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Dutch Scientist Proposes Circular Runways For Airport Efficiency (curbed.com)
An anonymous reader quotes a report from Fast Company: While airport terminal architecture has a solid history of style and innovation, rarely is a proposal put forth to utterly redesign the runway. But that's precisely the aim of Henk Hesselink, a Dutch scientist working with the Netherlands Aerospace Center. Dubbed the "endless runway," Hesselink's brainchild is a 360-degree landing strip measuring more than two miles in diameter. Since airplanes would be able to approach and take off from any direction around the proposed circle, they wouldn't have to fight against crosswinds. And three planes would be able to take off or land at the same time. Hesselink's team uses flight simulators and computerized calculations to test the unconventional design, and have determined that round airports would be more efficient than existing layouts. With a central terminal, the airport would only use about a third of the land of the typical airport with the same airplane capacity. And there's an added benefit to those living near airports: Flight paths could be more distributed, and thereby making plane noise more tolerable. BBC produced a video detailing Hesselink's circular runway concept. The concept is fascinating but there are many questions the video does not answer. Phil Derner Jr. from NYC Aviation writes via Business Insider about some of those unanswered questions in his article titled "Why the circular runway concept wouldn't work." The fundamental issues discussed in his report include banked runway issues, curved runway issues, navigation issues, and airspace issues. What do you think of Hesselink's concept? Do you think it is preposterous or shows promise?
I have the same concerns outlined. But I like and support someone revisiting the idea to see if it can be done better.
Maybe this proposal isn't it, but at least it's being discussed.
A computer doesn't give a shit if the runway is straight or curved, because it can handle a little more left (or whatever) while it's managing dozens of other things. But a human can't do that. You want to make pilots have to account for bank and curvature in addition to everything else? That's obviously a shit idea.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
... just make it octagonal or some other n-agon.
One of the major issues seems to be what happens when a plane comes in too fast. Straight runways handle that well. It is hard to handle that with circular runways. There are a lot of other safety advantages of the standard setup.
I love how he places his drawning in the middle of nowhere with no roads or train tracks, or even neighby restraints on the layout of the land. Sure you can pull all that underground, but he seems to just ignore it.
Would be tricky. Small planes already have to wait for larger planes for wake turbulence effects when the larger planes are taking off or landing. BTW: ever hear of "rotating the airport?" It's a pilot term.
Interesting. Because you have tried landing on a circular runway?
Disclaimer: I *am* impressed by you being a pilot.
My first thought was: how the heck are you going to keep this runway clear of snow? You've gone from a single (or dual) short strip to a (pi*2mi)= 6.28 mile loop. That's a lot of runway to plow.
Then there's the long taxi time from the outside to the terminal in the center. That's a 1 mile radius taxi. Lots of wasted time.
Then there's the poor saps living around the airport. Instead of a well-defined small number of houses with noise pollution, you've spread it all over a huge area. Lots more people to complain. I doubt people want to build houses *inside* that 2 mile loop of land, so the footprint of this beast will be impractical for an airport near anything existing at all.
And if there's a consistent level of wind (from any direction), that "3 at the some time" argument goes away, and you're back to a small strip of usable runway, at least until the wind dies down.
I think they are a few days early. Having flown private planes a bit, I REALLY have my doubts about this for a number of reasons.
Too fast, just do a turn "while landing" too fast!
No wind, which way do you land, and hope everyone else does the same.
Wind from the North, do you land going South on the left, or the right, and if you are both too fast do you head on collide each other while turning to lose speed.
Take off, and turn at the same time, I'm sure that is safe as hell with tricycle gear and questionable weight and balance.
Punta Gorda in Florida has a triangle runway. Made me think of flying in there, the off duty 2 runways become taxiways to get back to the active runway after landing. I was hoping his design was more of an octagon than a circle, but it wasn't.
Circular runways have been discussed in two posts on Quora (www.quora.com) which have yet to be merged.
Nate
We Dutchies have the best marijuana in the world. Assuming he wasn't actually sober when he came up with the idea.
instead of making one circular runaway - which is difficult for the pilots to use -, make 12 runaways in the shape of a dodecagon, or 16 in the shape of a hexadecagon. You'd have the advantage of being able to take of/land from mostly any wind direction, while still having a straight runaway for the pilot to use. And you would always have two working runaways all the time.
"life is a joke, and someone is laughing at me"
People on Aviation.stackexchange has asked/answered this already: Could you land a large airplane on short circular runways?
