LH A320 reportedly within 0.5m of crashing at FRA !!
 

As reported in Flight International today a Lufthansa A320 almost crashed at FRA on 20 March because of faulty reverse wiring on the captain's sidestick!!

The aircraft hit turbulence shortly after lift-off resulting in a left wing-down. The captain responded with a slight right input but the plane banked further left. A further right input resulted in a 21 deg wing-down at which point the wing dipped to within 0.5m of the ground!

At this point the first officer, realising what was happening, switched his sidestick to priority and recovered the aircraft, preventing an almost certain crash.

I'm glad I wasn't a passenger on that flight!!!

I wonder if LH do control checks on the ground? This should have shown up this fault. Airbus also recommend it and say that you should hold each stick position for 3 seconds as it takes that long to generate the fault message. They also recommend checking your screen to check that left stick really is left stick.
Interesting.

This seems almost implausible. The control check SOP requires the non-handler to monitor the inputs of the other guy on the flying control ECAM page. He then repeats the process himself with his sidestick. This is normally done during the taxy out.

Even if both guys do this with their eyes shut then an ECAM warning is generated to the effect that the spoilers or ailerons are not responding as expected to the pilot input.

The logic for this warning was changed after the Excalibur incident where due to a maintenance error the aircraft became airborne with several pairs of spoilers hydraulicly isolated and therefore not responding.

It was believed the crew missed it on that occasion because the trigger time was too long. This was corrected to a much shorter time for detection of lack of control response to pilot input.

FI don't usually get it wrong ???

The article does mention that on previous maintenance action two pairs of pins inside the connector of the captain's controls had accidentally been crossed. This resulted in a change of polarity of the sidestick. Apparently this bypasses the control unit which senses the error and triggers a warning.

This, of course, does not mean that they shouldn't have caught it on the flight control page of the ECAM during the flight control checks. The article does suggest that most pilots tend to look for a deflection indication rather than checking the direction is correct as well. In a rushed environment, or with a distraction, I don't think that is implausible.

And of course it was also signed off and fully checked by the best DLR tested engineers in the world, or was this done just to DLR test the pilots?

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We will do the drill according to the amendments to the amendments I er think?

Full marks to the F/O for quick thinking therby avoiding what would have been a tragic accident. That particular F/O has certainly earned a lifetimes worth of salary - well done!


Regards
Exeng

AirBus technology at its best. And, with a first class operator. Woe-be-tide the third world airlines who are stuck with this equipment.

Good grief...411a has an opinion on almost everything in aviation!! What a guy..or is that S.O.G.? See Fragrant harbour!

411A,

'AirBus technology at its best.' Perhaps 'Airbus technology at it's worst' might have been a more appropriate coment.

Clever though the Airbus is, the 'system' allowed both engineers and pilots to depart with an aeroplane that was cross controlled in roll. (Albeit on one side only).

That is worrying.

Again, full marks to the F/O who saved the day.


Regards
Exeng

P.S. I'm currently on an A320 course and after reading 'Flight' this morning haven't got any fingernails left!!

If the signal was capable of being reversed-why wouldn't the plug itself prevent it? The one round hole and one square hole idea.

Oldag84
If the pins in the plug are crossed (and they are all identical) then it will defeat the indexed plug, which they undoubtably are. The real problem is the after defect check out by engineers ( plus of course any preflight checks.

411A - is that the type of Cessna you fly ?

One wonders, if this had ended in tradgedy, where would that have left Airbus and it's much-vaunted technology? What would the public think? And I'm fully aware that this can happen to conventional control systems, as well ( I remember a C-130 and an F-4 having reversed controls, from my RAF days).

Worrying.

Piper Aircraft lost two flight test pilots in a Navajo that way, back in the seventies....

...and Roy Chadwick in the Tudor.

