LH A320 Rough Landing @ Hamburg
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24 year old girl is what I heard was the pilot flying as FO. I always looked at my yoke to see what the FO was doing during a wild approach knowing I could fix it. You don't get that feedback in the AB so you have to see the result before you can intervene. Not a good way to monitor an approach. I am so happy I retired flying a Boeing. Most of the wild approaches were pilot induced even though they always claimed turbulence. Monitoring the yoke you could see if the roll came before or after aileron input and knew the truth. Military pilots were prone to overcontrol a lot on short final causing their own turbulence. Flame away.
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Military Pilots were prone to overcontrol
Obviously Bubbers44 does not have a high opinion of Military pilots with his comment claiming "Military Pilots were prone to overcontrol a lot on short final causing their own turbulence".
Having had both a military and civil flying career as a Flight Engineer I flew with many pilots from both sides. To make a "broad brush" comment regarding one group or another is both unfair and unwise.
From where I sat the great majority of pilots displayed consistent high standards of airmanship and flying skills. Overcontrolling is not the sole province of Military, or ex-Military, pilots. There are some, thankfully very few, from both Military and Civil backgrounds who do not instill confidence in fellow crew members.
I firmly believe that it is usually unproductive to make comment on accidents or incidents in which one was not involved, however in the case of the LH incident at Hamburg the evidence presented would indicate that the decision to land in the prevailing conditions was not prudent and the missed approach should have been made somewhat earlier than was the case.
Having had both a military and civil flying career as a Flight Engineer I flew with many pilots from both sides. To make a "broad brush" comment regarding one group or another is both unfair and unwise.
From where I sat the great majority of pilots displayed consistent high standards of airmanship and flying skills. Overcontrolling is not the sole province of Military, or ex-Military, pilots. There are some, thankfully very few, from both Military and Civil backgrounds who do not instill confidence in fellow crew members.
I firmly believe that it is usually unproductive to make comment on accidents or incidents in which one was not involved, however in the case of the LH incident at Hamburg the evidence presented would indicate that the decision to land in the prevailing conditions was not prudent and the missed approach should have been made somewhat earlier than was the case.
Videos
Yes, XPMorten [Mar26/21:00] (and others),
The aeroplane does seem to sort itself out pretty well. But, after that, there's a definite point at which the flying improves...
Hi, galaxy flyer Mar26/01:22, currently post#321] and Bobbsy [post #326],
Ref the B747 video, I agree that the pilot on any type would be reasonably satisfied with this landing, in a fairly stiff crosswind. Don't pretend to know the conventional technique in the B747, so can only speak in general terms.
To be hyper-critical, it is evident that the de-crab is only about half complete at main-gear touchdown, which is marginally on the downwind (right) main-gear first – presumably not what the pilot had mind. The rest of the de-crab is smoothly completed even as the 4 bogies (sorry, "trucks") are settling firmly on the runway. In this sequence, it's not possible to see the ailerons and spoilers, but – when it comes into view – a substantial amount of downwind (right) rudder is shown for the de-crab, as expected. The wings are virtually level throughout, which probably indicates the vulnerability of the outer engine pods that ex-B707 drivers can identify with. [Touchdown with considerable drift may be standard 747 technique, for all I know, but is not on most types.]
On a very large aeroplane, flying at similar speeds to an A320, the success of the landing is even more dependent on the quality of the approach, which is beautifully stable in this case. The rest follows, because there is so much inertia.
Hi sabena boy [Mar26/08:06, currently post #335],
Ref the A380 video, it's shot from less-than-ideal angles. The aeroplane seems to have landed in one direction, then taken off in the opposite direction on the same runway (is it Brussels 02/20?). Later, in the dusk, it seems to be landing on the same runway as the first.
It is possible to see the drift being kicked off AND a tiny amount of into-wind bank being applied (by pilot OR auto-pilot input) during de-crab.
On the take-off, at rotation, the upwind wing is allowed to rise slightly – a common mistake on the A320, as on all types.
The A380 is likely to achieve similar handling characteristics to the other Airbus FBW types, for which there are various previous posts on this thread, including:
the Airbus link which 212man repeats, above;
my post of Mar04/13:35 (currently #207);
my post of Mar04/17:28 (currently #222);
bsieker's post and quotes of Mar04/21:07 (currently #243)
my post of Mar05/01:43 (currently #260);
PJ2's posts of Mar05/04:43 & 06:46 (currently #263 & #266), and Mar05/16:19 (currently #300);
and others.
