Cross wind landings
 

I've now got 30 hours on my RAA licence but have this hate/hate issue with crosswind landings. I think I know the theory for doing them but have never done one without an instructor. And every time I have needed him to help.
So have I got the theory right?
For a landing with a crosswind from the right - on final, crab into the wind so as to keep your track in line with runway centreline, don't use aileron - just before the flare point, straighten the plane by neutralising rudder, at the same time put in a little bit of right aileron, use rudder only to keep to centreline, but shouldn't need much. Continue with back elevator and keep the right aileron into the wind until right wheel touches first, then other settles.
This seems to be it - the wheels are straight, on the point of landing there should be just aileron into wind and no need for opposite rudder, sideslip?

I really need to get the theory straight so I can rehearse it in my head before I go flying next, scares me to think I night get caught out one day.
I seem to be having a problem with all the co-ordination, so I guess I would find sideslipping all the way down even more difficult.
Can anyone confirm this or have other ideas.

What type are you flying Jabba?

G

There are three techniques.

1. The method you mention, ie crab. A little more difficult, but not too much so unless the cross wind is close to the aircraft limits. Personally, I like to put the aeroplane down on both main wheels at one. Don't forget you may need a little in to wind aileron on roll out.

2. Wing down. Favoured by many in the USA. One merely flies down the glide slope with in to wind aileron applied which means touching down on one wheel. This technique will not be safe if flying aircraft with a very long wingspan, especially on low wing aeroplanes.

3. A combination of 1 & 2.

Of course. if the cross wind is 50 knots or so, one can always land into wind across the runway with a ground speed of 10 knots or so :)

You quote.... 'just aileron into wind and no need for opposite rudder,'

This is where you are getting confused, or just unable to describe it in words.

To align the aircraft fuselage with the runway will always require some rudder input, to correct for the wind forces blowing onto the Tail.
.
One method I found useful , was to keep slight pressure on the down-wind rudder pedal whilst on Final, so that you do not have a moment of thought whilst you decide which pedal to push during the flare.
This also works with a winch launch in a glider, in any sort of cross-wind.... Keep the wings level with aileron, (to prevent a wing-tip hitting the ground) and keep straight with, what you know to be, the down-wind rudder.
.

For most light aircraft the technique is the same unless you are a skygod who can kick a crabbed aeroplane straight at the last second.:)

Crab into wind with aircraft in balance i.e. the ball in the middle, if the aircraft is properly trimmed that should be more or less neutral rudder.

Somewhere around 100 ft, wherever seems comfortable, use the rudder to align the nose with centre line and drop the into wind wing to stop drift. Increase wing drop and bring nose back straight with rudder to stop downwind drift, reduce into wind wing drop and ease rudder to stop upwind drift.

I can land a TB 20 in 30 Kts cross wind doing that.

I think the opposite. It is much more difficult to get the yaw/roll balance setup just right if you only do it as you round out. If you are set up in a stable configuration halfway down final, there is much less to change/get wrong as you round out and flare.

You can practice this anywhere as long as there is a wind blowing - along any straight line such as a road, a railway, an edge of a field... Start off straight and level, then set up a gentle descent from say 1500 to 1000 ft agl. You can work up in stages and find straight lines with the wind more and more abeam as you improve.

I always think cross wind landings are more fun - you have to work properly :ok:

B.

Hi Jabba.

You have it almost right.

Crab the aircraft down the approach, in balance as you describe, then, as you begin to reduce power to land, align the nose with the runway, using the rudder. This will require a sustained rudder pressure.

From here on, keep it simple.

1. Use the rudder, as required, to maintain the alignment of the aircraft with the runway.

2. Use the ailerons to adjust the angle of bank as required to maintain the position of the aircraft laterally over the centreline.

3. Use the elevator to achieve, and maintain the landing attitude as always.

Remember that, as the speed reduces, you will need more control deflection for the same effect.

This will work with 90% of the aircraft you fly.

As Genghis suggests there are a few types that require something different, but it's very unlikely that you will be learning to fly on any of them.


MJ:ok:

All this stuff about neutralising the rudder just before the flare point & adding wing down suggests that you haven't really got the theory right.

The crab approach is flown with the aircraft heading offset into wind so that your ground track is along the centreline. The wings should be level, ailerons & rudder neutral (assuming no turbulence.) Maintain the crab throughout the roundout/flare, continue the crab through the hold-off until the nose is almost at your landing attitude & then apply enough rudder to align heading with the runway, or track. There should be no need to apply any aileron or wing down, using some rudder for a second or two will not change the direction the aircraft is moving. Centralise the rudder before the nose wheel touches down. Think of the crab as how you would fly from A to B at 2,000' in a stiff crosswind.

A wing down approach may well start out as a crab approach but use the rudder to align heading with the runway centreline much earlier. The rudder is not very effective at changing the aircraft's direction of flight but it will have some effect. The point of the wing down is to counteract the very slight tendency of the rudder to turn the aircraft, you shouldn't need too much wing down. You can set up the wing down method early in the approach & maintain it all the way through until landing, centralising the rudder after touching down.

What propswinger said - crab down the approach (ie wings level) and kick it straight as you hold off so that the aircraft is pointing in the direction it is moving before it encounters the ground.


My guess is that you are over-analysing, thinking too much and worrying about it un-necessarily. Just go and do it. It'll come and when it does you'll wonder what the problem was.

