Circular Runway

[dangerhamster]

Meh, I learnt to fly on grass airfield, take off and land straight into wind no matter the direction. And super soft for those sub optimal landings...

[pincushionman]

Players now:

"My plane veers to the left when I take off, and I crash!"

Players if we have this:

"My plane doesn't veer to the left enough when I take off, and I crash!

[kBob]

BBC has a follow up Q and A on circular runways:

http://www.bbc.com/news/magazine-39643292

[Kerbinchaser]

What... The heck... Is that.

[Red Iron Crown]

Leaving aside implementing such a thing in KSP for a moment: How the heck does a curving runway offer any benefit in real life? Runways are straight for a pile of very good reasons, this seems like a back-of-napkin thought experiment that someone is taking more seriously than they should. 

[Skylon]

57 minutes ago, Red Iron Crown said:

Leaving aside implementing such a thing in KSP for a moment: How the heck does a curving runway offer any benefit in real life? Runways are straight for a pile of very good reasons, this seems like a back-of-napkin thought experiment that someone is taking more seriously than they should. 

They can handle more air traffic, let you choose landing direction during heavy crosswinds and something else I can't remember. 

Unfortunately it makes aborted landing difficult, especially those due to steering failure, and will probably need new guidance systems to deal with a banked and curved runway.

[Azimech]

Some arguments I've read and want to comment on:
 

• A banked runway will work differently with real planes than with KSP planes -  that's something we'd need to test. I think it won't be a problem.
• Landing gear will produce unpredictable results -  that is true with the standard settings, automatic friction might seem a good idea but it's a disaster. The "AI" tries to predict what the player wants, the player expects certain results but gets a different one. Set friction to a realistic level and you'll be fine.

[kBob]

17 hours ago, Red Iron Crown said:

Leaving aside implementing such a thing in KSP for a moment: How the heck does a curving runway offer any benefit in real life? Runways are straight for a pile of very good reasons, this seems like a back-of-napkin thought experiment that someone is taking more seriously than they should. 

Take a look at the BBC article links by the OP and me.

[Ultimate Steve]

I couldn't really see this happening an actual KSP, but if this were a mod, I'd totally try it out.

[Speeding Mullet]

On 4/21/2017 at 0:02 PM, kBob said:

BBC has a follow up Q and A on circular runways:

http://www.bbc.com/news/magazine-39643292

Yeah I read this follow up after I read the original article and thought "terrible idea".  The guy basically agreed it's a fundamentally flawed idea at this present time.  Less clearance to wing tip, faster landing speeds to avoid stalling, potentially dangerous go arounds, increased stopping distance, movable ILS being far fetched etc.  No idea why this got so much traction (that was also cited as a major hurdle) in the media, beyond being something unusual.

Maybe I should start a design house and position massive trampolines as a way of getting to space cheaply.

SM

[kBob]

16 minutes ago, Speeding Mullet said:

 No idea why this got so much traction (that was also cited as a major hurdle) in the media, beyond being something unusual.

Maybe I should start a design house and position massive trampolines as a way of getting to space cheaply.

SM

Also because it looks cool and maybe people hoped it would make airports more efficient and reduce waiting in line .  I still think it would be fun in KSP though and look very Kerbally.  But as someone said maybe as a mod.  Of course back when they decided to go from landing fields to actual runways I'm sure people argued about all the problems that would cause (and indeed some of them were no doubt correct).

[The_Rocketeer]

16 hours ago, Speeding Mullet said:

No idea why this got so much traction (that was also cited as a major hurdle) in the media, beyond being something unusual.

In the UK (where the BBC comes from), particularly in the south east, airports are a major conflict issue between human interests and economic interests. One of the recent plans to deal with that problem (and perhaps the furthest-fetched) was to build a brand new airport on top of a nature reserve in the Thames estuary. Yah.

So in this region of the world, and in other places with similar problems, people like the idea of innovative technological solutions to these problems, and smaller, more efficient and less intensive airports are very attractive. Shooting down an idea because it was far-fetched would have seen a great many wonderful human inventions - not least this videogame - never exist.

This isn't a crazy idea, it's just one that conforms to different conceptual standards - planes that are designed to land on flat straight runways will always be working with narrower safety margins when landing on banked circular runways, just as they are when landing on, for example, ice or water. On the other hand, those margins can be widened again by designing your plane with this application in mind. I think circular runways are a great idea, and with population densities only increasing in major cities worldwide, I can imagine a future in which they are the norm... assuming of course that fixed-wing air transport remains viable in future.