It needs to be pointed out that we cannot tell if the videoed landings were "manual", or autolands!
The aeroplane does seem to sort itself out pretty well. But, after that, there's a definite point at which the flying improves...
Hi, galaxy flyer Mar26/01:22, currently post#321] and Bobbsy [post #326],
Ref the B747 video, I agree that the pilot on any type would be reasonably satisfied with this landing, in a fairly stiff crosswind. Don't pretend to know the conventional technique in the B747, so can only speak in general terms.
To be hyper-critical, it is evident that the de-crab is only about half complete at main-gear touchdown, which is marginally on the downwind (right) main-gear first – presumably not what the pilot had mind. The rest of the de-crab is smoothly completed even as the 4 bogies (sorry, "trucks") are settling firmly on the runway. In this sequence, it's not possible to see the ailerons and spoilers, but – when it comes into view – a substantial amount of downwind (right) rudder is shown for the de-crab, as expected. The wings are virtually level throughout, which probably indicates the vulnerability of the outer engine pods that ex-B707 drivers can identify with. [Touchdown with considerable drift may be standard 747 technique, for all I know, but is not on most types.]
On a very large aeroplane, flying at similar speeds to an A320, the success of the landing is even more dependent on the quality of the approach, which is beautifully stable in this case. The rest follows, because there is so much inertia.
Hi sabena boy [Mar26/08:06, currently post #335],
Ref the A380 video, it's shot from less-than-ideal angles. The aeroplane seems to have landed in one direction, then taken off in the opposite direction on the same runway (is it Brussels 02/20?). Later, in the dusk, it seems to be landing on the same runway as the first.
It is possible to see the drift being kicked off AND a tiny amount of into-wind bank being applied (by pilot OR auto-pilot input) during de-crab.
On the take-off, at rotation, the upwind wing is allowed to rise slightly – a common mistake on the A320, as on all types.
The A380 is likely to achieve similar handling characteristics to the other Airbus FBW types, for which there are various previous posts on this thread, including:
the Airbus link which 212man repeats, above;
my post of Mar04/13:35 (currently #207);
my post of Mar04/17:28 (currently #222);
bsieker's post and quotes of Mar04/21:07 (currently #243)
my post of Mar05/01:43 (currently #260);
PJ2's posts of Mar05/04:43 & 06:46 (currently #263 & #266), and Mar05/16:19 (currently #300);
and others.
It needs to be pointed out that we cannot tell if the videoed landings were "manual", or autolands!
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It needs to be pointed out that we cannot tell if the videoed landings were "manual", or autolands!
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Originally Posted by missterrible
I suspect in max crosswind at flare time most observing pilots are not looking inside at either a Byoke or an ABidestick
Even better, a light hand on the yoke, in a strictly damping mode will provide all kind of useful information.
I can't tell if it really was the case in that LH episode, but the PNF would have probably appreciated to know in live that there were maybe no or too little aileron solicitation ... The information, just a fraction of second earlier, it's all it takes to simply do the job, or at least to stay out of trouble.
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No one is looking at the yoke during an unstable approach to landing but out of curiosity I could see out of the corner of my eye if the weather and conditions were doing it or the pilot was. Sorry about the military pilot observation but I think their training is accelerated making them more prone to fly mechanically. Have you ever flown with a buff, B52, pilot? That is what I am talking about. I have flown with outstanding ex military pilots that don't fit into this category by the way. The video doesn't have the resolution to see the aileron input when she kicked the rudder in for landing but the results of the roll to downwind indicates she didn't use the required aileron to keep the wing from coming up as is required in that kind of cross wind landing.
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The information, just a fraction of second earlier, it's all it takes to simply do the job, or at least to stay out of trouble.
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TyroPicard quotes me and writes:
OK, maybe wrongly put, i am still learning AB and English........
To get better please tell me: If you approach with a constant small bank angle and then you kick in the rudder and a small roll will ensues that was not demanded. Does the AB roll back to what was demanded or does the new rudder induced roll prevail?
