Circular runways?
March 17, 2017 2:10 AM Subscribe
I read this headline, think to myself "What problem could this be solving?", answer myself "They must be more compact", then look in the article.
3.5km diameter? Guess it's not that, then. Although presumably it could save on taxiway space. If it worked, which it won't, as Philip Greenspun explained in detail in that second link.
posted by ambrosen at 2:51 AM on March 17, 2017
3.5km diameter? Guess it's not that, then. Although presumably it could save on taxiway space. If it worked, which it won't, as Philip Greenspun explained in detail in that second link.
posted by ambrosen at 2:51 AM on March 17, 2017
It's a nice idea, but my first thought was 'variable crosswinds', rhen 'wake turbulence', then 'traffic management during emergencies'. Retraining all the world's pilots and re-certifying all the world's highly automated aircraft? Also fun.
It's not inherently stupid. Aircraft carriers turn into the wind, and expansive grass aerodromes without runways allow considerable latitude in choosing the direction of takeoff and landing which people are happy to use, so there's some merit in that. But I doubt that passes any cost-benefit analysis for large commercial airports.
The good thing is, if the project is worth developing further (I guess not: the website's not been updated in two years), you can get a long way to answering these questions through flight sims. I did check the website to see if this had been done; there is a paper on simulation, but it appears to just cover simulating traffic patterns and management rather than flight dynamics.
Perhaps this sort of idea will be revisited once we have self-flying aircraft dominating civil aviation, but by then the issues it addresses - landing in difficult conditions and noise abatement - may not be issues at all
posted by Devonian at 3:21 AM on March 17, 2017 [9 favorites]
It's not inherently stupid. Aircraft carriers turn into the wind, and expansive grass aerodromes without runways allow considerable latitude in choosing the direction of takeoff and landing which people are happy to use, so there's some merit in that. But I doubt that passes any cost-benefit analysis for large commercial airports.
The good thing is, if the project is worth developing further (I guess not: the website's not been updated in two years), you can get a long way to answering these questions through flight sims. I did check the website to see if this had been done; there is a paper on simulation, but it appears to just cover simulating traffic patterns and management rather than flight dynamics.
Perhaps this sort of idea will be revisited once we have self-flying aircraft dominating civil aviation, but by then the issues it addresses - landing in difficult conditions and noise abatement - may not be issues at all
posted by Devonian at 3:21 AM on March 17, 2017 [9 favorites]
What's the thing about suddenly switching to black and white and filming his left profile every now and then?
posted by Segundus at 3:48 AM on March 17, 2017 [3 favorites]
posted by Segundus at 3:48 AM on March 17, 2017 [3 favorites]
Seems like the case where your landing gear or tires fail would have a less predictable result than with a straight runway. A triangle would be simpler
posted by mattamatic at 3:58 AM on March 17, 2017 [1 favorite]
posted by mattamatic at 3:58 AM on March 17, 2017 [1 favorite]
What I don't understand is why they don't just make the whole plane out of circular runways.
(Pours out a tiny 50mL airline bottle of Bacardi for the ground crews who would have to rotate the tires on each 767 every two days or so)
posted by phooky at 4:25 AM on March 17, 2017 [19 favorites]
(Pours out a tiny 50mL airline bottle of Bacardi for the ground crews who would have to rotate the tires on each 767 every two days or so)
posted by phooky at 4:25 AM on March 17, 2017 [19 favorites]
... huh. And given that the entire point of a runway is that planes using it are constantly either speeding up or slowing down, banking it at a constant angle makes absolutely no sense, since a banked turn is really only useful at a specific speed. Wouldn't it make more sense, then, to have a spiral runway? More aesthetically pleasing, with the possible downside of occasionally hypnotizing pilots and birds.
posted by phooky at 4:31 AM on March 17, 2017 [9 favorites]
posted by phooky at 4:31 AM on March 17, 2017 [9 favorites]
Not to derail but this post really should be about how wacko ideas can be taken seriously. With a brief look at the web site it seems like a sincere proposal and not a joke site. How anyone with even a single ride in a small plane let alone any aeronautics training could imagine this for a second.
posted by sammyo at 5:05 AM on March 17, 2017 [8 favorites]
posted by sammyo at 5:05 AM on March 17, 2017 [8 favorites]
If you built a circular runway on a large turntable and spun it in the opposite direction as the plane, would the plane take off?
posted by chavenet at 5:22 AM on March 17, 2017 [22 favorites]
posted by chavenet at 5:22 AM on March 17, 2017 [22 favorites]
Wait, but like, maybe you're moving, and I'M standing still.
posted by radicalawyer at 5:40 AM on March 17, 2017 [1 favorite]
posted by radicalawyer at 5:40 AM on March 17, 2017 [1 favorite]
My palms started sweating just watching that video.
Greenspun's points are good, but there are also significant infrastructure aspects that would break by adopting such a... novel runway idea. There's lots of stuff around the runway that depends on having a known, fixed, runway end to work properly.
Basically all instrument approach systems as we know them now would be unusable. Even modern RNAV/RNP approaches that use GPS and can be configured basically however you want them rely on a known "line" to fly as the final approach segment. We do have "offset" approaches that don't line up with a runway direction, but you can't get as low as you can with a normal instrument approach and they're really only used at small airports where slow aircraft can maneuver very close to the runway to maintain visual contact with it while you're positioning to the final approach.
ILS systems will all be unusable, since they rely on straight, level ground to bounce the radio beams off. Even if you could modify the systems to work with a banked runway, you still end up limiting the number of touchdown points on your big circle because you can only install so many localizer/glideslope transmitters.
In a lot of ways, multiple straight runways can handle more traffic than a single, curved runway. Smart airport design takes in to consideration the prevailing wind, which is why you'll usually see two or three runways all pointed in the same direction - the wind is usually blowing that way. In order to accommodate multiple parallel takeoffs and landings on a circle, you would need to have one plane flying clockwise around the track and the other plane flying counterclockwise. This means you end up with the planes pointing at each other on takeoff, which is probably the worst situation I can imagine. Compare to somewhere like Atlanta, which has five runways that all go in the same direction.
posted by backseatpilot at 5:47 AM on March 17, 2017 [9 favorites]
Greenspun's points are good, but there are also significant infrastructure aspects that would break by adopting such a... novel runway idea. There's lots of stuff around the runway that depends on having a known, fixed, runway end to work properly.
Basically all instrument approach systems as we know them now would be unusable. Even modern RNAV/RNP approaches that use GPS and can be configured basically however you want them rely on a known "line" to fly as the final approach segment. We do have "offset" approaches that don't line up with a runway direction, but you can't get as low as you can with a normal instrument approach and they're really only used at small airports where slow aircraft can maneuver very close to the runway to maintain visual contact with it while you're positioning to the final approach.
ILS systems will all be unusable, since they rely on straight, level ground to bounce the radio beams off. Even if you could modify the systems to work with a banked runway, you still end up limiting the number of touchdown points on your big circle because you can only install so many localizer/glideslope transmitters.
In a lot of ways, multiple straight runways can handle more traffic than a single, curved runway. Smart airport design takes in to consideration the prevailing wind, which is why you'll usually see two or three runways all pointed in the same direction - the wind is usually blowing that way. In order to accommodate multiple parallel takeoffs and landings on a circle, you would need to have one plane flying clockwise around the track and the other plane flying counterclockwise. This means you end up with the planes pointing at each other on takeoff, which is probably the worst situation I can imagine. Compare to somewhere like Atlanta, which has five runways that all go in the same direction.
posted by backseatpilot at 5:47 AM on March 17, 2017 [9 favorites]
Hah - I hadn't thought about ILS. And PAPI becomes... interesting to implement, too. Perhaps you have banks of them under the runway and pop up the ones you need on each approach? Practically, thinking about how on earth you line up on a curved runway, the only way would be to have some sort of HUD projecting the correct approach over the actual one. Otherwise you're aiming at a point on the ground with very complex visual cues (which may be either left or right oriented, depending on which approach you're taking.)
You do have to assume a completely different precision guidance infrastructure. Which, again, may well be the case once we're in fully automated aviation world: PAPI's only needed for the Mk 1 eyeball, and ILS is rooted in pre-war technology.
