Cross Wind Landings

[Joe Lavery]

I've done some cross wind landings when I was training for my pilots license, but some of these are right on the limit. Makes me glad I'm not a commercial pilot, at least in FS you get the chance to pause and have another go at it.
Have a look they're pretty scary, it's twelve minutes long but worth a look.

Crosswind Landings during a storm at Düsseldorf on an icy runway. Boeing 777, Airbus A340, A330

Joe.

[nicd]

wow.. cool video!  Some skid marked undies that day I'll bet.

A few years back I was going in to Glasgow on an Emirates 777 with a crosswind similar to that. For some reason the nose-wheel cam was on on all the entertainment screens in the cabin and a lady seated in front of me started screaming just before we landed because she couldn't see the runway! I guess she thought he was landing us in the grassy field next door. She settled down once we touched down and the pilot kicked it around with rudder to show us perfectly on the centreline. 

[Maurice]

I have watched that incredible  video several times in the past and every time I wonder about one thing....are the main wheels able to swivel like they do on a few tail draggers so that the plane can land while going sideways? This is a very useful feature especially on a tail dragger to avoid ground loops. I don't know of any tricycle GA airplanes with swivelling main wheels but I have no idea if any or all airliners have that feature. If not, there must one heck of a lot of strain on the tires when they land while going sideways.

I'm sure that the pilots must try & kick the rudder just before touching down to straighten the plane but when looking at some of these landings, it is obvious that the plane must have landed while still going sideways.

Does anybody know the answer? Mike... Rhys... Bjorn ?

Thanks,

Maurice

[Garys]

No swivel gear on airliners. Just makes a mess of the tires, but unless it takes the tread down to the chord then there is no need for a tire change.

Gary

[bernard S]

When the main gear swivels it is not a good thing  http://www.askthepilot.com/untold-concorde-story/   ... the long and short of it 6 tonnes overweight taking off in the wrong direction and main gear that swiveled... oh and C/G out of wack by 54%

@ Maurice... yes the rudder is kicked into place as you put it.. or if you small like me you stand on it. 

[Maurice]

No swivel gear on airliners. Just makes a mess of the tires

Gary

Hmmm! I would think it would be the other way around since the main wheel would already be pointing in the right direction once the nose is pointing in the right direction. True, the wheels would be going sideways on initial impact but should quickly assume the right position. It worked with some tail draggers so I wonder why it wouldn't work for larger planes.

Ideally, the main wheels should automatically always point in the true direction the plane is going but that would certainly complicate the design and add more failure scenarios 

Maurice

[Maurice]

When the main gear swivels it is not a good thing   

Absolutely, but not if they are designed to freely swivel. In this case, they weren't designed that way and went out of alignment and locked in an incorrect position because of defective parts.

But I'm sure smarter people than me have already thought about this and probably dismissed it for whatever reason. 

Maurice

[Boeing Skunk Works]

The B-52 has gear that will swivel. The C-17 might have it too, but not sure about that one.

[Garys]

Sorry Maurice, I realized what I wrote was confusing. Some older aircraft like the B-52 that Mike refered to use hydraulics to match the main wheels to runway heading. Today most airliners use shimmy dampeners, which only offer protection to a few degree's of crabbing. Anything over and above that the tires are skidding across the runway. Your right in that a swivel gear in itself would not cause a mess of the tires. That was just me being an idiot and not wording my sentence correctly   

Gary

[nicd]

In the video there are (generally) different techniques being used with different aircraft types. The 777, for example, has an incredible ability to handle crosswind forces with the main gear already fully touched down, then bringing the nose around with rudder before the nosewheel touches. There's Boeing test flight video around of 777s doing insane crosswind touchdowns like this. Some of the smaller/older jets require different techniques it seems.

In the lighties (real ones) I still use what I was taught as a student.. crab to the flare, then correct lateral alignment with rudder while applying opposite aileron (wing down into the xwind ) to counter drift and any nasty surprises. Easy in theory, not so easy in practice!

[saabpilot]

Maurice:

Yes you have to use the rudder and also dip the wing down into the wind just before the touchdown to counter the crab.
Your windward main gear will touch down first and when releasing the aileron a bit the downwind gear touches down.
When both main gears and nose gear are safely on ground you have to steer with the rudder for a while and keep the ailerons towards the wind side.
Otherwise your tires will be beaten to death 
This is sometimes called "crossed rudder".   A bit tricky the first times, but rather "easy" when not too gusty.

If the procedure is not sufficient to align you with the runway - there is too much crosswind so a go-around will be necessary.
Thats why all a/c has a max demonstrated X-wind number 
The "demonstrated" means that is what the manufacturers testpilot could handle in respect of available X-wind at the time of CAA/FAA certification so it is not a limit. The operators set the max X-wind limit for their own fleets (in the CAA approved SOP:s) but usually in accordance with the X-wind test demonstrations results.

Usually when gusty and near limit X-wind you ask the TWR to read out the wind continuously on short final to help the decision of land/go around.

Bjorn

[Maurice]

Yes Bjorn, I realize that and I have used that same procedure in a Cessna, but that was not what I was asking. In some of the crosswind landings in that video, the planes were definitely not aligned with the runway on touchdown, so if the main landing gear was able to swivel a bit, I would think it would be much easier on the tires.
And as Michael mentioned, this was done in the B52s so why not in commercial airliners?

Maurice

[jskibo]

Not cheap, not easy to maintain.

....and no its not on the C17

[saabpilot]

I am not aware of any commercial that has swiveling main gear, but maybe some Russian one ??
Some of them has heavily "hanging" wings that makes it difficult to lower the windward wing in an X-wind landing.
So the may use swivels, but I am not sure.

[jskibo]

I am not aware of any commercial that has swiveling main gear, but maybe some Russian one ??
Some of them has heavily "hanging" wings that makes it difficult to lower the windward wing in an X-wind landing.
So the may use swivels, but I am not sure.

That's why the B52 uses it.  Huge winspan, wing flex and an already fairly low wing to the ground with out-riggers prevents dipping the wing.  The problem is magnified if it is aborting and returning with fuel.