"Every time you solve one problem, you create two more." * My guess is that circular runways would solve a few problems and create dozens more.
* I went looking for the source of that quote. Couldn't find it, but it appears in Popular Science, May 1942.
https://books.google.com/books...
Dear Slashdot: next time you want to mess with the site, add a rich-text editor for comments.
Airports have exactly defined approach charts for every runway that might be so detailed that the pilot has to time every segment and every turn of the approach to the second. That would be really difficult with a circular runway and would add serious workload to what is already the most difficult part of the flight.
A circular runway might work for either GPS assisted fully automatic landing, or general aviation.
"It's such a fine line between stupid and clever" -- David St. Hubbins, Spinal Tap
And Popular Mechanics, 40-odd years earlier.
This is great and all during the day and in clear weather, but constantly changing approach vectors means you can't have any approach lights unless you have a ring of lights around the whole ring that extends at least an additional 1000 ft. So your "3km" footprint for the whole airport is now about 5km. Either that or all landings with less than 1 mile visibility would require autoland. You'd also need to have a system that dynamically turns the lights on/off as approach vectors change. You'd also have to completely redesign the airport charts and the approach vector would already have to be known 30-60 minutes out so that the crew can do a landing briefing which might negate the benefits of using a round runway as the winds could shift in that timeframe so you still have crosswind. You'd have to cross the runway for access to hangars, maintenance facilities, cargo warehouses, etc which most likely wouldn't fit inside the ring. Which means you are losing a quarter of your landing space pretty much constantly to allow aircraft to be towed across, cargo to be delivered to/from flights, etc.
The only thing necessary for evil to triumph is for it to be pitted against a slightly greater evil
It wouldn't cost much to model this in a simulator, and let a couple dozen pilots try it out. We'd find out pretty quick how easy or hard it really is. It would be an interesting semester project for some students at Embry-Riddle.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
For the one benefit of your initial landing possibly being inline with the prevailing wind, you're adding dozens of safety issues, inefficiencies, and implementation issues.
Isn't there a circular airfield in Lithuania already? Pochunai or some place like that? Grass airfield for light aircraft, but the point is the same.
This idea was studied in the 1940's, and was rejected then, it's still a bad idea.
The video is pretty funny, they say you can always take off and land into the wind, but then state you can take off or land 3 planes at once at different places along the circle, but that would require one of those planes to land in a 60 degree crosswind, and the other to land in a 60 degree quartering tailwind, unless you had the planes on crossing approach paths (a really, really bad idea). A rejected landing would either put the plane right into another's approach/departure path or put wake turbulence right into short final approach of another aircraft. Wake turbulence from a heavy plane can flip a smaller plane, an A380 flipped a business jet 3 times flying 1000 feet below it last week*, the business jet landed, but the airframe is totalled. Another one also nearly flipped a 737 about the same distance away**. Ignoring it is idiotic, wake turbulence is at it's worst with heavy planes at low speeds, and drifts downwards and outwards. 3 simultaneous take offs still has the problem that if one plane takes off directly into the wind, the other 2 have to take off with a 60 degree crosswind & 30 degree tailwind unless you cross departure paths, at the other extreme it's a 30 degree crosswind into the wind, 90 degree crosswind, and a 30 degree crosswind/60 degree tailwind. You also put wake turbulence into the approach path of the next runway. You really can only use 2 runways on the circle if you account for the wind. Maybe I'm missing something, but I've made a bunch of diagrams and haven't found a solution that actually works for using 3 runways and accounting for the wind with non-crossing flight paths.
All the other potential benefits mentioned ignore the wind as a factor. It also later ups the capacity to doing the work 4 runways without explaining why. But let's ignore all the flaws in the concept itself and think about building one anyway.
11,480 foot runways would fit inside of the space of the circle, and you could build 3 at the same width for less concrete that the circle would use. But the circular runway looks a bit wider then needed, so you probably can get 4 standard runways out of the same area of concrete, probably a lot more since you don't need 50 taxiways. Even if that's not the case, 4 normal runways would use less land, and would not require building an enormous banking underneath the concrete, or the reinforced tunnels under the runways for passengers, cargo and equipment. The banking doesn't sound expensive until you realize that there's about 7 miles of it. The tunnels would need to be able to withstand a fully loaded A380 doing repeated hard touchdowns on it (remember, they can land anywhere on the circle) plus a safety factor, and be large enough for everything the airport needs. There would need to be enough land to build it near a large enough city to require an airport this size, which usually don't have large areas of inexpensive land available. And where are the cars parking?
6 runways - 3 pairs in a triangular format, with terminals and parking, uses far less land than the circular format, and is much easier to expand. The 3.5km runway idea mentioned earlier would use 5.3 km^2 or area for the triangular runways, where as a circular 3.5km diameter runway would require 9.6 km^2 of land, and in the picture much more than half of that area is for the runway and taxiways. You can fit a lot of terminals and parking in the 4.3km^2 you have left over with the triangular runways (and that does not include the area in the center of the triangle). And why would you want the terminal in the middle? It makes ingress/egress more difficult, for little to no benefit. On days with any wind (which is the vast majority of them), you'd only be using one pair of runways/2 upwind paths on the circle.
A complete, well thought out presentation of a bad idea is still a bad idea. They use the wind to justify one "benefit", but then pretend the wind doesn't exist as it is a massive problem to nearly
Oh boys, where to begin.
The obvious one is to take off and land while turning, but this could be corrected with a few straight runway connected around the circle (Kinda like an "angled" sun shape). I'm actually surprised they didn't propose that instead. Of course, that also mean you'll need a lot more space.
Then there's the air traffic management, it's going to be a pain since all plane that either lift-off or land will use the "same" runway at the same time.
Furthermore, if you want a 3.5 km diameter circle, that mean that you'll need to put a lot of infrastructure "undergound". Highway, parking, car renting etc. That's a lot of digging and a lot of concrete.
Also, I have serious doubt it'll raise the traffic. a 747 need over 2 kilometer for landing and take-off. A 3.5 km diameter mean 11 km circumference. So if you're really efficient, you'll have to shut down like ¼ of the runway. In other word, you'll only be able to run 2 corridor of landing and 2 corridor for lift-off at all time at ~90 angle. And that mean you bring back the problem you have been trying to solve in the first place.
So yeah, a lot of new problems only to solve one that isn't that bad to begin with.
Elok
Landing on a runway with a curve is certainly doable, I've known pilots to land on all sorts of odd surfaces. Many of the issues about traction etc. can be trivially solved by making the circle a bit bigger.
The excitement of managing the airspace is touched upon in the Business Insider article but not really fleshed out and I believe handling it in practice would diminish many of the suggested benefits.
The standard single runway is currently managed with a basic queue (simplified version). The planes circle in large loop around the airport. The airspace controller lines them up on a fixed marker above the end of the runway and they are passed on to the control tower for the landing. Take off is the same in reverse, they lift off, fly to a fixed marker and are then handed from the tower to the airspace controller.
Running a circular runway with three approaches would be doable, you would have three fixed approach markers, the same process would be used. Issues like turbulence from adjacent planes would need to be managed but this is standard in a multi-runway airport and would actually be greatly improved compared to two parallel approaches.
Once you start rotating the approaches with the wind things start getting far more exciting. Dynamic marker points aren't going to work, too much communication required and futzing around to communicate the approach point to every plane. So you are going to have to have multiple fixed sets, keeping it simple with only 3 options, 3 approach markers, 3 departure markers you have a total of 27 waypoints in a tight area around the airport. The odds of a plane flying to the wrong waypoint is huge (multiply it out by the number of flights a day, the number of passengers in a plane etc) and the consequences catastrophic, without extensive changes to the way planes are managed the risks are just far too high.
...they wouldn't have to fight against crosswinds. And three planes would be able to take off or land at the same time...
If three are landing at the same time, I'd say that at least one is fighting cross-winds.
As if a straight landing was not hard enough, you now have to land on a turn. Wait till it snows, or gets icy.
Instead of a loop, we should make the runway a Möbius strip! That way, planes can taxi along both sides of the tarmac, allowing it to last twice as long!!
A circular runway has too many problems as others have pointed out: Weather making the runway slippery, the need for approach lights, etc. So why not stick with straight runways, but gain the advantage of a circular runways by putting the entire airport on a giant turntable? Then you can rotate the runways to always be at the optimal alignment for the wind. :)
http://archives.chicagotribune...
How do you get to the terminal? Does everything go through tunnels or do cars wait at the strip like a train crossing?
I could be doing my math wrong but the Nardo Ring is about 4KM in diameter https://en.wikipedia.org/wiki/...?