It is possible - just - to envision a world with circular runways. Just not ours.
posted by Devonian at 6:14 AM on March 17, 2017 [1 favorite]
You do have to assume a completely different precision guidance infrastructure. Which, again, may well be the case once we're in fully automated aviation world: PAPI's only needed for the Mk 1 eyeball, and ILS is rooted in pre-war technology.
It is possible - just - to envision a world with circular runways. Just not ours.
posted by Devonian at 6:14 AM on March 17, 2017 [1 favorite]
Does it actually help with "scary crosswind landings" or does it just acclimate pilots to scary landings?
posted by randomkeystrike at 6:17 AM on March 17, 2017 [1 favorite]
posted by randomkeystrike at 6:17 AM on March 17, 2017 [1 favorite]
This is in the class of things that sounds good to those people on the outside but is blatantly insane to those on the inside. Could it work? yes Would it require a wholesale rethinking/reworking of existing systems? yes Would it be worth it? No
I'm a low-time private pilot and even seemingly minor stuff breaks this. Just thinking about take-off, ground-effects are going to be messed up - as soon as you lift off you're going to be sliding into the center unless you level off but then you lose the runway under you for emergencies. And then there is stopping on a slick runway. Turbulence induced by the runway-banking-berm. This is nuts for so may reasons.
posted by achrise at 6:22 AM on March 17, 2017 [3 favorites]
I'm a low-time private pilot and even seemingly minor stuff breaks this. Just thinking about take-off, ground-effects are going to be messed up - as soon as you lift off you're going to be sliding into the center unless you level off but then you lose the runway under you for emergencies. And then there is stopping on a slick runway. Turbulence induced by the runway-banking-berm. This is nuts for so may reasons.
posted by achrise at 6:22 AM on March 17, 2017 [3 favorites]
There's also likely a centrifugal force issue so to be effective the runway should probably be banked like a velodrome.
The automated controls are the least problematic, hard problems and requires a full new set of algorithms and certification but SpaceX is landing rockets on a dime, we have the technology! Now imagine the dialog between the tower and a VFR dentist "line up on approach one oh one", "roger that, oh one one", "NO one oh one", "WHAT? One Oh Oh?", "Oh never mind... oh oh"
posted by sammyo at 6:25 AM on March 17, 2017 [2 favorites]
The automated controls are the least problematic, hard problems and requires a full new set of algorithms and certification but SpaceX is landing rockets on a dime, we have the technology! Now imagine the dialog between the tower and a VFR dentist "line up on approach one oh one", "roger that, oh one one", "NO one oh one", "WHAT? One Oh Oh?", "Oh never mind... oh oh"
posted by sammyo at 6:25 AM on March 17, 2017 [2 favorites]
Because the wind would never cut across a circle. It wouldn't dare!
Actually, I can do his idea one better. The circles should be vertical. Loop the loop runways for landing could be much shorter because a landing plane would quickly burn off momentum going up and around the loop, bringing it much more quickly to a safe stop.
This would help with takeoffs as well, though you'd get less of a speed boost from inverting the aircraft in a huge robot arm and having begin its run upside down at the top of the loop.
Basically, this is yet another way in which the world would be so much better if it were designed for Hot Wheels.
Which is why I don't buy the whole "we're living in a simulated reality" idea. If we were, we'd have programmed it to have big loop the loops everywhere and cars would be like Hot Wheels.
posted by Naberius at 6:27 AM on March 17, 2017 [6 favorites]
Actually, I can do his idea one better. The circles should be vertical. Loop the loop runways for landing could be much shorter because a landing plane would quickly burn off momentum going up and around the loop, bringing it much more quickly to a safe stop.
This would help with takeoffs as well, though you'd get less of a speed boost from inverting the aircraft in a huge robot arm and having begin its run upside down at the top of the loop.
Basically, this is yet another way in which the world would be so much better if it were designed for Hot Wheels.
