Are Circular Runways the Future of Aviation?

[Clara D.]

I rather suspect this "plan" from the "Netherlands Aerospace Centre" may be the product of a bunch of engineers hitting that ol' Dutch wacky tabacky to excess.

And some very old Popular Science.

Popular Science

Popular Science gives our readers the information and tools to improve their technology and their world. The core belief that Popular Science and our readers share: The future is going to be better, and science and technology are the driving forces that will help make it better.

books.google.ca

 

[Myficals]

That Popular Science article is about an actual US Airforce trial that returned positive results. Pilots found neither takeoffs nor landings particularly troublesome, so it's clear the idea isn't a complete fantasy.

That's not to say there aren't problems with the idea. Those trials were back in the 1960s and despite working as a proof of concept, they didn't convince the airforce to swap away from the typical runway design. Clearly there are still issues.

Flight Operations on a Circular Runway

 

[Caete]

No one mentioned all planes have to fly same speed for it to work yet?

If you look really closely at their mock up, there's speed limit signs. Problem solved!

 

[danielravennest]

Or even have a basic comprehension of flight. Yet they want to have 3 planes on the runway at once?

I happen to live near the worlds busiest single airport, in Atlanta. They have five main runways, all parallel east-west. But if you go on Google Maps and look at the satellite view (it's ~10 miles south of downtown), most of the land area is taken up by taxiways and terminals. The actual runways are the ones with black streaks from the tires suddenly spinning up as you touch down. And the taxiways need a certain amount of space between them so the wings of planes don't hit each other. At a busy airport, you typically have half a dozen planes taxiing around for every one that is actually taking off or landing. Saving runway space is the last thing they need to worry about.

What some airports are starting to do is fill in the grass with solar panels. They are low to the ground and don't particularly mind jet engine exhaust pollution, which, for example, growing crops would. The flight line also has nothing tall that would create shade. Airports also use a lot of electricity, so solar would help offset their electric bill.

 

[danielravennest]

Existing airports aren't sitting still either. For example, Atlanta has a $6 billion, 20 year upgrade program in progress. It's drawing in nearby construction too. The airport is now connected by a shuttle train across the interstate to a convention center, hotels, office buildings, and rental car center. The rental cars were moved off the airport itself to make room for other stuff.

 

[danielravennest]

And, sure enough, even the A380 -- destined to soon be as much a dinosaur as the 747 -- only requires 9,020 feet for takeoff, and much less for landing. (I'm sure pilots have some sort of saying about, "No such thing as too much [something], [something], or runway," but those are the requirements, and the A380 is the civilian airplane with the longest runway requirements at the moment

Runways have to be long enough for a "rejected takeoff". That's when something happens to the plane just before takeoff, and they have to come to a full stop. When they do that, the brakes get red hot and the tires deflate so they don't explode from the heat, but that's better than running out of runway and killing people.

(You spend a career at Boeing, and you learn a few things about airplanes, even if you work in a different part of the company )

 

[danielravennest]

Also, having it accessible for landing from any angle means you would need approach lighting systems for all those landing angles. That means even more land having to be reserved, secured, maintained, power supplied, repeated for the decision bars (in the US) so whatever minimal land savings they get from the oval design of the runways they are losing an then some for the support systems.

Also noise issues. The area close to the airport is typically filled with industrial buildings rather than residential. When the runways are aligned, you only have to do that on two ends. A circular airport would have noise issues in all directions.

 

[Kara Spengler]

Now someone will try to scale this up:

 

[Noodles]

So does this work like one of those money things they have to change donations? Where you stick a quarter in and is spins spins until it falls into a hole?

 

[detrius]

Will Circular Airport Runways Ever Take Off?

Dutch researchers are proposing banked, continuous runways to handle traffic more efficiently and take up less space.

science.howstuffworks.com

The idea is interesting, but one I'm having a hard time wrapping my head around. Usually when you have to go in a circle, you slow down. How would aircraft - especially large ones - get up enough speed to take off? Or land safely?

I heard about this idea a few years ago when I watched this video from an actual pilot, explaining the problems with the concept:

 

[Kara Spengler]

I heard about this idea a few years ago when I watched this video from an actual pilot, explaining the problems with the concept:

Before watching it I am going to guess the word 'wind' is in there somewhere?