Cross wind landings

[king rooney]

Hi all, what are people thoughts on this.

there are basically 2 methods of crosswind landing that I am currently learning, the "crabbed approach" where you approach the runway with the plane yawed into the wind, and then straighten it up just b4 the wheels touch the ground, and the "wing down" method, which involves banking the plane towards the wind, and then applying opposite rudder to keep it straight, with the wheel nearest the wind touching the ground first.

Am finding the crabbed approach much easier, and have pulled it off in cws of 20 kts with fair ease, but cannot for the life of me get the wing down method to work without hopelessly cocking up the landing!
Does anybody else have the same problem?
Is it ok just to rely on the crabbed method, or will the wing down method be required in say a ppl or cpl skill test?
What do u all think about the comparative merits of each method?

Cheers, Rooooooney.

[Keygrip]

I've always thought it a personal preference. Personally, I've always gone with crab method, but that's what I was taught (Rule of Primacy?).

Indeed, it wasn't until moving to the USA that I ever heard of the wing down method - but I see nothing wrong with it for a light aircraft, especially a high wing.

Idle curiosity - what aircraft type are you being taught to land in a 20 knot cross wind (presumably as a student).

As for the "test" - you will be regarded as "Assuming all the responsibilities of the pilot in command", so the decision will be yours alone as to which method you use. It just has to work.

[king rooney]

Plane is a C172, was being a bit cheeky doing solo circuits in said wind, perhaps I exagerate a bit, the CW was 12kts, gusting to 20, so probably wasnt eaxctly 20 when I was landing. 15kts is the limit for the C172 right?

As an aside, what can happen if one pushes ones plane past the CW limit? is it an absolute no no to go over the limit, or is there a bit of leeway if for example the airport does not have an alternate runway and a stronger than the limit cw needs to be tackled?

[Ropey Pilot]

First thing you need to ask yourself when pondering questions of this sort is "what would the subsequent board of inquiry say?".

If you feel confident that you could state your case and defend it (assuming you are around to) then you are probably on the way to making a decision.

You can probably answer your own question as to what they would say if you got out of a smouldering C172 which you had attempted to land outside of the a/c limits!:\ .

If your field only has one runway you could consider holding till the wind drops/ diverting. If you are a solo student without the training to consider this and the winds are that high then your instructor probably needs to have a long hard look at his duty of care!

[navoff]

You may well run out of rudder authority.

[king rooney]

Fair do´s, ropey, I am by no means advocating landing in an excessive crosswind if , ur response is a fairly unimaginitive one which says "do not do it because it is against the rules," ie not very interesting.

Hypothetically, what will happen to a plane physically if one tries to land in a excessive cross wind?
How is the crosswind limit set, and can it be exceeded safely, and by how much, if its is absolutely necessary?

[navoff]

You will run out of rudder control and not be able to line up the aircraft for the landing.

[king rooney]

sounds fair enough, and with no rudder ull end up careering off to the side, perhaps into the nearest tree/ building. You might be able to increase ur rudder control by landing at a higher speed though? What would be the highest speed that one could land at, assuming an infinite runway?

[navoff]

If it is an infinite runway then nothing. The drift effect will certainly be reduced at higher airspeeds. But, alas not very practical. A C172 will easily cope with upto 20 kts crosswind. Although more to the point will you (ie how current/confident are you?)

[Keygrip]

K.R. - so now you're saying that you are a solo student, doing crosswind landings in a 172, with a crosswind of 12 gusting 20 and no long briefing from your flying school/instructor as to the principles and sciences of crosswind landings?

Just a thought - if you want to save yourself some money in the future - don't bother taking out any insurance for the aircraft. I doubt you'll be able to make a claim on the subsequent incident.

Whilst I do fully agree that you are right to ask these questions - I do think they should be to your flying instructor, and before you go solo to practice it.

Whichever school you are paying for training is doing you a great dis-service.

More idle curiosity - next time you go to the school, could you look in their operations and training manuals as to the wind/weather conditions allowed for solo student operations. Would you mind posting them?

[Hufty]

Even if you land at a higher airspeed, as the aircraft slows down you will get to a point where you have maximum rudder deflection and you will begin to drift off downwind before it is ready to settle down on the runway. Once you go beyond the maximum demonstrated crosswind you are a test pilot and I echo Keygrip's comments - your school are putting you into a difficult and dangerous position by letting you go off on your own when you still have some questions unanswered.

Remember if anything happens and you get injured, you are the pilot in command and it will be your fault.

[A.Einstein]

I am concerned that you are asking questions to which you should already have answers too, before being let loose in a plane! I agree with Keygrip! You should be being set parameters as a student pilot and tutored in these skills ,monitored as to your progress, ability and skill. You appear to be on a very dangerous learning curve.

[king rooney]

Those of you that say that I should have been properly briefed by my FTO about the cross wind situation are right. I have been growing increasingly concerned with the quality of the instruction, whilst I am learning how to fly a plane fairly competently, getting decent scientific explanations for things, such as the crosswind landings etc, is like getting blood from a stone. There is simply no "background eduaction" to the whole training process, hence finding out things like the consequences of exceeding crosswind limits is up to me, hence the reason for this post.
Have been seriously considering switching FTO for a while now, believe me.

Keygrip however, I do not like your patronising tone a great deal, there really is no need.

[navoff]

Why shouldn't you ask questions? It is quite healthy to theorise, we all know its not sensible to fly outwith the limitations laid down, but if the wind is 10 gusting 20 are you going to elect not to make an approach? You always have the option to go-round. A solid crosswind landing technique is an essential skill if you live anywhere near Wick!!

[king rooney]

Hufty,

Fairish point, but if one touches down at a speed which is sufficient for ones rudder to work in an excessive crosswind, when one slows down ones wheels will be in contact with the runway, and therefore the plane will not be susceptible to drift in the wind as it would if it was in the air.

Touching down and settling on the rw at say 90kts rather than 65 (in C172) might knacker the landing gear but would allow the rudder to work enough to keep you straight.