Which is why I don't buy the whole "we're living in a simulated reality" idea. If we were, we'd have programmed it to have big loop the loops everywhere and cars would be like Hot Wheels.
posted by Naberius at 6:27 AM on March 17, 2017 [6 favorites]
I have a friend who's a retired naval aviator and landed jets on carriers for years, and even he said a big "HELL NO" to landing on a curving runway.
posted by drlith at 7:20 AM on March 17, 2017 [2 favorites]
posted by drlith at 7:20 AM on March 17, 2017 [2 favorites]
Devonian: "Hah - I hadn't thought about ILS. And PAPI becomes... interesting to implement, too. Perhaps you have banks of them under the runway and pop up the ones you need on each approach? "
There are a handful of airports that have multiple sets of PAPI indicators (DCA probably being the most noticeable one, due to the sharp turn near the end of the River Visual approach), so there's a tiny bit of precedent for this.
The rest of the plan is still insane though. Among other things, traffic patterns would need to change constantly. The plan seems like it creates hundreds of difficult problems to dispense with one manageable one.
If crosswinds are such a problem, build more runways at the appropriate angles. That's it.
posted by schmod at 7:35 AM on March 17, 2017 [3 favorites]
There are a handful of airports that have multiple sets of PAPI indicators (DCA probably being the most noticeable one, due to the sharp turn near the end of the River Visual approach), so there's a tiny bit of precedent for this.
The rest of the plan is still insane though. Among other things, traffic patterns would need to change constantly. The plan seems like it creates hundreds of difficult problems to dispense with one manageable one.
If crosswinds are such a problem, build more runways at the appropriate angles. That's it.
posted by schmod at 7:35 AM on March 17, 2017 [3 favorites]
40 years ago this would be a page in Popular Mechanics titled "How airplanes will land in the future!" and you'd read it and go "huh!" and then turn the page and that would be the last you'd ever hear of it. Now this dumb idea is going to be on the web forever.
"Let's take the most critical parts of any flight and totally fuck with it!"
And while I suppose it doesn't matter much with highly automated planes but doesn't landing while banked make it that much easier to stall at the exact moments when you really do not want to stall?
posted by bondcliff at 7:45 AM on March 17, 2017 [2 favorites]
"Let's take the most critical parts of any flight and totally fuck with it!"
And while I suppose it doesn't matter much with highly automated planes but doesn't landing while banked make it that much easier to stall at the exact moments when you really do not want to stall?
posted by bondcliff at 7:45 AM on March 17, 2017 [2 favorites]
What's the thing about suddenly switching to black and white and filming his left profile every now and then?
Occasionally the hot air changed, and the cameraman had to shoot into a headwind.
posted by Celsius1414 at 7:48 AM on March 17, 2017 [3 favorites]
Occasionally the hot air changed, and the cameraman had to shoot into a headwind.
posted by Celsius1414 at 7:48 AM on March 17, 2017 [3 favorites]
In the 1950s, Heathrow had six runways in a Star-of-David arrangement, to ensure that there were always a pair within 30 degress of the wind direction, developed from an original triangular set of three. You can still see that pattern in the layout, but only two are in use as runways now, the rest being taxiways. I don't know why the original idea wasn't followed, presumably because it was too complicated to manage and conferred no particular advantage, but it doesn't bode well for our man's bold idea.
posted by Devonian at 7:53 AM on March 17, 2017 [2 favorites]
posted by Devonian at 7:53 AM on March 17, 2017 [2 favorites]
Perhaps they could hybridize this concept into an existing airport, landing normally on a flat stretch and then taking a round-about ramped turn into the elevated central boarding area when taxiing. On take off, same thing in reverse. The ramping up and down will save some fuel and some space, and a new one can be built around an existing hill.
posted by Brian B. at 7:59 AM on March 17, 2017
posted by Brian B. at 7:59 AM on March 17, 2017
Ah, here's what happened at Heathrow: 1970: Terminal 3 was expanded with the addition of an arrivals building in 1970. Other new facilities included the UK's first moving walkways.[27] Heathrow's two main east-west runways, 10L/28R and 10R/28L (later redesignated 09L/27R and 09R/27L) were also extended to their current lengths to accommodate new large jets such as the Boeing 747.[40] The other runways were closed to facilitate terminal expansion, except for Runway 23, which remained available for crosswind landings until 2002.
I suppose that one advantage of circular runways is that you never need to lengthen them...
posted by Devonian at 8:09 AM on March 17, 2017 [1 favorite]
I suppose that one advantage of circular runways is that you never need to lengthen them...
posted by Devonian at 8:09 AM on March 17, 2017 [1 favorite]
doesn't landing while banked make it that much easier to stall at the exact moments when you really do not want to stall?
It makes it easier to turn that stall in to a spin which will definitely put a very large hole in that fancy new runway of yours. You also lose a significant amount of lift because now you're pointing the lift vector at an angle instead of straight up and down. To compensate, you'd need extra thrust as well as an opposite rudder correction to counteract the lateral lift forces you're introducing. This is a pretty common way to land in a crosswind for small aircraft, but many large airliners are not designed to perform slips like this.
posted by backseatpilot at 8:15 AM on March 17, 2017 [3 favorites]
It makes it easier to turn that stall in to a spin which will definitely put a very large hole in that fancy new runway of yours. You also lose a significant amount of lift because now you're pointing the lift vector at an angle instead of straight up and down. To compensate, you'd need extra thrust as well as an opposite rudder correction to counteract the lateral lift forces you're introducing. This is a pretty common way to land in a crosswind for small aircraft, but many large airliners are not designed to perform slips like this.
posted by backseatpilot at 8:15 AM on March 17, 2017 [3 favorites]
Perhaps they could hybridize this concept into an existing airport, landing normally on a flat stretch and then taking a round-about ramped turn
I was thinking this too, then I remembered you also have to take off and have room to abort. Not sure how a banked off-ramp would work.
If we really want to save runway space, I think catapults and arrestor cables would be more practical.
posted by RobotVoodooPower at 8:26 AM on March 17, 2017 [1 favorite]
I was thinking this too, then I remembered you also have to take off and have room to abort. Not sure how a banked off-ramp would work.
If we really want to save runway space, I think catapults and arrestor cables would be more practical.
posted by RobotVoodooPower at 8:26 AM on March 17, 2017 [1 favorite]
There's also likely a centrifugal force issue so to be effective the runway should probably be banked like a velodrome.
But the banking for a 747 landing at 160mph would be way different and steeper than the banking needed for, say, a Cessna landing at 60mph.
posted by JoeZydeco at 8:28 AM on March 17, 2017 [1 favorite]
But the banking for a 747 landing at 160mph would be way different and steeper than the banking needed for, say, a Cessna landing at 60mph.
posted by JoeZydeco at 8:28 AM on March 17, 2017 [1 favorite]
One thing that always surprises me, coming from a city that I always thought had pretty much the world's blandest weather and amongst the most unexceptional geography (not even a proper river, for goodness sake), is that in the age of YouTube, Birmingham Airport (BHX) is pretty much the place for crosswind landing videos. I mean, maybe Funchal's scarier, but Birmingham's where the video cameras are (and where the B roll of crosswind landings in that video comes from). It's bizarre.
posted by ambrosen at 8:37 AM on March 17, 2017 [1 favorite]
posted by ambrosen at 8:37 AM on March 17, 2017 [1 favorite]
Perhaps they could hybridize this concept into an existing airport, landing normally on a flat stretch and then taking a round-about ramped turn
This already exists in a way, and it's called a high speed or rapid exit taxiway.
posted by backseatpilot at 8:48 AM on March 17, 2017 [1 favorite]
This already exists in a way, and it's called a high speed or rapid exit taxiway.
posted by backseatpilot at 8:48 AM on March 17, 2017 [1 favorite]
but many large airliners are not designed to perform slips like this.
That didn't stop the guys flying the Gimli Glider!
posted by bondcliff at 8:56 AM on March 17, 2017
That didn't stop the guys flying the Gimli Glider!
posted by bondcliff at 8:56 AM on March 17, 2017
I propose a flat disc runway. Take off and land in any direction. It would be huge, but oh well.
posted by under_petticoat_rule at 9:00 AM on March 17, 2017 [2 favorites]
posted by under_petticoat_rule at 9:00 AM on March 17, 2017 [2 favorites]
40 years ago this would be a page in Popular Mechanics titled "How airplanes will land in the future!" and you'd read it and go "huh!" and then turn the page and that would be the last you'd ever hear of it. Now this dumb idea is going to be on the web forever.
