Technique for X/W landing a B777

[Crosswind Limits]

I ask this question as I very recently flew a B777 from London to Chicago. I am not sure of the exact runway used at ORD but it was one of the westerly/south westerly ones. Anyway I felt the right mains touchdown first followed a couple of seconds later by the left mains. I then felt the aircraft swing to the left which I suspect was the rudder being applied. I presume the mains can take such heavy side loads! Thanks.

[Notso Fantastic]

Sitting int he cabin, you have less idea than you think of what is going on. What you probably felt was the rear part of the undercarriage truck hitting the ground followed by the weight of the aircraft pressing the truck horizontal and settling the aircraft weight on it. I would be very surprised if you could feel one undercarriage then the other touching down.
http://www.airliners.net/open.file/544188/M/

[Crosswind Limits]

Notso,

Thanks for the input and of course I am no backseat driver! I just stated what I felt might be happening as I was asked by a passenger next to me at the time. I suspect you may well be correct.

[Felix Lighter]

There is very little scope on big-jets to use the 'wing down' x-wind technique that we are all taught as PPLs.

Instead we tend to 'kick it straight' and accept a bit of sideways drift.

At the upper end of the x-wind limit there will be a little sideways component to the landing.

I suspect the swing/yaw that you felt was possibly a combination of rudder and directional stability.

The big old gal does swing around a bit!

[Notso Fantastic]

Because the main undercarriage hangs the way it does, the initial touchdown on the rear pairs of wheels is quite light. The front of the truck then slams down quite violently and I think it is this that gives a far more powerful 'thump' felt as the main touchdown. I suppose the reason the undercarriage hangs front up like this is if it was designed to be horizontal, the rear half of the truck would take a great strain in a nose up landing.
I've never been able to work out why some Russian aeroplanes have gear hanging the other way:
http://www.airliners.net/open.file/547719/M/

[Maxrev]

As does the 767..think it has something to with the way in which it retracts into the wells.

[ETOPS]

My crosswind technique in the '77 is firmly based on wings level, normal flare and correct heading with rudder. "Kicking off " the drift is a misnomer as the rudder is so powerful only a squeeze is needed. If I have mis-timed things and she doesn't touch down smartly I will put a little wing down into wind to prevent drift but I always bear in mind future types I fly might not be so forgiving and I can't afford the cost of a pod!

[ratarsedagain]

Etops,
That is your preferred technique, however, the wing down technique is one taught to 777 crews, so it's quite possible 'X-wind limits' felt one gear touch before the other. The majority of x-wind landings i see on the aircraft are done this way.
Notso,
Were you on the 75? Most landings on that were achieved 'one bogey first' to reduce the shimmy felt on touchdown.
Just my observations of course............
Rat.

[Notso Fantastic]

Not the 75/76. I've never found anything wrong with the crab technique. I believe Boeings are certificated up to max crosswind limit drift touchdowns. All you have to do is gently remove it before touchdown, which is not a problem. The wing down technique, what I've seen of it, involves cross controls and is uncomfortable and unnatural, and on top of flying an approach, just seems to me harder, though I know many people prefer it. They're 'drift wimps'!

[threestable]

Angle of dangle of trucks dependant on how Boeing designed the holes they retract into, as previously mentioned. Strange but true... if 757 and 777 can trail maybe 767 was designed on a Friday afternoon....
Regarding x-winds, 75,76 anyway..... upto max demonstrated limit (40 kts dry) it MAY be necessary to combine crab and slideslip when approaching this limit say Boeing, which leads me to believe that it would be prudent...;). Must admit, not quite been that far up the scale yet, but as both methods are approved to max demonstrated, I suppose it depends on pilot preference. Decrab in flare is less work once mastered, but leaves less time for correction if not quite mastered and subsequently more blushing :\
...didnt matter on the 727:{

[ratarsedagain]

Notso,
drift wimps! ;)
Having seen the infamous TAP video, maybe you 'Airbus' boys just can't get the hang of the 'wing down' technique! :D :D :D
All in jest, of course,
Rat.

[Crosswind Limits]

Thanks everyone for the input! My flight to ORD was actually last Saturday arriving at 1055 local. I'm still out here having fun! :p Is there any way of retrospectively finding out what the winds were and active runways at that time?

[Lump Jockey]

Of course heavies such as the 767 and 777 can land one bogie down first.
http://www.airliners.net/open.file/543673/L/

[SuperRanger]

i tend to agree with ratarsedagain on the side-slip technique. my personal preference is side-slip (XW < 10kts) as i find it easier to point the nose straight down the runway rather than looking at the side. moreover, XW is almost never constant. it is either gusty or tend to reduce as you get closer to the ground. therefore, i find the side-slip method much easy to control .even the autoland does side-slip!

i must agree when the XW starts to get significantly stronger, side-slip method may not be a good idea. i believe in the FCTM, boeing recommends a combination of technique. correct me if i'm wrong.

SR

[Human Factor]

The 777 was designed, according to Boeing (this via a trainer) to land using crossed-controls rather than 'kicking off the drift'. This is the way it lands during an autoland, so it works! My preference is to kick (actually squeeze) the drift off in the flare, which is fine unless you screw it up, in which case you start drifting down wind in a hurry! :ooh: