What about manual gear extension!
 

During these Acceptance/Hand Over Flights often a demonstration of "manual gear" extension is performed.
This may have been started?
What is the procedure on the A320 to perform this?
Any related issues that could have resulted from this?

below MDA, very valid and timely post. In fact some accident CVR transcripts I've read have the "human frailty" dialogue officially removed, as irrelevant...I hope this becomes the case for this accident.

are you sure that is what was released?

it's one thing to release an actual recording for subjective interpretation by the public and quite another to release decoded spoken words.

For sounds other than words the CVR team typically paraphrases these into descriptions appropriate to the investigation in the language of the lead investigator You typically do not leave unstated a blank area in a recording unless it actually has no data.

What words that you use to describe an area in a recording that has sounds other than spoken words is the provence of the langauge of the decoding expert since you have to put something down on paper factually.

I'm not sure if it is the translated word "scream" that bothers you or that you would have preferred some other factoid in its place.

lomapaseo:

Quoted in the NZ Herald
Perpignan state prosecutor Jean-Pierre Dreno said the pilots "were having a lot of difficulty controlling the plane", and that in their last seconds "they were screaming" as they hit the water.

Firstly I don't think anything of this nature (the CVR) should be released to the public as it serves no constructive purpose. Maybe others can see a good reason for it to be out in the public but I can't.

Once the investigation is complete, then I accept that portions of the transcript will make it into the public arena, however this current snippet is just crass.

Once again: fellow who leaked it is state prosecutor, in charge of criminal investigation, has no relations with BEA and is not aviation expert at all. BEA made no new statements regarding the contents of FDR or CVR.

Thanks Clandestino.

Competence, discretion, ethics, and so on and so forth, are not very high on their list of priorities.

CJ

I'll leave the wannabees to their comments.

But you do not normally carry out two test flights of some duration without being aware of sensors being "taped off".

CJ

I see in this that MAYBE a sensor was not covered during painting and it subsequently became ineffective rather than not having the protection (tape?) removed. Paint, or paint chips, in a static line could cause all sorts of havoc.

Perhaps this might help?
 

Air New Zealand says a safety alert distributed by aircraft manufacturer Airbus may indicate part of the reason behind the airline's fatal crash off the coast of France.
Five New Zealanders and two Germans were killed when an Air New Zealand-owned Airbus A320 crashed into the sea near Perpignan on 27 November.
It had been leased to a German airline and was being tested before being returned to Air New Zealand.
On Thursday, Airbus sent a notice to airlines reminding them of the importance of flight check requirements and maintenance, in particular to be careful of data sensors when painting aircraft.
Data sensors give pilots key information to enable them to fly the plane.
Air New Zealand chief executive Rob Fyfe says from the information in the safety alert, it may be that the investigators think the plane's data sensors were not working properly.
However, he says as the crash investigation has not been completed, the safety message should not be regarded as a definite finding.
The Air New Zealand plane had just been repainted in the company's livery when the crash happened. That work was completed by the German company which leased the plane.
Aviation commentator Peter Clark says the air safety notice may mean the plane's data sensors were somehow damaged or covered when it was being repainted.
Mr Clark says Airbus does not want the notice to be taken as a pre-judgement, but the infomation comes from the preliminary work completed by investitgators looking specifically at the Air New Zealand crash.
Recommendations followed - Air NZ boss

Mr Fyfe says Air New Zealand already follows the safety recommendations.
He says it is important that Airbus issues the notification, but it should not be taken as a pre-judgement of the official crash investigation.
He says any speculation would be premature and remains pleased with the performance of Air New Zealand's fleet of Airbus aircraft.
Air New Zealand is to send specialist staff to France this weekend as investigations continue into the crash. The visit is at the invitation of the French investigating body, the BEA.
Personnel from the New Zealand Transport Accident Investigation Commission will also take part.
A preliminary report into the crash is expected by the end of January.

Copyright © 2009 Radio New Zealand

Whatever the cause of this accident and I hope they find out and the findings are published soon, will not alter this fact. "One of the most dangerous aircraft you can fly, is one straight out of maintenance".

This is not a dig at engineers as we as pilots are not infallible either.

As an example of how sensitive air data sensors are/can be on modern FBW aircraft , try googling the B2 crash at Guam in feb last year !

Strangely enough I proposed the tape over static port scenario in post 109 (http://www.pprune.org/rumours-news/3...ml#post4561998)

What happens is the sea level pressure bleeds out in climb, and then the statis pressure stays low giving an artificially high indicated airspeed when the aircraft descends. The delta pressure across the tape seals the 'low pressure' in. Airbus aircraft do not have pitot-static probes, they have pitot probes with separate static ports on the fuselage.
If the MRO uses aluminium speed tape to cover the static ports, it is easy to miss as it is the same colour and appearance. Hence reputable MROs use bright orange covers with a streamer.