But wait until you see the plans for my flying airport!
posted by GuyZero at 9:01 AM on March 17, 2017 [2 favorites]
But wait until you see the plans for my flying airport!
posted by GuyZero at 9:01 AM on March 17, 2017 [2 favorites]
As my high school chemistry teacher used to tell us about tasting the chemicals in lab - you can do it, but only once.
If you actually want to land at a curved airport, you could go to Provincetown, MA where the taxiways are curved to accommodate the turning radius of the DC-3s that used to land there.
posted by backseatpilot at 9:01 AM on March 17, 2017 [1 favorite]
If you actually want to land at a curved airport, you could go to Provincetown, MA where the taxiways are curved to accommodate the turning radius of the DC-3s that used to land there.
posted by backseatpilot at 9:01 AM on March 17, 2017 [1 favorite]
But wait until you see the plans for my flying airport!
Finally, somebody who's vision of the future has a place for the flying airport airports I've been working on! If we team up, we can do a staggered version of a space elevator (I call it the space escalator) and pretty soon it'll be runways all the way down.
posted by mattamatic at 10:02 AM on March 17, 2017 [2 favorites]
Finally, somebody who's vision of the future has a place for the flying airport airports I've been working on! If we team up, we can do a staggered version of a space elevator (I call it the space escalator) and pretty soon it'll be runways all the way down.
posted by mattamatic at 10:02 AM on March 17, 2017 [2 favorites]
But wait until you see the plans for my flying airport!
/sighs, remembering fondly the dreamy flying aircraft carriers in Sky Captain & The World of Tomorrow
posted by Celsius1414 at 10:18 AM on March 17, 2017 [4 favorites]
/sighs, remembering fondly the dreamy flying aircraft carriers in Sky Captain & The World of Tomorrow
posted by Celsius1414 at 10:18 AM on March 17, 2017 [4 favorites]
Here's some video footage of actual takeoffs and landings from a curved, err, "runway". Aviation in Congo is the stuff of nightmares.
posted by ambrosen at 10:37 AM on March 17, 2017 [4 favorites]
posted by ambrosen at 10:37 AM on March 17, 2017 [4 favorites]
As others have pointed out, the required angle of bank depends on the speed of the airplane. Not only do different airplanes have different takeoff and landing speeds, but every plane's speed varies from zero to V2 during takeoff.
I would rather have a constant crosswind at 90 degrees than have a continuously varying cross wind angle during takeoff and landing. In road racing terms, having a continuously varying crosswind angle would be similar to the difficulty of maneuvering an increasing or decreasing radius turn. It just make things more tricky and prone to error.
posted by JackFlash at 2:06 PM on March 17, 2017 [1 favorite]
I would rather have a constant crosswind at 90 degrees than have a continuously varying cross wind angle during takeoff and landing. In road racing terms, having a continuously varying crosswind angle would be similar to the difficulty of maneuvering an increasing or decreasing radius turn. It just make things more tricky and prone to error.
posted by JackFlash at 2:06 PM on March 17, 2017 [1 favorite]
My first thought was how many complaints you get about airport flight paths in urban areas when there's just one or two runways, but now you can get them flying off in any direction.
My second thought was get a much smaller circle and a really strong cable and just slingshot them into the sky. Or buildings, or whatever.
posted by ckape at 3:16 PM on March 17, 2017
My second thought was get a much smaller circle and a really strong cable and just slingshot them into the sky. Or buildings, or whatever.
posted by ckape at 3:16 PM on March 17, 2017
The more I read this thread, the more I'm impressed by how many completely different ways there are for why this is a bad idea.
posted by schmod at 4:28 PM on March 17, 2017 [3 favorites]
posted by schmod at 4:28 PM on March 17, 2017 [3 favorites]
You guys clearly are ready for my new startup, Landr™. Our secret? Our fans will tell you.
