Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Inclined runways

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

Inclined runways

Thread Tools
 
Search this Thread
 
Old 13th Jan 2010, 06:02
  #1 (permalink)  
Thread Starter
 
Join Date: Aug 2007
Location: USA
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Wink Inclined runways

I was recently contacted by the inventor of a "revolutionary" airport layout:
Earth Wise International - Starrport

The basic idea is that the runways are built on inclines (4% to 5% grade) so that all takeoffs are downhill and landings are uphill. The terminal is located underneath the peak of the pyramid structure. The inventor makes some pretty dramatic claims about the fuel saved by this design.

Is he missing something obvious, or does this seem like a plausible concept to those who know something about aviation?
HomelessScientist is offline  
Old 13th Jan 2010, 14:59
  #2 (permalink)  
 
Join Date: Dec 2006
Location: The No Transgression Zone
Posts: 2,483
Received 6 Likes on 4 Posts
We don't like steep RWY gradients and that would make opposite departures very bad; anyway most RWY's are inclined some what

further, would you like to stop a fast jet running down hill,...

and if the runway were unidirectional well then you save lots of fuel,...by idling on the ground forever waiting for a departure slot,...or holding forever waiting for an approach,...

just another useless 'new idea'---let's just float away on pink balloons and hope the wind carries us home

Last edited by Pugilistic Animus; 13th Jan 2010 at 15:31. Reason: s
Pugilistic Animus is offline  
Old 13th Jan 2010, 17:54
  #3 (permalink)  
 
Join Date: May 2007
Location: Manchester, UK
Age: 38
Posts: 128
Likes: 0
Received 0 Likes on 0 Posts
Actually, it appears that the gradient is only at the beginning of the departing runway and vice versa for the arrivals. This would presumably give a reduced accelerate-stop distance since the bulk of the speed is gathered on the downhill, while the stopping is on the flat.

I can see problems with this (a runway overrun on arrival would involve a slide right through the terminal...) and the go-arounds might be tricky with departing traffic directly ahead. They're not insurmountable, though.
David Horn is offline  
Old 13th Jan 2010, 20:17
  #4 (permalink)  
 
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 81
Posts: 1,330
Received 0 Likes on 0 Posts
Might as well have a 2 foot deep over-run lake to put out the brake fires, douse the engines and stop the craft with minimum damage.

What planet does your mate live on?

mm43
mm43 is offline  
Old 13th Jan 2010, 22:21
  #5 (permalink)  
 
Join Date: Feb 2005
Location: UK
Age: 62
Posts: 363
Received 9 Likes on 4 Posts
And some very poor arithmetic!
Sepp is offline  
Old 13th Jan 2010, 22:29
  #6 (permalink)  
bearfoil
Guest
 
Posts: n/a
We actually had a runway just like that here in the Sierra foothills. 5k long, 07/25.

Big hump in the middle, at the lounge/FBO. 07 was not used by veterans taking off, it was net uphill and into trees. 07 was great for landing. Uncontrolled strip, some transient thought he was entitled to a 10 mile final to 7, no radio, that could be a problem. Besides taking off into a hump that hid the departure action, one landed on 25 and exited as quickly as possible. Stopping to chat with a student on the active could put one in danger of an S2 up your tail. (Fire Base). The second turn off was well hidden from departing a/c on 25.

Cost 7 million to grade the hump down and repave, plus loss of business while closed.

Bad idea. Bad. Hump/Danger. Hump/Danger

bear
 
Old 13th Jan 2010, 23:01
  #7 (permalink)  
 
Join Date: Feb 2008
Location: Where its at
Age: 41
Posts: 228
Likes: 0
Received 0 Likes on 0 Posts
How many of you have actually clicked the link and seen the actual proposals?

Animated demonstration at USAToday.com

Its not so much about having a runway on an gradient, its more about always having the terminal right at the end of the runway for arrivals, and right at the beginning for departures. This virtually eliminates taxiing, thereby saving fuel. No hump in the middle of the runway. No idling on the ground.

Personally I think its pretty ingenious. Not saying it will work, but the discussion would be more informed if people were aware of what they were debating rather than throwing negative comments around willy nilly...
Anansis is offline  
Old 13th Jan 2010, 23:04
  #8 (permalink)  
ENTREPPRUNEUR
 
Join Date: Jun 2001
Location: The 60s
Posts: 569
Likes: 0
Received 0 Likes on 0 Posts
Excellent

What a good idea!

Note to other posters - take-off and landing are in the same direction. You need to appreciate this is two separate runways joined in the middle by an apron.

The London Underground uses this principle a lot.
twistedenginestarter is offline  
Old 13th Jan 2010, 23:28
  #9 (permalink)  
 
Join Date: Aug 2007
Location: Godzone
Posts: 391
Likes: 0
Received 0 Likes on 0 Posts
All well and good until you land short, and have to use 95% power to taxi up the hill to the terminal, or you have to taxi back to blocks, or something goes wrong on the take off roll and the stop distance is increased by 50% beacuse of the down slope. Imagine how many snails would be killed by the manufacture of these new airports - they would have to be new as the infrastructure would take too long to build at an existing one
toolowtoofast is offline  
Old 13th Jan 2010, 23:38
  #10 (permalink)  
 
Join Date: Nov 2007
Location: Texas
Posts: 1,924
Likes: 0
Received 1 Like on 1 Post
It's funny, they say the Denver airport is wasteful, yet it was designed as a pinwheel with the terminals in the center. Also check the layout of KNMM and KNKT, both US Naval Air Stations with the ramp areas in the middle of runways laid out like wheel spokes.
MarkerInbound is offline  
Old 13th Jan 2010, 23:51
  #11 (permalink)  
bearfoil
Guest
 
Posts: n/a
My caution was that airports should be humpless. Not necessarily spokeless. Undergrounding is remarkably different than surface engineering, and could easily cost twice the sum a standard aerodrome might. For instance a tunnel can be ten times as expensive as a surface roadway of the same length. Plus all connections to appurtenant services, infrastructure.