Quote:
(Just to complete a earlier contribution:
We all agree that in roll demand mode the AB strives to keep the demand, which before decrab was the actual bank angle. Logically the computer then commands a slight roll to get back to that bank angle. THAT's the input i was mentioning,
Sorry, that's incorrect. In normal law the FBW does NOT return the a/c to the original bank angle - it merely tries to maintain the roll rate demanded by the side-stick. The bank angle is irrelevant.
(Just to complete a earlier contribution:
We all agree that in roll demand mode the AB strives to keep the demand, which before decrab was the actual bank angle. Logically the computer then commands a slight roll to get back to that bank angle. THAT's the input i was mentioning,
Sorry, that's incorrect. In normal law the FBW does NOT return the a/c to the original bank angle - it merely tries to maintain the roll rate demanded by the side-stick. The bank angle is irrelevant.
To get better please tell me: If you approach with a constant small bank angle and then you kick in the rudder and a small roll will ensues that was not demanded. Does the AB roll back to what was demanded or does the new rudder induced roll prevail?
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XPMorten,
I think there are a few issues here as to how the A320 flight control works
You don't know what the crew did by looking at the outside of the airplane; you only know what the airplane did under the commands given by the crew. If the stick is neutral and the airplane starts to roll, the FBW will countermand the roll because 0 roll rate is commanded by the crew. And to countermand that roll the ailerons may well actuate.
Indeed, on your first grainy still, I see a shadow in the position of the starboard aileron which might will indicate it has risen.
Sorry, as I understand it this does not happen. If sidestick is neutral, wing does not come up due to yaw-roll coupling. The FBW control system compensates for the coupling. (This also answers GMDS's question.)
I think it was a gust.
PBL
I think there are a few issues here as to how the A320 flight control works
Originally Posted by XPMorten
In fact, I dont think they gave aileron at all during the whole maneuver;
Indeed, on your first grainy still, I see a shadow in the position of the starboard aileron which might will indicate it has risen.
Originally Posted by XPMorten
Wing comes up due to yaw induced roll.
I think it was a gust.
PBL
A320 Yaw-Roll Coupling - in practice
Quote from GMDS:
To get better please tell me: If you approach with a constant small bank angle and then you kick in the rudder and a small roll will ensues that was not demanded. Does the AB roll back to what was demanded or does the new rudder induced roll prevail?
[Unquote]
No, she will not roll back (that is to say, not automatically).
Yes, the bank-angle resulting from the displacement will become the new datum, and the FBW will try to maintain it.
These displacements are normal during de-crab, in my experience. Whether they are due to coincident gusts, is arguable. I have seen this happen on crosswinds from moderate to strong; smooth and gusty. That is why it soon became my practice on the A320 to pre-empt the undesired roll by "putting the wing down" slightly, during de-crab, i.e., inducing a slight sideslip.
I agree with PBL [above] in at least one respect:
this aeroplane was not only conducting an approach in a MEAN crosswind-component that was at or above limits; it was also affected by at least 2 gusts that, in my opinion, were outside the gust limit.
In my 14 years' experience, the roll-yaw coupling was not something to be relied on.
The take-off, which – prior to lift-off – is conducted in Roll-Direct Law (if memory serves), is also worthy of comment. On rotation, prior to lift-off, the upwind wing invariably rises, even though the pilot is easing off the usual slight downwind rudder. [You would expect the upwind movement of the rudder, at the latter point, to counteract the tendency of the upwind wing to rise, but it is not enough, in practice.] The solution, again, is to pre-empt it with aileron; just like a conventional aeroplane
Hope this helps.
To get better please tell me: If you approach with a constant small bank angle and then you kick in the rudder and a small roll will ensues that was not demanded. Does the AB roll back to what was demanded or does the new rudder induced roll prevail?
[Unquote]
No, she will not roll back (that is to say, not automatically).
Yes, the bank-angle resulting from the displacement will become the new datum, and the FBW will try to maintain it.
These displacements are normal during de-crab, in my experience. Whether they are due to coincident gusts, is arguable. I have seen this happen on crosswinds from moderate to strong; smooth and gusty. That is why it soon became my practice on the A320 to pre-empt the undesired roll by "putting the wing down" slightly, during de-crab, i.e., inducing a slight sideslip.
I agree with PBL [above] in at least one respect:
this aeroplane was not only conducting an approach in a MEAN crosswind-component that was at or above limits; it was also affected by at least 2 gusts that, in my opinion, were outside the gust limit.
In my 14 years' experience, the roll-yaw coupling was not something to be relied on.