The fastest a car, with suspension for cornering, can go on the highest banked part of the track is 240 km/h. A Boeing 747 takes off at 260+ km/h.
So the banking would have to be increased to prevent possible tipping but approaching a runway on a bank, or taking off, seems like it would have serious stall issues.
A non banked runway could avoid this but what kind of suspension would an aircraft need (could it be done with a tricycle?) to handle the amount the aircraft would want to roll. Plus on approach, you would have to slew with the rudder, at those speeds is there enough force from the air to keep the aircraft from sliding sideways or would you have to slew twice as much as the runway angle or more so the engines would be driving the turn?
My local gliding club is a great big grass area. They have six winch points, but can shift the launch point to suit the wind. It also makes emergency landings safer as you have a huge area to aim for. The question isn't "will it work", it's "is paving the area worth it", and I very much doubt it. Take Dallas/Fort Worth for example - it has 7 runways. The total paved area of those runways is about 147 hectares (0.6 sq miles), assuming the average width is 60m.
To fit just a single 4,085m runway in a circle the paved area would have to be 1310 hectares (5.1 sq miles) - an increase of almost 800% on the current paved area. It would be even greater as the circle would need to be bigger to have parallel 4,085m runways. Granted, I'm not including taxiways, but even so I can't see it being economic.
One issue I see, at least for passenger flights, is the distance that one would need to taxi to the appropriate terminal (especially if landing from an unusual direction). The difficulties could probably be negated by using more general purpose terminals, which seems feasible with better mass transit and faster people-processing. Also, could lead to increased response times for emergency services if something did go wrong.
Also, 2 miles diameter seems rather short to be landing modern airliners on. Even smaller aircraft (e.g. B737, A320) tend to require no less than 1200m (the proper requirements are usually significantly higher) to land safely, and ground steering is not possible until the aircraft is at relatively low speed. Even if the track was banked somewhat (disregarding any aerodynamic/stability issues with this), it seems likely that a much larger radius would be needed. Increased tire wear and lateral stresses on the landing gear are also a possible concern.
Personally, I believe the even-numbered n-gon arrangements that are being suggested by people here retain enough of the purported advantages of this setup that they are what should be considered.
There is no XUL, only WebExtensions...
It's not circular but equally out-of-the-box. Skyscraper Airport
Support Right To Repair Legislation.
If we are going to smoke some serious weed here, I propose this idea: tunnels.
Dig a bunch of tunnels, airplanes can land onto a shorter strip and go underground. You can have as many tunnels pointing in as many directions as you want and the cool part is that all you have to worry about is ... floods and the under ground zombie people.... but it will look cool
You can't handle the truth.
The Navy tried that already in 1964. Popular Science ran an article about it: https://books.google.fr/books?...
Nobox: Only simple products.
Centripital force is
F = mv^2/r
or a = v^2/r
At a typical takeoff speed of 150 knots, the lateral acceleration needed to keep the plane centered on a round runway with a 1.5km radius is 3.97 m/s^2, or 0.40g. On a freeway you'd just tilt the roadway based on the expected transit speed (about 24 degrees for 0.40g). But with a circular runway, planes are going to be traversing every part of it at all speeds from 0 to 150 knots, so there's no single tilt which will eliminate the problem. Likewise, during the takeoff roll the required lateral force will increase with velocity. So you can't just tilt the wheel/joystick at a certain angle and hold it there while taking off. You have to constantly adjust it as your velocity increases.
If a plane has to make a no-flaps emergency landing at 200 knots (which also happened to be about the regular takeoff speed of Concorde), now you're talking a lateral force of 7.06 m/s^2, or 0.72g. Which brings us to why runways are straight in the first place. It's not because it's easier to design and build. It's because it's a stable travel path. If for whatever reason during takeoff or landing the plane's controls stop working, the plane will want to go straight. Making the runway straight means the plane naturally (and with a little luck) will stay on the runway. Making the runway round means if you lose that lateral force being applied by your control surfaces for whatever reason, the plane is guaranteed to depart the runway at speed.
Aircraft landing gear are designed to land in a straight line, they are not designed to handle side loads.
It doesn't take much side load for that gear to fold up under the airplane.
Not to mention instrument approaches... I'd love to see a precision instrument approach chart to a circular runway.
Most large airports have several parallel runways. LAX for example has 4 parallel runways, normally all in simultaneous use - 2 are used for departures, and 2 for arrivals. This gets a lot of airplanes in and out at the same time.
