Brand new Etihad A340-600 damaged in Toulouse; several wounded

[L Peacock]

Yep I see it. I know it's a foreshortened telephoto pic but that does look like a very short skidmark. Wheels not initally locked?

[mary_hinge]

That photo shows just how much the aircraft moved over to the right after the impact with the wall. The report and down loads will be interesting!

Any news as to how the injured are?

[aerotransport.org]

Any news as to how the injured are?
One still in hospital

[PAXboy]

miniGuys, forgive me, I have not read every single post.

But, if you're going to do run up tests surely the manual states the braking/anchorage requirements.If you HAD have read every single post, you would have read the statement from AI that the a/c had completed it's tests and was departing from the the test bay. We await official confirmation.

[Mr @ Spotty M]

Paxboy, if you had read all the posts you would have found the post from AI stating that it was not exiting the bay and official confirmation that it should have been chocked as per the AMM.

[PAXboy]

Mr @ I'm sure you noticed that I wrote: We await official confirmation. Given how much money is at stake, only a final report will do.

[CONF iture]

Look at this photograph.Can you see a solid black strip going towards the wall outboard of the left hand bogie?It may not be in line with the current hull position but if you move the hull to the left towards where it was when the no1 engine contacted the wall I think they line up.Locked wheel???
If you apply the translation, that mark is not coming from left set of wheels, but from the center one !

And a tire is not that large, these wheels were not braking, but crabing.
Now, try and find any braking mark from left hand bogie ?
There is none.

... I'm afraid that airplane was not braking at all !

[tubby linton]

Conf I think you are correct.I am not familiar with the braking system of this variant of bus are there any brakes fitted on the body gear?

[hetfield]

@confiture

But it seems, the whole thing swept to the right. Look at the markings of engines 1 and 2.....:hmm:

[lomapaseo]

Mr Spotty

.... if you had read all the posts you would have found the post from AI stating that it was not exiting the bay and official confirmation that it should have been chocked as per the AMM.

I believe that if we read all the post we can conclude that nothing untoward happened since it is only in our dreams.

There are so many contradictions in what has been released to the press that we still have to guess at what might have happened.

I tend to believe what the BEA releases and updates. I don't believe that Airbus has any intent to mislead, but since they can only release what is confirmed by the BEA, their safest course of action, early on, is to confirm the applicability of their recommended procedures under the circumstances of the earliest reports.

Should the investigation later reveal circimstances not covered by these procedures, then I would expect Airbus to release updates to the procedures without compromising the investigative perogatives of the BEA.

Someday mayby somebody will post a timeline synopsis of all published news reports on this accident so we can see that we are mostly pawns to the interpretations of the news by non-aviation professionals as we post on these forums

[CONF iture]

are there any brakes fitted on the body gear?
It seems there are, they talk about that earlier in the thread.
But as I say, these mark is not from a braking action.
But it seems, the whole thing swept to the right. Look at the markings of engines 1 and 2.....
Absolutely, but note that the initial "climb" on the wall by #1 is in line with the overall movement of the approaching airplane.
As #1 "climbs" the 45 deg or so wall, Left set of wheels lift up, most off the weight transfers on Right set of wheels, and Center set of wheels drags side ways ...

And to get such a result, I would not be surprised at least #1 is still pushing ... a lot.

I know ..., not really what Airbus and BEA pretend ... ?

BTW, very interesting picture !

[Mr @ Spotty M]

Yes "lomapaseo" l agree with what you believe, and that you can not take anything for granted from a press release.
I have seen to many over the years, even some from my own company giving even the incorrect aircraft type, so l take them with a pinch of salt.
My point earlier was we do have some official confirmation, in that it was not chocked, was using parking brake and that the persons on board we being vigilant as they did notice the a/c moving within seconds and applied the main brakes.
We have no idea why they did not retard the throttles straight away as most of us would do however.
The reason this was official confirmation is because it was released to the airlines and not the dam press.:(

[Tediek]

Does anyone know if they have pulled the a/c loose from the wall?

[c130jage]

The nose section was removed mid week and the main fuse removed late on Friday, It now waits continued investigation within the facility/

[Tediek]

thanks for the info, are there any pictures available of this operation?

[CONF iture]

spot on bsieker (http://www.pprune.org/forums/showpost.php?p=3711858&postcount=118) :ok:

[navtopilot]

It was an A300-B4 not a 600

[Profit Max]

It was an A300-B4 not a 600:rolleyes: Why would you think that??

[saman]

Sorry navtopilot, I think you'll find Airbus stopped building A300 B4s a while ago. Even the A300-600 is now but a happy memory. This was an A340-600; 4 fairly big donkeys and the longest fuselage in production. It looked really nice before the nose job.

[robbreid]

From Aviation Law Service;

An unconfirmed account has it that a person in the cockpit fell onto the pedestal; in a 16 November press release, Etihad maintained that none of its staff were involved in the accident. The investigation is centered around the nose wheel steering, which was reportedly unlocked in order for the airplane to move out of the area after the tests had been conducted. It was apparently locked again for an unknown reason, putting the aircraft in front of the wall with engines running. The accident site makes sense if someone forgot to re-engage the nose wheel steering before heading to the exit taxiway. Then, the person lunging for the switch (to help the apparent lack of directional control) fell across the throttles – this at least is a reasonable scenario.


A few years ago there was a similar accident at Vancouver, Canada involving an engine test run on the ground of an Airbus A310. In that case, only line maintenance chocks were used during the engine run (as opposed to Airbus special ground run chocks that cannot be jumped). In the Vancouver case, avionics technicians pulled a circuit breaker that put the aircraft’s computers into flight mode. Presto! The engines went to flight idle, there was no reverse thrust, brakes or nose-wheel steering. The airplane jumped its chocks so fast the mechanics in the left and right cockpit seats did not know what happened (and they were not aware of avionics technicians fiddling with the circuit breakers). The airplane basically was on an uncontrolled taxi, right into a ground equipment building, and with enough force to shear off 6-inch steel I-beams.

[lomapaseo]

An unconfirmed account has it that a person in the cockpit fell onto the pedestal; in a 16 November press release, Etihad maintained that none of its staff were involved in the accident. The investigation is centered around the nose wheel steering, which was reportedly unlocked in order for the airplane to move out of the area after the tests had been conducted. It was apparently locked again for an unknown reason, putting the aircraft in front of the wall with engines running. The accident site makes sense if someone forgot to re-engage the nose wheel steering before heading to the exit taxiway. Then, the person lunging for the switch (to help the apparent lack of directional control) fell across the throttles – this at least is a reasonable scenario.


The pedestal story is back again:\

This is like reading a mystery novel where the stars are supposedly killed off only to reappear again in later chapters in new sub-plots.

[robbreid]

As it states; "Unconfirmed", however with that said, it comes from one of the foremost aviaition litigation firms.
http://www.aviation-safety-security.com/current-newsletter/articles/french-investigating-mishap-at-airbus-fa.html

Quote from another aviation forum;

"Ah yes, the cockpit of tomorrow equipped with a pilot and a large dog.

The pilot's there to feed the dog.

The dog's there to bite the pilot if he attempts to touch the controls."

[PJ2]

Hm...like the cat-and-duck IFR method , a very old story.

Whether someone fell on the thrust levers will be a simple matter to resolve using the QAR/DFDR, (which, unlike the TAM accident, doesn't seem to have emerged quite as quickly...)

[hetfield]

The French will manage to explain it quickly..........

[CONF iture]

Whether someone fell on the thrust levers will be a simple matter to resolve using the QAR/DFDR
And do not discard CVR ...
If at least one guy from Toulouse was in the flight deck, I cannot imagine a loud "Putaing con !???" would not have emerged !?
Didn't BEA say after all:
Elles sont de bonne qualité
True, looking at "the minimally-damaged tail" it would be embarassing to pretend otherwise.

[PJ2]

No, not discounting the CVR but recognizing that words provide reactions to data, not data itself. The CVR will absolutely be of high collaborating interest. It is the TLA's which were either already at 45deg or suddenly became 45 deg (or close), closely followed by forward movement as sensed either by wheelspeed or IRS groundspeed plus the 'g' in all 3 axiis. We already know that the TL's were closed 2 seconds before impact, so it will be interesting to see when they were moved up into the EPR = 1.26 regime. I suspect it will be more than a minute before the aircraft began moving as I don't subscribe to the "falling on thrust levers" theory, but the data including any expressions of surprise on the CVR will tell us - if it's ever released.

[fox niner]

OK, let's look at it from a legal, judicial standpoint.
The airplane was not yet delivered to its new owner. Therefore this could be regarded as an internal Airbus manufacturing "incident". It certainly was not a comercial flight with paying passengers on board. Therefore certain legal guarantees are not provided.

I only fly airplanes, and I have no knowledge whatsoever about legal stuff. But I can imagine that Airbus is not obliged to provide any information as to the chain of events that led to this incident.

So maybe we will never find out what happened? Perhaps someone who knows more about legalities can comment on this....

[barit1]

A somewhat related case in KLAX 2006 (http://www.pprune.org/forums/showthread.php?t=228919)

In both cases the engines were running for purposes of ground test, not for flight. Ergo, the definition of "aircraft accident" was not strictly met.

In the LAX case, the NTSB immediately became involved because of obvious safety-of-flight implications, even though the US OSHA would ordinarily cover it.

In TLS - who knows? Would the French equivalent of OSHA have primary responsibility?

[manrow]

If the French can cover it up in a teccie way they will! But their press releases so far leave them little room for manoeuvre?

[mokane99]

The accident, since in occurred in France, will be covered under, that is, subject to French law. The contract between Airbus and Etihad may well have specific provisions concerning loss and responsibility; normally one would expect to see an arbitration clause given a buyer in the Middle East. The technicians, though, were from a different company.

Under French law, where a tort (a wrong) is committed a remedy exists. There are so-called 'force majeure' events for which no one is deemed to be responsible. In these cases, the insurance--probably Factory Mutual in the U.S., but maybe not--would 'simply' pay the loss.

But here it's possible that the technical company's employee's are at fault, especially if one of them fell on the pedestal; unless the fall was precipated by a tortious act of an Airbus employee. If Airbus can show that the accident was caused by one of the non-Airbus technical employees, i.e., the tests were finished when such an employee acted imprudently and fell on the pedestal--then the technical company will be responsible in whole or part for the loss. If the third-party technical personnel were merely observers and had nothing to do with the accident, then they would not be liable.

While it may seem that the fact the technicians were from a different company would shield Etihad, because of the theory of agency, these employees may be deemed to be under Etihad's control, and if they are, then Etihad may ultimately share some of the responsibility. Based on the 'facts' as they have been developed, at this point there's really no way to tell. In this regard, it's not uncommon in the Middle East to have employees "seconded" from one employer to another. If this was the case, it's possible that the technical case were "seconded" to Etihad, and thus, assimilated to Etihad employment.

There may be a good deal of finger-pointing down the line; the main thing, in order to determine tort liability, is to try to determine exactly what happened.

[lomapaseo]

I wouldn't hold out a lot of hope for recorders where one of the engines was left running until it ran out of fuel. Of course mabe even that rumor is false or dead waiting for new life.

Even if this is purely a test aircraft function not intended for flight Airbus has a responsibility to report any anomalies found that could releate to intended flight.. If that pedestal story continues to hold up even the dog in the cockpit wouldn't help

[J.O.]

Not to mention the fact that maintenance people who conduct engine runs need to be aware of the hazards involved as identified by this occurrence. As for the recorders, the CVR on most new aircraft runs for 2 hours, and I can't imagine it took that long to get the engines shut down. The DFDR should be good for 24 hours, so for sure there's no issue there.

[forget]

the CVR on most new aircraft runs for 2 hours,

An earlier post, which went unchallenged, said that (at least) one engine ran for 7 hours.

