Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Crosswind Runway In Relation To Primary Runway  
User currently offlinenaruto38700 From Singapore, joined Dec 2012, 7 posts, RR: 0
Posted (1 year 8 months 3 weeks 6 days 11 hours ago) and read 4178 times:

Hi everyone, this is about the project I am doing now. We are asked to design an airport with relevant details on the runways.

So here is my question, I wonder if crosswind runways are always perpendicular to the primary runway, or are they just oriented to the prevailing crosswind?

One more thing, according to the question paper, only one runway is needed to satisfy current traffic demand. However, prevailing wind is at 050° while Crosswind is at 120°, so is it safe for me to assume that a crosswind runway will be needed?

Thanks!

17 replies: All unread, jump to last
 
User currently offlinevikkyvik From United States of America, joined Jul 2003, 10036 posts, RR: 26
Reply 1, posted (1 year 8 months 3 weeks 6 days 10 hours ago) and read 4148 times:
Support Airliners.net - become a First Class Member!

Quoting naruto38700 (Thread starter):

So here is my question, I wonder if crosswind runways are always perpendicular to the primary runway, or are they just oriented to the prevailing crosswind?

My suggestion would be to go look at airport diagrams. Many US ones are available here:

www.airnav.com

You'll find that runways have all sorts of orientations, and most of them aren't exactly perpendicular.

Quoting naruto38700 (Thread starter):
However, prevailing wind is at 050° while Crosswind is at 120°, so is it safe for me to assume that a crosswind runway will be needed?

That's not enough information to make that determination. If the crosswind only gets up to, say 2 or 3 knots, then I'd say no, you don't need it. But there are more factors that would have to be considered.



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 79
Reply 2, posted (1 year 8 months 3 weeks 6 days 8 hours ago) and read 4111 times:

Quoting naruto38700 (Thread starter):
So here is my question, I wonder if crosswind runways are always perpendicular to the primary runway, or are they just oriented to the prevailing crosswind?

Exactly perpendicular is relatively rare. If you're going to go to all the trouble to make a crosswind runway, you might as well align to the prevailing crosswind. Especially since exactly perpendicular takes up the most space so you only want to do it if you really have to.

Quoting naruto38700 (Thread starter):
However, prevailing wind is at 050° while Crosswind is at 120°, so is it safe for me to assume that a crosswind runway will be needed?

As noted, it's going to depend a lot on the wind. But also on other weather factors (do you have enough capacity on your single even if the weather is bad? could you do simultaneous operations on the crossed runways?). And what shape is your land plot? Who's under the approach and departure ends of each runway? This all factors in.

Tom.


User currently offlineMir From United States of America, joined Jan 2004, 21641 posts, RR: 55
Reply 3, posted (1 year 8 months 3 weeks 6 days 6 hours ago) and read 4084 times:

Quoting naruto38700 (Thread starter):
So here is my question, I wonder if crosswind runways are always perpendicular to the primary runway, or are they just oriented to the prevailing crosswind?

It really depends. Normally, you would have it aligned with the prevailing crosswind to the extent practical. But if you're going to start talking about using it not only as a crosswind runway but as a second usable runway (i.e. have two runways going at the same time to improve traffic flow), then a perpendicular runway has some advantages.

-Mir



7 billion, one nation, imagination...it's a beautiful day
User currently offlinerfields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 31
Reply 4, posted (1 year 8 months 3 weeks 6 days 4 hours ago) and read 4035 times:

A great many runways / airports around the world have runways based on the early history. The runways at Heathrow evolved from three runway pairs to the current two runways.

Chicago's O'Hare was a mess of runways for different wind conditions - slowly being converted to a predominant wind direction runway setup.

Airports like JFK, LGA, EWR, PHL all have physical geography constraints which limited the way the runways could be built. SAN is an example of successfully combining wind direction and physical geography to allow a busy airport to operate near the city center. It just has absolutely no possibility of growth, or alternate operation if winds are bad.

Quoting tdscanuck (Reply 2):
Exactly perpendicular is relatively rare.

True, but back before WWII - perpendicular runways seemed to be a preference which make it common at many of the older airports - i.e. SFO, JFK, LGA, PHL.

The Army Air Corps built many training bases across the US, which the USAF later upgraded to jet bases with perpendicular runways, and 45 degree cross runways. Seemed to be a standard pattern many places, despite normal wind speeds and directions.

Perhaps a good example of modern wind directed airport design (even though the design is 50 years old) is DFW with a primary wind direction 5 runways, and an alternate pair usable most of the time, and occasionally the only usable runways in wind conditions like we had a couple weeks ago.

Or DEN - where the wind change possibilities must be extreme with four north/south runways and two east/west runways.