If the runway was a circle, you might be able use on side for arrivals and the other for departures at the same time, but that's it.
Circular runways remains a stupid idea.
Disclaimer: I'm also a pilot.
Just my $.02 as a private pilot...
The claim that 3 planes could be landing at once is only valid if the winds are cooperating...you don't land with a tailwind. With any serious wind, you've now limited everything to a single queue because the planes will all need to go single file into the wind.
Just another day in Paradise
1. Dig a big hole.
2. Build all the support infrastructure in the hole - parking, terminals, support vehicles, etc.
3. Cover the hole and pave a big circle over it.
4. Put the tower right in the middle of the circle.
5. Mount lasers on the tower.
6. Use the lasers to 'paint' runway markers wherever you want based on the wind conditions.
7. Have 'pop up' structures to expose runway entrances to the underground complex on an unused portion of runway.
Ta-da!
The linked Business Insider article breaks down every objection I had and confirms they're worse than I thought. I like his conclusion, too: It won't work, but it's good to see people coming up with new ideas. You never know what might come out of it.
Nope, no sig
not worth a body
...logged flight time has seen these ideas crop up time, after time, after time. The radical change in pilot skills required, the creation of entire new solutions to low-visibility landing navigation signals, and the fact that it only applies to commercial airports (small airstrips take less space than the circle (unless you're willing to accept wing bank angles over 30 degrees during the most critical phase of flight) mean mostly only major destination passenger-service airports would be appropriate. Finally, every runway has two "approach plates" (pilot instructions on how to fly the approach to landing over all potential obstacles), one for each end. Pilots practice with each to ensure they know the ropes. How many "approach plates would be needed with a circular runway? Perhaps 36? And, many of those would be prohibited because they would require approaching the airport at altitudes lower than the tops of existing high-rise buildings!
This is an example of "thinking in the small." This designer is like a politician: Solve one problem by creating 30 more that "weren't anticipated."
Idea rating: DOA.
You're obviously not a pilot...and simulators are very, very sophisticated in the past 30 years. I flew the F-5 simulator once. The F-5 has the odd side-effect that when you first release the brakes, the "nose" bounces up an down slightly for a few seconds. Even THAT detail was clearly reproduced in the version I "flew."
> A computer doesn't give a shit if the runway is straight or curved, because it can handle a little more left (or whatever) while it's managing dozens of other things.
It's not "a little more left", it's nearly a 1G turn at the proposed dimensions - about the maximum turn rate an airliner will ever do outside of test flights.
Just as important, probably, it would mean rolling the broad side of the wings into a cross wind. This is hard to explain in words, but imagine the wind is coming from the left. With a normal, straight runway, the wings are level, so the plane looks like this:
----o----
The wind doesn't hit the wings much. But if to make a sharp turn, we need to bank the wings at 45 degrees or so:
\
\
o
\
\
You can see a wind from the left (or right) will exert a MUCH stronger force on the plane, blowing it off course. Software can't magically fix that. It may or may not manage to crash softer than a human pilot would manage.
I've seen Traffic Circles, these can be mistaken for Roundabouts by a non-fetisist.
How on Earth would you do an ILS approach to this?!?
It would be a great political solution for airports that already have issues with the flight path of people living around airports. Instead of pissing of a few, you can piss of many more. Why is this a great solution?
You know it won't ever be actually done and you just leak this great plan to the opposition who then can commit political suicide by stealing your leaked plan.
Don't fight for your country, if your country does not fight for you.
ALL runways will be runway 360 now.
slashdot: A failed experiment.
Hi, fellow pilot.
I hope you're enjoying this explosion of ignorance and conceit as I am.
To the rest of you: If you don't have a license, or are not an aircraft design engineer a warning: You ignorance is showing!
And I ask you: Have YOU every dived off the highest diving board into an empty pool?
Maybe a 'dutch rudder' would help an airplane land on a circular runway?
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Scientists do science (hypothesis, theory, test, publish repeat). Engineers apply science and business.
That's the old fashioned way.
The new way is:
1) Do a study with lots of measurements
2) Crunch the numbers looking for an interesting trend
3) Create a plausible explanation for the trend
4) Publish!
