Ok, I don't get this. I've now got some more experience, I've done some more land aways, and I've now flown in the USA \ Canada and Europe.
There seems a real tendency to have runways roughly located east to west. They are always 24/06 or 27/09 type layouts.
Yes I know there are north \ south or north east \ south west runways out there but it seems where ever I fly in the northern hemisphere runways are almost always *roughly* east west. Why is this ?
I was wondering if it were due to the earth rotating to the east so we were being pushed into an eastery wind. The thing is, I always seem to spend more time flying 2* runways than 0* runways.
Maybe it doesn't mean anything and it just so happens that I've flown a LOT of 2*/0* runways. I can't help feeling though, there are far far far more 2*/0* runways than anything else so what is causing this phenomena ?
The prevailing winds in UK are mainly westerly: many single strip airfields are orientated E/W.
The classic A layout of wartime airfields was to always ensure an into wind runway and always to be able to takeoff into wind, a pretty essential requirement for fully laden bombers.
While that used to be true, I am convinced that, in the last year or so, we have had more northerly or southerly winds than westerly. This is probably due to the fact that depressions which used to pass mainly to the north of the UK, now seem to travel much more south. I understood that this because the jetstreams are pushing more to the south than normal.
Or maybe I just think it is because I now fly a more limited crosswind type which is based at a field with a east/west r/w.
Simple answer - prevailing winds. In fact you will find that in most of western Europe the vast majority of runways is oriented roughly west-east. There are, of course, local exceptions, mostly to do with morphological features (mountains).
Come to the Bay Area. Nearly everything is within 20 degrees of 12/30. Prevailing wind as the air blows in/out of the Golden Gate (and other gaps in the hills, e.g. west of Hollister).
Prevailing wind is fine for inland airfields. See breezes often determine the direction of runways near the coast. Best built at 90 degrees to the coast line.
Other factors like local topography have a bearing too. Look at the runway direction at Plymouth - it is 13/31 (06/24 rarely used although I departed 06 yesterday). Both 13 and 31 approaches are clear from the looming peaks and tors of Dartmoor which lies North East. The instrument procedures also reflect this.
Digressing slightly, it always amazes me how much our ancestors understood the weather (without recourse to the gadgetry we currently have available). You just have to consider the way farmhouses were orientated and their surrounding barns. The barns were usually planned to be wind and rain breaks and were on the "weather" side of the property - usually the South and West sides (in Cornwall).
Here is graphical analysis ("wind rose") of 10 years of hourly wind data for a busy international airport in Scotland.
Hopefully, the diagram speaks for itself. Most other wind roses for UK aifields are broadly similar.
Be cautious, though. A northerly or a southeasterly gale is unknown in most parts of mainland UK, but you will get them in some regions - usually when you have to go there .
"Digressing slightly, it always amazes me how much our ancestors understood the weather (without recourse to the gadgetry we currently have available). You just have to consider the way farmhouses were orientated and their surrounding barns. The barns were usually planned to be wind and rain breaks and were on the "weather" side of the property - usually the South and West sides (in Cornwall)."
I like that one, scooterboy. It is an interesting subject.
If you browse UK meteorological publications going back to, say, the 1860s, such as the annual "British Rainfall" (zzzzzzzzz...., I know!), you will find along with the rainfall returns, many notes on natural features such as the date of various flora coming into flower and when the various crops were harvested and got in. Diaries for the purpose of retaining this information were kept by most estates for generations in some cases. Doctors who kept rainfall readings often commented on the illnesses affecting the local community during each year, and I have seen annual mortality graphs they prepared for the publication.
In "the old days", of course, many (most?) of the ordinary UK population worked out of doors on the land. You will find that, consequently, for example, the annual number of fatalities from lightning strikes, compared with today, is staggeringly high.
As a nation, we (and others) have all but lost the skills of how to read the signs the natural world presents to us. Spending so much more time indoors in, normally, comfortable heated conditions is obviously the reason.
Recent interest in climate change is bringing back an interest in the science of phenology (sp OK IIRC). At Botanic Gardens, I believe the scientists have been keeping records of the date of flowering, etc. of up to several hundred species of shrubs/trees for years and these data are coming right into the spotlight after decades in obscurity.
