Wind checks on approach.

[need to know]

As a newly qualified ATCO, I wonder if fellow ATCO's or flight crew could tell me, how many wind checks are enough and how many are too much? How many miles from touchdown should one give the final check??? I have had different answers from my colleagues. I would be interested in your opinions...

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And that's what I think about that.

[This message has been edited by need to know (edited 10 June 2000).]

[karrank]

Like a good marriage, Give 'em nothing, take 'em nowhere....

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"Cut him off and call him shorty!" - Lorenna Bobbit (Patron Saint of ATC)
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[squeakmail]

Give 'em wind checks until the crosswind is within company limits for landing...then shut up.

(Just teasing).

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Animals...it's their World too!!

[RTB RFN]

need to know

I believe the optimum is like this:


1. they get it from the ATIS as a heads up

2. don't care what the books say - a check at 1000ft is good as a reminder/update and usually given with landing clx

3. any downwind and crosswind component which reach the book amounts.

4. a 500ft/1000ft wind, obtained recently, if conditions are variable - it's probable quite different to surface wind and indicates likely shear.

5. Any discernable difference between windsocks

Bottom line - all part of the service captain.

[Fokjok]

WRT giving the wind checks until it's within limits, remember the F27 in GCI - and don't risk ending up in the dock.

Seriously, though, it's worth remembering that most aircraft with 'proper' FMS have instant wind read-outs displayed to the pilots, with a head/tail and cross-wind analysis on an FMS page, generally displayed during the approach.

Smaller or older aircraft could probably do with more wind reports, and everyone will appreciate being up-dated on any major fluctuation.

Finally, if you're sharp enough to pick your moment and give reports at a time when things are not likely to be busy, then it means the crew are more ikely to copy the wind report without interrupting their other duties.

Busy times include GS capture, passing the FAF or OM, 1000AGL, 500AGL (one of these depending on company), 100 above DA/MDA and DA/MDA itself.

Finally, if the crew are doing a Cat 2 or 3 approach, they probably don't want to be interrupted below about 1500AGL.

[Carnage Matey!]

If it's gusty or the wind is varying from either side I quite like a windcheck at about 100 feet to remind me which wheel is upwind. We have the full inertial wind read out on my aircraft but at that height I'm looking out, not in. As for Cat 3 approaches, I find windchecks a bit academic because the wind won't be that strong and the aircraft will cope with it much better than I can anyway!

[Fokjok]

Carnage Matey,

At 100ft I am starting to flare, and it's a bit late to be finding out where the wind is from.... Try briefing your FO to call (for example) 'Ten from the left, eight head' from the FMC if you need it - no self-respecting ATCO would talk to an aircraft at 100ft other than to say 'Go-around.....'.

So far as Cat 3 is concerned, you're right not to worry too much so long as your aircraft has auto-roll-out. However, on a type which requires AP disconnection at touch-down, knowledge of the wind is critical, as there's a lot of sorting out to do to get the thing tracking down the runway and keep it there.

[This message has been edited by Fokjok (edited 11 June 2000).]

[erpel]

You should always take into consideration that the wind shown to you is the the average of the last two minutes including minimum and maximum of the last 10 minutes. ATC does not have an actual wind available as before apprx. late 80`s. The idea behind is, than any actual wind shown to ATC will be a history wind when transmitted to the pilot anyway. It was found that using the 2 minutes history value ist most valid for touchdown if transmitted within two minutes before touchdown. That means one windcheck within the last threee miles should be sufficient. Continues windreadings will not give a better information to the pilot. In any case the FMS windreadings can not take the place of the transmitted surface wind, as the surface wind will be shown via FMS not before the plane has touched down. Anyway datalinks may replace our verbal work soon.

[NudgingSteel]

Regarding the post from erpel (above), many towers in the UK have fancy new electronic dials giving both 2-min average and instant windspeeds, also 2-minute max and min with direction variation. Sensors located at each touchdown point.

Incidentally, for any pilots reading this....at our airport you wouldn't believe the number of times the wind is completely different at each end of the runway. Which is more relevant for departing traffic - the wind where you start the roll or where you get airborne?

[Ausatco]

At the airport where I work there are six wind analysers, one at each end of three runways.

Each one provides instant wind (updated every 2 seconds), two-minute average and peak in the last 10 minutes.

