Why no Crosswind Component info on final?
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This seems a very simplistic view on what the wind does.
In the real world the air is fluid, changing constantly. All the tower can do is give you an average and perhaps a late update.
Furthermore the wind at the tower can differ from the wind at the threshold.
In fact at a couple of nearby fields to me if the wind is northerly the windsocks at either end of the runway can be seen pointing opposite directions.
D.O.
In the real world the air is fluid, changing constantly. All the tower can do is give you an average and perhaps a late update.
Furthermore the wind at the tower can differ from the wind at the threshold.
In fact at a couple of nearby fields to me if the wind is northerly the windsocks at either end of the runway can be seen pointing opposite directions.
D.O.
Couldonlyaffordafiver
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Luckily there's an easy way to work it out, close enough anyway. You don't need any fancy charts, computers etc.
Suppose the wind is reported as 12 @ 350 and runway is 31.
First work out the relative bearing. RB = 350 - 31*10 = 40 degrees.
Now xwind component = wind speed * RB/60, i.e. 12 * 40/60 = 8. If RB is >60, then x-wind = wind speed.
This is as close as the reported winds are ever going to be accurate anyway, and dead easy to do in your head. Worst case error is about 15%.
Not sure about other people, but I found that a confusing explanation of the clock code I explained earlier - and in reality you only need the 15/20/30/40/45 degree off ones which are the easy ones to work out - anything below 15 degrees off is not normally worth worrying about, and above 45 degrees I would work out the 45 degree amount and estimate from there, knowing that at 60 degrees I am looking at full Xwind.
Luckily there's an easy way to work it out, close enough anyway. You don't need any fancy charts, computers etc.
Suppose the wind is reported as 12 @ 350 and runway is 31.
First work out the relative bearing. RB = 350 - 31*10 = 40 degrees.
Now xwind component = wind speed * RB/60, i.e. 12 * 40/60 = 8. If RB is >60, then x-wind = wind speed.
This is as close as the reported winds are ever going to be accurate anyway, and dead easy to do in your head. Worst case error is about 15%.
Not sure about other people, but I found that a confusing explanation of the clock code I explained earlier - and in reality you only need the 15/20/30/40/45 degree off ones which are the easy ones to work out - anything below 15 degrees off is not normally worth worrying about, and above 45 degrees I would work out the 45 degree amount and estimate from there, knowing that at 60 degrees I am looking at full Xwind.
15 degrees off = 15/60 = 1/4 of windspeed is crosswind component
30 = 30/60 = 1/2
45 = 45/60 = 3/4
60 = 60/60 = all of it
Ask yourself, does it really matter if it's 29 degrees off or 31 for a fifteen knot crosswind?
If the demonstrated crosswind component for your aeroplane is more than the windspeed given, there's no need even to do the sum. Look out of the window, fly the aeroplane and if you're not happy go-around.
It works quite well for nav too using maximum drift rather than windspeed.
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With the correct (standard?) equipment fitted in the tower, the cross wind is displayed on the same screen as the current "instant" wind, the 2 minute wind, the 10 minute wind, and maximum gust within a similar time period but I forget whether its 2 or 10 minutes
Calculating the crosswind component is entirely the pilots responsibility, we've got enough to do as it is (calculating the solution to 8 down and 9 across, finishing off the last custard cream and occasionally attending to aircraft....
).
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15 degrees off = 15/60 = 1/4 of windspeed is crosswind component
30 = 30/60 = 1/2
45 = 45/60 = 3/4
60 = 60/60 = all of it
Ask yourself, does it really matter if it's 29 degrees off or 31 for a fifteen knot crosswind?
30 = 30/60 = 1/2
45 = 45/60 = 3/4
60 = 60/60 = all of it
Ask yourself, does it really matter if it's 29 degrees off or 31 for a fifteen knot crosswind?
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Yates, It's been standard kit in UK mil towers for at least the last 15yrs, but I don't recall seeing it in a civvy tower.