[stue]

I was always taught the crabbed method and it has never been an issue the fact that I haven’t done the wing down method. Landed in a 12kt crosswind (club limits for PPL holders on club a/c) on Tuesday and the crabbed method worked great. Although, I wouldn’t have liked to have done it as a solo student. Even of there wasn’t a limit on club a/c landing in crosswinds, iv set my limit at 12 kts for the min, not much higher than that.

Said airport that I think the king is learning at though seems to always have a massive crosswind on landing. Its like the runway is just at right angles to the prevailing wind! Good cup of tea though in the tower;)

[king rooney]

Where do you think im learning at then stuey? :)

[stue]

sunny sunny Hawarden?

[king rooney]

Nah, the only "hawarden" I know is the one I get everytime I see my girlfriend. :)

[Sky Wave]

What would be the highest speed that one could land at, assuming an infinite runway?

Depends on the tyres maximum speed rating. I've seen the effects of a warrior landing at 100kts and the tyre didn't look pretty.

[stue]

where you learning then?

[king rooney]

Only joking, mate, Hawarden is the place. Cross wind is a bastard there, comes in off those Welsh hills. Ur description of H as "sunny" is in fact remarkably correct. Hawarden is actually statistically the place which has most sunshine in the UK. It is regularly the hottest place in the country during summer, hence my tan.

[stue]

on my QXC i landed there and the crosswind was a complete b1tch! its a nice place though, you get to see the big airbus flying out of there. :)

[navoff]

Guys

12 kts is not bad, most aircraft are 25 kts plus+. It's not a measuring thing, but rather a daunting thing which needs practise!

[Hufty]

King Rooney, so you reckon you can land your C172 at 90kts?

A Cessna 172 will stall at around 55kts depending on weight (can't remember exactly) so at 90kts your aeroplane is still going to want to fly and won't be ready to settle down on the runway. You will likely bounce and get airborne again and in any case even if you manage a smooth touchdown the wing will still be producing a large amount of lift and there is probably going to be so little weight on the main wheels that it is going to begin to drift away from you. Don't forget too if you try to touch down at 90kts the aircraft is going to be in a level attitude (any attempt to flare is going to result in a HUGE baloon) so if you do try and land it, there is a strong chance that you'll land nosewheel first. The fin presents a large area, so it is going to weathercock and the wind is going to try and lift the upwind wing. You could put in a bit of wing down aileron to stop this happening, but at 90kts you will have a lot of aileron authority and you might end up groundlooping it. All in all, trying to manage an aeroplane hopping and skipping across the runway at cruise speed while trying to counteract the effects of a crosswind outside the manufacturer's limits isn't the best place to be. In a strong crosswind you are going to need to use the rudder and into wind aileron pretty much until you come to a halt, so your experimental techniques are going to get you into a lot of trouble.

My advice to you would be to find a better FTO and get a good insructor to sit down with you and go through the theory and practice of crosswind landings. You are paying them to teach you and if they're not, then you're being ripped off. Then go off and practice them with her or him. When you're off on your own, you should begin by landing in light crosswinds then as your experience builds, tackle some stronger ones. Maybe a post on the instructor's forum will generate some useful information for you?

But remember, if you are outside the manufacturer's limits then you're on your own.

[paco]

If you intend to fly 737s in the future I would get used to the crab method as having the wing down will result in the engine scraping along the runway!

I don't like the wing down method myself, as it involves a fair amount of cross controlling and doesn't feel natural. Neither did the Army, where I did my training. I certainly wouldn't use it if I was learning by myself as you seem to be.

Phil

[ifleeplanes]

The XW limit is the DEMONSTRATED limit, it is not the maximum that the ac could land in. It has been demonstrated by a test pilot up to that speed to be achievable by the average pilot. Now if you consider yourself an above average pilot as a student, your demonstrating that your not! The limit is there to stop people killing themselves, ignore it at your peril!

[FlyingForFun]

The choice of wing-low or crabbed depends very much on the type of aircraft. As Paco says, a B737 needs to be landed crabbed because of its underslung wings.

But try flying something small and light with high wings - say a Piper Cub - crabbed, and as soon as you kick it straight the wind will pick it up and you'll loose the centre-line - wing-low is the only way to land that type of aircraft in anything other than very light cross-winds.

Most training aircraft - C172 included - can be landed using either method. The crab method is the one I prefer, purely because it can handle higher cross-winds than wing-low. I normally teach that to all my students. But if a student is having trouble with this method, I will teach them the wing-low method, and I'm quite happy for them to use that if they find it easier, because it is very much personal preference.

As for cross-wind limits, the 15kt "limit" on the C172 is not a limit, and it explicitly states this in the manual, in the definitions in Section 1:Demonstrated Crosswind Velocity is the velocity of the crosswind component for which adequate control of the airplane during takeoff and landing was actually demonstrated during certification tests. The value shown is not considered to be limiting.(I've added the italics.) However, having said that, I would be very surprised at any school letting solo students fly with a crosswind of the kind you are describing..... :\

FFF
-------------------

[PAPI-74]

If any of you fly outside of the xwind limit, you are not insured at all. Do you fancy a bill for the aircraft, loss of earnings, airport crash if they are mean etc...
The crab techinque is ok till ground effect, then aim to drop the wing very slightly into wind to stop the drift. The risk of keeping the crab on till the last minute is cocking it up and exerting a side load, especially in a retractable. Rapid changes in rudder input require opposite aileron. This causes drag on all surfaces, mainly the lifting ones giving obvious downfalls.
If in a twin, do not put on too much bank or risk a prop strike. This is called the 'combination technique' and is the more commercial way of doing it.
If approaching in gusts, add half the gust factor to your normal approach speed eg wind 320 20G30 gust factor is 10 kts. Half is 5 kts so add 5 kts. BE76 short final is 85 so I would fly at 90kts to the threshold and add 5 kts to that giving 81kts. Check also you gust limit eg max of 30 with no Xwind Component.
These numbers all come from the Vmca speed and adding a factor to it. Vmca being the speed at which you have control in the air of your aircraft. It is a control and stability speed NOT a performance speed, so don't expect and favours if you get that slow, which a gust will do to you.
With the wing down method, you can, with skill, exceed the limit, bit it is very foolish. Don't forget that if you add roll and introduce a sideslip that you will get tailplane stall as the angle that it is introduced to the relative air flow is like sticking you arm out of the window, so a positive arrival may be needed, one wheel only very slightly before the other.
If in doubt, some instructors don't remember a great deal as you have to keep reading all of the time to remember it all, so you may not get the whole picture. Get a good book and learn why things are done. It may save you life and your pax.
Try and anticipate how much control input you need to reduce a draggy unstable approach...bad for you and worse for your pax.