Each of those provides crosswind and trackwind components.

Need To Know,
If the wind is per the ATI we don't give a wind check unless asked. If it is variable or gusty, then we do - with the landing clearance.

When a pilot asks for a wind when on short final, he gets the instant wind.

The wind on the ATIS is a composite that reflects the situation at both landing thresholds and also at the DER. If we can't quote a reasonable composite due to wide variations between threshold winds and/or winds at the DER, then the most representative threshold wind will be on the ATIS and others will be quoted individually as necessary.


Nudging Steel - same situation at our airport re winds different at threshold and DER. See above re ATIS. Departing aircraft can be given a wind at the DER, or that too can be put on the ATIS, saves a lot of R/T.

I would think the answer to your question about which is more useful for departing a/c depends on whereabouts along the runway you expect the aircraft to get airborne. If likely to be airborne early, threshold wind might be more useful. If likely to be airborne further down, then the other. When in doubt I give both both to help the pilot assess the transition!

Do you have a centre-field wind? We used to but it went when the mulitple threshold wind analysers were installed http://www.pprune.org/ubb/NonCGI/frown.gif

AA



[This message has been edited by Ausatco (edited 12 June 2000).]

[Spotter]

Changing the subject slightly.... I try not to make any transmissions to other a/c when an a/c is about to touch down. Sometimes it is unavoidable. When you are landing do you find transmissions to other a/c distracting when in the flare, or do they not bother you?

[Grandad Flyer]

Transmissions to other aircraft during flare/touchdown - doesn't bother me in the slightest, in fact at any point on the approach, after landing clearance is received, I tend to turn the radio down slightly if its very busy anyway (obviously I can still hear you though). I find it easy to ignore the radio unless there are some similar callsign aircraft being talked to (ie. same company).
However, if I am landing I am landing and it makes no odds what you are saying, unless of course I'm in cloud, then I listen more closely, or if there is something on the runway and/or you want me to go around. But then if the weather is that bad there probably won't be quite so many transmissions.
As for wind checks, I find it really annoying to have a wind check with other clearances, its usually a really busy time, with the guy in the other seat calling for stuff, checklists being completed, etc. and then I have to respond to the clearance and I don't always catch the wind. What would be perfect would be to get the clearance then separately get a call "wind check, 210 at 5" (or whatever) a few seconds later. Then we have time to look at what we have at our current height, and see if there is going to be much change.
However,it depends on how high you are when landing clearance is given. If it is a bit later, say 3 miles out, then its not so bad as we are likely to be fully configured, checklists completed.
Just as a guide, our company procedure for a standard ILS is to start dirtying up when on the glide at c2000' above the field. We should be fully configured and stable by 1000'. Then we have a brief checklist and then I can give you my full attention.

[PPRuNe Towers]

Hang on - just popping my anorak on - ah, that's better.

Regarding 'historical' wind readouts. Your average pilot's FMC/FMS processes the wind through a kalman filter. That was the science bit.

What this means is that the readout you are seeing is a minimum of six seconds old. Your eyes and botty may well be far ahead of the game in terms of any wind information supplied.

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Regards from the Towers

[email protected]

[Bagheera]

On first call you are given your position in traffic and usually a wind check...this is the average wind and will include any mins or maxs...together with any recect reports of windshear/turbulence etc...As you approach short final you should be given the instant wind,together with the words surface wind instant..However like a previous contributor we often find the winds swirling and inconsistent so we give wind checks roughly after any 20 degree change or 5 knot increase/decrease ( this is not a rule but is followed by most of the controllers)...the winds often swirl around our airport and i would be interested to know...particularly from EFIS and none EFIS aircraft when it is useful and when its a distraction...For instance I have had 2 pilots of the same...EFIS...aircraft...tell me I am distracting them...or not giving enough Info?

[Houston737Pylot]

My 2 cents are: First, I get the wind off the ATIS, Second, if the conditions are so bad that I might need another check; I can ask. The input is a nice thing to have but not always at the right time. I grew up flying in and out of dirt strips where we didn't have the luxury of having a professional on the other end of a radio to help us out. If the wind was so bad we couldn't land we would go somewhere else. There really is no difference in the plane I fly now as to the one I flew then except maybe about 145,000 pounds and 100 knots. Bottom line is an airplane is an airplane. I think more often than not when somebody had to ask more than once there may be a confidence problem. It's real easy to see what the wind is doing on all approaches just by looking either out the front window(or side window in a good cross wind) or looking at the fancy instruments. You controllers do a fantastic job! Thanks for all of the help.

