High winds at Schipol. What a landing!

[misd-agin]

In general you can fly the 777 just like you fly a 727, 737NG, 757, or 767. Twenty plus years ago a newbie asked "how do you land the 727?" Uh, just like any other airplane? It's not a monster. "Well guys have been telling me all sorts of techniques." Uh, slow down on the roll inputs, fuselage alignment and zero drift, start flaring and bring the power to idle. "You land at idle? Guys said to NEVER do that." Yes, every landing is at idle, it's an airplane. Guys talk themselves into believing it's some seven headed monster. It wasn't. It only had two heads, the happy one or the sad one if you didn't fly it just right.


Basic flying - have the fuselage aligned with the runway and zero drift(almost always downwind, very rarely upwind). Drift = lateral load. Landing on the downwind landing gear ruins a decent sink rate touchdown.


If you're landings are 'close' but are 'harsher' than you'd expect verify that you have no lateral drift and the fuselage is tracking straight at touchdown. In this sense they ALL fly the same. The 727 and 737NG(with flaps 40) punish the landing quality the most if track/drift isn't perfect. 757/767 are nicer, and the 777 is the easiest. It just absorbs less than sterling track/drift or sink rates. It makes everyone look good at touchdown.


Now there are a couple ways that the larger jets, IMO, are different.

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.


Due to the FBW the 777 flies slightly differently. It's not night and day. After a couple of flights I completely forget what my initial impressions were. I just remembered it was different. The 777 is very nice flying. But it requires gentle roll inputs to avoid shaking the airplane.


I just watched the 777 landing again and again. You can see the right wing inboard aileron and the amount of roll inputs being made. You can also see some of the pitch inputs (large screen helps). Right before the last right wing drop you can see that a significant right roll input (aileron up). Without FDR data, or being in the cockpit, it's hard to tell how much of the wing drop is from a roll command vs. a possible wind gust.




Navy friend said 'spoiler bumping' was actually a technique used getting onto the aircraft carrier. 'Golden hook' winner, he said it was a 'cheating' way to get the F-14 to drop slightly - rapid left and right roll inputs would result in some roll spoiler deployments. Done fast enough he said it would result in a slight altitude reduction if you felt you were going slightly long.


And mistakes? Ha. Who said they're perfect? Flew two legs recently. Arrival and departure at the first stop were under difficult conditions. We did well. Next arrival was in clear skies...and we ended up missing a step down so we ended up high on profile and ended up capturing the glide slope from above. Quickly fixed, but three pilots, with 40,000-50,000 hrs TT, and at least 15,000+ hrs in type, flat out missed it. No excuses. But rapidly corrected.

[FullWings]

Due to the FBW the 777 flies slightly differently. It's not night and day. After a couple of flights I completely forget what my initial impressions were. I just remembered it was different. The 777 is very nice flying. But it requires gentle roll inputs to avoid shaking the airplane.

This is true. Due to the long and fairly stiff wings, sudden roll inputs send a sort of reverberating ripple across the airframe. It’s amazing how “turbulence" stops sometimes as soon as the AP is engaged.

As far as the landing into AMS goes, it seems like they hit a rather gusty patch and some over/under controlling is inevitable in those kind of conditions. The camera angle I think made the roll angles look more dramatic than they actually were - ground contact with the wingtip and/or slat needs something more than 13/14degs in a normal landing attitude. It did skip a little bit from one main gear to the other during touchdown but that’s more because the rate-of-descent was low and it took a while for the ground spoilers to trigger.

It’s very easy to criticise when you weren't there but it was gusting to 50kts at the time (and probably some nasty lulls as well) and it looked like they landed on the centreline in the right place at the right speed. If it had been me, I would probably have requested a FDR playback to see exactly what happened and whether I could have done anything about it, otherwise job done.

Remember the definition of a good landing? One you can walk away from. An excellent landing is when you can use the aircraft again...

[aguadalte]

a330jokey:

On the A330, I used to let the autopilot fly the airplane down to about 300' before disconnecting. The autopilot is fantastic on that airplane! A copilot was making an approach in bumpy and crosswind conditions one day and he disconnected the autopilot about 6 miles out and hand flew the approach. I suggested he reconnect the autopilot and let it do the job. He continued hand flying and fought the airplane the whole way while I jumped nervously in my seat. After we landed and slowed down, he said next time he will use the autopilot!!

