Jet pilots - a "wind" question if I may......
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Jet pilots - a "wind" question if I may......
A question for all you jet types out there. As you may or may not know, wind information on the ATIS is surface wind. Sometimes jet pilots let us know that at ......feet the wind was .......(tail). Now, what is your preference? Would you rather a headwind all the way to 500ft and then 10 knots tailwind for the landing or would you rather it the other way round?
The reason I ask is that I heard of an incident where an aircraft landed long and fast with a 5kt tail wind ("yeah, we'll accept that tail wind") and then tried to blame ATC for the subsequent nosewheel in the over run as "there was 20kts of tailwind at 1000ft". Why the pilot didn't elect to go around is anyones guess. What I am getting at is the question of what is more important to pilots: the surface wind or the wind on final? Any hints would be appreciated. Thanks,
NFR.
The reason I ask is that I heard of an incident where an aircraft landed long and fast with a 5kt tail wind ("yeah, we'll accept that tail wind") and then tried to blame ATC for the subsequent nosewheel in the over run as "there was 20kts of tailwind at 1000ft". Why the pilot didn't elect to go around is anyones guess. What I am getting at is the question of what is more important to pilots: the surface wind or the wind on final? Any hints would be appreciated. Thanks,
NFR.
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Was the aircraft with its nosewheel where it shouldnt be a commercial jet in DRW? Tailwind limitations the way I understand it, are an aircraft operation limitation and if the tailwind exceeds this on final then a go around should be commenced from a suitable hieght above the threshold.... say 500' Staaable?
Preferably I would rather fly into a head wind at lower levels.
Preferably I would rather fly into a head wind at lower levels.
Moderate, Modest & Mild.
The tailwind limitation is a LANDING limitataion, ie. at touchdown. It`s quite possible that the wind at 500` may exceed the aircraft max tailwind LANDING limitation. The 500` call is a "stabilised" ie. the aircraft is in a position and configuration that WILL allow a SAFE landing, without exceeding rate of descent (pitch), bank angle, and airspeed, as it is assumed the aircraft configuration at 500` will be maintained to threshold crossing.
In situations where the tailwind IS in excess of the landing limit prior to touchdown, it is encumbent upon the PIC (and the F/O, in a 2-crew configuration) to ensure that it is not exceeded at actual touchdown, hence an approach COULD be flown to the flare before a go-around is executed.
The situation of a tailwind all the way down finals swinging to a headwind on landing (and vice versa) is a common occurence for all professional pilots, as are increasing head/tailwinds.
The final decision whether to land or go-around rests with the pilot(s), based upon the considered judgement of whether a safe landing can be made, taking into account factors such as their experience, runway condition, aircraft performance - and the "Pucker Factor"!
In situations where the tailwind IS in excess of the landing limit prior to touchdown, it is encumbent upon the PIC (and the F/O, in a 2-crew configuration) to ensure that it is not exceeded at actual touchdown, hence an approach COULD be flown to the flare before a go-around is executed.
The situation of a tailwind all the way down finals swinging to a headwind on landing (and vice versa) is a common occurence for all professional pilots, as are increasing head/tailwinds.
The final decision whether to land or go-around rests with the pilot(s), based upon the considered judgement of whether a safe landing can be made, taking into account factors such as their experience, runway condition, aircraft performance - and the "Pucker Factor"!
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No Further Requirements I would rather have the surface wind (head wind prefered) than say the 500ft wind. The surface wind, your "last look" IAS and surface conditions (wet, dry etc) govern your landing distance.
If the 500ft wind is fairly different from the surface indications, then it is nice to know so as to prepare yourself for possible windshear. (hence some pilot's reports).
You may notice that most QF aircraft "bother" the tower and ask for a wind check when on finals even though the wind is given on the ATIS, it is done so that a min. G/S can be calculated for windshear protection. Note the ATIS wind can be different from actual wind and hence the check.
If the 500ft wind is fairly different from the surface indications, then it is nice to know so as to prepare yourself for possible windshear. (hence some pilot's reports).