[322997am]

Ok, but "it is kerbal" is better evidence than all the evidence the entire media industry has ever used.

[Speeding Mullet]

4 hours ago, The_Rocketeer said:

In the UK (where the BBC comes from),

I'm British.

4 hours ago, The_Rocketeer said:

particularly in the south east

I was born in the South East.

4 hours ago, The_Rocketeer said:

build a brand new airport on top of a nature reserve in the Thames estuary.

Ah yes Boris Island!

4 hours ago, The_Rocketeer said:

smaller, more efficient and less intensive airports are very attractive.

a 747 requires a minimum safe distance of 2.3km of runway to stop.  A 3.5km diameter runway means an 11km circumference.  So if you are super efficient as a pilot, then you'll have to shut down 1/4 of the runway to land.  With any form reasonable cross/tail wind (quite likely on any given day) you'd be limiting your 11km loop to one plane landing at any one time.  A 747 max tail wind landing speed is 10 knots, and Heathrow airport average wind speed for 12 out of 12 months of the year is 9 or 10 knots for example.  Your smaller, more efficient and less intensive airport just became the opposite for a large percentage of it's design life.
 

5 hours ago, The_Rocketeer said:

planes that are designed to land on flat straight runways will always be working with narrower safety margins when landing on banked circular runways, just as they are when landing on, for example, ice or water. On the other hand, those margins can be widened again by designing your plane with this application in mind.

It would be an unprecedented change so fundamental to flying aircraft that every pilot would become a student again.  Enormous retraining globally in procedures on top of new instrumentation inside and outside the cockpit would be required.  Future plane designs could indeed be built with circular runways in mind, but for the next 30 years or so (average time to reach the cycle limit (long and short haul) of a commercial aircraft) you will be operating with much reduced margins of error for 100% of commercial jets (reducing over time) on things like:

Landing gear shear limits
Engine nacelle strikes
LAHO procedures (Land and Hold Short)

Then you have to consider so many other factors, for example:

ice and rain landings. 
Rejected takeoffs. 
Go arounds bringing you dangerously close to other air traffic.  
Max breaking scenarios.

The list goes on.  If a plane has to make a no flaps emergency landing at 200 knots (or any other type of emergency landing whatsoever quite frankly) then you want a stable path.  If for whatever reason during takeoff or landing the planes controls stop working the plane will not go straight.  Making the runway straight means the plane with a little luck will stay on the runway.  On a circular runway if you lose lateral force being applied to control surfaces for any reasons, the plane is guaranteed to depart the runway at speed.

 

This is an example of solving one problem by creating 300 more.  It was a bad idea in the 1940's and it's a bad idea still.

 

[Red Iron Crown]

On 4/23/2017 at 8:43 PM, kBob said:

Take a look at the BBC article links by the OP and me.

I have, and it makes even less sense after watching. It's as if they think the only infrastructure needed to land a plane is a runway, ignoring the lighting and ILS systems that mark the approach. Plus the safe area to land is much shorter, so the margin of error for under/overshooting is much smaller, and the landing must be done at the exactly correct bank angle. This would turn the relatively routine airliner landing into something about as difficult as a carrier trap. The noise reduction argument is silly on its face. But the best part: They claim you can have three planes using the runway simultaneously, but it takes up and area that could easily fit half a dozen or more conventional runways.

I guess I should give the guy props for thinking outside the box, but the box is there for a ton of very good reasons.

[kBob]

5 hours ago, Red Iron Crown said:

I have, and it makes even less sense after watching. It's as if they think the only infrastructure needed to land a plane is a runway, ignoring the lighting and ILS systems that mark the approach. Plus the safe area to land is much shorter, so the margin of error for under/overshooting is much smaller, and the landing must be done at the exactly correct bank angle. This would turn the relatively routine airliner landing into something about as difficult as a carrier trap. The noise reduction argument is silly on its face. But the best part: They claim you can have three planes using the runway simultaneously, but it takes up and area that could easily fit half a dozen or more conventional runways.

I guess I should give the guy props for thinking outside the box, but the box is there for a ton of very good reasons.

