Cross Wind T/O and Landings
Thread Starter
Cross Wind T/O and Landings
What is the cross wind technique currently being taught for narrow body airliners? Dip a wing, or just tap the rudder? Or just land in the crab? I've heard conflicting opinions from various captains. Wasn't taught anything specific during initial at my current job.
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In Airbus the wing low technique is not recommended. However bank can be used only to make wings level or max five degrees of bank to get to the center line. After flare crab should be removed using rudder. In case of strong winds touching down with partial crab, maximum five degrees is permitted.
Depends much on type. Technique for low slung pods is somewhat different to a type with narrow gear and high wing.
As Bloggs says, let the FCTM be your bible. Also it can be instructive to watch how the autoland does it.....if you have an autoland that is.
As Bloggs says, let the FCTM be your bible. Also it can be instructive to watch how the autoland does it.....if you have an autoland that is.
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Auto Land and xwind !
M E Avelli, Correct the FCTM is any type companys bible . You would think they would hire pilots that can read more then a few lines in pprune for future Cpts.
With regards to watching autoland ,dont do that on an 737 a it does not even track the centerline properly in xwind and has no rudder canal.
( Forget the number but ca under 130 feet the bank is restricted )
Regards
Cpt B
With regards to watching autoland ,dont do that on an 737 a it does not even track the centerline properly in xwind and has no rudder canal.
( Forget the number but ca under 130 feet the bank is restricted )
Regards
Cpt B
Folks,
I always like the crosswind section of the B767-200/300 manual, in short, "whatever works for you". It was just a few lines on an otherwise blank page.
An auto-coupled approach at low level was all wing down and sideslip across the wind, and the accuracy was always impressive, the lack of lateral dispersion at touchdown was always a confidence maker for genuine Cat III conditions.
But, Cab, the word is RTFM.
Tootle pip!!
I always like the crosswind section of the B767-200/300 manual, in short, "whatever works for you". It was just a few lines on an otherwise blank page.
An auto-coupled approach at low level was all wing down and sideslip across the wind, and the accuracy was always impressive, the lack of lateral dispersion at touchdown was always a confidence maker for genuine Cat III conditions.
But, Cab, the word is RTFM.
Tootle pip!!
Last edited by LeadSled; 27th Aug 2018 at 13:20. Reason: typo corrected
T/O.
I have been taught, on the T/0 roll use as little or no, into wind aileron. The more control deflection, the more drag of course. Certainly you don't want spoilers raised.
At initiation of the rotation, anticipate the into wind wing rise by applying sufficent aileron to at least keep the wings level but best is slightly into wind wing down. Depending on wind strenght that into wind wing will rise if not anticipated. Additionaly if you have rudder defiection to keep straight, then you have secondary effect, compounding the wing lift. When airborne, the rudder should be slowly centralized and that should keep you tracking on the extended centre line. If the departure states R/W HDG after t/o you still need to stop that into wind wing rising at lift off. Rreason being, if you get a sudden gust at lift off you may bang a pod or tip on the downwind wing.
This is the procedure I have used through out my career from light aircraft to heavy swept wing aircraft and in between as the basics are the same. IMHO
The above works for me and have made a point of suggesting it when asked and always tried to teach it.
At initiation of the rotation, anticipate the into wind wing rise by applying sufficent aileron to at least keep the wings level but best is slightly into wind wing down. Depending on wind strenght that into wind wing will rise if not anticipated. Additionaly if you have rudder defiection to keep straight, then you have secondary effect, compounding the wing lift. When airborne, the rudder should be slowly centralized and that should keep you tracking on the extended centre line. If the departure states R/W HDG after t/o you still need to stop that into wind wing rising at lift off. Rreason being, if you get a sudden gust at lift off you may bang a pod or tip on the downwind wing.
This is the procedure I have used through out my career from light aircraft to heavy swept wing aircraft and in between as the basics are the same. IMHO
The above works for me and have made a point of suggesting it when asked and always tried to teach it.
Last edited by Dan_Brown; 28th Aug 2018 at 08:33.
Theory and practice
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.on the T/0 roll use as little or no, into wind aileron. The more control deflection, the more drag of course.
Spoilers work by spoiling lift, not creating drag (the form/profile drag of spoilers at takeoff speed is naff-all.) During the takeoff roll, you're not creating lift so the only extra drag is the tiny frontal area of one roll spoiler and deflected ailerons.
The cross wind limit of the 737 is pretty high, and in anything near those conditions, anyone who applies just 1 unit is going to have the wing lifting dramatically, and they'll be squirreling all over the runway. But they do it because the manual says so.
My TriStar instructor taught me to hold in full aileron in any significant crosswind, including during the rotation. It works, although I do limit its use during the rotation, because then you are spoiling lift, and that increases risk of tailstrike.... That said, the guidance of "enough aileron to keep the wings level" is kinda meaningless, because with a weedy input, they rotate, the wheels leave the ground and "bam" - the upwind wing lifts and you've got a sudden 20 degrees of bank. So that's a balance.
But extra drag during the roll ... No, not in any significant way.
Last edited by Time Traveller; 27th Aug 2018 at 15:47.