Managed by a tower.. that's the real problem here. I don't fly, but I've listened to a LOT of air traffic control and ground traffic control. Ground traffic is tough to manage, runway incursions are a huge risk, so how do you communicate to a pilot on *which* runway to land when there's only one, and the divisions or segments are ambiguous? How do you communicate to ground crew that they can or cannot cross the runway, and where? It seems that the ground logistics alone make this a perilous idea. If you've never heard it, search for ATC on YouTube and give it a listen, when there are crashes on the runway, there is a TON of radio traffic trying to keep people from making things worse.
I don't know how common this is in the rest of the country, but my local international airport has two runways, but both go north/south. Weather is almost always favorable for that profile, and when it's not, it doesn't matter because geographic features prevent any other landing profile. Is it really common in other parts of the US to need every possible landing direction?
Which has more power: the hammer, or the anvil?
I wonder how Harrison Ford would do attempting to land.
This would never work for human-piloted planes. It's tricky enough trying to land on a straight runway. What you are doing is not so much landing as stopping flying at just the right second to meet the runway. Doing that on a curve is a much bigger level of complexity.
Sig for hire.
Much negative opinion. Little evidence.
...if an airport opens up in his area, and the Dutch gov't uses whatever kind of Eminent Domain laws they have over there to make way for this new runway.
...near "poor" neighborhoods, I can see cities using this as an underhanded means of getting rid of their "undesirables"
If you have multiple planes trying to land and any pilot can approach from any direction, only one can land at any given time unless somebody coordinates the touchdown point for each of them. Lotsa luck ensuring proper separation while trying to control how many degrees of the arc is allocated to each plane. A traditional airport will have several runways operating at any given time, so the circular runway does not seem to be much of an advantage. And then there is the side loading problem that comes from takeoff and landing on a curved runway.
One way to solve both problems is to make the entire runway revolve to match the speed of the current aircraft on final approach. As soon as the wheels touch down, the pilot hits the brakes and the runway decelarates to match. The aircraft lands in place, with very little space required. Then the plane taxis to the inner track of taxiways, while the runway accelerates to match the speed of the next approaching aircraft.
Although I think the idea of a circular runway is crazy, and the concept of a revolving runway is a monumental challenge, it might actually work.
Sounds to me like this Dutch scientist should actually be working for Fisher Price.
File under 'M' for 'Manic ranting'
The proposed runway has a circumference of 6 miles. Meaning it turns by 60 degrees per mile.
A 747 lands at about 160 MPH and has a minimum runway length of 9,743 feet (1.85 miles). If a 747 touched down headed north into the wind, it would be headed southeast as it completed the landing, and the headwind at touchdown would become a 90 degree crosswind while the plane was travelling about 80 MPH.
Approaching the runway at 160 MPH while turning sharply, the apparent wind direction would change 90 degrees every 30 seconds.
A square, pentagonal, hexagonal, heptagonal, or octagonal runway arrangement would have most of the proposed benefits of this idea without the enormous downsides of trying to land on a curved runway.
"When information is power, privacy is freedom" - Jah-Wren Ryel
Aircraft landing gear are designed to land in a straight line, they are not designed to handle side loads.
You'll be happy to know that when landing you actually land in a straight line, and when you go around a circle with a radius as big as the one we are talking about your landing gear will be just fine.
Look more closely at the diagram.
The dual-circles around the buildings are taxiways. (Notece that, in addition to being far narrower than an airplane and too close in, they're also not circular, but have a flattened area at the right side, making it more like a "D" than an "O".
The runways are the wide, straight, "roads", of which you see just a tiny chunk at the very boundary of the picture. They're essentially tangent to the taxiways - slightly out from them.
This is just a standard airport designs with straight runways.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
And unless the terminal building is two miles in diameter, there is a lot of wasted space in the centre.
Well, I certainly hope you [Fast Ben] are a better pilot than I was (which wouldn't be difficult), but you didn't consider the width. If the runway is reasonably wide and you control your approach properly, then you would be landing straight and slowing down to a safe taxi speed well before you need to start following the curve.
If your approach is bad, then you're supposed to go around anyway. From that perspective it might actually increase the safety if there is a clear buffer zone around the airport. I still remember the time I was on final and a sudden crosswind lined me up over the parked planes... However, the "sudden crosswind" is a case that this design would still be vulnerable to, so you still need planes and pilots that can handle such situations. (No mention of "sudden" in the comments, but that doesn't much surprise me on Slashdot these days. Maybe I should be surprised to see another pilot here at all? A lot of today's comments are from people who know little whereof they speak... (Though I still miss the "funny" more.))