[Click Here]

K R a little something to remember whilst ur trying to break yourself and kill a perfectly serviceable aeroplane, people on the ground are watching and you never know when the "authority" might also be watching. You might find a certain flight examiner debriefing you on x wind limits whilst bashing you accross the head with the nearest heavy thing, it also reflects quite poorly on your flight school that they allow to fly in such conditions when you must be at your most dangerous i.e not qualified and alone.
Also spare a thought for the chaps and f chaps that have to go outside in the cold or possibly the hot, pending how bad you mess up, to clear up your mess.

If you did click here you must feel quite disappointed, I can only offer the following advice:

Click here and follow the link to get £10000 p.a for free for life:

www.lebillyofthesilly.com

[Andy_R]

If any of you fly outside of the xwind limit, you are not insured at all

No offence but that is rubbish.

As stated by several posters, the POH only ever states a DEMONSTRATED crosswind limit. This is not an absolute limit.

That does not mean that clubs/schools will not impose their own limits, because they will.

[Hufty]

Well, Andy R if you have an accident and you were attempting to land in a crosswind outside the aircraft's demonstrated limits then you are in a sticky situation nonetheless. If you injure anyone and you find yourself getting sued - it is going to be tough to defend your actions in such a situation. The "....well I know it is technically outside the limits but everybody does it" defence isn't a strong one.

You're right that is is a DEMONSTRATED crosswind, but even though it may not be limiting it doesn't automatically guarantee that the aeroplane CAN operate in stronger crosswinds. Sure, with common types like Cessnas, there will be plenty of people who will say they have operated the equipment in stronger crosswinds than the POH states but once you are outside the limits in the book you're going to have to explain why.

[paco]

I think what papi-74 is trying to say is that if you fly outside the flight manual limits you are not insured, since the C of A is automatically invalid and the flight is illegal, so you are notinsured. If the limitations section states an absolute limit, then he is correct, but some only say that the xwind limits mentioned have been demonstrated - however, if they are actually in the limitations section, I wouldnt want to argue the point in court

Phil

[Hufty]

...and in any case, as commander you will have taken a look at the weather prior to departure and as such will be aware of the strength and direction of the wind at your destination and your alternates. You will also have a view on the risks of the weather situation changing and be in a reasonable position to avoid having to land your machine outside its limits!

As such, if you check the ATIS and it is outside limits, then you should be in a poistion to go somewhere else with a runway that is more into wind.

[FlyingForFun]

Hufty and Papi-74, that is complete rubbish.

I agree that if the manufacturer sets a cross-wind limit, you must stick to it or you will not be insured. Also, if you fly a club aircraft, you must comply with any limits in the club's Flying Order Book, or you will not be insured.

My club's FOB gives no cross-wind limit for holders of a CPL or higher license.

The POH for the aircraft I fly the most only gives a demonstrated crosswind. What's more, the manual explicitly states that this is not a limit!!! I'm not sure how much clearer I can make it.

FFF
------------

[stue]

Navoff,

I know that 12kts isnt bad but i wouldnt feel happy going flying in something much stronger that that. I dont care what the a/c can deal with, its what i can deal with that i care about. As a low hours PPL, i just wouldnt like to be landing in something above 12kts (ish) up until i had abit more experience behind me.

[PAPI-74]

Flyingforfun,
I am not sure what you are driving at. You say that you agree with both Hufty and myself and then say we are talking rubbish. Forgive me, but which is it chap.

My comment was to the original thread about landings and the best way to achieve this safely, which I think I did. I did also state that it is more than possible to fly beyond the aircrafts crosswind limit (demonstrated). I also mentioned the gust limit of which I bet most of you don't know for you aircraft, demonstrated or recommended, but I am sure you will find out and put in a slating reply (I hope you do...it's funny).
I also mentioned that you won't be insured. Ever tried to cross hire an aircraft on a windy day....9/10 won't give you the aircraft. The cert. of ins. may not mention that you have to stay within the demonstrated xwc, but the first thing the insurance companies will do is contact ATC, be it at the airfield or the MET office and get the wx. Do you really think that they will pay if you have been a bit keen to prove what a great pilot you are, and do you really think that ATC won't file a repport to the CAA if you hit one of the runway side lights or Jonny at the hold.....they will.
How clever will you feel then?
What if it goes really wrong and the gear decides that it isn't in a good mood and buckles....and it will one day. If the gear doesn't buckle, you could always spin it in when cross controlling. I do speak from experience, but luckely I had enough power available and rudder authority to recover (during my Bulldog days). With a full tank of fuel you may have a few seconds to get yourself and the no longer impressed pax out before you painfully burn to death. There is always tomorrow!
For Christ sake, it is illegal to depart your airfield if the fc at your destination is out of limits. Fly somewhere else or fly in the morning / late evening when it is calmer (usually). You have a duty of care. What do you gain if you regularly play with fire (ok the odd approach where you feel the conditions to your commital height, 200' ish), respect.....a well done.....a wow maybe i'll try it then.....I hope not. More like a frown and noone will trust you to make a sound decision when it matters.

[PAPI-74]

This is better than Eastenders:}

[Hufty]

...yes it is!

