizable right away, it's just if you read it you find out that people have thought of it :-)

Edited March 29, 2017 by Green Baron

[YNM]

As I've saw this surfaced up in another forum I'm member of (surprised to see this comes on here late !) I'll just "repost" :

It's an Amsterdamer, what do you expect ?

Fair amount of problems :

- On straight runways, the aircraft doesn't experience changes in wind heading during takeoff / landing rollout. On circular one, they will.

- On straight runways, pilots have clear cues to take. How'd they do it on a circular one ?

- Performance is still limited to 1 (at most 2, but I'm sniffing tenerife^2 there) aircraft landing / takeoff simultaneously - you want to be upwind during descent / ascent.

- Tangentially sloped landing surface ? Sounds fishy...

- What about "IFR is foggy" ? How'd they do the ILS/Localizer ? I bet they haven't simulated in heavy gust there !

- Surrounding environment restrictions - I mean, airports today suffer from glideslope obstacle restrictions or noise restrictions. Their circular runways will suffer from the same problem, unless you want crosswind approach to a circular runway !

Having Kai Tak / Isafjordur approach is still more feasible than having to use the rudder pedal just to keep yourself going around a runway !

Edited March 29, 2017 by YNM

[pincushionman]

Very dangerous. The only advantage of the concept (that of being able to always take off/touch down directly into the wind) is completely wasted because the runway is only close enough to "into the wind" at two points at at time. The plane would have to turn during its takeoff and landing rolls, and planes are bad bad bad at turning at speed, due mainly to that whole "v" part of momentum. There's also a great risk of creating congestion on the runway itself due to the fact that in this sort of design, there can only one runway of a certain size, whereas major airports can often have two or three parallel runways with their current designs, if they need it for their flight volume.

Furthermore, there's this thing called "prevailing wind". In most parts of the world, one can generally assume that the wind will come from a certain set of directions, and thus align your runways to take advantage of that. This is especially important at smaller airports, who can't afford to have more than one runway. Even the circular runway would use far more pavement than just picking a direction and building a straight runway. And even if the wind is off-direction, at least the runway is straight enough the pilot can effectively crab or sideslip down. These are well-understood, well-practiced maneuvers.

If you look at a picture of my local airport, you'll notice the runway is aligned to take advantage of a wind blowing from the south-southwest. If you pan to the east, you can easily find three more airports/airfields aligned in nearly the same direction. I can quickly find an additional two pointed north-south in town (but that's of course because I live here and know where they are), and was able to just find several more just by grabbing the map and looking. I scrolled until I got to Topeka before I found an airport with a significant direction difference. This is no coincidence. Airport developers are well aware of the local wind conditions, and don't need to resort to esoteric solutions to get reliable landings.

In short, not only is this a dangerous solution, it's also a solution in search of a problem. Learn your local wind directions and deal with it.

Edited March 30, 2017 by pincushionman

[kerbiloid]

A snowflake or hexagon of runways have all advantages and no disadvantages of this horror.

P.S.
After landing on the curvy runway pilots can be visually distinguished: those from London are walkign turning to left, from Tokyo - are walking turning to the right. No one of them can pass the door without hitting the glass with forehead.

[YNM]

1 hour ago, pincushionman said:

Learn your local wind directions and deal with it.

Sometimes in some part of the world it doesn't help with morning and afternoon flights (or flights during storm) - either you have the runway faces the wind most of the day but not most planes going off it, or have most flights advantaged but having crosswinds most of the day ! (I'm well aware of multi-heading airports but let's say unless you get an old airbase or old airfield upgraded until modern day, or a full-fledged airport with a lot of land beside like those in the Netherlands it doesn't happen anymore.) We haven't even talked about airports in valleys or islands or mountains (where the idea of runways aligning with prevailing wind can be quite bogus) !

Some pilots, however, can show their prowess on it.

Edited March 30, 2017 by YNM

[Green Baron]

I go and help farting full the shuttle :-)

 

[55delta]

Well, that's an interesting design. Good thing aircraft don't use rotary engines anymore. First thing I thought when I saw that design was, "This airport looks like it was designed to crash WWI airplanes."

[Mad Rocket Scientist]

This isn't a new idea:

https://books.google.com/books?id=2CkDAAAAMBAJ&pg=PA77&dq=popular+science+circular+runways&hl=en&sa=X&ved=0ahUKEwiksuDDyv7SAhUDOiYKHW35BaoQ6AEIHDAA#v=onepage&q=popular science circular runways&f=false

It seems like a large problem is how to scale it. If you wanted two runways, you'd need some kind of plane tunnel below the inner one.