The take-off, which – prior to lift-off – is conducted in Roll-Direct Law (if memory serves), is also worthy of comment. On rotation, prior to lift-off, the upwind wing invariably rises, even though the pilot is easing off the usual slight downwind rudder. [You would expect the upwind movement of the rudder, at the latter point, to counteract the tendency of the upwind wing to rise, but it is not enough, in practice.] The solution, again, is to pre-empt it with aileron; just like a conventional aeroplane
Hope this helps.
Last edited by Chris Scott; 7th Mar 2008 at 11:44. Reason: Correction and clarification of the take-off case.
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Chris,
I guess we only disagree on how effective any roll-yaw decoupling is. You flew the airplane for 14 years, and suggest it doesn't work quite "as advertised". Thanks for the datum.
I imagine the engineers who designed the airplane knew that there would regularly be displacement to a new baseline datum in bank, not only because mother nature does not follow engineering models to the letter, but also because one wants to consider stress allevation on the airframe and "go with the flow" quite often.
However, the official recommended technique on landing in gusty conditions, as I understand it, is still not to wiggle the stick around to compensate but to use steady, deliberate motion as necessary.
PBL
I guess we only disagree on how effective any roll-yaw decoupling is. You flew the airplane for 14 years, and suggest it doesn't work quite "as advertised". Thanks for the datum.
I imagine the engineers who designed the airplane knew that there would regularly be displacement to a new baseline datum in bank, not only because mother nature does not follow engineering models to the letter, but also because one wants to consider stress allevation on the airframe and "go with the flow" quite often.
However, the official recommended technique on landing in gusty conditions, as I understand it, is still not to wiggle the stick around to compensate but to use steady, deliberate motion as necessary.
PBL
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I am no doubt going to touch on a previously mentioned and very personal subject to all pilots, so sorry to all whom this offends.
I personally feel this is an advert for a cross control approach setting off the drift early on allowing the PF to assess the x wing comp before 20feet. This probably would of ended in an earlier GA or a more controlled touch down and would be much more comfortable for the pax and crew in the back. I only say this because this is how I have been trained and demonstrated to me.
I personally feel this is an advert for a cross control approach setting off the drift early on allowing the PF to assess the x wing comp before 20feet. This probably would of ended in an earlier GA or a more controlled touch down and would be much more comfortable for the pax and crew in the back. I only say this because this is how I have been trained and demonstrated to me.
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Wind readings at EDDH
just to stop this endless discussion wether RWY 23 or RWY 33 was better : Working at EDDH TWR as one of the ATCO´s during that incident, here´s a short summary of R/T and coordination with Approach:
10 min prior DLH 040, TWR issued information to Approach about winds getting stronger ( from 250/30 changing to 270/34-45). RWY 33 as altenative landing RWY was offered to all approaching aircraft. DLH 040 choosed RWY 23. After freq change to TWR, TWR reported increase of Wind and velocity (280/40-50)and offered swing over for RWY 33. Crew of DLH 040 asked about percentage of go-arounds within the last 20 Minutes ( total 50%...). Crew stated:" we try one for RWY 23..." Last windcheck by TWR at 1NM final.The rest is known...
10 min prior DLH 040, TWR issued information to Approach about winds getting stronger ( from 250/30 changing to 270/34-45). RWY 33 as altenative landing RWY was offered to all approaching aircraft. DLH 040 choosed RWY 23. After freq change to TWR, TWR reported increase of Wind and velocity (280/40-50)and offered swing over for RWY 33. Crew of DLH 040 asked about percentage of go-arounds within the last 20 Minutes ( total 50%...). Crew stated:" we try one for RWY 23..." Last windcheck by TWR at 1NM final.The rest is known...
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what to learn
flycheaper
I learn from this incident that if the runway is not straight ahead of pilot's eyes and aircraft's ground track is not on runway centerline at runway threshold then a safe landing is not possible. It may be possible with small plane on a long runway, but big aircraft on suitable runway for normal operations with nasty crosswind - no.
I want to learn from this incident
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Cabus, you are right, and using this technique a pilot would be forced to keep the upwind wing down or do as they did and go off the downwind side of the runway. Doing the decrab in the final touchdown stage works too but you can't test for drift if you float. Letting the upwind wing come up is poor airmanship either way. If the public thinks they are heros I think the pilots know they just screwed it all up.