FFF is right though - if it states explicitly that it isn't a limit then technically you can operate the machine in any crosswind that it is able to deal with. My point is that you need to be able to justify everything you do. If you're in court trying to argue that you had the skills to do something that the factory test pilot wasn't able to demonstrate then you're going to need to be confident in your argument!

[High Wing Drifter]

My personal and limited experience suggests this whole demonstrated limit business is somewhat inconsistent.

The US aircraft do seem to be consertative in this respect. I've had the oportunity to land both the AA5 and Arrow outside of the demonstrated limit in about 20kts of crosswind component and it was clearly within the limits of said aeroplanes. Indeed, the French types seem to have quite high limits, the Robins, Socatas and Wassmers with demonstrated limits of 25kts, which I imagine would be more challenging than exceeding the demonstrated limit in the Arrow.

On a point of possible interest, the Cub has a demonstrated limit of 10kts and frankly I find it challenging landing it with a component of only 8kts. The Super Cub a demonstrated limit of 12kts and yet again about 8kts was challenging enough for me.

[blueplume]

Crab on approach until you have to straighten to land. As you probably shouldn't land sideways (bad for the undercarriage) you have to straighten out which will require dropping on wing and using opposite rudder to stop the turn. If you are carrying pax it's much nicer to be sitting up than falling over to one side. Much easier to maintain a wind-corrected heading than a bank angle.

[FlyingForFun]

I am not sure what you are driving at. You say that you agree with both Hufty and myself and then say we are talking rubbish. Forgive me, but which is itSorry, Papi, I could have made it slightly clearer where I agree with you and where I don't.

I agree that if your manual states that there is a limit and you don't comply with it, you are almost certainly not insured since compliance with the POH is normally a requirement of insurance.

I also agree that if your club's Flying Order Book gives a limit and you don't comply with it, you are almost certainly not insured since compliance with the FOB is normally a requirement of insurance for club aircraft.

However, what I do not agree with is that the "demonstrated cross wind" is a limit which must be complied with. Many aircraft manuals give a demonstrated cross wind, but do not give a limit. And in these cases, if the aircraft is privately owned, or if it is a club aircraft and the club does not set a limit (or you are exempt from any limits the club sets), then there is no limit. The example I have given of a C172 (complete with a quote of the relevant section of the manual) is an aircraft which does not have a limit.

My club, which operates two C172s, imposes a limit of 8kts for solo students and 12kts for PPLs for depature, and the same limits on forecast winds for landings, with a warning that if the wind becomes outside these limits during flight, consideration should be given to diverting. Solo students and PPLs must comply with these limits to be insured, and we will not rent aircraft to anyone if the wind, or the forecast wind, is outside these limits. However, we do not have a limit for holders of CPL or higher licenses.

Since I hold a CPL, I regularly, legally, and being fully insured, fly in cross-winds far exceeding the 15kts demonstrated limit of the aircraft, to carry out trial lessons for example. I will also teach students (with an appropriate amount of prior experience that they will benefit from it, of course) or existing PPLs how to handle these strong crosswinds, because a) it will give them confidence to improve their personal limits up to the club's limits, and b) there is always a chance that the wind will do something other than forecast during a trip, and the wind will be outside their limits when they return. (The club's rules do not prevent them from making an approach in these conditions, they merely caution that consideration should be given to diverting.)

To the best of my knowledge, the rules my club sets are fairly typical of the majority of other clubs.

FFF
-----------

[Stjuk]

I prefer the crab method as well, but I have to disagree a bit with some of you saying that you should lower the wing when straightening out. It is not completely wrong, but you should use enough opposite aileron to level the wing, and THEN if you start to drift you should lower the wing into wind. I agree that in strong x-wind conditions you probably always have to add that extra correction...

A reason why I don't like the wing low in for example a c-172, is that on many 172's there is only one static port on the left hand side. And the wing low is a slip condition, and in a slip you will have over -or under reading IAS with only one static port, and over read of the IAS is not something you wan't on final if not aware of it.

[A320rider]

for a novice: align the nose, then use aileron.
if you know the plane well, and know how much rudder you have to give, the crab method is OK.

guys, whatever method you use is OK, as long you are happy with.
the most dangerous situation is people turning from base to final and using to much rudder.this is a spin departure, ...

[Andy_R]

Thought that may provoke a reaction (and then couldn't get near a computer for 24 hours - drat!!)

Well, Andy R if you have an accident and you were attempting to land in a crosswind outside the aircraft's demonstrated limits then you are in a sticky situation nonetheless.

Wrong.

It is a demonstrated limit, not an absolute limit. A test pilot will only have a small window to test in, if the crosswind available was only 15 knots that day, then that is what the demonstrated crosswind limit will be.

If you injure anyone and you find yourself getting sued - it is going to be tough to defend your actions in such a situation. The "....well I know it is technically outside the limits but everybody does it" defence isn't a strong one.

Wrong.

It is not "technically outside the limits of the aircraft, see above.

You're right that is is a DEMONSTRATED crosswind, but even though it may not be limiting it doesn't automatically guarantee that the aeroplane CAN operate in stronger crosswinds. Sure, with common types like Cessnas, there will be plenty of people who will say they have operated the equipment in stronger crosswinds than the POH states but once you are outside the limits in the book you're going to have to explain why.

It is limiting when you run out of rudder authority. Simple as that. If you do, then you go around.



in any case, as commander you will have taken a look at the weather prior to departure and as such will be aware of the strength and direction of the wind at your destination and your alternates. You will also have a view on the risks of the weather situation changing and be in a reasonable position to avoid having to land your machine outside its limits!

I agree. Though the limits are far more likely to be personal limits rather than the aeroplanes limit. The ability to turn round after you have reached the halfway point is also a good thing, but irrelevant to this thread.

As such, if you check the ATIS and it is outside limits, then you should be in a poistion to go somewhere else with a runway that is more into wind.

Outside what limits? If it is outside my limits then I will stay at base, otherwise I will go. My limits are a lot lot less than the aeroplanes, but the aeroplanes limits are far far more than the demonstrated.

I agree that if the manufacturer sets a cross-wind limit, you must stick to it or you will not be insured. Also, if you fly a club aircraft, you must comply with any limits in the club's Flying Order Book, or you will not be insured.

The POH for the aircraft I fly the most only gives a demonstrated crosswind. What's more, the manual explicitly states that this is not a limit!



I know that 12kts isnt bad but i wouldnt feel happy going flying in something much stronger that that. I dont care what the a/c can deal with, its what i can deal with that i care about. As a low hours PPL, i just wouldnt like to be landing in something above 12kts (ish) up until i had abit more experience behind me.

Very sensible.


I also mentioned that you won't be insured. Ever tried to cross hire an aircraft on a windy day....9/10 won't give you the aircraft. The cert. of ins. may not mention that you have to stay within the demonstrated xwc, but the first thing the insurance companies will do is contact ATC, be it at the airfield or the MET office and get the wx. Do you really think that they will pay if you have been a bit keen to prove what a great pilot you are, and do you really think that ATC won't file a report to the CAA if you hit one of the runway side lights or Jonny at the hold.....they will.

You are talking about club aircraft and club aircraft only. It is for the clubs sake that these limits are imposed, due to the varying skill level of the renters. However, it does NOT imply that you cannot legally fly the same type outside of the club, therefore the demonstrated limit is not limiting nor illegal, unless a club/school has imposed rules to safeguard themselves.


For Christ sake, it is illegal to depart your airfield if the fc at your destination is out of limits. Fly somewhere else or fly in the morning / late evening when it is calmer (usually). You have a duty of care. What do you gain if you regularly play with fire (ok the odd approach where you feel the conditions to your commital height, 200' ish), respect.....a well done.....a wow maybe i'll try it then.....I hope not. More like a frown and noone will trust you to make a sound decision when it matters.

Nobody is saying that they have no respect for the weather or for their aircraft. They are saying that a crosswind needn't mean a cancelled flight as long as it is not above the pilots limits. "Playing with fire" is a little of an extreme way of describing someone safely and sensibly pushing their limits (and therefore their skill level) up.

[notdavegorman]

Guys, whatever you do, be careful whatever you do. It's not a testicle-size competition. If you want a future in professional aviation, I'd recommend you not try to land a light aircraft beyond your or the aircraft's limits. I'd suggest your limits should be lower.

[scroogee]

My 2 cents, personally found x/w landings to be a nightmare until I was taught the wing low technique. Later as I gained actual skill my judgement improved and could use either efficiently. Was inclined to teach the crab/kick straight method when instructing.

FFF and Andy_R are correct, the Demonstrated Crosswind is not a limit, but a Demonstrated Component. It would help if people didn't refer to it as a limit- unless it is refered to as a limit by a particular aircraft flight manual.

I also add (from memory) that in Cessna aircraft the Demonstrated Crosswind figure is not found in the limitations section but the Normal Operations section of the Flight Manual (if someone has one handy colud they confirm this?).

I believe also that the Demonstration can be limited by the conditions encountered during the test flight phase- if the cross wind component never exceeded value X then that that is where the notation occured, some aircraft types have had their crosswind component uprated when retested in stronger conditions.

[Muddy Boots]

Dear King Rooney,

"Have been seriously considering switching FTO for a while now"

Have you considered switching to OAT as a different FTO as you seem so unhappy where you are? :E

MB

[tescoapp]

I believe the difference between the apparent difference between demonstrated cross wind componets is the method which they are obtained.

Some are demo'd without using the rudder other's do use the rudder.

The ones which do use the rudder are usually listed as limits and the ones without are demonstrated.

I presume these days its all liability.

[High Wing Drifter]

The ones which do use the rudder are usually listed as limits and the ones without are demonstrated.
Guys, whatever you do, be careful whatever you do. It's not a testicle-size competition.
There seems to be many theories on this. As Sgroogee says, it just happens to be the strongest crosswind demonstrated to the authority during the certification phase. If the wind didn't blow then it is low, if it is then it maybe the limit of the aircraft, but you don't know that. Therefore, I don't believe the demonstrated limit actually tells you much at all about the true limit of the aeroplane. My experience is that I am more than capable of landing in excess of the demo limit on some aircraft and am not really upto it on others. That isn't a recipe for gonad growth, simply an understanding of what the numbers mean.

FYI
http://www.gulfstream.com/product_support/technical_pubs/pdfs/GIV/GIV_OIS_09.pdf
http://www.gulfstream.com/product_support/technical_pubs/pdfs/GV/GV_OIS_01.pdf

[supercruise593]

Just to try and address some of these technicalities a bit further.

Crosswind techniques:
In truth there are 2 methods,

1) Side Slip technique. i.e. Windward wind down for finals (The amount being dependent on strength of xwind component). This counters the drift and allows for an approach straight in on the runway 'heading'. In other words no adjustment needed on roundout.

2) The Combination technique. (I find this works best for me). This involves a 'crabbed' approach. i.e. You track the centre line on finals with the a/c weather cocked into wind. As you reach roundout, you straighten the a/c's heading to the runway heading and then lower windward wing.

There isn't really such a thing as just a 'crabbed' approach. Remember there still remains several seconds during round out before you touchdown. During this period the crosswind will move you off centre line or worse still. How is this counter acted? By roll. i.e. Windward wing down. The other important reason for lowering the windward wing is to enhance stability and ensure you don't get blown over, especially in gusting xwinds. Windward wind down ensures the wind blows over the wing and the rest of the a/c. Windward wing not down means wind blowing under the wing. Not good! (It's sometimes good to lower the windward wing very slightly on finals as well in gusts. Even if crabbed).

