PPRuNe Forums - High winds at Schipol. What a landing!

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Good example of a nice landing technique

SAWH nicely done... fortunately it looked like a reasonably steady wind, reference any gusts

Winds from the North in Ushuaia SAWH/USH are never steady because of the montains near the airport. Gusts of 40 to 50s kts are very common.
It is a very challenging flight condition because of the turbulence, sometimes it is so strong that the AP is kicked off when flying the ILS.
The crosswind component could be very easy over limit in that condition, wind from the North approaching to Rwy 25.

AP performance in turbulence?

"...sometimes it is so strong that the AP is kicked off when flying the ILS" ??!!

Wow... That certainly shouldn't happen!!!

O:)

It's no big deal if it does kick off as it sometimes does because now you get to fly instead of watch. That is a lot more fun.

Disconnect for turbulence alone, isn't good

Any AP self-initiated disconnect due to turbulence alone, without w/o some other internal AP or servo failure happening, or some prior saturation indication, isn't good, ...particularly when coupled to an ILS or GLS. In fact for any FAIL OP Mode, that kind of AP anomaly behavior is inappropriate, and can be dangerous, if not even uncertificable, ....or if for a system already certificated, grounds for issuance of additional operating limitations, or even issuance of an AD until corrected, or otherwise use limited.

O:)

Ops normal for the conditions?

Quote:

Originally Posted by atakacs (Post 9060156)

Admittedly no experience with the 777 here but to my untrained eyes this one was way too close for comfort... Stabilised approach, really?!
Glad everyone walked away but surprised that it does not raise more concern...

Finally a landing has to be made somewhere. If the alternates have similar winds, it might be preferable to use fuel at destination rather than elsewhere.
An understandable degree of PIO might be present, and it would be hard to suggest a substantially unstable approach based on the video. I would also hesitant to call the nice touchdown a lucky break.
Old school options, like extra fuel, wonderfully opens up the holding and alternate choice possibilities.

Quote:

Originally Posted by d192049d (Post 9081092)

Some nervous but appreciative ATC....

LiveLeak.com - No place for mistakes Airbus 340

A good outcome. No shredding. Touchdown with a wee bit too much crab angle remaining.

Not too sure about the A340s but on the A300s the outcome may not be too happy. Just saying.

Quote:

Originally Posted by Aluminium shuffler (Post 9081011)

From misd-agin:

"The 767 and 777 are more roll sensitive than the smaller jets. Not completely sure why. Friends have talked about it but we're not sure if it's a fuselage flex issue (ie wings move fractionally before the fuselage which attempts to 'catch up'), the size of the engines creating a greater mass that is offset from the roll C.G., or perhaps a gyroscopic effective from the large N1's? We don't know. But we do know the w/b a/c tend to have a bit of a sideways 'lurching' or 'bump' if you make large, or rapid, opposing roll inputs. The 777 in particular gets a sideways bumping motion (hate to say this but it's probably the easiest way to explain... similar to braless lateral motion...). More than the 767 it requires a slight pause before changing the roll rate request or reversing the roll request.

The 727, 767, and 777, to my recollection more than the 737 and 757, get a wing dropping sensation if large roll inputs are made. At larger roll control inputs the roll spoilers start deploying and with large inputs it literally feels like the wing is falling as opposed to rolling. And the typical reaction, sometimes called 'startle reflex(?)', is to counter-act that roll input with a large roll command to the other side, to correct the drop/roll, and the 'drop' is now done to the other side. And the over-correction starts towards the first roll direction, and back and forth it goes. If you feel that look at the wing. If you see large spoiler movements that is some of the motion. It could also be caused by gusting/shifting winds. And if you're in a 777 and feel a slight sideways lurching movement, look at the ailerons and see if they're going up and down. If they are you've found the source of the motion. It's not uncommon to feel it on the 777. So it that sense I'd agree, you can't fly a 777 like a 757/767. It will exposure less than smooth control inputs while the 767, and especially the 757, aren't quite as roll sensitive."

The 73's flight controls are manual cable and pulley affairs with hydraulic assistance, rather than all out power controls, so I suspect that is why they are relatively small and have less authority than on other types - so that they can be used in manual reversion with no hydraulics without being so heavy as to be unmoveable. The same may apply to the 727, but I don't know that aircraft's systems.

To be honest with you, I found both the 727 and 737 to be more roll sensitive in turbulence and remember using quick jabs of aileron input to counteract turbulence induced roll. The 747 was definitely more of a lumbering aircraft and less responsive. While my 777 experience is limited at this point, it is more sensitive than the 747 and I was definitely overcontrolling it in the sim which was said to be more sensitive due to the fly by wire system. On the line, I have had some daytime heating thermal type approaches and with small inputs have had no problems.

Jammed - my comments were about how the planes respond to control inputs and not their responses to external(turbulence) inputs.

Jammed Stab,

I should have been clearer about what I meant - I think the 73 has less aileron sensitivity and less roll authority because of small control surfaces, and I'm making an educated guess that design was because of the potential for manual reversion. They are relatively sensitive in roll to gusts and shear, especially the NG, due to the low inertia of such a sized aircraft and the light wing loading, especially the bigger and longer (more moment) winged NG. I found having extra fuel reduced the roll induced by wind effects considerably because of having greater mass outboard - the fuel not only gave us a better chance of getting in with allowing a second attempt before getting near reserves but also by markedly improving gust alleviation. It saved me numerous diversions and a lot of subsequent costs. Of course, it wasn't in the books, so I'd get told off by the bosses for having extra fuel... No room for common sense in modern flying.

Chuck Canuck

'Touchdown with a wee bit too much crab angle remaining'

A whole lot better than landing D/W of the centreline. The A340 (and all modern jets) are tested on many max x-wind landings using full 'crab' on touchdown.

See B777 trials video in KEF

This was a terrific landing.

Have a look at some Youtube videos of rough weather landings on RWY34 at NZWN/WLG.