8 down is "gnu" and 9 across is "paradox". Put the custard cream down & stick to the chocolate digestives!
8 down is "gnu" and 9 across is "paradox". Put the custard cream down & stick to the chocolate digestives!
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Calculating the crosswind component is entirely the pilots responsibility
Agreed. But I can never be bothered to work out the crosswind. All I need to know is whether it's significant and if so whether left or right by a little or a lot, the aeroplane will do the rest.
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Sometimes Armchair discussions loose what happens in reality? On really strong wind days ATC will call winds on final a number of times to help you get a feel for whats happening on the ground.
They do this not expecting a reply from the pilot.
" 240 15 ! 260 30! 230 10! 270 30 etc" What are you supposed to do with your calculator bouncing around cracking your head on the roof?
What are they supposed to do add the changing crosswind component on every call? Get real fly the plane not the calculator or the armchair
Pace
They do this not expecting a reply from the pilot.
" 240 15 ! 260 30! 230 10! 270 30 etc" What are you supposed to do with your calculator bouncing around cracking your head on the roof?
What are they supposed to do add the changing crosswind component on every call? Get real fly the plane not the calculator or the armchair
Pace
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You'll know if the crosswind is a bit iffy 'cos the wheels will come off when you land. Always a good pointer I think.
You'll be standing there scratching your head at the three stubs at the bottom of the fuselage. It won't be an undercarriage, it will be a tripod.
You'll be standing there scratching your head at the three stubs at the bottom of the fuselage. It won't be an undercarriage, it will be a tripod.
Coming late to the discussion - I actually think it's a good idea. With a lot of hours I can handle the mental arithmetic - but when I had maybe a few hundred hours, or was unable to fly more than 20 or so hours per year, I really was not sharp enough to do those calculations quickly and reliably during an approach and landing, when I really was working bloody hard.
Let's say I was landing on runway 24, and the wind was 300/15.
To say "Wind three hundred degrees at one five knots" takes about 3 seconds (I just timed it).
Inventing some phraseology, to say "Headwind zero eight, Crosswind one two right" takes about the same time. It's the same information, but already interpreted.
As for ATC having to work it out? Sorry, but we're in the 21st century - any halfway competent IT geek could make a machine to display that information from the anemometer readout in a couple of quiet afternoons.
So yes, I think it's a fair question - crosswind (and head/tailwind) data could be calculated continuously and automatically, and given on RT in the same time, reducing the mental workload of a pilot who may well already be working fairly hard. Automation would eliminate additional ATC workload, and there's nothing to stop the more conventional wind information still being available on ATIS or on request.
G
Let's say I was landing on runway 24, and the wind was 300/15.
To say "Wind three hundred degrees at one five knots" takes about 3 seconds (I just timed it).
Inventing some phraseology, to say "Headwind zero eight, Crosswind one two right" takes about the same time. It's the same information, but already interpreted.
As for ATC having to work it out? Sorry, but we're in the 21st century - any halfway competent IT geek could make a machine to display that information from the anemometer readout in a couple of quiet afternoons.
So yes, I think it's a fair question - crosswind (and head/tailwind) data could be calculated continuously and automatically, and given on RT in the same time, reducing the mental workload of a pilot who may well already be working fairly hard. Automation would eliminate additional ATC workload, and there's nothing to stop the more conventional wind information still being available on ATIS or on request.
G
I'm never that interested in the figures. It's too scary to know the detail, makes you worry. I just look at the sock
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As already said, the wind is constantly changing, so for limits it should have been worked out well in advance, once on finals it it really a case of looking at what drift you have offset and saying "am I comfortable with this" - if not, Go Around!
As for ATC having to work it out? Sorry, but we're in the 21st century - any halfway competent IT geek could make a machine to display that information from the anemometer readout in a couple of quiet afternoons.
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So yes, I think it's a fair question - crosswind (and head/tailwind) data could be calculated continuously and automatically, and given on RT in the same time, reducing the mental workload of a pilot who may well already be working fairly hard. Automation would eliminate additional ATC workload, and there's nothing to stop the more conventional wind information still being available on ATIS or on request.