You may notice that most QF aircraft "bother" the tower and ask for a wind check when on finals even though the wind is given on the ATIS, it is done so that a min. G/S can be calculated for windshear protection. Note the ATIS wind can be different from actual wind and hence the check.
Last edited by Sopwith Pup; 20th Jun 2002 at 05:56.
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Find out the touchdown point wind and fly a constant groundspeed approach.
This technique is for landing into a decreasing headwind or increasing tailwind, or runways with golf courses at the end.
This technique is for landing into a decreasing headwind or increasing tailwind, or runways with golf courses at the end.
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great to know the wind at say 500 feet as per reasons above, but certainly on runway selection issues, the landing distance data calculations are made on the 50' agl wind (crossing threshold and assumes such wind exists on the runway). Tailwind on final preferable to tailwind on landing for sure.
Windshear considerations aside, tailwind on final will really only mean you will need less power to maintain the stable slope. Doesnt matter whether you are in a jet or a C150.
I presume you are ATC hence good on you displaying your interest.
great to know the wind at say 500 feet as per reasons above, but certainly on runway selection issues, the landing distance data calculations are made on the 50' agl wind (crossing threshold and assumes such wind exists on the runway). Tailwind on final preferable to tailwind on landing for sure.
Windshear considerations aside, tailwind on final will really only mean you will need less power to maintain the stable slope. Doesnt matter whether you are in a jet or a C150.
I presume you are ATC hence good on you displaying your interest.
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The A330 has such a slippery wing that it is very difficult to fly a decelerated approach in a large tailwind and manage to be stabilised by 1000'. On the other hand, a 15 knot tailwind (our max) only increases landing distance by 15% or about 250m.
Thus, if there is a wind change at lower level, I would prefer the headwind on approach swinging around to a tailwind for landing. This assuming of course plenty of LDA.
Thus, if there is a wind change at lower level, I would prefer the headwind on approach swinging around to a tailwind for landing. This assuming of course plenty of LDA.
Nunc est bibendum
The two fold effect of landing in tailwind when there is a stronger (tail) wind a little higher is also the overshoot you will get from a decreasing tailwind.
Tailwinds on final are just uncomfortable. Different thrust settings, different attitude and therefore different picture, different perspective as you reach the flare point etc etc. Combine all that even five knots of overshoot shear and it can all turn messy in a hurry.
5 knots is my personal limit at touchdown but only on certain runways (IE about 3000 metres of runway and visual) and all other things considered of course. Wind also has to be less than 10 knots tail at 500'. I developed that rule after flying into DN about midday in Summer. Seabreeze was just coming in and so had 290/15 all the way to about 50' when it changed to 110/2. Floated a LLLLOOOOONNNNNNGGGGG way down 11. No one else had any clue that it was going on. They changed runways after our arrival.
Good question though and worthy of discussion.
Tailwinds on final are just uncomfortable. Different thrust settings, different attitude and therefore different picture, different perspective as you reach the flare point etc etc. Combine all that even five knots of overshoot shear and it can all turn messy in a hurry.
5 knots is my personal limit at touchdown but only on certain runways (IE about 3000 metres of runway and visual) and all other things considered of course. Wind also has to be less than 10 knots tail at 500'. I developed that rule after flying into DN about midday in Summer. Seabreeze was just coming in and so had 290/15 all the way to about 50' when it changed to 110/2. Floated a LLLLOOOOONNNNNNGGGGG way down 11. No one else had any clue that it was going on. They changed runways after our arrival.
Good question though and worthy of discussion.
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Thats exactly what the V***** 737 did in Darwin the other day according to the NT News. Mr Godfrey denied it and said it was a normal landing. If the aircraft used all of the runway and stopped with its nose wheel on the overrun, it must have been some tail wind to use up 3000 m of runway.
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Thnaks for the replies.....