Indeed looks more and more like some sort of problem post maintenance relating to sensors.

That being said is the WaterBus(tm) so hard to fly and land during daylight in direct law so that you end up crashing ? I have numerously advocated for a big red "kill all automation, let me fly this" button and I have been told that it was indeed available... still somewhat puzzled by what happened here.

atakacs
 

If you were not "still somewhat puzzled by what happened here" you'd be a genius, since you are presumably not an accident investigator and have no access to the recorded data.

I wonder why Air New Zealand do not mention this?
Check flights must be performed in compliance with flight order within the Certified Flight Envelope. In particular tests such as low speed test must be performed at safe altitude and be preceded by a recall of basic rules as regards to minimum speeds and recovery actions.:=

Mmm! the a/c had been airborne for rather a long time, surely taped up statics etc., would have been apparent a lot earlier. The 757 crash off the S.A coast knew their was a problem almost immediately.
Lets wait for the interim report. and get some facts.

Configuration change?
 

If speed brakes (extension/arming), slats/flaps, or gear were commanded or extended either alternately or normally - does this change any auto-pilot, stall, FADEC logic and perhaps use sensor inputs that may have not been noticed or required until that point in the test flight - thus a sudden change in flight characteristics/inputs that the crew did not expect nor have a chance to react to timely?

As someone with command time on he A320 as well as having done the A320 maintenance course I have to say that even with the help of 26 pages of PPrune wisdom I would not like to speculate on the cause of this accident.

So I will wait for the offical report before making comment

AFAIK, plenty......

Many years ago I remember being told on my DC9 course that you should always lower the gear before arming the speedbrake for landing, the reason given was that in case of a problem with Air/Ground logic you would receive full ground spoiler on selecting gear down. :eek:
I was led to believe that someone had learned this the hard way, and continued to respect this sequence of selection in 20 yrs of 737 flying.
Can someone tell us if this failure mode is feasible with A320 Air/Ground logic failure.

There are no alternate procedures for extending flaps/slats or arming ground spoilers on A320. Manual gear extension will leave the gear bay doors dangling and will deprive you of nosewheel steering. Extending the slats or activating engine anti-ice rises minimum idle N1 but otherwise doesn't affect "FADEC logic". A320 isn't difficult to fly in direct law - it evens feel livelier and trimming by wheel, C-172 style, felt quite fun, at least for me. Mind you, that was in the sim, I can't recall that my company's fleet ever suffered degradation into alternate law. A colleague of mine, flying in the ME, once had dual radalt failure. He claims that real aeroplane behaves even better in direct law than sim. Air/ground sensing on A320 controls much more than just ground spoilers and spoilers are armed after the final hi-lift devices config is set, anyway. Please be patient and wait for the report. Thank you.

Conjecture ?
 

French newspaper "Le Figaro" quoted this evening on Catalan TV as stating accident was definitely caused by a sensor remaining covered following of work on aircraft, described as "grave error" by factory.

I have no idea as to whether Le Figaro have inside information or this is a conjecture expanded to a cause.

From "Le Figuro" - conjecture after all.
 

Perpignan : un défaut de peinture à l'origine du crash


Thierry Vigoureux
24/01/2009 |
INFO FIGARO - Une panne des instruments de bord après la révision en atelier semble probable et Airbus vient d'envoyer un bulletin de sécurité à tous ses clients sur les vols de contrôle après révision.

http://www.lefigaro.fr/icones/coeur-.gif Les techniciens du Bureau d'Enquêtes et d'Analyses pour la sécurité de l'aviation civile (BEA), basé au Bourget, semblent avoir avancé sur le scénario de l'accident de l'Airbus A 320 survenu en mer au large de Perpignan le 27 novembre dernier. Sept personnes, des pilotes et des techniciens aéronautiques, avaient trouvé la mort.
Lors des opérations de peinture effectuées dans un atelier de Perpignan qui remettait l'avion loué à XL Airways Germany aux couleurs d'Air New Zealand, des capteurs sur le fuselage auraient été cachés par une couche de protection. Ce qui auraient rendu inefficaces les calculateurs et les commandes électriques de vol.Le déroulement de cet accident intriguait les experts car il était, théoriquement, impossible.
En approche finale avant d'atterrir à Perpignan, l'A 320 s'est cabré puis a décroché. Une manœuvre censée être impossible car les commandes électriques de vol de l'A 320 stabilisent automatiquement l'avion, éventuellement contre le gré du pilote. Les situations scabreuses sont donc impossibles. A moins que les sondes et les capteurs aérodynamiques situés sur les ailes et le fuselage n'aient pas rempli leurs rôles et n'aient pas alimenté en données les calculateurs de bord sur la vitesse, la pression, l'attitude de l'avion, etc. Les systèmes de sécurité intégrés aux commandes de vol deviennent alors inefficaces.

Scénario plausible


Reste à savoir pourquoi ces circuits de mesure doublés, voire triplés, n'ont pas fonctionné.Ce scénario est suffisamment plausible pour qu'Airbus ait envoyé hier à ses 218 compagnies aériennes clientes un bulletin de sécurité rédigé en collaboration avec le BEA à partir des premières informations tirées des enregistreurs de vol. Cette note, diffusée dans le monde entier, vise avant tout à éviter qu'un accident semblable ne se produise et recommande des mesures préventives comme le demande l'Organisation mondiale de l'aviation civile. C'est une garantie essentielle pour permettre à la sécurité dans le transport aérien de progresser.
L'enquête judiciaire ne doit pas interférer. Elle passe après l'enquête technique et s'efforcera plus tard de déterminer des responsabilités. Airbus met aussi en garde sur la conduite des vols de contrôle effectués après des opérations de maintenance, comme ce fut le cas à Perpignan.
L'avionneur rappelle les consignes sur les vols à basse vitesse qui ne doivent pas être effectués à basse altitude et donner lieu à un briefing spécifique.La presse néo-zéalandaise, alimentée la semaine dernière par des déclarations du procureur de Perpignan faisant état de données techniques incomplètes ou mal comprises, évoquait la possibilité d'une poussée soudaine des moteurs avant l'accident. Mais cette information ne peut être interprétée, faute d'être resituée dans la chronologie du vol.

OFSO

Translation sil vous plait.

Google translation:

Perpignan: a failure to paint the cause of the crash


Thierry Vigoureux
24/01/2009 |
INFO FIGARO - A failure of on-board instrumentation after revision workshop seems likely and Airbus has just sent a security bulletin to all its customers on flights after revision control.

The technicians at the Bureau of Investigation and Analysis for the Safety of Civil Aviation (BEA), based on location, appear to have advanced on the scenario of the crash of the Airbus A 320 occurred at sea off Perpignan November 27 last. Seven people, pilots and aviation technicians, had died.
During the operations carried out in a paint shop Perpignan calling the aircraft leased to XL Airways Germany in the colors of Air New Zealand, sensors on the fuselage had been hidden by a layer of protection. What would make ineffective the computers and the electrical vol.Le course of this accident puzzled experts because it was theoretically impossible.
On final approach before landing at Perpignan, the A 320 reared then stalled. A maneuver meant to be impossible because the electrical flight of the A 320 automatically stabilize the plane, possibly against the will of the driver. Egregious situations are impossible. Unless the probes and sensors on aerodynamic wings and fuselage have not fulfilled their roles and are not supplied with data onboard on speed, pressure, the attitude of the aircraft, etc.. Security systems integrated with the flight controls become ineffective.

Plausible


It remains to know why these circuits measuring doubled or even tripled, not fonctionné.Ce scenario is plausible enough that Airbus had sent yesterday to its 218 airline customers a security bulletin written in collaboration with the BEA from Initial information from the flight recorders. The note, circulated throughout the world, is intended primarily to prevent a similar accident from happening and recommends preventive measures as requested by the World Organization for Civil Aviation. It is an essential guarantee for the security in air transport to grow.
The judicial inquiry should not interfere. It goes after the technical investigation and will try later to determine responsibility. Airbus also cautions about the conduct of flights made after control of maintenance operations, as was the case in Perpignan.
The manufacturer recalled the instructions on flights at low speed which should not be conducted at low altitude and give rise to a press briefing spécifique.La New zéalandaise, fueled last week by statements by the prosecutor Perpignan reporting data Technical incomplete or poorly understood, evoked the possibility of a surge engines before the accident. But this information can not be interpreted, if not viewed in the chronology of the flight.

That translation is so poor...

This implies that if the "electrical flight" (what a crap term) is erroneous, for whatever reason, the stabilization might be erroneous as well, possibly against the will of the driver.

This quite sums up the design flaw of the Airbus system. Murphy said quite rightly that if something can go wrong, eventually it will. Even in a Bus. Therefore depriving the driver of the final authority is a serious flaw.

I don't know where atakacs got his information from:
I have yet to find that button, but it would make the Bus a safer equippment to fly.

I dont think you can take any stock in these automatically generated translations. 'Electric flight' is a term google translator came up with. Meanins and terms can be mixed up.

You should have seen the babel translator version :o

I am no expert, but what about:

1: FAC 1+2 off. (Alternate law)

2: Gear down (Direct law).