I'm not surprised with that quote, but would totally disagree.

The best way to land an A330 in difficult/crosswind conditions is to disconnect the AP and the ATHR and fly the bird with minimum stick and power changes.

At 300', in very poor conditions, the pilot has no time to "feel" the weather, nor the reactions of the aircraft. The best way to get a grip to what's going on (especially after a long-haul night flight) is to start working out the landing, as soon as we have visual contact, and while mistakes are still manageable.

Also, if one disconnects the AP at 300', one looses a great opportunity to gain experience on how to hand-fly the aircraft in bad weather...

No wonder pilots are loosing their skills. The more they rely on AP, the less they feel comfortable to take control, when things go wrong.

[RAT 5]

aguadalte: totally 100% in agreement. See my comments reference the accident report into HV B757 runway excursion at AMS many years ago. Late A/P disconnect was high up their list of comments about actions that didn't help. They were at max X-wind and gusts a little beyond.

[bubbers44]

Good to see some posts backing flying skills being important again. Obviously they could have been used to make this landing just another landing instead of being an exciting news report. Seems like a lot of the old school posters here have left in the past year. Wonder why?

[misd-agin]

Read the NTSB SW 345 @ LGA incident. VFR light winds, a/p disconnected at 500', and divergent flying started shortly afterwards.

[Giolla]

All I can say is that rwy 27 wouldn't be my choice in NW BFT 7-8 conditions.
No idea why one might choose a runway almost at 90 angle on 28-33 knots crosswind.
Wind was later on veering between NW and SW with terrible blows now and then.Schiphol has its own microclimate and the name is derived from Ship's Hell, a name when the Haarlemmermeer was still an inland lake.
I was with my yacht last wednesday and thrursday travelling from Hoorn to SPL and the conditions were far from normal.

[wingview]

Giolla.

EHAM 251125Z 29032G43KT 250V320 4500 RA BKN008 OVC020 OVC018 15/14 Q0996 RERA TEMPO 30032G48KT 7000
EHAM 251055Z 28030G42KT 7000 RA FEW007 BKN009 OVC018 15/14 Q0995 RERA TEMPO 30032G48KT 4000

So nothing with 90 degrees crosswind which would have been out of the limits anyway.

[armchairpilot94116]

https://www.youtube.com/watch?v=jd2aaQ9XSKc

Aviation enthusiast posts this vid of operations at Taipei SungShan Airport as Super Storm Soudelor approaches.

Cutting it a bit thin maybe?

[7478ti]

Would need more data to properly assess PIO/APC

To conclusively determine if there is any evidence of PIO/APC, one would need much more data. Depending on the sample rate available, and parameters recorded, it some times is even difficult to make these judgments for certain from an FDR or QAR. The PSD of the 3 axis time history of the wind and gust environment also needs to be established, along with the related amplitude and phase angle of the control inputs. In flight test, very high data sample rates are typically used, as well as external sensing of the atmosphere, to be able to definitively tell what's appropriate control system response, and appropriate pilot response, and what component is potentially PIO/APC. At this point all one can reasonably conclude about this KLM landing is that the pilots landed successfully, in a challenging environment, and the B777 is [arguably] a pretty great jet in very tough WX circumstances. I've seen this all first hand for decades, in these kinds of jets ranging from RA001 to WA001 and all their later kin, and cousins (including even Airbusses), ...and the B777 stands out as remarkable in its ability to reliably handle very tough WX.

[silvertate]

TWR reported wind shortly before landing at RWY27: 300 deg, 33 knots, gusting 48

So they had a crosswind component of 16 knots gusting 22 knots on rwy 27. As usual the Daily Mail making news out of nothing.

That is not the full story.

At AMS with strong westerly winds, low level turbulence is always to be expected. It is written on the 27 Jepp plate.

The problem at AMS is the sand dunes on the beach, which are just high enough to set the low level wind bouncing. Ask any glider pilot - a small rounded hill can often produce more rotor than a craggy hill or mountain. So yes, this approach probably did experience severe low level turbulence.

Was their an element of PIO? Probably. Many pilots do not react quickly enough, and don't realise that a big aircraft will fly in and out of one region of turbulence and into its diametric opposite partner in an instant. And if you are late correcting, you end up correcting at completely the wrong moment, when the turbulence was correcting the roll itself anyway. And the result is unnecessary wing waggling.