Quote from Rumet [Mar05/09:55, currently post#278]:
Since direct law kicks in 5 secs after touchdown, can someone please explain what the correct use of the sidestick is to keep wings level during decrabbing ?
I see it clearly after those 5 seconds, but before that how is commanding a roll rate with both main landing gears on the ground made equivalent to applying a required aileron deflection ?
[Unquote]
My previous have not covered this 5-second period (which I confess was news to me, but makes sense if you consider the case of a bounced landing, with or without go-around). I've argued that, as soon as the second main gear is firmly on the ground, you can use into-wind AILERON to hold the wings level.
This is obviously not strictly correct; with into-wind stick you are actually commanding a roll-rate during those 5 seconds after touchdown. In practice, though, a moderate amount of stick - very much like you would use on a conventional aeroplane - is not enough to lift the downwind gear off the runway, but will counteract the tendency of the upwind wing to lift.
Quote from CABUS [above]:
I personally feel this is an advert for a cross control approach setting off the drift early on allowing the PF to assess the x wing comp before 20feet. This probably would of ended in an earlier GA or a more controlled touch down and would be much more comfortable for the pax and crew in the back.
[Unquote]
The problem with the FULL sideslip technique, for the A320, has already been covered by me and others. The sideslip angle required in a limiting crosswind would probably lead to winglet-scrape.
By the way, I have had to EDIT my post earlier today, in respect of an error I made in the take-off case. [Nobody spotted it...]
Since direct law kicks in 5 secs after touchdown, can someone please explain what the correct use of the sidestick is to keep wings level during decrabbing ?
I see it clearly after those 5 seconds, but before that how is commanding a roll rate with both main landing gears on the ground made equivalent to applying a required aileron deflection ?
[Unquote]
My previous have not covered this 5-second period (which I confess was news to me, but makes sense if you consider the case of a bounced landing, with or without go-around). I've argued that, as soon as the second main gear is firmly on the ground, you can use into-wind AILERON to hold the wings level.
This is obviously not strictly correct; with into-wind stick you are actually commanding a roll-rate during those 5 seconds after touchdown. In practice, though, a moderate amount of stick - very much like you would use on a conventional aeroplane - is not enough to lift the downwind gear off the runway, but will counteract the tendency of the upwind wing to lift.
Quote from CABUS [above]:
I personally feel this is an advert for a cross control approach setting off the drift early on allowing the PF to assess the x wing comp before 20feet. This probably would of ended in an earlier GA or a more controlled touch down and would be much more comfortable for the pax and crew in the back.
[Unquote]
The problem with the FULL sideslip technique, for the A320, has already been covered by me and others. The sideslip angle required in a limiting crosswind would probably lead to winglet-scrape.
By the way, I have had to EDIT my post earlier today, in respect of an error I made in the take-off case. [Nobody spotted it...]
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EDDHATC,
Unfortunately, your intervention will only do that if everyone believes you are who you say you are and were where you say you were. I've no reason to doubt it, but I can't speak for others.
Wind at 280 is 50° from runway heading of both Rwy 23 and Rwy 33, so I don't imagine wind direction played a role in choice of runway.
PBL
Originally Posted by EDDHATC
just to stop this endless discussion wether RWY 23 or RWY 33 was better
Wind at 280 is 50° from runway heading of both Rwy 23 and Rwy 33, so I don't imagine wind direction played a role in choice of runway.
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Wind
The only practical point I can add to the above post by PBL is the common phenomenon (northern hemisphere) that during a gust the wind usually veers, so that gusts would increase the problem for RW 23 and decrease the problem for RW 33.
Interesting in the ATC post is the term by the crew - give it one try. Indeed, with a parameter as variable as wind, you can try, and perhaps land in a quiet spell, or go around during a gust.
Whether the aircraft handling was proper or not is difficult to ascertain from a distant camera shot - I expect that recorder readout will provide the necessary details, also solving all the riddles about flight control inputs versus actual control surface deflections.
Interesting in the ATC post is the term by the crew - give it one try. Indeed, with a parameter as variable as wind, you can try, and perhaps land in a quiet spell, or go around during a gust.
Whether the aircraft handling was proper or not is difficult to ascertain from a distant camera shot - I expect that recorder readout will provide the necessary details, also solving all the riddles about flight control inputs versus actual control surface deflections.