Just to add, on a point of order. The phrase 'kick straight the rudder' is a bit misleading and shouldn't be used. You don't 'kick' the rudder straight. You promptly & smoothly starighten with rudder as not to over do it. Then you continue to maintain runway head with rudder control until the roundout is complete and you have touched down. ;)

Regarding rudder authority: The selection of runway should deal with this. Imagine landing on a runway 360 and you have an xwind say 15kts coming from 090. The wind blows on the right-hand side of the empennage and naturally weathercocks the a/c back into the wind. On roundout, you apply left rudder. The point some of you are raising is that you may 'run out' of left rudder before the a/c is straight. Remember on a single engine the slipstream from the prop blows in a clockwise twisting motion around the fuselage of the a/c, which means it eventually hits the left-hand side of the empennage, giving rudder more authority. (Hence right rudder during a standard take off!)

Of course, you lower the windward wing so rudder authority is not an issue and the ailerons then counter the drift). If you tried landing on runway 18, things would be more difficult as the slipstream and the wind would act on the same side of the empennage and reduce your rudder authority unnecessarily.

Obviously most a/c have a max 'demonstrated' xwind limit. The Katanas we fly have 20kts. You can breach the limit and have a go, but not really advisable as there is only so much you can do!

Hope this helps. Crosswinds can be a difficult thing for a pilot to learn. You are moving the a/c on all 3 axis all more or less at the same time. It took me a while to get the hang of these. I used to fear a good xwind. Now they're a nice challenge. Good landings are always satisfying, but a good xwind landing is even better.

REMEMBER THOUGH. Dont get sucked into getting it down if things get difficult. GO AROUND and have another try!

Here's a link for your viewing pleasure. Technique is a bit different but the principle is the same..
http://www.linhadafrente.net/bin/Pousos.wmv If it doesn't work then type in '777 crosswind landing' into yahoo and access it from a different source.

Enjoy :ok:

[RatherBeFlying]

It depends on how wide the runway is and yes, the C-172 can land with considerable drift on and stay on the runway.

What I like about wing-down is that you get a clue ahead of time when there's not enough rudder to keep the plane lined up. Mind you, there will be less wind at the surface.

If the wind picks up another 10 kt or so, do you know where to find another runway that's pointed into the wind?

Once you're down in a wind over 20 kt. and still on your wheels, be very careful about taxying downwind.

As for the FTO, they may be used to the prevailing winds and if you have demonstrated acceptable landings dual in similar conditions, they may have decided that you're up to the job. Students botching landings gets the attention of the CAA and raises the insurance premiums.

[Basil]

Re comments about DEMONSTRATED limitations, I flew on a twinjet fleet where we'd two different marks of engine, one more powerful than the other.
Curiously, Vmcg on the lower powered variant was higher than on the more powerful machine :confused:
Boss reckoned it was entirely due to test pilot assessment - don't think more powerful had more rudder authority.
Anyway, I just flew it - didn't have to make one.

[FlyingForFun]

Supercruise,There isn't really such a thing as just a 'crabbed' approachI would disagree with that.

A crabbed approach involves entering the flare with crab, then just before the wheels touch down kicking it straight with rudder - sorry, "promptly & smoothly starighten with rudder as not to over do it" ;) As the rudder is applied, a little oposite aileron is required to keep the wings level, in order to counteract the secondary effect of the rudder. The landing is made with wings level, both main wheels together, before the aircraft has a chance to start drifting. (Obviously a very light aircraft would start drifting very soon after straightening up, which makes this technique very difficult on some very light aircraft.)

The key here is that the landing is made wings level.

If the rudder is applied too soon (either deliberately or due to a slight lack of judgement, makes no difference), the aircraft will start drifting if it is not corrected. The correction which is made is to apply more into-wind aileron to lower the into-wind wing. As the aileron is applied, more rudder is required to avoid the yaw which occurs as a secondary effect of the rudder. The landing is now made with the into-wind wheel first, followed by the other main wheel, followed by the nose wheel. This is the Combination technique, and it is slightly different from the crab technique in that the landing itself happens with one wing low.

However, I think lots of people use the phrase "crab technique" to refer to this one, probably because they have never seen a properly executed crab technique and therefore don't appreciate the difference. This was certainly the case with me, until I did my FIC. In around a 25kt cross-wind in a PA28 my instructor demonstrated a crab technique properly - it was a work of art, and not something I've ever been able to replicate since.

FFF
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[supercruise593]

FlyingForFun,

Interesting comments & you sound like someone who has alot of experience of this. However, just a few more points. Forgive me for quoting you out of context or being too subjective but...

"The landing is made with wings level, both main wheels together, before the aircraft has a chance to start drifting".

"The landing is now made with the into-wind wheel first, followed by the other main wheel, followed by the nose wheel".

A bit of a contradiction in terms?

Before the a/c "has a chance to start drifting". That's rubbish.

Not even the best pilot can really everytime on a perfect roundout with more or less instantaneous heading alteration (rudder) and touchdown. Lots of xwinds variate and as someone said 'they reduce as you approach the surface'. Well generally, that is what is expected. Once well below the friction layer on approach though things could happen that are difficult to predict, especially at a point of pilot high workload.

Many xwinds variate through a range of degrees. Everyone has seen examples of this from the socks as they come in. Anything could happen. You may float, bounce, a gust may come along and tip your windward wing up, sudden windshear etc. I landed in approx 12 kts xwind the other day. The x component increased as I got to the surface! Generally unexpected.

Why rely on "chance"? Why not follow a preventative method that stops last minute drift and enhances stability? (Your correct in that you may realise there is very little drift during roundout hence so little windward aileron is required that your wings are almost level, depending on how much you are countering secondary effects). Why do you need to land with wings level if there is still drift?

Why not follow your second correct statement and land with windward wind down (hence windward main down as well). Gosh we even see the Saabs (commercial) doing it whilst we wait for RWY entry. Don't ever rely on chance unless there is a technique that removes it from the equation!

[john_tullamarine]

Not going to enter the argument about this and that as that would be a recipe for getting no-where. However I do recall learning many things about crosswinds years ago on Types such as SuperCubs on towing operations. Probably some of the things I did then I wouldn't do now ... ?