I think the instrument landing part is where you earned the "insightful" mod, though I doubt the moderator knows why. However, I think it is basically a software problem. Yes, you'd need more beacons, but mostly you'd need to be able to interpret their data from more orientations. I think you'd have to calculate every instrument approach for the current conditions, and probably for the individual plane.
Freedom = (Meaningful - Coerced) Choice != (Speech | Beer^2), and sad sock puppets' bad mods avail them naught.
Lasers ?
Noooo
Sharks with Lasers !
Yees
aaaaaaa
"Aircraft landing gear are designed to land in a straight line, they are not designed to handle side loads."
Better tell that to all the pilots before they start landing in crosswinds! Oh wait...
Obviously, airport designer has never flown a plane. Let's debunk this thing with a touch-and-go or balked landings. With a 1-mile radius and typical touchdown speeds of 140 knots (about 161 mph) for commercial aircraft, essentially this circular runway is the pattern of a standard rate turn (assuming left turns for all my illustrations here). Flying 50 feet above the runway, but tracking its centerline, the plane is in about a 25-degree bank turn. Thus, there is enough horizontal lift component to cause the turn (as coordinated by the rudder). Now bring that flight down to ground level: assuming left turns on the runway, the pilot lands the plane with the left main touching first, which quickly slows the plane down. But the plane needs to continue to track the circular pattern and maintain the horizontal lift component and, because the plane is now going slower, the bank angle must be significantly increased to compensate deceleration: the pilot adds more bank angle and clips the left wing (assuming a low wing or a mid wing), and crashes the plane.
I also point out that at touchdown, in order to track the circular pattern and because the main wheels are non-steering wheels, the turning can only come from the horizontal lift component of increased bank angle ... in other words, the right wing is flying (producing lift) but the left wing is not flying (because the left main wheels are supporting the plane) ... this condition is known as a Spin, it's very very very dangerous, and spins are never performed at low altitude (maybe at 10,000 AGL). So this circular configuration is really deadly (and that's ignoring the side loading on the higher speeds of take-off and landing).
Now let's pretend the pilot did not crash, but decides to abort the landing (e.g., seeing runway ice/water ahead). At that point, the airport designer is expecting the plane to be taking off in a spin condition (one wing flying, the other not, all to get enough horizontal lift to support the curved runway). First of all, no one purposely gets into spin configurations near the ground. And, second, the only maneuver we are trained on for getting out of a spin is Nose Down immediately (to get air over the wings so the plane is flying again), use the rudder to stop the spiral, and then to pull up from the dive. There are NO OTHER standard maneuvers in response to a spin condition for these categories of aircraft ... you don't just add more power and fly yourself out of it (as this airport designer would have pilots do) because spins are uncontrolled and unpredictable aircraft flying regime.
And every aircraft would have to be re-certificated because "Spins At Ground Level" would need to be added to the Normal and Transport category of aircraft operations.
This airport designer should take flying lessons and learn to do landings in light aircraft on runway conditions where the crosswinds are at the maximum crosswind component for his/her aircraft (the point where you're worried about crapping your pants and thinking Can I Make This?). And when that airport designer is doing crosswind landings precisely with (say) left main touching first, right main next, and nose wheel last ... well that will be the moment when he will know in his bones why circular runways make no sense. And the instructor is not going to let a student pilot experiment with adding another 25 degrees of bank to see if he/she can make the plane follow the circular track ... the flight instructor won't allow it because he/she wants to go home alive that day.
Oh, and did I mention bad weather and instrument landings? Assuming night time and fog, the airport designer is expecting the pilot to follow the track (which means looking down), while the other side of the plane is up in the air and hiding airport/obstacle/horizon visibility at night? With no visible horizontal reference for the pilot during takeoff and landing, at that point the pilot is in IMC (ins
Frank Farance
The whole point of air travel is that it operates in three dimensions. Obviously what we want are spherical runways.
Better tell that to all the pilots before they start landing in crosswinds! Oh wait...
Crosswind landings are no different - you'd BETTER have that airplane lined up straight on touchdown, or you'll have trouble.
Sure, the approach is flown crabbed into the wind, but you'd better have transitioned into a slip before touchdown, or, as the airliners do, kick out of crab just before the mains touch (slipping would likely drag an engine nacelle or wingtip on the ground).
I suppose I should have said "landing gear is built to handle very light side loads only" instead. The pilot's operating manual for every certified airplane in existence will tell you what the maximum allowed crosswind component is for that particular plane.