GotTheTshirt---
Indexed plugs, wrong wiring, a bad combination. Wonder if the investigation will be swept under the rug. Sure hope not.
The F/O sure was on the ball.
'Tis a very good reason WHY the F/O should have plenty of sectors. Wonder if the CX guys are listening?
CE411A is the personal aircraft, L1011 the professional type.

[This message has been edited by 411A (edited 22 May 2001).]

Hypothetical here - despite the magnificent efforts of the F/O, should the whole thing have gone pear-shaped with the unfortunate crash of the aircraft, would there have been enough evidence to have shown that crossed pins was a cause rather than erroneous banking associated with turbulence?

.......or the flight control check not allegedly being carried out properly.

Also 411A does have a valid point about a first class operator, what happens a few years down the line

I hope that the Lufty pilot's make full use of this incident in pursuing their pay rise.

It would be interesting to see how the "Management" tried to tell the travelling public that this FO was not worth a rise.

Right there, the two LH pilots earned the payrise that VC is demanding. Manyfold!! Good job guys!


Oh sorry Bigpants, I just mirrored your post :)

[This message has been edited by Hung start (edited 22 May 2001).]

Have any of you guys that continually slate Airbus technology, stopped to consider what would have happened, if it had have been a conventionally controlled aircraft that had its controls rigged the wrong way round?

They wouldn't have stood a chance, even if the F/O was as quick as lightning, at least on an Airbus you can isolate the opposite control stick.

So I would say that on this occasion it was BECAUSE of Airbus technology that a major incident was avoided!!!!!!!!!!

Oblaaspop, great minds think alike. I am very pro Airbus myself and I stongly agree with the point you're making. HOWEVER, flying being the dangeourous bussiness it is, this incident shows that aircraft safety technology as well as good pilot training still have a long way to go. Don't get me wrong, the pilots did a great job in catching a possibly leathal fault, but the fault passed two safety "filters". The first one was the fact that the fault was not detected by ECAM (technological problem) and the second one was the fact that the pilots did not spot the fault during one of the most important checks we do: the flight controls check. I say again, I am not pointing my finger at pilots (bless them), we all miss out things. But from a pilots' point of view this incident shows that you can never take anything for granted and that there is still a very good reason why there are TWO pilots(humans) in a cockpit.

Indeed a very valid point in favour of the 'bus'.
Have been a Boeing driver haven't flown the bus but see no reason to knock it. The problem of crossed contols can and has been done on convential aircraft and in this case the plane has been saved by it's design.
Well done Airbus.

Mr Benn
Regarding your post, can you please point out where exactly did you come across the 3 second delay for the fault flight control to come up?
I got that info as well but with no referance (FCOM or FCTM)
Thanks in advance

Did you lot read the rest of the report or were there too many big words? F/O did a great job (I mean that!)
Connector - whether indexed or not, crossed pins would not have prevented the connector from correctly engaging. (Contacts/receptacles are the correct term). If Flight report is true, there is no excuse for not having done a continuity check on completion (a primary FCS!!!)but there again, what did ADRES tell him to do? This constitues a repair and would be covered under ATA 20 Wiring Practises.The engineer had allegedly only done a flight control function on the right stick. Do Lufthansa/LBA procedures demand a duplicate inspection? Do Airbus classify it as a "vital point"? They may have deemed this incident impossible with the system as currently designed. Another problem, FBY systems make such a repair or maintenance (on the side-stick) the reponsibility of both ATA 27 & 22 (flying controls and auto-flight) disciplines. Was there confusion or another Human Factors issue? Was the engineer being pushed to get the job done quickly? Had the crew performed a correct sense check (think about Excalibur a few years ago)?
Accidents are caused when a chain of relatively insignificant incidents link up. Think of James Reason's analogy of the spinning discs or the Swiss Cheese model.


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Bus429 - the pilot's pal!



[This message has been edited by Bus429 (edited 22 May 2001).]