Couple of things to consider -

(a) the Design Standard will define a minimum crosswind for the certification exercise. If the test program gets more, fine, but practicality may become a limiting factor

(b) the demonstrated value may have been able to be pushed up had the program found a tad more crosswind .. the problem is the line pilot doesn't know what the TP found and how much pad there might be. I can recall a quite nice line of singles which came on the market quite some years ago. The demonstrated crosswind was quite low (15 -16 kts or so as I recall) and we redid the certification for the crosswind limit. This particular design had an interlinked aileron/rudder and we ended up deciding that discretion was very much the better part of valour at around 18-20 kts if memory serves me correctly .. that few knots increase definitely presented some limitations for handling in the landing flare and roll out.

(c) there may be other dragons waiting in the far reaches of the known world for careless would-be TPs .. consider things like tail blanking and uncommanded pitch excursions .. just what you might not want to experience during the flare ?

[supercruise593]

lol..

Good points John.

You're not suggesting we are careless would-be TP's are you? ;)

[john_tullamarine]

.. Heaven forbid, mate.

On the other hand, I have to admit that greasing a strong crosswind landing on is a matter for great delight and satisfaction. Used regularly run down to a crosswind landing at one hub airport in another life ... 25-35 kts often was the order of the day and a fistful of throttles made for interest.

[supercruise593]

Awesome...

[FlyingForFun]

Supercruise,"The landing is made with wings level, both main wheels together, before the aircraft has a chance to start drifting".

"The landing is now made with the into-wind wheel first, followed by the other main wheel, followed by the nose wheel".

A bit of a contradiction in terms?No, I am describing two different methods of landing. The first line you have quoted from my earlier post relates to a crabbed landing. The second relates to either a wing-low or, in the context in which I intended it, a combination landing. No contradiction since the two quotes are in two different contexts.Why not follow your second correct statement and land with windward wind down Because both statements are correct in their context. Your assertion that landing with wings level is incorrect and chancy and that wing-low is the only correct way because "we even see the Saabs (commercial) doing it" is not true.

And it's not just me who thinks that, either. The same view was held by Wolfgang Langeweische, who I think is universally recognised as one of the experts in handling aircraft. I quote from his book Stick And Rudder, where he describes the crabbed method as it relates to a crosswind from the left:Just before ground contact, at the very last half second, the pilot then applies rather abrupt right rudder and thus yaws the nose into the direction in which the airplane is actually traveling - that is, straight down the runway. The wings are held level during the yaw manoever.(The emphasis is added by me.)

I would guess that the reason you see Saabs landing with a combination technique is because it is easier than a crab technique: as I said earlier, I've only ever seen one person who can reliably use a crab technique properly without it becoming a combination technique. But it is is possible, because I've seen it. Langeweische also says it is possible, and remember he is talking about tail-draggers, where getting it slightly wrong could well result in a ground-loop - so there is less need for absolute perfection in modern aircraft than there was when he wrote this.

FFF
---------------

[bookworm]

I can recall a quite nice line of singles which came on the market quite some years ago. The demonstrated crosswind was quite low (15 -16 kts or so as I recall) and we redid the certification for the crosswind limit. This particular design had an interlinked aileron/rudder and we ended up deciding that discretion was very much the better part of valour at around 18-20 kts if memory serves me correctly .. that few knots increase definitely presented some limitations for handling in the landing flare and roll out.
Sounds like the Mooney 201 and friends, introduced around 1980. The max demonstrated is 11 knots (exactly 0.2 Vso). I also remember 17 knots as being the number that stuck in my mind as delimiting the routine from the ... interesting landings. Crosswind take-offs were challenging too.

[FullWings]

I think FFF is on the right track:D here.

I always ask (or state myself) whether people are going to use the 'wing down' or 'crab' technique if we are going to experience a serious x-wind component, as it saves me a short period of uncertainty as we approach the runway.

I have to say that 99% of those who 'crab' are, in fact, using the 'very late wing down' method, much as FFF has described. I also agree that the perfect 'crab' landing involves achieving alignment of the centreline of the aircraft with that of the runway, at the moment of touchdown (the process having started shortly before). After touchdown the wings are level, being kept that way by an appropriate amount of into-wind aileron.

I have to say (and this is personal to us all) that I prefer the 'wing down' approach as it is stable and you don't have to guess where the main gear (or nose gear, depending on how you fly) is going to end up. Also, showing my yellow streak, if you are running out of control at 200' with the wing down, you get a chance to throw it all away earlier than when you start drifting onto the grass at ten feet...

[marsman]

FFF and Fullwings,

Why do you mention that most crab landings are actually a combination of both crab and wing down methods. This is not true. As you straighten up using rudder you also use opp aileron into wind, however you touch down with both main wheels and with the wings level.

The main disadvantage of the wing down method is that the pax will be uncomfortable during the approach, leaning over to one side seems crazy to me.

Crosswind take offs are more limiting and demanding anyway, although most people thing the landing is the most difficult.:hmm: its not.

[eire757]

Marsman,

Impolite sentence deleted .. keep it nice, chaps ...

You will only touch down wings level if you kick the drift off at exactly the right time, otherwise you will need a small amount of wing down. This is basic PofF. Nobody can repeatedly get this right. Neither method can ASSURE a wings level touchdown unless you never kick the drift off which I strongly recommend against. It twists the gear and even on a modern jet will result in a very uncomfortable feeling. (I've been there!)

[scroogee]

marsman: FFF and Fullwings are closer to the mark about what actually happens with most attempts at crab landings- whether intentionally or not. This is particulary true of the majority pilots. However the initial intention is for the landing to result both main wheel touching down at the same time, tracking the runway centreline.

Regarding my earlier post supercruise593 is correct regarding the "kick straight" part, after the initial "kick" most students would try and land normally, then wonder why the squeeling was occuring, as the aircraft weathercocked back into wind, and landed sideways.

[eire757]

Scoogee,
What say is perfectly correct however I dont believe this is repeatable several times in a row. The only way for the 'average' pilot to get the a/c on the ground is to use 'very late wing down' as described previously. This is not therefore a wings level landing. The only way to land wings level is with no x-wind or complete luck-FACT

[Old Smokey]

Q. Why does a B747 have 4 sets of main undercarriage units?

A. Because it needs them to acommodate the aircraft weight, particularly during Landing.

Q. Would it be advisable to use only one quarter of the undercarriage units to absorb the landing load?

A. NO!

You figure out the rest, and the preferred landing technique:*

Regards,

Old Smokey

[RatherBeFlying]

OS -- The 4 sets of 747 MLG bogies are there for takeoff and aborts at max weight. Landings, generally at half the weight, can be done on just the body or wing gear -- although a landing on just the body gear is best done with a minimal crosswind.

There is considerable vertical travel on the wing gear oleos; however, the limiting factor in bank is the outer engine pod.

Also the rear axles of the bogies hang down; so, there is a complex gradation of weight transfer from lift to the gear as the various axles and bogies come into contact and the oleos compress.

Bottom line is that the first gear contacting the runway does not immediately assume the entire landing weight -- assuming a reasonable descent rate.

[huckleberry58]

Scoogee,
What say is perfectly correct however I dont believe this is repeatable several times in a row. The only way for the 'average' pilot to get the a/c on the ground is to use 'very late wing down' as described previously. This is not therefore a wings level landing. The only way to land wings level is with no x-wind or complete luck-FACT
Agreed... in a lighty. However in a heavy, kick the rudder in around 100ft to 50ft AGL and keep the wings level or with a VERY slight wing down. The inertia of the aircraft will maintain centreline and you won't have a pod strike.

[Old Smokey]

RatherBeFlying,

I read loud and clear where you're coming from, and agree with you.

The intent of the suggestions implied in my post was that it's always preferred to not take any part of the aircraft all of the way to it's limits (e.g. allowing one set of landing gear to do the work of four), hence the use of the words "advisable" and "preferred" in my post.

Regards,

Old Smokey

[White Bear]

As a student my instructor insisted I use, what has been described here as the ‘combination’ xwind landing method. His view on a ‘wing low’ approach was “Why cross your controls and increase your stalling speed when you are already low and slow?”
I have read this thread with interest but have not seen any mention of this.
He did eventually teach me both, but always warned me to keep my approach speed a little higher when making a ‘wing low’ approach compared to making a ‘crabbed’ approach.
Was he wrong?
Regards,
W.B.

[Say again s l o w l y]

Neither type of approach is "wrong" or "right." Use which ever you feel comfortable with and which is sensible for the type you are flying.
Most jets with underslung engine pods aren't very good at wing down. It tends to get expensive very quickly! A Cessna is a bit more forgiving.

One question for everyone. Why is the demonstrated cross wind limit on the 152 and 150 different?

Could it be due to the difference in techniques of the test pilots? Answers on a postcard.

[185skywagon]

Try landing any of the Cessna Tailwheel types without applying sufficient into wind aileron. Crossed controls are the order of the day for almost all landings except nil wind conditions.
Transition from crab to wing down is a must, and is called the combination method. If you do not roll in aileron and apply opposite rudder, you will surely start to drift.
One advantage tailwheels types do have, is that they can be held on at any speed. It is quite possible to hold them on at 100kts, although it is a bit hard on the gear. With a X-wind at the higher speeds, you would still have to hold into wind aileron and opposite rudder to maintain your line without drift.

[Dan Winterland]

Wing down Vs crab? It's down to what you've been tought and what you're used to. I once checked out in a school in the States prior to renting an aircraft. The CFI insisted I did the wing down method as that is what his school did and 'it was superior'. After cocking up a couple he declared that 'I had obviously never flown taildraggers' (actually I had about 1500 hours on them) so I demo'd a perfect crab method on the other runway with 25 knots of cross wind. He conceded.

Also, what id a limit? If you look at a lot of aircraft's POH (esp American ones) the crosswind is a 'max demonstrated cross wind', in otherwords it's the maximum the manufacturer has tested to. It's up to the operator what he does with that limit - whether he want's to treat it as a limit or not. I flew a very large jet with two companies. One treated it as an absolute limit, one left it to the pilot's discretion.

[185skywagon]

Dan, I agree that demonstrated crosswind component is not an absolute by any stretch of the imagination.
There is a time and place for each method of dealing with X-winds. I use either as required in the 185.

[greek-freak]

Sorry for the SLF intervention,
just found this link in the spotters forum, nice demonstration of crosswind landings :ok:
http://www.youtube.com/watch_fullscreen?video_id=-CPd5lY-BNw&l=177&fs=1&title=crosswind%20landings

[pilgrim flyer]

KR quote:
'Keygrip however, I do not like your patronising tone a great deal, there really is no need.'

If Keygrip is who I think he is then he's the best instructor/examiner I've ever flown with, bar none. In any case he was just trying to give you some advice which will save you breaking an aeroplane, boosting all of our insurance costs and preserve what seems to be an unjustifyably large ego intact.

To (miss)quote another aviation guru ' most common cause of a broken (aeroplane) is to have been talking when you should have been listening'..... Hope this helps.

PF

PS I find that most students in both gliders and aeroplanes seem to get the combination technique quite quickly - i.e. crab + a touch of wing down in the flare etc. The wheel doesn't take all of the weight because the wings are still producing lift. When wing stops producing lift you loose aileron authority and the other wheel gently touches the ground- evey time. Works on taildraggers and twins too. Admitedly I've never tired it in a 747, or at 90 kts.

[Wrong Stuff]

Sounds like the Mooney 201 and friends, introduced around 1980. The max demonstrated is 11 knots (exactly 0.2 Vso). I also remember 17 knots as being the number that stuck in my mind as delimiting the routine from the ... interesting landings. Crosswind take-offs were challenging too.
Bookworm - I was thinking the same thing as I was reading John's post.

If I remember correctly, your aircraft was a later J. Out of interest - was the 17 knots transition level with full, half or zero flaps? Did you have any personal guidelines for how much flaps you'd use with different levels of crosswind?