[This message has been edited by Houston737Pylot (edited 13 June 2000).]

[U R NumberOne]

As a rough guide, this is the way I do it...

Wind check when cleared to land - lets assume at 4 miles, further wind checks then dependant on the conditions - if its 5 kts straight down the strip then why bother unless you enjoy hearing the sound of your own voice on the RT? If it is wild and gusting, I tend to give further checks at 2 miles and 1 mile final - plus any others if requested or I observe a big gust on the instant wind.

On the subject of the mean versus the instant - I really don't like the mean wind. In breezy conditions you just don't get a feeling for what the wind is doing around the field - and if I think the information is useful to the crew I'll give the instant without being asked - despite what it says in the book.

I would also warn against trusting the FMS indicated wind - as has been mentioned this can be several seconds old, and unlike the surface wind we give you isn't taken on the ground (obviously :rolleyes: ) and won't take into account the turbulence-generating effects of large airport buildings (the Tower excepted, we just generate hot air :)) )

[Goldfish Jack]

As an aerodrome controller, with quite a few shifts behind me, I give the wind when I clear an aircraft to land. Any further windchecks are on request, or if the crosswind component is greater than 10, I will give one at about 1 - 1.5nm from touchdown.

Never fround this to be a problem and never had any comeback with this procedure.

[schnapper]

Personnally speaking,I tend to give extra wind checks if the wind is more than 30 degrees either side of centre line and more than 10 knots but I never require acknowledgement as it is for information only
and always on request.

[Bagheera]

Thanks guys,
whilst I agree with these replies you must understand that the airfield I work at has crosswind problems on the main runway together with the fact that the mean wind moves 20-30 degrees every sweep...what i would like to know is...do you want me hollering every 30 seconds or would you prefer a big bright wind sock?
EFIS guys have told me to shut up...EFIS guys have told me to keep them coming....dont know what to do...please help????

[Carnage Matey!]

Well I'm sticking to my guns and saying I like a check at approx 100 feet if the wind's all over the place. I don't start flaring until 30 feet at the earliest, but I will be looking out and don't need the distraction of trying to find the inertial wind of my EFIS. I've been close to a go-around in the flare on a gusty, dark and rainy night at Bagheeras airport and I would have appreciated some guidance as to where the wind was coming from.

[bird on the wire]

Agree with houston 737 - the best wind check is to see what the aeroplane is doing.

If the wind's not out of limits, then the numbers don't really matter. You either deal with it and land or you go around.



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they bought their tickets - they knew what they were getting into

[fweeeeep]

I issue the wind on first contact (which may include the landing clearance). I issue the wind with the landing clearance, which may not be first contact. If there is a considerable wind variation or gusting, then I will issue a wind-check at about 1nm from Touch-down.

Pilots are clever enough to remember the wind that you give them, and if it changes one is morally obliged to tell them about that.

[fweeeeep]

I have previously thought about the whole wind issue, Wouldn't it be neat if they came out with some equipment that was adjacent the landing threshold that gave a big digital readout of the surface wind at that position. Either an arrow with the strength in the form of a number, or two digital readouts. Nice Bright day glow yellow on a red background ?

The pilots could read it from a few hundred feet, and glance when they had a chance.

[Stunty]

I'm a big fan of asking the pilot what the aircraft's max crosswind limitation is - then subtract one or two knots and then just give that figure as the crosswind with the landing clearance. Who can tell the difference between 22 and 24 knots crosswind - really. If you give the crosswind as their max just after you have asked them they cotton on, and also after a while you learn the max crosswind for each type and can get away with it even more.!!!!

[aluminium persuader]

Hmmm very interesting, Mr Bond!
I still get my wind from those round things with pointy bits on them...MK vi's I think...
And some of the guys I work, if I gave them the wind at 3 miles would wonder why I told them when they won't got to the rwy for another half-hour!

aahh...de Havilland! :)

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Once more unto the breach, Dear Friends...