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-   -   LH A320 Rough Landing @ Hamburg (https://www.pprune.org/tech-log/316096-lh-a320-rough-landing-hamburg.html)

bubbers44 6th Mar 2008 13:40

It looks like after watching their x-wind landing technique they will be practicing in the sim for a while before going back on the line.

NOR116,20 6th Mar 2008 13:49

Zrh - Ham
 
fendant,

I mentioned ZRH to point out that there are very often considerations other than air safety for allocating a certain runway.
I didn’t want to say that all circumstances in ZRH and HAM are equal.
But thanks for your explanations anyway.

Huck 6th Mar 2008 14:08


Once again the pilots fell into a bad situation and may have made some judment errors. But when the S#*t hit the fan they had the ability to get it right and real quick, right in front of out eyes.
That's not what I saw. I saw a modern airliner with pax aboard that was out of control for a time, low to the ground. I would have broken that sidestick off before I'd let that right wing up like that. They may have fixed it eventually, but not real quickly.

chefrp 6th Mar 2008 14:13

a different prospective
 
Aviators,

I am not a pilot, just someone who has much respect for flying and your chosen profession.

I have read this thread for the past few days and agree with many of the points made:

*the captain should have been at the controls during the 1st attempt because of the extreme conditions
*he should have called for a go around sooner...

the fact of the matter is these pilots found themselves in a very difficult situation, and on top of that it was recorded for all the world to view and dissect.

I think it is importatant to look at this incident and ask why did they pull out of it instead of the dreadful alternative. Has all the training and technology paid off? After all, the Titanic was a similar situation, the ship was put into a compromising position by errors of judgment, but they could have recovered her, unfortunatly technology and training failed.

As a pax I have complete confidence in Luftansa, Airbus and Boeing...for that matter.

Once again the pilots fell into a bad situation and may have made some judment errors. But when the S#*t hit the fan they had the ability to get it right and real quick, right in front of our eyes.:D

chefrp 6th Mar 2008 14:31

S#*t hit the fan meant "out of control"

sorry :(

Denti 6th Mar 2008 14:36


It looks like after watching their x-wind landing technique they will be practicing in the sim for a while before going back on the line.
As far as i know both pilots are allready back on the line.

Clandestino 6th Mar 2008 14:49

Seemingly the respected forummembers, who have reached the definite verdict on crew performance during the attempted landing, know what was the last wind passed from ATC to crew, what was the wind recorded in TWR as A320 touched down, what was the stick(s) displacement by the pilots and what did the spoilers and ailerons do as the upwind wing rose.

So would they please come forward and share it with us, please.

Thanks for the educational video, Lamer. It just shows how not to fly A320 (ref. post #243 by Bernd Sieker)

sevenstrokeroll 6th Mar 2008 15:09

clandestino:

I too would like to know the winds at touchdown and the way the control stick was being manipulated (rudder and throttles too).

we are responding to the video. a horrific video.


a video that we should be happy to have to remind us of how things can go to hell in a handbasket quickly.

I think chefrp is right:

<<<*the captain should have been at the controls during the 1st attempt because of the extreme conditions
*he should have called for a go around sooner..>>>

no more nite flights 6th Mar 2008 15:10

A320 X/Wind landing
 
:ooh:Watched video with interest.If crosswind component within Co and A/C limits...no big deal.Usually,F/O s have crosswind limits in most companies so I guess Capt. should have been handling pilot.Aircraft was on centreline until Pilot corrected drift with Left rudder nicely but someone forgot to tell him that the induced yaw from such a large rudder input would cause the wing to lose lift and he should have applied down aileron (co-ordinated with rudder input) on the opposite wing.Flown both Boeings and Airbus in similar conditions and provided you coordinate rudder/ailerons ,should not be a problem.Interesting though,in 35yrs of flying never been given max crosswind tasks in Sim!!...maybe time to go back to basic airmanship checks?

bubbers44 6th Mar 2008 15:19

I've seen some interesting x-wind techniques used by high time FO's that would make your hair stand on end like putting the nose downwind and side slipping with full rudder to the runway with a 15 knot x-wind component. No taildragger pilot has ever done that more than once however.

TyroPicard 6th Mar 2008 15:37

GMDS said..


(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.

KC135777 said...

I believe I remember reading about how the AB sidestick does NOT move, but that the pilots actually put pressure on it? is this correct?
No, the sidestick moves! Perhaps you are thinking of the original F-16 side stick....

TP

412SP 6th Mar 2008 15:39

I've seen some interesting crosswind "techniques" from "left seaters" that have made me a bit anxious. It goes both ways.:}

D&M 6th Mar 2008 15:42

Yep, Airbus sidestick definitely moves!!

Notice the flight controls check at 1:45 on this video... http://www.youtube.com/watch?v=MFkm_x454ks

Original F-16 didn't I believe, although it was later revised to a small movement all around.

Chris Scott 6th Mar 2008 15:47

Airbus FBW - Background
 
Quote from Rananim [Today/00:57, currently#320]:
I have to reference this to what I know,which is Boeing.If during/after landing,no right-roll input is made by co-pilot,this would be clearly and instantly apparent to the Captain(before the wing has a chance to rise).On the Boeing.However,on the Airbus,he cant see/feel what the co-pilot is commanding so he can only react until/when the upwind wing starts coming up.Plus he has to press an override button for his sidestick to take control.Am I right?
[Unquote]

For an ex-A320 pilot's thoughts on sidestick aspects, see my post #229 [Mar04/19:07]. CONF iture [Today, 04:59, currently #330] has put the case against the Airbus sidestick succinctly. You have read his post. But he is wrong when he argues for Direct Law in roll only for the final approach. At what stage would it be introduced, and how suddenly? I can assure him that the transition from Normal Law to Direct Law with gear extension in some failure cases is one most A320 pilots contemplate with trepidation, because the handling changes so much in roll, as well as pitch.