Thanks for all the feedback on my question. About the little article in the NT News, the runway had a displaced threshold of about 1000M (or one third of the total length). I tried last night letting EVERYONE know on first contact the actual wind as reported by a 737 just landed, ie, 15 kts up the clacker until 300ft and then 4 kts tailwind. He suggested we switch runways for departures (which we did). All the arrivals (DHC8, B737, BA46 and PA31) accepted the wind as is. Full length was available. So I guess it is up to ATC to pass the exact wind (and get the reports on final) and let the PIC decide. This of course depends on what the duty runway is and how the arrival/departure sequence unfolds as to how flex the runway allocation is.
On a side note, the main reason I asked this question is becuase I hear tower controllers get curry from (some) jet pilots in the form of "Tower, we had a 15kt tailwind at 1000ft" in a not to pleased tone. Some controllers are smart and say "Thanks, but you did have a 15 kt headwind on landing didn't you?" or "Thanks, I will let the next guy know". However, what do they want us to do about it? Would 1000ft wind on the ATIS help if it is a#$e about from the surface wind? I just don't like people getting grilled when they don't know about the wind. The only instuments we have are on the surface.
Again, thanks for the previous posts and keep them coming....
NFR.
On a side note, the main reason I asked this question is becuase I hear tower controllers get curry from (some) jet pilots in the form of "Tower, we had a 15kt tailwind at 1000ft" in a not to pleased tone. Some controllers are smart and say "Thanks, but you did have a 15 kt headwind on landing didn't you?" or "Thanks, I will let the next guy know". However, what do they want us to do about it? Would 1000ft wind on the ATIS help if it is a#$e about from the surface wind? I just don't like people getting grilled when they don't know about the wind. The only instuments we have are on the surface.
Again, thanks for the previous posts and keep them coming....
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Yep giving a 1000ft wind on the ATIS would be good if it is substantially different from the surface wind.
In NZ they give it on the ATIS as a matter of course, forecast or an actual report.
I believe that any pilot who gets a little hot under the collar with a change in wind on finals, should not be taking it out on the blokes in the tower. His report may well be the first they have heard about it and would be usefull information to following traffic. After all there have been accidents caused where changing approach conditions have not been passed onto aircraft.
In NZ they give it on the ATIS as a matter of course, forecast or an actual report.
I believe that any pilot who gets a little hot under the collar with a change in wind on finals, should not be taking it out on the blokes in the tower. His report may well be the first they have heard about it and would be usefull information to following traffic. After all there have been accidents caused where changing approach conditions have not been passed onto aircraft.
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NFR, re the NT News they didn't really explain it weill. Would you mind filling us in.
My understanding from the article was that the Virgin 737 landed with a light tailwind on a runway with works in progress, couldn't stop in the available runway, and came to a stop some where in the area where the works were being carried out. Was there anybody working there at the time, did the workers have to scatter, markers taken out ?
My understanding from the article was that the Virgin 737 landed with a light tailwind on a runway with works in progress, couldn't stop in the available runway, and came to a stop some where in the area where the works were being carried out. Was there anybody working there at the time, did the workers have to scatter, markers taken out ?
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I believe giving low level wind variations either on the atis or forecast can be very important not just to the big boys but also the lighties and even helicopters.
For instance at a certain time of the year in Malta, a runway headwind of 15 knots becomes a downwind of up to 40 knots at heights of 100 ft and above. Consequently those pilots familiar with these conditions generally do what looks like a downwind take off. It was often frightening to watch pilots going the other way.
For instance at a certain time of the year in Malta, a runway headwind of 15 knots becomes a downwind of up to 40 knots at heights of 100 ft and above. Consequently those pilots familiar with these conditions generally do what looks like a downwind take off. It was often frightening to watch pilots going the other way.
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NFR,
Landed on 11 at o'dark thirty the other morning with very little wind reported on the ATIS. All the way to touchdown the magic box was indicating 20+ kts of HWC, the windsock was limp, yet no shear whatsoever during approach .
So unless more modern equipment has better magic boxes than the smurfjet, I'm somewhat sceptical of spot winds given from an aircraft that is manouvering for landing.