Cross wind component is rarely static. Lets look at the situation where ATC are calling out winds for your information as I posted above 220/15 240/30 270/35 200/10.
You have given yourself a crosswind limit of say 15 kts ?
Now I can land ? Now I cant? Now I cant ? now I can?
Its the big picture, your ability and the aircraft limits not the demonstrated limits. What is the windshear like? How constant is the wind and its direction ?
These are all questions which determine whether you chuck away the approach and go elsewhere.
Pace
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I think that expressing crosswinds as a numeric value has merit, but not to the point of really worrying about on short final. It's kinda like buying a Rolls Royce, if you have to ask "how much?", you can't afford it.
Knowing the wind direction and intensity is obvioulsy worthwhile, as it helps you to make a decision to land at that airport. Once on final, if in doubt, simply ask yourself if you are able to track perfectly down the final approach. If you cannot fly final on the runway heading, chances are that landing there might exceed your skill.
As mentioned, the crosswind value for any certified aircraft is not legally limiting. It is a guidance for your judgement, and a demonstration that the aircraft met the certification requirements. Often times, the aircraft is easily capable of much larger crosswinds, but the manufacturer did not wish to declare that - they just stated the minimum required. This is evident in that many pilots land in much stronger crosswinds with no difficulty.
What's going to challenge you will be the instantanious variations in wind direction or intensity. On Friday I approached to land with the surface wind reported as "5 to 10 knots, variable from 030 to 170 degrees". The runway choices were 18 or 36. The 10 knot crosswind would be no problem, but the variation can make it really interesting!
On the other hand, I did crosswind testing in a modified Cessna Caravan, with a direct 25 knot crosswind. Aside from reaching full rudder travel a few times on the runway, it was really quite easy, as the wind was very steady.
Like many things with flying light aircraft flying, it's probably better to simply look out the windshield and fly, rather than concentrate on numbers.....
Knowing the wind direction and intensity is obvioulsy worthwhile, as it helps you to make a decision to land at that airport. Once on final, if in doubt, simply ask yourself if you are able to track perfectly down the final approach. If you cannot fly final on the runway heading, chances are that landing there might exceed your skill.
As mentioned, the crosswind value for any certified aircraft is not legally limiting. It is a guidance for your judgement, and a demonstration that the aircraft met the certification requirements. Often times, the aircraft is easily capable of much larger crosswinds, but the manufacturer did not wish to declare that - they just stated the minimum required. This is evident in that many pilots land in much stronger crosswinds with no difficulty.
What's going to challenge you will be the instantanious variations in wind direction or intensity. On Friday I approached to land with the surface wind reported as "5 to 10 knots, variable from 030 to 170 degrees". The runway choices were 18 or 36. The 10 knot crosswind would be no problem, but the variation can make it really interesting!
On the other hand, I did crosswind testing in a modified Cessna Caravan, with a direct 25 knot crosswind. Aside from reaching full rudder travel a few times on the runway, it was really quite easy, as the wind was very steady.
Like many things with flying light aircraft flying, it's probably better to simply look out the windshield and fly, rather than concentrate on numbers.....
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If you cannot fly final on the runway heading, chances are that landing there might exceed your skill.
As Pilot Dar points out if there is enough control authority to maintain the centreline on approach chances are there is enough control authority to handle a landing.
It is rare that surface winds are stronger than approach winds. They maybe slightly different in direction and prone to terrain and obstruction influence but chances are the above criteria is a good indication.
As for the pilots ability that is another question.
Pace
Cross wind component is rarely static. Lets look at the situation where ATC are calling out winds for your information as I posted above 220/15 240/30 270/35 200/10.
You have given yourself a crosswind limit of say 15 kts ?
Now I can land ? Now I cant? Now I cant ? now I can?
You have given yourself a crosswind limit of say 15 kts ?
Now I can land ? Now I cant? Now I cant ? now I can?
G