Interesting exceptions in Switzerland (often orientated along valley) & Rhone Valley of France (N-S to cope with Mistral).
What's scary is how many fewer N-S runways there are than say 25 years ago in the UK. Some were inherited from the old generous WW2 fields, sure, but can anyone think of a major x-wind runway being built in the Uk since then?!?
I can think of plenty that have closed....Heathrow, Bournemouth, Norwich.
bookworm said: Is there a local topographical reason for the 060 peak at the "busy international airport in Scotland" or is that a general trend?
Well spotted b'worm. Frequent ENEs due Forth/Clyde valley topographical/sea breeze effect. In this part of the world, the ENE wind at some sites is the next most common wind direction after W - SWly. At Turnhouse the sea breeze, or surface thermal wind, is about 070 (had it most of yesterday and today - will be here for a few more days, too.) and this commonly pushes thro' to Abbotsinch at night - sometimes with haar/stratus, too.
Abbotsinch's "other" sea breeze on hot days is roughly from 290, but, personally, I do not recall it as being very common. The 060s from the North Sea seem most willing to push through towards Glasgow.
IIRC, gradient wind (isobar direction) frequency tables showed that at both EGPH and EGPF you could still have the stubborn 060/070 surface wind with isobars as far round as southerly in some situations - strong at 2000-3000ft, too. Many of you will be familiar with the vertical wind shear associated with an approach made on these occasions. Fortunately, tho' often mentioned by aircrews it has never caused an acutely serious problem over the decades, to my notice.
Here is annual wind rose for island site in far north of UK. Less channelling by topography at this site, giving a more even rose.
Winds centred around 240 and 270 are most common and strong, too.
Quite a lot of S - SElies up here. The further north in Scotland you go, the more strong S - SElies are encountered. IIIRC strong southerlies are dominant at Dyce.
As you travel south towards London, a good deal of the southerlies are replaced by winds from other directions.
Wind roses for seperate named months also reveal patterns. May has the highest regularity of NElies at many places due to the relative frequency of the type of synoptic situation we are experiencing right now. A best bet for breaks in the West Highlands, May is. No guarantees every year, of course, but if you went there for ten Mays you would get a lot more dry, warm weather than if you went in any other month.
Moving from aviation forecasting to climate ("the average of a lot of weather"), as did yours truly, it could be seen that there are many stats that would be of interest to aviators, but the way things are, and time being at a premium in life, upper winds, etc and TAFS and METARS for the day in question are almost certainly enough to deal with.
The Met Office sells "raw" data & frequency analyses of thousands of hourly wind data over periods of up to about 30 years in length to the Wind Energy sector. Like human fingerprints, each graphical display for each site is different, but in a way they are all broadly similar, too.
Location: Down at the sharp pointy end, where all the weather is made.
Age: 64
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When planning a new runway, it used to be a reuqirement to furnish decades of 'prevailing wind' data to determine runway direction, when crosswind component was more important to commercial aircraft. however, my experiences of nearly 2 decades at a large aerodrome in the South-East with a currently 08/26 orientation was that this 'prevailing wind' idea is no longer relevant. A North-South orientation would have been much better at LGW, because whilst all the current a/c using it would have been easily able to cope with 260/10-15 winds, almost invariably the Winter lows brought surface winds of 180/30G45, a real challenge on 26L, especially coming out of the lee of 'Laker's Revenge' or Hangar 6 as it used to be called.
Generally the operational split between 26 & 08 ops at LGW was/is around 70/30 respectively. The results for LHR are slightly skewed as they operate a Westerly preference i.e. will accept up to a 5kt tailwind on 27L/R - easily accommodated by the length of the runways. The recent closure of 23 at LHR was I suppose a demonstration of the cross-wind tolerance of many modern large aircraft(05 closed many moons ago). STN's runway 05/23 remains the best dirty-weather runway in the South-East.
Of course non of the above helps us types flying a/c with a demonstrated crosswind performance of only 17kt!
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