Literally. Landr uses the latest advances in house fan technology and scales is up! When landing your airplane, the wind speed just outside of the fan will be just above the stall speed of your aircraft. As you fly towards the Landr™ eqipped airport, your air speed appears to be constant, but as you approach the fan ground speed falls dramatically. Just before you get to the fan, it becomes 0.
That's when your plane is gently settled onto one of the Landr™ system's interconnected platforms (which move in a loop from the fan, over it to the elevated taxiway, and then back around to the fan). As you power your aircraft down, the fan is simultaneously powered down. One equilibrium is reached, your platform is raised to the taxiway.
As you are taxiing off your platform, a new plane is landing. We can land up to 60 plane per hour per system, perfect for the busy modern airport.
Takeoff is via our patented system that takes less than half the runway length needed by giving plane a "running start" with a 30 degree bank and then a "jump" not unlike the ones seen at monster truck rallies.
Investors can contact me via memail.
posted by maxwelton at 7:49 PM on March 17, 2017 [1 favorite]
Literally. Landr uses the latest advances in house fan technology and scales is up! When landing your airplane, the wind speed just outside of the fan will be just above the stall speed of your aircraft. As you fly towards the Landr™ eqipped airport, your air speed appears to be constant, but as you approach the fan ground speed falls dramatically. Just before you get to the fan, it becomes 0.
That's when your plane is gently settled onto one of the Landr™ system's interconnected platforms (which move in a loop from the fan, over it to the elevated taxiway, and then back around to the fan). As you power your aircraft down, the fan is simultaneously powered down. One equilibrium is reached, your platform is raised to the taxiway.
As you are taxiing off your platform, a new plane is landing. We can land up to 60 plane per hour per system, perfect for the busy modern airport.
Takeoff is via our patented system that takes less than half the runway length needed by giving plane a "running start" with a 30 degree bank and then a "jump" not unlike the ones seen at monster truck rallies.
Investors can contact me via memail.
posted by maxwelton at 7:49 PM on March 17, 2017 [1 favorite]
The real advantage of this idea is that if you need to add another runway, you can just stack it on top of the first one, like pancakes!
posted by TedW at 4:52 AM on March 18, 2017
posted by TedW at 4:52 AM on March 18, 2017
If we really want to save runway space, I think catapults and arrestor cables would be more practical.
And then put the runway on the roof of the terminal. This, but bigger and without the water.
Of course, the cats and arresting gear on that probably could not deal with the momentum of a 787 full of 200-pound people, and the airport building wouldn't be able to make up for low headwind by driving faster into it.
posted by ctmf at 5:45 AM on March 18, 2017
And then put the runway on the roof of the terminal. This, but bigger and without the water.
Of course, the cats and arresting gear on that probably could not deal with the momentum of a 787 full of 200-pound people, and the airport building wouldn't be able to make up for low headwind by driving faster into it.
posted by ctmf at 5:45 AM on March 18, 2017
Planes should be launched by trebuchet, making the runway irrelevant for takeoff. This also reduces noise since the pilot doesn't even have to turn the engine on till they're in the air.
For landing, passengers should parachute into large urban parks. This way the same flight could serve several destination cities in a row but only have to land once.
posted by bracems at 6:08 AM on March 18, 2017 [2 favorites]
For landing, passengers should parachute into large urban parks. This way the same flight could serve several destination cities in a row but only have to land once.
posted by bracems at 6:08 AM on March 18, 2017 [2 favorites]
Naberius: "Actually, I can do his idea one better. The circles should be vertical. Loop the loop runways for landing could be much shorter because a landing plane would quickly burn off momentum going up and around the loop, bringing it much more quickly to a safe stop."
The tricky part is timing the landing so that you don't hit the blade of the windmill.
posted by Chrysostom at 11:48 AM on March 18, 2017 [1 favorite]
The tricky part is timing the landing so that you don't hit the blade of the windmill.
posted by Chrysostom at 11:48 AM on March 18, 2017 [1 favorite]
How much altitude do you need to recover from a zero-airspeed stall in an airliner? Tall tower with an elevator, drive it off the edge. No takeoff runway.
posted by ctmf at 4:22 PM on March 18, 2017 [1 favorite]
posted by ctmf at 4:22 PM on March 18, 2017 [1 favorite]
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