Welcome to PPRuNe Jabba,

In addition to Mach Jump's advice, which I quite agree with, I will add a suggestion that you think about this differently in the bigger picture; Let your brain fly the plane.

Your brain knows where the plane should go, right down the runway centerline, neatly touching down on the runway, and thereafter following the centerline, until its time to turn off. Have your brain make the plane do this, don't focus on what your hands and feet are doing, or similarly what flight control is being moved how. Watch out the windshield, get the sight picture, and do what it take to maintain it. Forget about the "circuit" of control which makes that happen, it'll work itself out, if you stop thinking about it.

If you can fly an approach down the centerline, and it's not terribly gusty near the ground, your should feel confident that you can make a decent landing out of it. If you doubt, go around. If the upwind main wheel touches first, very nice, that means your brain held a little into the wind roll for the aircraft. The aircraft will happily continue straight on the runway, if your brain commands it to roll a little more as you slow.

When I mentor pilots I focus on giving airplane attitude advice if needed, rather than saying "up elevator" or "left aileron". I do admit to occasionally firmly saying "XX Rudder!" when taildragger training, but that's to get the pilot's brain thinking faster ;)

Absolutely good advice, but only works if you're a bit more experienced.

When I was still very low on hours, my crosswind landings worked fine with this method:

Fly the crabbed approach as mentioned earlier. At around 100 feet of whatever feels fine (maybe 10 seconds before touchdown), align the fuselage with the runway centerline with the rudder. Then keep the rudder in this position with your feet, and simply forget about it. The wind gradient changes and speed changes you will experience from now on are going to be so minor that they will have no consequence anymore to the alignment of the fuselage with the runway centerline.

With the rudder locked in this position, you now only have to fly the aircraft to the touchdown point. If you're drifting to the left, correct with right aileron and so forth. The only thing that feels "odd" at this time is that the horizon is not, well, horizontal.

Learning to control an aircraft in three dimensions is hard. This way you take one of the dimensions out of the equation, which is a lot easier for a novice pilot.

(Oh, and before anybody complains - this only works for a nosewheel aircraft. A tailwheel aircraft needs to be steered positively with the rudder, especially after touchdown.)

It's a bit like learning to Ski no matter what is said here your brain needs to get around it ) I can remember being told what to do skiing and still I was taking everyone out off the ski lifts still my legs were going in every direction they should not be in and by the end of the day I was black and blue
One day it clicked and suddenly all the correct movements became natural without thinking about it / it's the same with landing ))

Neutralise rudder? As Prop says, you shouldn't have any on during the approach in the 'crab' method. You just fly a heading that tracks you along the extended runway centreline.

I agree with Prop's post, except the when applying the left rudder to align the aircraft's heading with that of the runway, a little opposite aileron should be used to offset any yaw-induced roll (in other words, use aileron as required to keep the wings level).

In fact to do it really properly and prevent the aeroplane being blown to the downwind side of the runway by the xwind once you are on the runway heading, the 'crab' should be converted into a slip on the runway heading just above the ground (so after aligning with the runway heading apply a bit of into-wind aileron with enough opposite rudder to prevent the aeroplane turning off the runway heading). Then hold off as usual, and allow the into-wind main wheel to touch down before the other one.

It sounds complicated, but soon becomes automatic.

Imagine the discomfort for passengers if airline pilots flew a slipping approach while on final.

... not to mention the discomfort for the wingtips scratching the concrete.

Seriously though: I have trained for the 3-axis microlight with several instructors and none of them advocated the crab technique, indeed it was never mentioned to me. I always had to keep the plane aligned with the centreline with rudder, and lower the "into the wind" wing with aileron. The field where I finally got the license has its runway oriented 15-33 with the prevailing winds from 270-240 so I became quite good at landing in crosswinds. One instructor enjoyed teaching me to land onto the "into the wind" wheel first, then wait for the plane to drop onto the second wheel, and still hold off and hold off until finally dropping onto the nosewheel, too - but that would be at taxiing speed, ideally.

GtE asked for the type of plane and that was a good question. Now if we could get an answer to it...

The real problem is the basics are not taught properly from the start.

The understanding of attitudes and movements and the ability to produce and control them must be taught and understood by the student before take offs and landings are ever started.

I'm flying a jabiru lsa, 80 hp. Not thr easiest, but a great training plane. Have to always use correct rudder input. Scary sometimes, but fun.

Hence why I, at least, haven't offered any advice until we know a bit more about what aircraft the OP is learning to fly in.

G

I was taught the "simple" method of kicking off the crab just before touching down.


Which works fine ... ... ... so long as you do actually touch down immediately after kicking off the crab, otherwise you're going to touch down drifting sideways downwind at an ever increasing speed.


I subsequently taught myself the "complicated" second half of the process, which is to go wing down with crossed controls after kicking off the crab, probably landing on the upwind wheel first. Which produced "nice crosswind technique" from the last instructor I flew with, so I can't have got it completely wrong.


(Cessna 152/172. Floatplanes now ... "what's a crosswind?")

Thanks to everyone who has replied. I can see that my theory was a bit of everything jumbled together.
The flight manual recommends using the sideslip but my instructor uses the crab. But there has been no crosswind to try either so thats why I thought slideslipping would be more complicated to get my head around. The picture won't "look" right with the wing down.

I've booked training for next week so I can specifically try these methods. I know that once you get it clear in your head, the rest tends to follow. Just need to do it a few times correctly, then practice.
Is it normal to feel this aprehensive?