choosing the direction for runways

[cforst513]

what determines the headings for runways when people are designing airports? are there studies done in the years leading up to the building phase that determine prevailing wind directions? or am i totally off?

 

[Kream926]

prevaling winds, from what i heard

 

[greygoose]

Look at a nationwide map, the runways generally go in the same direction for the area that they are located.

 

[User546]

I saw a show on the Discovery channel one time about this same thing, and what they did was go back and look at hisotrical wind studies from the previous 10+ years. From that they determined what the prevailing wind was the majority of the time, and would orientate the runways in that fashion - of course when terrain, and shape of the available land would dictate.

Tried doing a search all over Google for it, and wasn't able to find any good links for you, but start looking in that direction and I bet you'll find your answer.

 

[shamrock]

Seems to me that when deciding which way to line up the runways they just look for the most desirable area of land just off the airport property and aim the runway at it. This allows developers to build an upscale, gated community there and gives the stay-at-home moms and trophy wives something to bitch about after they realize that the airport departures buzz their new $500K townhouse at 300 feet, a fact that somehow escaped them when they were purchasing it.

Committees form and public meetings are called. Soon, noise abatement procedures appear, treshholds are displaced, and plans for a new runway (2000' shorter with obstacles at both ends) are drawn up.

And that's how runway layouts are created, or so it seems.

 

[2000flyer]

Look at a nationwide map, the runways generally go in the same direction for the area that they are located.

Say what?????

User997 is correct. I don't know for how many years they study, but it is from historical wind data. Don't you find it odd that most of the time the wind is blowing relatively close to your longest runway direction?

2000Flyer

 

[2000flyer]

Look at a nationwide map, the runways generally go in the same direction for the area that they are located.

greygoose, Say what?????

User997 is correct. I don't know for how many years they study, but it is from historical wind data. Don't you find it odd that most of the time the wind is blowing relatively close to your longest runway direction?

2000Flyer

 

[GravityHater]

I have seen a plot of these prevailing wind charts - they look like Rorshack inkblots the psycho docs use.
I think they cut-off all winds below 10kts (insignificant winds), and above 40kts (because who flies then).
The plot looks like a multi-lobed 'blob' around a central dot on a circular sheet (360 compass degrees). The longer the wind is coming from a certain direction, the further the 'blob' reaches from the center.
The blob usually has a certain specific shape... where I was, the prevailing wind was onshore and the blob was very large in the direction of the water. There was also a small blob towards the NW because of the prevailing winter winds.
Where I am now, the majority of the winds are from the SW so you would think the main rwy would be 21/03. Nope - its 12/30.
I found out why last week. The AAF in about 1942 wanted an aux field to train their pilots in xwind landings so they built this strip 10mi from the main 'triangular' base. And all these years I'd cursed that &$^#*@) runway!! No bloody wonder! (35kts at 60 degrees one night last week, I was lined up, with the runway out the side window for gods sake)

So they position runways for reasons other than to make our jobs easier.... If they can only find a strip of land that is long enough in one direction, that's it pal. Like Sedona Az, Aspen Co, Angel Fire NM.
(those are terrain examples but 'market' or 'financial' examples exist too).

 

[2000flyer]

He *might* be saying that airports near each other have similar runway alignments.

EWR, JFK, and LGA all have 4/22.

LGA and JFK both have 13/31, and EWR has 11/29, so thats close too.

I could be totally off base tho.

Could be. Still makes you scratch your head though!

 

[jknight8907]

Two airports around here have the same runways as well, 42A and MPJ.

 

[Pilot124]

The main runways always point to the strip clubs!!!!!!!!!!!!!!!

 

[Illini Pilot]

a diagonal runway on a square plot of land is also going to give you a few hundred more feet than a runway aligned N/S or E/W...thats probably why there are a fair amount of 4/22 and 14/32 out there

 

[Immelman]

Extensive study is performed into the prevailing wind. The runway is then constructed exactly 90 degrees from this direction..........

 

[aucfi]

The military had the right idea when building airports and runways. Build lots of them!

Most of the smaller airports inland here along the east coast (and im sure elsewhere) favor the "triangle" runway layout. Where I learned to fly there was never a big concern for crosswinds because the majority of the time the wind was never more than 10-20 degrees off a runway heading.

This is changing though as many of these smaller airports cannot maintain this many runways. My local airport KFKN already lost 4/22 and will soon loose 32/14 due to lack of funds. And yes, 4/22 was the runway the winds favored 80% of the time.

 

[A Squared]

Yeah, wind studies are aften a factor, sometimes though terrain is the major factor. I fly into a number of airports where there's only one way you could build a runway due to ridges valleys shorelines, etc.

Here's a place we go fairly often. Doesn't matter what the wind studies show, there's only one place to put the runway.

http://www.alaska.faa.gov/fai/images/AKPEN/DUT-b.jpg

 

[redneck jihad]

Seems like I heard that they use the prevailing wind when the field is IFR.

 

[s0ldier93]

Prevailing winds are taken for at least two years. The runway is then place where an aircraft can land with less than 10 knot crosswind component 80% of the time. Or as close to that as the runway can be practically place.