Hi everybody,
I'm the author of the FI article and unfortunately it got a bit shortend.
To get the heat a bit down (or turn it up - as you might see it) here some more facts, which are as well available on my webpage at www.aviationsafetyonline.com :


A proper flight control check has been conducted. By the mechanics and by the crew, prior to take off. The problem, as I see it after consulting with some AI mechanics are
the wiring lists. Figure that out: even among the same type of modern airbus FBW aircraft the sidestick connector pin might be wired differently. According to the Murphys law rule this implements incidents and accidents to happen. The connector pin is a 164 pin connector (similar to those you have for you printer cable at your pc). Apparently the wrong wiring list was consulted (though it was for an A 320-200 aircraft) and the wires for the roll input and the associated control channels were reversed. This resulted in the ELAC computer indicating proper aileron deflection while the ailor was actually reversed. This failure is impossible to detect, as long as nobody outside the cockpit visually checks if the corresponding aileron deflection (up/down right and left wing)is consistent with the control input.


Airbus Industrie did not respond on several requests for comment.


Happy landings and let's all be careful out there


Tim v. Beveren
(independent) editor aviation safety
www.aviationsafetyonline.com

[This message has been edited by TvB (edited 05 June 2001).]

Crickey! If all this extra info is true it beggers belief. For such a condition to exist in such a modern, technically advanced, well maintained aircraft is truly scary.

Don't the French have a version of Murphy's Law?

Chaparral

The only reference to the 3 second 'delay' that Mr Benn mentioned was in some extra literature that was not FCOM related. I have searched in vain for more info but nothing is published in my books.

The delay itself is to prevent the FWC (flight warning computer) from faulting every single peice of equipment during electrical transients.

I am alarmed at the information from FI but I was under the impression that the ECAM gets its control position indications straight from the surface. Too technical, I know, but I find it difficult to believe that the F/CTLs and all of the Spoilers were indicating correct position just because the sidestick was in the 'correct' position.

TvB. Thanks for further explanation. If I understand it correctly, it was actually a wrong placement of the wires because it is in a different order on each specific type of Airbus, yet the pin is the same on all types? In the military the ground personnel visually checks the flight controls before departure. Why not in civil? Shame on AI for messing up the design like that! But having said that never forget that things are always designed in a certain way for a certain reason.

Not only in this wonderful modern aircraft but throughout the entire Airbus FBW family, Thunderbug. I was told and had proof in my hands that even within one line series there might be differences in the wiring list for the respective sidesticks.


According to the sources, close to the German BFU investigation, the pins in the connector were wired 100 percent to the diagram, but unfortunately for the wrong aircraft serial no's. The correct diagram for the "incident" aircraft had these connections reversed (control channel and roll channel = total of 4 pins). Thereby the next step "safety feature", the control computer was "bypassed" and showed the correct(wrong)deflection on the ECAM screen.


Again, only somebody outside the a/c with radio communication might have catched it, when the wrong aileron turned up - instead of (desired)down.


I believe something VITAL as the flight controls, specially in an FBW aircraft, should be failsafe on this end.
I recall talking to a former top manager at AI some years ago, where we discussed such an issue and AI was trying to convince me that a screw up as it was the case in the famous B 727 accident(flight control cabels connected reversed) is more than unlikely to happen with an Airbus. Well Murphys Law...


BTW: there were 108 pax and a crew of 7 on board during this event. A/c registration was D-AIPW. Take-Off RWY was 18 and this is a pretty long one, as I recall. Big, big luck for all, as the aircraft was still above the runway and not close to the ajecent forrest...

[This message has been edited by TvB (edited 23 May 2001).]

Back to basics,

After maintanance affecting the flight controls, a visual check needs to be performed, and this in all possible modes the FBW is supposed to function, Airbus or Boeing.

I am sure the manuals will be updated respecting this logic.

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Smooth Trimmer

[This message has been edited by Streamline (edited 22 May 2001).]

There we go again, the magnificent-state-of- the-art-fly-by-wire-"puesch-beton" (french for "push button")-fully-computerized-and-controlled-best-aircraft-ever-built!