Flamboyant Architecture was passe in the thirties, and from whence cometh the Bonds? China's tapped, my friend.

bear, not gopher
 
Old 14th Jan 2010, 04:22
  #12 (permalink)  
 
Join Date: Jul 2001
Location: Gold Coast
Age: 58
Posts: 1,611
Received 0 Likes on 0 Posts
Pffft .... no big deal having a steep runway.



Fane in Papua New Guinea, averages about 12° slope and the middle is about 15° I think. Yes it's a one-way strip but because it's close to the equator there's never much wind so you don't have to suffer much head/tail at any time. The 2,000' drop at the end also does wonders to help build up airspeed if needed.

I can see how the idea of an inclined runway could work, but it'd be very difficult to work in the real world, with varying winds and so on.
18-Wheeler is offline  
Old 14th Jan 2010, 09:09
  #13 (permalink)  
 
Join Date: Sep 2009
Location: Iceland
Age: 34
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Crap......

wat bout the different winds


wat if u have strong tailwind taking off
vikrant soni is offline  
Old 14th Jan 2010, 10:22
  #14 (permalink)  
 
Join Date: May 2007
Location: Manchester, UK
Age: 38
Posts: 128
Likes: 0
Received 0 Likes on 0 Posts
Then you just use the opposite runway for landing and departing...
David Horn is offline  
Old 14th Jan 2010, 10:32
  #15 (permalink)  
 
Join Date: Jan 2008
Location: Finland
Age: 77
Posts: 465
Likes: 0
Received 0 Likes on 0 Posts
Didn't/doesn't Montreal Mirabel have the runways laid out so the terminal is at the end of the landing runway and beginning of the take off runway - been a few years since I went there, so I may be wrong.
finncapt is offline  
Old 14th Jan 2010, 10:44
  #16 (permalink)  
 
Join Date: Jul 2007
Location: Germany
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Has anyone here landed on a 5 degree upslope here? I have and its horrible. Really bad visual illusion means that you need to be talked down practically on a visual approach. the flare becomes a six degree pullup affair, which, if you pork, means going around and burning even more fuel.

Oh, what happens when the wind isnt in your favour and you have to get airbourne on the upslope? Does wonders for your performance, meaning you may need to flag somewhere, at massive increase in fuel burn!

Flat runways are the best!
VinRouge is offline  
Old 14th Jan 2010, 12:01
  #17 (permalink)  
 
Join Date: May 2001
Location: London,England
Posts: 1,391
Likes: 0
Received 1 Like on 1 Post
Having a raised terminal at the end of a raised runway would make your go-around gradient calculations interesting wouldn't it. Overrun would be quite spectacular as well, pity he didn't consult anyone who knows about aircraft operations before designing this.
Max Angle is offline  
Old 14th Jan 2010, 12:58
  #18 (permalink)  
 
Join Date: Oct 2009
Location: UK
Posts: 1,270
Likes: 0
Received 0 Likes on 0 Posts
Courchevel Airport, France, CVF

Good job the airport designers of CVF didn't read some of the posts here first.

"The French however, have decided not to let a simple matter like density altitude get in the way. By simply making the runway follow the slope of the mountain, and decreeing that takeoffs are downhill and landings uphill, gravity is used as a replacement for air molecules. Large twins and even four engine turboprops are able to takeoff and land on a runway which totals 535m (from the drop-off at the bottom to the mountain face at the top) a TODA or LDA which would be marginal if it was at sea level, and flat.

At Courchevel, with varying gradients along the length of the runway (to a maximum of 18.5% for the central 238m) the mere fact that the local QFE on a standard day would be 793mb is no obstacle either to take-off or to landing. It does however put paid once and for all to the argument about always landing on QFE. Just try winding off 6000' from your altimeter as you enter the circuit to see why..."

World's Most Dangerous Airports: Courchevel Airport, France, CVF || Jaunted

higher.flyer.co.uk

YouTube - Beech Baron landing at Courchevel Airport, France

Last edited by rudderrudderrat; 14th Jan 2010 at 15:16. Reason: spelling
rudderrudderrat is offline  
Old 14th Jan 2010, 18:10
  #19 (permalink)  
ENTREPPRUNEUR
 
Join Date: Jun 2001
Location: The 60s
Posts: 569
Likes: 0
Received 0 Likes on 0 Posts
Has anyone here landed on a 5 degree upslope here?
The proposal has you landing on the flat. It's only towards the end of the run that you hit an incline. Similarly it's only the start of the take-off run that is inclined.

Clearly you would need a whole new set of calculations for V1 etc. With regard to complications with go-arounds, I guess you would just have to make sure the incline was less than the go-around flight profile.
twistedenginestarter is offline  
Old 14th Jan 2010, 19:46
  #20 (permalink)  
 
Join Date: Dec 2000
Location: on the golf course (Covid permitting)
Posts: 2,131
Likes: 0
Received 0 Likes on 0 Posts
EHBP/BUD/Budapest works very well.

They have offset 13L/R and 31L/R with the terminal in the middle, so you land on 13R or 31L and take off on 13L or 31R hence minimising taxi distances after landing and nefore take off; works well!
TopBunk is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.