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I've never understood the into-wind aileron on the landing roll obsession. In a PA28, maybe, but any Airbus or Boeing has so many spoilers dumping lift I'd be astonished if the ailerons do anything. Certainly on a modern Airbus both ailerons are deflected upwards symmetrically with the spoilers so if anything you're just increasing your landing distance. Used to scare me when you'd see someone touch the nose gear to the runway and then force the sidestick full forward and full deflection left or right.
Thread Starter
Thanks for all the info. As I suspected, there is no single right answer. I asked the question because there was an incident recently at my airline where a new FO dropped a wing farther than the captain liked. Blood pressure was raised, emails were written. The senior captain who was ranting to me about it informed me that the wing should never be dropped on a large jet. Got me wondering where he got that idea, and what theories existed around the industry. Our manual calls for using bank as necessary to prevent drift, with the caveat that wing strike occurs at 8 degrees. I've seen several captains use zero aileron on T/O roll and landing roll-out in crosswinds, and it always feels very wiggly and uncomfortable. A large jet doesn't actually slide sideways on a dry runway, but it feels like it really wants to.
But extra drag during the roll ... No, not in any significant way.
I know this is as per the Boeing fctm, but I really find it poor theory and poor practice.(I agree with everything else you say though).
Spoilers work by spoiling lift, not creating drag (the form/profile drag of spoilers at takeoff speed is naff-all.) During the takeoff roll, you're not creating lift so the only extra drag is the tiny frontal area of one roll spoiler and deflected ailerons.
The cross wind limit of the 737 is pretty high, and in anything near those conditions, anyone who applies just 1 unit is going to have the wing lifting dramatically, and they'll be squirreling all over the runway. But they do it because the manual says so.
My TriStar instructor taught me to hold in full aileron in any significant crosswind, including during the rotation. It works, although I do limit its use during the rotation, because then you are spoiling lift, and that increases risk of tailstrike.... That said, the guidance of "enough aileron to keep the wings level" is kinda meaningless, because with a weedy input, they rotate, the wheels leave the ground and "bam" - the upwind wing lifts and you've got a sudden 20 degrees of bank. So that's a balance.
But extra drag during the roll ... No, not in any significant way.
Spoilers work by spoiling lift, not creating drag (the form/profile drag of spoilers at takeoff speed is naff-all.) During the takeoff roll, you're not creating lift so the only extra drag is the tiny frontal area of one roll spoiler and deflected ailerons.
The cross wind limit of the 737 is pretty high, and in anything near those conditions, anyone who applies just 1 unit is going to have the wing lifting dramatically, and they'll be squirreling all over the runway. But they do it because the manual says so.
My TriStar instructor taught me to hold in full aileron in any significant crosswind, including during the rotation. It works, although I do limit its use during the rotation, because then you are spoiling lift, and that increases risk of tailstrike.... That said, the guidance of "enough aileron to keep the wings level" is kinda meaningless, because with a weedy input, they rotate, the wheels leave the ground and "bam" - the upwind wing lifts and you've got a sudden 20 degrees of bank. So that's a balance.
But extra drag during the roll ... No, not in any significant way.
Agree on almost all you said
Theres a lot of needless hysteria
regarding the use of into wind
aileron on a crosswind
take off
The spoilers extended on the
upwind wing are not creating
significant drag until airborne,
at low speed with full into wind
deflection there’s little effect
anyway, as you accelerate and
flight controls become more
effective your inputs will naturally
be reduced
If you’re easing off control
deflection too soon it’s quickly
apparent with increased
difficulty in maintaining the
centerline
But it’s important to maintain that
into wind deflection throughout
rotation, too much or
too little is easily determined
depending on upwind or downwind
bank and an immediate
correction can be made
Either times have changed or we are talking about FCTM from Renton versus Payne Field.
I can't speak for the B737.
But I can for virtually all varients of B707/767/747, and in maximum crosswinds T/O you will need considerable into wind aileron to keep the wings level. You will need the "appropriate" rudder and aileron to just stay on the runway, you have to "fly" the aeroplane all the way. I am speaking from having had to use full control deflection to counter the actual (as opposed to reported) wind, on both takeoff and landing.
And, on takeoff, keep your fingers crossed that the "wrong" engine doesn't fail, because published Vmcg and the real thing are two different animals.
Tootle pip!!
https://assets.publishing.service.go...pdf_500631.pdf
The aircraft manufacturer also analysed the FDR data and stated that the magnitude of the lateral sidestick input during rotation was sufficient alone to cause a tailscrape with a 'normal' pitch sidestick input.
Into-wind aileron on the TO run and through rotation performs two basic functions: a) countering some/all of the anticipated rolling tendency and b) letting the PM know that the PF is aware of this and is doing something about it (conventional controls).
I think it comes under the heading of good airmanship. Some people I fly with (not many) effectively let go of the controls as soon as a wheel touches the ground. In benign conditions this doesn’t matter but in a gusty crosswind there is still opportunity for uncommanded roll, especially if the aeroplane is not level to begin with. Add in slow spoiler deployment and high body angle and you are right in the danger zone for airframe contact.
Put it this way, it doesn’t do any harm and could be greatly beneficial, so why not? It’s a good habit to have and can be essential on smaller aircraft. Aerodynamic effects do not cease on first touch with terra firma...
I've never understood the into-wind aileron on the landing roll obsession.
Put it this way, it doesn’t do any harm and could be greatly beneficial, so why not? It’s a good habit to have and can be essential on smaller aircraft. Aerodynamic effects do not cease on first touch with terra firma...