Ooops!!!

What scares me is something like this happening to a major player like Lufthansa and their "above" standart skilled and trained mechanics.

Highest scores for this crew. 1.6 feet at full power and 20 deg bank? Scary, scary.

On top I find it pretty disturbing that there is not one unique wiring layout for the sidestick connectors. Hopefully it will be adressed soon but so far I'm only aware of a short bulletin for the Airbus jockeys
with instructions on "how to perform a flight control check". As I understand the issue here the ELAC won't sense this condition and the ECAM will indicate proper aileron movement (despite it will be exactly to the opposite direction). I believe this will go undetected as long as no one with sufficient understanding of this system, carefully observing desired aileron deflection according to (announced???) sidestick input is outside the bird.

Yeah, but I have to agree, this crew are good canidates for a salary increase.
Cheers...

I wonder what the cost would be to LH to settle with the pilots?

What would the cost be, including liability, litigation and hull loss, had the F/O not done his job?

No, I don't speak German.

Ficky,
depending on how many US citizens have been on board somewhere between US $ 500,000,000.00 and 800,000,000.00! This is what the insurance usually calculates with.
Germans don't count for that much (seriously), they don't have the same amounts and specially not such high punitive damages in Europe as we have it in the US.
But sure it will be a hell of negative pr for
Lusthansa.

411a

Lufthansa a '1st class operator' ??

mmmmmmmmmmmmmmmmmmmmmfm !! haHA!

"Wonder if the investigation will be swept under the rug. Sure hope not"


I realise that the Europeans have a lot to learn from our US cousins but the following pprune topic is an interesting read !

Topic: TWA 800 - the acceptable cost of accidents.
The moral Have a good,long,expensive,open investigation and dialogue - then sweep it under the rug!

At least Lufthansa looks a lot more safer than most of the African Airlines, according to the statistics...

[This message has been edited by Midnight Blue (edited 23 May 2001).]

I'm not convinced about the wiring list differences as stated here. I know you do get wiring variations but If it were the case that control wiring differed at the ELAC connector between models of the same type, the ELACS would not be interchangable between these various models and this is not the case.
If the two pairs of left and right signal wires were crossed there would be no ECAM warning, you'd only get the warning if it couldn't deliver what you asked, in this case they got what they asked, an aileron input, so no warning was generated.
Wiring checks as per the WDM rather than the wire lsit would have detected this.

We are talking the sidestick (output) connector pins, not the ELAC.
Do these go straight into the ELACS? Not to my knowledge, but I'm not an Airbus mechanic.

Rgds
TvB

Just to settle all discutions on 1 topic at least. The reason the ECAM diplay indicated the "correct" deflection is because the Ail., and all othe flt control, surface position sensor is a syncro, not a resolver, ei. it only measures amount of deflection and not direction. The syncro signal is fed to the FCDC (Flight control Data Consentrator), an Analog to Digital converter, and from there to the DMU´s for ECAM display. But to get back on track, the syncro signal is a AC voltage and the FCDC simply converts it to a Digital signal, the up or down deflection is based on sidestick direction.
Brgds
Doc

A couple of questions spring to mind here.

1. Following maintenance activity to a primary control system, was a duplicate (independent) inspection completed on the affected systems.

2. Was the maintenance carried out by an Avionics or Airframe technician?

3. Was the certifying engineer an Avionics technician, or an Airframe engineer?

I think that many answers to this incident may lie in the responses to these questions.

Even the very best people and systems screw up. The importance in an incident like this, is to ensure that the entire chain leading to the occurence is identified and the information be provided industry wide to ensure that the lesson is learned as painlessly as possible.

Mechanical control systems and autopilots get connected incorrectly and also cause crashes. The final inspection of any control system is to ensure complete and free range of movement, and also correct control response. The danger in an electrical system such as this, is the possibility that the engineer performing (or certifying) the activity does not understand the complete implications of the system concerned.