The differences between Airbus and Boeing are honourable ones, dating from the mid-1980s, when Bernard Ziegler (head of Airbus FBW engineering design) made at least two radical and irrevocable decisions on A320 design. These were based, I believe, on engineering considerations of simplicity, reliability, and weight-saving; as follows
1) The throttle levers would be FBW; with no cable connections, and no motors to drive them forward or backward in mimicry of autothrottle commands. In manual thrust, however, their transducers would send throttle-by-wire signals to the FADECs in response to the pilot's movement of the levers.
2) The sidesticks would: (a) not be interconnected [to save the weight and jamming risks of cables]; and (b) not move to mimic AP commands when the autopilot was engaged. The inputs of the sticks would be algebraically summed, except that there would be a means of one stick being prioritised by its AP-disconnect push-button.

BALPA pilots, as well as others engaged in technical study, tried hard to persuade Airbus to change some or all of the above, but Mr Ziegler prevailed. On the first conversion course at Blagnac, ordinary airline pilots first flew the simulator in January 1988, and the aeroplane in February/March. We found that - although some of us still had reservations on the throttle and sidestick logics the bottom line was that the OVERALL PACKAGE was more than acceptable. Twenty years later (14 of them line-flying the A320 family), I think this assessment has been vindicated by the safety record, which compares very favourably with other types.

The A320 was formally type-certificated while we were on the course, and we put it into service in the Spring. Even as late as 1989, however, IFALPA was in formal discussion with Bernard Ziegler at a meeting hosted by Airbus test/training pilots. My talented copilot from our conversion course, Richard P, put a strong case for modifications to the auto-thrust logic on our behalf; but was successful only in obtaining a DMC mod to improve the presentation of current IAS on the PFD. The non-driven-autothrottle-lever debate was over, and we had decided that the sidestick logic was acceptable, if not ideal for training/monitoring situations.

So is the current crop of Airbuses over-automated, leading to pilots being out of the loop and/or lazy?
Has Boeing found a better balance, or is it merely following in the safe wake of Airbus?
Automation was nothing new in 1988. For example, even the ageing B707s I flew in the 1970s had a yaw-damper, anti-skid brakes, and thrust-reverser inhibition in flight.
But we had to select our own spoilers on landing (no lift-dumpers) and there was no autothrottle, no auto-land, and no rudder-fine steering.
Like Airbus; all the others – including Boeing – have moved a long way in automation since then, and the trend continues inexorably...

HalloweenJack 6th Mar 2008 16:06

http://www.flightglobal.com/articles...different.html


German investigators have yet to release initial findings about the recent highly public wing-strike incident involving a Lufthansa Airbus A320 at Hamburg, but the carrier says the crew was offered an alternative runway before embarking on its crosswind approach.

they were offered 33 but opted for 23 based upon better ILS and guidance systems

Chris Scott 6th Mar 2008 16:52

Rwy 33 versus Rwy 23 ? No contest.
 
The LLZ-DME approach (ILS localiser-element only, but with distance-to-go information) on Hamburg Rwy 33 is a cinch on the A320, because of the FPV (Flight-path vector) flight-director. [Improvements in its presentation on the PFD, and in the selections display on the FCU, were made after the Strasbourg accident.]

Given the W/V that posters (and the video) suggest, the choice between Rwys 33 and 23 would have been a "no-brainer".

However, I am not convinced, yet, that ATC would have made such an offer without caveat. See my post of Mar05/10:53 [currently #284], re ATC at Hamburg in particular, and in Germany generally.

XPMorten 6th Mar 2008 20:00

To me it looks like a case of no aileron into wind.
In fact, I dont think they gave aileron at all during the whole maneuver;

Below, the moment before decrab. Crab angle about 15 deg.

http://www.xplanefreeware.net/morten/DIV/LH1.jpg

1. Below, rudder gets kicked in
2. Plane decrabs to 0 deg, beta angle now about 15
3. Wing comes up due to yaw induced roll. No sign of roll spoilers.

http://www.xplanefreeware.net/morten/DIV/LH2.jpg

4. Pilot releases rudder pedal, wing hits ground, STILL no sign
of aileron or rollspoiler.
http://www.airliners.net/uf/53688288.../phpOltUWB.jpg

5. Being in a beta angle and bank without any controls input, the acf will now
swing back to equlibrium. The nose will swing back to 0 beta (crab 15)
and the wing will drop.

http://www.xplanefreeware.net/morten/DIV/LH3.jpg

So, no gust or aileron input needed for this to happen.

M

bubbers44 6th Mar 2008 20:29

She just needs 5 hrs of x-wind landings in a J3 cub and she will be good to go.

ihg 6th Mar 2008 20:46

@XPMorten: Thanks for your illustrative posting...although I guess it is hardly possible to identify definitive control surface deflections at this resolution, your description resembles pretty much of what I think has happened.... no 'unfortunately timed' gust , but simply insufficient, or no, roll compensation during decrab to keep the upwind wing down....no reason for reviving popular Airbus FBW discussions, but maybe more an opportunity to see basic flight mechanics at work...

Just my 2cents,

regards, ihg

NOR116,20 6th Mar 2008 21:05

XPmorten,

I think you made a valid point.
Having seen the video it seems after or while de-crabbing no upwind aileron at all has been applied.

Some pictures in this link:

http://www.hamburg-airport-friends-f...tid=763&page=1

The 3rd picture shows LH044 on its landing on RWY33 in the second attempt.
Landing takes place using a good side slip technique: upwind gear touches first due to upwind aileron and rudder to opposite direction.


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