User currently offlineStarlionblue From Greenland, joined Feb 2004, 17044 posts, RR: 66
Reply 5, posted (1 year 8 months 3 weeks 6 days 1 hour ago) and read 3985 times:

Another issue is the type of traffic. Modern airliners can handle way more crosswind than smaller aircraft, particularly GA planes. Compare KMCO, which services airliners, and KISM, which services primarily GA. They are quite close to each other, so wind conditions are close to each other. KISM has two runways at 90 degrees while KMCO has parallel ones. No way a Cessna 172 can handle 20 knots crosswind, something an airliner lands in without problems.

BTW for an airport with V-shaped runway layout, check out KGNV. http://155.178.201.160/d-tpp/1213/00973AD.PDF



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineJoeCanuck From Canada, joined Dec 2005, 5471 posts, RR: 30
Reply 6, posted (1 year 8 months 3 weeks 6 days ago) and read 3975 times:

YYC has two runways crosswind to the main north/south runway. They are both significantly shorter but since they are only in to airliners during severe crosswind situations, they don't have to be as long.

The crosswind runways also serve to keep smaller GA aircraft out of the landing and takeoff patterns used by the airlines. There is more than enough room for most smaller aircraft to stop short of the intersection.

That being said, crosswind ops seem to be a real pain sometimes, resulting in lots of holds and delays.




A larger version is available here;

http://www.gcmap.com/diagrams/pdf/CYYC.pdf



What the...?
User currently offlineLU9092 From United States of America, joined Oct 2007, 69 posts, RR: 1
Reply 7, posted (1 year 8 months 3 weeks 5 days 8 hours ago) and read 3854 times:

Quoting rfields5421 (Reply 4):
Or DEN - where the wind change possibilities must be extreme with four north/south runways and two east/west runways.

Having grown up in CO, I was somewhat surprised to learn that the prevailing wind in DEN is from the south, except for the month of April, where it is instead from the north. My impression from having lived there for nearly 30 years is that the typical case is light winds that allow any runway to be used. The most common high wind scenarios - and this is based only on my own observations - would be high, gusty downslope winds, mostly in winter and spring, and then straight line thunderstorm winds caused by downdrafts in the summer that can be from any (or all!) directions. Less common are the steady 10-15kt upslope winds from the east or southeast that tend to herald the arrival of wet, heavy snow from late winter through spring. If you notice a strong upslope from mid-July into August, keep your eye on the sky. Someone is likely to see serious flooding, as in Ft. Collins on July 26-27, 1997, or the Big Thompson River basin in 1976.

Bringing it back to perpendicular runways, DEN certainly has the space for them, and the fact that when there are crosswinds, they tend to be strong and gusty, makes that pair of east-west runways essential. I believe that DEN's master plan allows for two more parallel east-west runways and four additional north-south.


User currently offlinenaruto38700 From Singapore, joined Dec 2012, 7 posts, RR: 0
Reply 8, posted (1 year 8 months 3 weeks 5 days ago) and read 3784 times:

Quoting vikkyvik (Reply 1):
Quoting vikkyvik (Reply 1):
My suggestion would be to go look at airport diagrams. Many US ones are available here:

www.airnav.com

Thanks for giving me this website! We are also asked to draw the layout of the airport so this will be very helpful!

So I think I will be adding a crosswind runway oriented to 120°/300° since the prevailing crosswind is at 45 knots  


User currently offlineDiamondFlyer From United States of America, joined Oct 2008, 1548 posts, RR: 3
Reply 9, posted (1 year 8 months 3 weeks 5 days ago) and read 3779 times:

Quoting Starlionblue (Reply 5):
No way a Cessna 172 can handle 20 knots crosswind, something an airliner lands in without problems.

Say what? A 172 can absolutely handle 20 knots of crosswind.

-DiamondFlyer


User currently offlineStarlionblue From Greenland, joined Feb 2004, 17044 posts, RR: 66
Reply 10, posted (1 year 8 months 3 weeks 4 days 22 hours ago) and read 3758 times:

Quoting DiamondFlyer (Reply 9):
Quoting Starlionblue (Reply 5):
No way a Cessna 172 can handle 20 knots crosswind, something an airliner lands in without problems.

Say what? A 172 can absolutely handle 20 knots of crosswind.

Ok fair enough but it is well beyond the demonstrated max.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlinenaruto38700 From Singapore, joined Dec 2012, 7 posts, RR: 0
Reply 11, posted (1 year 8 months 3 weeks 4 days 18 hours ago) and read 3721 times:

Quoting JoeCanuck (Reply 6):
The crosswind runways also serve to keep smaller GA aircraft out of the landing and takeoff patterns used by the airlines. There is more than enough room for most smaller aircraft to stop short of the intersection.

Hi, I understand you are saying that crosswind runways serve two purposes, both for airliners to take off and land when crosswind prevails, as well as for GA aircraft to operate under normal conditions.

But in the case of YYC, would it not be a problem if GA aircraft operate on crosswind runway while airliner operate of main runway at the same time? You know, since they intersect each other, would it not reduce the efficiency of both runways?


User currently offlineStarlionblue From Greenland, joined Feb 2004, 17044 posts, RR: 66
Reply 12, posted (1 year 8 months 3 weeks 4 days 18 hours ago) and read 3718 times:

Quoting naruto38700 (Reply 11):
But in the case of YYC, would it not be a problem if GA aircraft operate on crosswind runway while airliner operate of main runway at the same time? You know, since they intersect each other, would it not reduce the efficiency of both runways?

I'll speculate that if you can get GA to use another runway you're increasing efficiency even if they intersect. Just the decrease in wake turbulence separation between airliners and smaller GA planes will save you a boatload of time.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlinenaruto38700 From Singapore, joined Dec 2012, 7 posts, RR: 0
Reply 13, posted (1 year 8 months 3 weeks 4 days 8 hours ago) and read 3623 times:

Quoting Starlionblue (Reply 12):
I'll speculate that if you can get GA to use another runway you're increasing efficiency even if they intersect. Just the decrease in wake turbulence separation between airliners and smaller GA planes will save you a boatload of time.

Now that is very true! I failed to take the wake turbulence into consideration, especially since I will have A380 operating in my airport! Truly grateful for the answer, have a happy new year since we are in the same time zone :P


User currently offlineJoeCanuck From Canada, joined Dec 2005, 5471 posts, RR: 30
Reply 14, posted (1 year 8 months 3 weeks 4 days 5 hours ago) and read 3598 times:

Quoting naruto38700 (Reply 11):
But in the case of YYC, would it not be a problem if GA aircraft operate on crosswind runway while airliner operate of main runway at the same time? You know, since they intersect each other, would it not reduce the efficiency of both runways?

While ATC won't let 2 aircraft land or take off at the same time on intersecting runways, they don't need the same kind of spacing if everybody is one behind the other on the same runway.

Basically, ATC will give the planes time and space to execute a go-around in case of runway excursion. Everybody will know a crosswind runway is being used so everyone is ready to act if an incursion takes place. With proper spacing, time is allowed that even if the landing or taking off plane does cross the intersection, it will probably not be an issue. The plane just has to make it across the taxiway hashmarks to be clear of the main runway...which only takes a few seconds.

You also don't have the wake turbulence issues which are a large consideration to approach spacing.



What the...?
User currently offlinevikkyvik From United States of America, joined Jul 2003, 10036 posts, RR: 26
Reply 15, posted (1 year 8 months 3 weeks 3 days 8 hours ago) and read 3528 times:
Support Airliners.net - become a First Class Member!

Quoting JoeCanuck (Reply 14):
Basically, ATC will give the planes time and space to execute a go-around in case of runway excursion. Everybody will know a crosswind runway is being used so everyone is ready to act if an incursion takes place. With proper spacing, time is allowed that even if the landing or taking off plane does cross the intersection, it will probably not be an issue. The plane just has to make it across the taxiway hashmarks to be clear of the main runway...which only takes a few seconds.

Or (at least in the US), they use LAHSO operations, if the pilots/airlines accept them.



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlineJoeCanuck From Canada, joined Dec 2005, 5471 posts, RR: 30
Reply 16, posted (1 year 8 months 3 weeks 3 days 3 hours ago) and read 3486 times:

Quoting vikkyvik (Reply 15):

I've done that in a Cherokee at YYC. Even with this, they still have to stagger the crosswind flights since an incursion could happen despite best efforts...but you don't need anywhere near the gap that all using the same runway would.

It's a bit of an awkward system but when it's working right, it's better than a single runway.



What the...?
User currently offlinealaska737 From United States of America, joined Feb 2006, 1063 posts, RR: 5
Reply 17, posted (1 year 8 months 3 weeks 3 days ago) and read 3463 times:

Quoting Starlionblue (Reply 10):
Ok fair enough but it is well beyond the demonstrated max.

So...? And it isn't much beyond the demonstrated max just FYI.


Top Of Page
Forum Index

Reply To This Topic Crosswind Runway In Relation To Primary Runway
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Flying In Formation To Save Fuel? posted Tue Aug 11 2009 22:44:30 by Scutfarcus
Crosswind Landings In Airliners posted Mon May 16 2005 10:43:39 by Powerofpi
Aircraft Performance In Relations To Weather posted Sun Sep 8 2002 14:22:18 by SOHK
Airports With Worst Runway Condition In The World posted Fri Feb 17 2012 07:29:51 by Tupolev160
Towing Planes From The Gate To The Runway posted Sun Apr 10 2011 05:55:42 by 4tet
Runway Lines In Canada posted Wed Jun 9 2010 19:11:39 by StarAC17
Runway Too Close To Pax Terminal? posted Fri Nov 6 2009 03:07:58 by Faro
Runway Numbers That Don't Correspond To Headings posted Thu Sep 3 2009 23:25:37 by QF744FAN
Runway Problems At Bristol Airport, Report In. posted Fri Jan 9 2009 06:08:51 by Readytotaxi
What If G-YMMM Had Made It To The Runway? posted Wed Jun 25 2008 14:30:45 by Starglider

Sponsor Message:
Printer friendly format