Landed on 11 at o'dark thirty the other morning with very little wind reported on the ATIS. All the way to touchdown the magic box was indicating 20+ kts of HWC, the windsock was limp, yet no shear whatsoever during approach .
So unless more modern equipment has better magic boxes than the smurfjet, I'm somewhat sceptical of spot winds given from an aircraft that is manouvering for landing.
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How would the TWR be able to offer a reliable 1000' wind?
The problem has always being around, Hobart is a classic case, you can have a tailwind of 15 - 20 knots at 1000' and then descend into the sea breeze with a head wind of 15 kts landing RW12.
Perhaps the other night's experience in DN may have had contributing factors, tailwind, ref + etc.
The problem has always being around, Hobart is a classic case, you can have a tailwind of 15 - 20 knots at 1000' and then descend into the sea breeze with a head wind of 15 kts landing RW12.
Perhaps the other night's experience in DN may have had contributing factors, tailwind, ref + etc.
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It always brought sly smiles to the faces of Ansett crews when we (very regulary) heard the usual piggy-squiels from the poor Qantas pilots about the "wind at 1000'...." Someone needs to tell the Qantas gurus that ATC have NO idea of 1000' winds. Maybe they're just paranoid about a certain golf course incident???
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Great to hear this thread getting some interesting input. It was not intended have a go at anyone or any company, just an education thing for me. Have taken on board all comments.
Balinda, I can't comment on the specifics of the long landing as I don't really know much more than what was in the paper and an investigation is in progress - it would be wrong of me to comment.
Anyway, just wanted to say thanks and I am glad that most people understand that the tower monkeys have no idea of the ACTUAL 1000ft winds until they are told.
Cheers,
NFR.
Balinda, I can't comment on the specifics of the long landing as I don't really know much more than what was in the paper and an investigation is in progress - it would be wrong of me to comment.
Anyway, just wanted to say thanks and I am glad that most people understand that the tower monkeys have no idea of the ACTUAL 1000ft winds until they are told.
Cheers,
NFR.
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Most of the modern aircraft have autothrottle capability.
This allows for a reasonably 'stable' approach on final ('stable' being defined by individual companys). With the notable exception of Boeing aircraft, the autothrottle system works quite well. Boeing's philosphy is "autopilot off, autothrottle off", whereas both Airbus and MD (now Boeing South) strongly recommend the ATS remain in unless broken.
By using the normal practice of flying a jet, ie, thrust for speed, pitch for vertical speed, it is desirable to land the airplane without putting the nosewheel, or more, into the soft stuff beyond the runway.
I would prefer to have a large tailwind on final backing/veering to a headwind at 50ft. Both the Airbus family and the MD11 ATSs work remarkably well in handling fluctuations in airspeed on final approach.
A quick check of an old QRH shows the MD11 at MLW, approach speed is about 165kts. With a 10kt tailwind, the increase in landing distance is approximately 450m for a wet runway and approximately 200m for a dry runway. Also, MD recommends that only 5kt be added to VREF up to 20kt of windspeed, except for a tailwind, which is still only 5kt additive irrespective of TWC.
This allows for a reasonably 'stable' approach on final ('stable' being defined by individual companys). With the notable exception of Boeing aircraft, the autothrottle system works quite well. Boeing's philosphy is "autopilot off, autothrottle off", whereas both Airbus and MD (now Boeing South) strongly recommend the ATS remain in unless broken.
By using the normal practice of flying a jet, ie, thrust for speed, pitch for vertical speed, it is desirable to land the airplane without putting the nosewheel, or more, into the soft stuff beyond the runway.
I would prefer to have a large tailwind on final backing/veering to a headwind at 50ft. Both the Airbus family and the MD11 ATSs work remarkably well in handling fluctuations in airspeed on final approach.
A quick check of an old QRH shows the MD11 at MLW, approach speed is about 165kts. With a 10kt tailwind, the increase in landing distance is approximately 450m for a wet runway and approximately 200m for a dry runway. Also, MD recommends that only 5kt be added to VREF up to 20kt of windspeed, except for a tailwind, which is still only 5kt additive irrespective of TWC.