Unfortunately, Sims are not good at replicating this, so it is difficult to train for. And unless you are a UK pilot (lots of runways not aligned with the prevailing wind), you might not have much experience of it.

Tate

[Hotel Tango]

Cutting it a bit thin maybe?

I didn't see anything out of the ordinary. All perfectly good landings and take-offs under the prevailing conditions. Why comment on something you clearly know nothing about?

[RAT 5]

The problem at AMS is the sand dunes on the beach,

The effect at AMS, having operated out of there for many years, and which can be quite surprising in the dark, is the result of passing over the Bos (forest) at low height on finals. The thermal effect of the trees-open terrain is pronounced and the trees can also act with an orographic effect when the wind is strong. Sometimes, when the thermal effect is lost at low height, the a/c sinks as to pass over the boundary of he trees; at other times the trees create an orographic effect & the a/c is ballooned on the up draft and then sinks. Either way you need to be prepared.

[silvertate]

Duplicated comment, for some reason.

[silvertate]

From RAT 5

The effect at AMS, having operated out of there for many years, and which can be quite surprising in the dark, is the result of passing over the Bos (forest) at low height on finals. The thermal effect of the trees-open terrain is pronounced....

Thermal effects in the dark eh? My, my, you were never a glider pilot, were you...?

The turbulence at AMS has nothing to do with trees. It happens in westerly and northwesterly winds, because of the low-level winds being disturbed by the sand dunes. And yes, those dunes are quite large enough to produce ridge-lift, wave patterns and wave-rotor. And yes, those effects can easily travel as far as the airfield.

Here is a glider, ridge-soaring the Dutch dunes:

[RAT 5]

Yes I am a glider pilot - paragliders. You may be quite correct about the dunes, and thank you for the information that they can cause wave effects so far downwind.
I was not alluding to thermal effects in the dark, although they can happen. The hot air is trapped in the trees during the day, especially if there is light breeze. If the wind strengthens this can disturb the stagnant hot air and cause it to burst from the trees; restitution thermal bubbles of a sort. The orographic effect can happen at any time of day, and if you can not see the forrest the sink can be surprising at low level as you pass over the boundary of the tree. This can also happen in daylight and any orographic effect combined with any thermal effect can make the last 500' quite interesting.
I have experienced exactly the same effect at other airfields with large woods in the undershoot: no sand dunes or other sea breeze effects. The same is more obvious at PMI 24L and VLC 12. In those places there are large areas of dry sandy hills and that can also make going down & slowing down challenging if you leave the drag configuration too late. And that is even more surprising in the dark, just after sunset, as the stored heat is released with a gentle breeze over the rising terrain.

[silvertate]

The hot air is trapped in the trees during the day, especially if there is light breeze. If the wind strengthens this can disturb the stagnant hot air and cause it to burst from the trees; restitution thermal bubbles of a sort.

But as you will know, a stonking summer thermal will give 6 to 8 knots.
A good sunny thermal will give 4 to 6 knots.
An evening thermal over a forest in calm condition will give 1 knot at best.
An evening thermal over a forest in strong winds will give nothing, because the weak thermal will be broken to pieces.

The westerly turbulence at AMS is definitely a wave-rotor effect, which is why it occurs at low level.

And this really should be understood by AMS crews, because the effect is predictable and more easily countered if you understand why it is happening. (ie: it will more pronounced in stable warm-sector conditions with straight isobars, or at night under an inversion.)

[Aluminium shuffler]

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.

I have seen plenty of pilots use a little roll in a floating flare to lower the wheels on to the ground - a combination of tilting the lift vector, cracking the spoilers on one wing and rolling that side's wheels down the few inches they're above the tarmac all combine quite effectively. I didn't make a habit of it, but have done it myself from time to time.

As for this landing, it doesn't pay to second guess the crew unless you have to as an investigator - we have no way of knowing the exact circumstances, but if the engines were winding down as part of the flare, then continuing the landing may have been much safer than a go around and another try, which would likely have resulted in another flare in similar circumstances with a more tired and anxious crew with less fuel. The pilots made a snap decision and the aircraft landed without harm. Well done them.

[d192049d]

When you get it just right...crosswind

Some nervous but appreciative ATC....

http://www.liveleak.com/view?i=d25_1438987275

[flyhardmo]

Great video. Very nice landing.