Well I do agree with him on the ILS it's becoming rather antiquated given all that satellite can do.  But as he said it's a work in progress, and there will need to be refinements to the system.  Though maybe the best thing to do would just be to have a nice green landing field ala KSP.  Touch down anywhere like in the good old days (well ok I wouldn't care to land a jumbo jet on grass).  It's a new idea give it time if there is enough merit in it (i.e. it provides more benefits than disadvantages) then someone will probably conduct experiments (you only need an arc for testing).  I don't see where you got the margin for under/overshooting being smaller as it's a wide circular runway (and there would be ramp not a cliff if someone did slide off); it would actually be much safer for aborting a takeoff.  I'll grant you the bank does pose some problems, but then there are some pretty dangerous straight runways too (and yes I like to fly on them in Prepa3d) that could use a bend or two  .   Another option is to just keep adding more straight runways and moving the airports further out into the boonies.  People seem rather upset about the bank that planes would need especially on landing, guess they have never seen a plane landing in a strong crosswind...happens at my local airport all the time.

Anyway it's in interesting idea and has provided a good discussion both here and elsewhere.

Edited April 25, 2017 by kBob

[The_Rocketeer]

I didn't realise I was dealing with so many experts on aviation safety limitations, pilot training standards, and international airport administration. The EU are clearly wasting their money here. The dummies...

[worir4]

24 minutes ago, The_Rocketeer said:

I didn't realise I was dealing with so many experts on aviation safety limitations, pilot training standards, and international airport administration. The EU are clearly wasting their money here. The dummies...

I study Aviation Technology at University  (I am no expert though, just my humble opinions)

 

It is a good idea in theory, execpt that in reality things go wrong. The video says they will have up to 3 planes on it at a time, To me that sounds a bit dangerous. If one plane has to abort the takeoff, it could cause some trouble for the others. Also the planes will be taking off directly into the wake of the planes in front.

It would be very difficult to fly. The stalling speed will be higher because of the bank angle so planes will be flying in much faster. Also those wings look really close to the ground. What would be a minor mistake on a straight runway could be a disaster on one of these.

I could go one about what could go wrong but i think it is clear that the dangers completely outweigh the benefits of it.

 

As for KSP, i think some one around here is going to be tempted to make it out of the 2x2 square parts. 

[NotAnAimbot]

Glider pilot with 10 hours in both solo and duo flight here.

Even taking aside all the other points, simply banking and the resulting yaw would be deadly to any pilot who doesn't have pitch perfect (badum tsss) control of his plane. Even with Schweizer 233s (Which are 51 feet in wing length), we're heavily discouraged from doing any turn below 150 feet of altitude, so I can't see how this will go well. Good idea to make money from stupid investors though.

[The_Rocketeer]

What's hilarious tho is that every comment on why this shouldn't be done in real life reads exactly like a reason why this would make a great Kerbal facility.

[thewayshemoves]

Wouldn't a CatIII landing be impossible on a circular runway without completely redesigning automated systems and the like?  I mean it just seems that this can only work if you completely redesign aircraft for every major airliner, and then the consumer would get stuck with that cost and flying becomes too expensive.  Aside from the physics problems alone, it's not a practical thing from a cost point of view.  I read the Q&A with the engineer and he's basically talking about planes that work 100% of the time on automation and there's never ice or snow.  His answer to the ice and snow question was basically, "procedures change on straight runways with ice and snow too."  Yeah, but not impossibly.

Just read the diameter is supposed to be 3.5km minimum.  Couldn't you fit multiple straight runways in that?  Does this even actually save space?

Edited April 25, 2017 by thewayshemoves

[Red Iron Crown]

7 hours ago, The_Rocketeer said:

What's hilarious tho is that every comment on why this shouldn't be done in real life reads exactly like a reason why this would make a great Kerbal facility.

This point is quite valid. Plus it would double as a racetrack for rovers. 

[Speeding Mullet]

16 minutes ago, Red Iron Crown said:

Plus it would double as a racetrack for rovers. 

That's a great call RIC, and @The_Rocketeer you are right, it makes a far better case for KSP than it does for real life.  In the middle of the circular runway you could also have a rover proving ground.  no need to waste all that space

SM

[qzgy]

3 hours ago, Speeding Mullet said:

rover proving ground

That is something I would support.

[Benjamin Kerman]

They could put it off to the side of the existing one and you just choose which one to launch from...