Having just re-converted back onto the bus. After 12 yes on boeing. I still can not understand how they could have flown around for so long without any problems only to have the machine do something un-controlable on approach.???

Before this thread ends up going in the ridiculous direction of Boeing/Airbus, Fly-by-wire/Manual control lets not forget one thing.

There has already been accidents due to this type of mistake and all were Boeings are far as I can remember. The aircraft could not be manually controlled due to erroneous air data readings.

So erroneous air data information is just that, erroneous. It will in all probability lead to tragedy and has no respect for aircraft manufacturer. Therefore the boeing/airbus, manual/automated nonsense is not required here.

Actually there was an A300 in Kenya (?) which crashed at takeoff because of erroneous stall warnings to the crew (although the exact cause of those bogus warnings where not established it was definitely sensor or computer related).
That being said most if not all "bad sensor" induced crashes where during night operation, in which case getting inexact readings from some or most instruments is obviously quite challenging (albeit survivable in most cases with the benefit of hindsight). Here they were flying with reasonably good visibility yet they still lost the aircraft. I can certainly foresee surprise and panic when the Bus decides to do something unexpected (this time because of possibly paint damaged sensors) but I am still convinced that there is no adequate takeover procedure for the pilot to regain control when things get out of hand. One can mention the A330 test flight that went bad and where the chief test pilot did not manage to recover in time because (among other factor, admittedly) he did not understand what the plane was doing or the TAM 320 where the crew was refused any kind of braking because the automation systems did not like what the pilot was doing. In both (and other cases) the pilots might have had a chance if they could quickly revert to a fully human controlled flight. I'm pretty sure this will be the case here too...

One might argue that the various automation built into the Airbus FWB systems did actually save the day more often than not by overriding the pilot and it is quite conceivably the case. But I would still be more reassured if there would be a quick way to get back full control of the plane and if the FWB pilots would be actually trained to take over when they don't understand what's going on (just remember the Flash Airline pilot whose only answer to increasing excessive bank angle was to revert to the autopilot... it was a 737 but it's NOT the attitude to have).

Birgenair B757
 

A Birgenair B757-225 crashed in 1996. Speed indications were wrong because of obstructed pitot tube. But back then problems started very early in the flight.

The Airbus Safety message text seems to have been removed (?) But from the Flight article, which I think fairly accurately reproduces what was said:Might I suggest we do not think this is, as suggested above, exclusively applicable to "Static Ports". It might have been... but these are not the "sole" sensors.

I find the second paragraph more interesting... and possibly making comments such as: not relevant ;)

There are numerous types of sensor, and numerous versions of each sensor. We do not what, or how many, were affected and when. But the second para seems to be giving out some clues as to the conduct of the "tests", possibly when combined with some sensor errors :ooh:

NoD

well we can speculate about many different scenario's but won't know the facts until they are published.

I would agree though that under normal circumstances blocked/covered probes/ports should become apparent immediately.

Angle of attack probes though could be a different story.

- I know not about the 777 (nor Airbus), but certainly up to that model ALL Boeings can ALWAYS be 'manully controlled' in that situation. It is not easy, by any means, due to misleading and confusing instrument readings, but it is something we practice in the simulator with success. There are specific Boeing procedures and settings for crews to help with this, and I would expect the AB to be the same.

IF the problem was a taped over static port, it must surely have shown itself earlier in the flight, so there should be discernable data? It would result in an increasing airspeed indication during descent which, I suppose, could have caused the auto system to reduce actual speed to compensate until Alpha Floor AoA was reached? As to why this may have caused loss of control, I know not - any AB folk to comment? I appreciate that the unexpected onset of TOGA could cause a huge pitch up but I thought the AB control system was designed to cope with that - unless of course it was being flown manually.

I have not read right back in the thread, but do we know the wx conditions prevailing around the crash site?

@BOAC

you are of course correct and I could have worded it better. My point though was that it really makes no difference whether it was a digital aircraft or analogue. Erroneous air data is a difficult situation to handle.

I do not subscribe to this Boeing manual control or Airbus automated control nonsense. Both manufacturers aircraft are inherently safe.

I truly understand the uproar of the Airbus lobby, them therefore bringing up the (somewhat childish) "but it can happen and happened to Boeing too....."
This is true and it also lead to accidents, yes.

Fact is simply, that in a sensor malfunction with erroneous data and electronic flight signals, the one still allows to be flown with the good old a$$ relying on attitude, RPM, sound and so forth. The other one does not, see Qantas incident.

For my part, I simply and sincerely prefer the earlier, even if the systems are less elaborated and sophisticated and those marvels might have saved one or two. This however applies just as much to the other system (beeing childish myself). And remember: You do not HAVE to disconnect everything, but at least there you CAN.