[Rhys S. Negative]

I wouldn't hold out a lot of hope for recorders

But post #193 on page 10 of this thread purports to describe "the sequence of events according to the recorders".

RSN.

[forget]

The Flight Data Recorder will track events long beyond 7 hours. The Cockpit Voice Recorder may well have been overwritten (2 hours) so what was said on the flight deck (very significant here) may be lost.

[EDML]

However, I am sure they removed the CVR and DFDR before that time.
There should be enough people around who know why and how to
stop or remove it.

Marcus

[Profit Max]

The CVR probably stopped recording anyway since the signal from the cockpit probably became unavailable when the front section tore off.

[OccasionalFlyer7550]

It looks like the engines (and probably other individual components) might be salvageable. So, it might not be a complete w/o.

[CONF iture]

After reading BEA (http://www.bea-fr.org/francais/actualite/com20071120.html) and Airbus (http://www.flightglobal.com/blogs/flightblogger/2007/11/etihad-a340600-preliminary-tim.html) bulletins
No other alternative than to blame the crew (I should say the two guys) seated at the controls at the time:

These guys failed to retard the THR LEVERS for 11 seconds !?

They did rapidly notice they were moving
They did quickly push on the brake pedals
They did quickly turn the PARKING BRAKE OFF
But they failed to retard the THR LEVERS for 11 seconds …
As the wall was dangerously approaching, they kept substantial thrust (1.24 to 1.26 EPR) for 11 seconds !

How surprising is it ?

Still, it could be possible … as long as you don’t have a look at the pictures (http://www.flightglobal.com/blogs/flightblogger/2007/11/etihad-a340600-accident-photos.html), and you don’t realize the magnitude of destruction, and you don’t note the absence of braking mark.

So possibly one of these official statements is false, if not all of them:
· Airplane was at 30 knots
· Power was at idle
· Airplane was braking

DFDR / CVR did deliver all the story already, but very surprisingly they waited (as officially told) 4 days before reading them, and even there they precise they waited in the afternoon to do that, at tea time.

But this information is not avail to anyone, it would be too simple to know what happened, it really has to stay in “good hands”.

... and be assure:
THERE IS NO EVIDENCE OF ANY AIRCRAFT SYSTEM OR ENGINE MALFUNCTION
A ce stade, aucun dysfonctionnement technique au niveau des systèmes de freinage et des moteurs n’a été mis en évidence
CVR will tell us - if it's ever released
Usually it is, ……. as soon as doctored !

[captplaystation]

Well, better doctored, than swapped. . . . like the one caught by aerial picture from a helicopter after Mont Odile, or Air Inter "air-show" (don't remember which but I think the
latter) which was a different colour to the one they produced at the Press Conference. Insp Clouseau would have appreciated that gaf.

[jaadu]

AAAAAh that explanes the order for a palet load of speed tape:suspect::suspect::suspect:

[Mad (Flt) Scientist]

very surprisingly they waited (as officially told) 4 days before reading them

What's so surprising. This happened late on a Thursday, no? So Friday to recover the bits and pieces and check out the externals of the boxes once they get to the lab.

Sat & Sun - weekend. It's an incident during a ground test, not an inflight incident with immediate implications for inservice flight safety.

Monday afternoon, they read the data.

Like I say, what's the rush? If they were to say "oh, we rushed to read the tapes ASAP and accidentally erased some data - which COULD happen - the finger pointing/conspiracy-theorists would have a field day. Rule #1 in accident investigation - take your time, don't destroy evidence.

[N1 Vibes]

So Friday to recover the bits and pieces and check out the externals of the boxes once they get to the lab.

Agree with your other comments MFS, but check out the externals of the boxes? These things DFDR/CVR are designed to survive a crash and burn from 40,000ft, so a 30 kt ram into a concrete wall with no fire is hardly going to render them unreadable! :8

Bgrd's

N1 Vibes

[CONF iture]

It's an incidentNothing to worry - Business as usual (http://www.pprune.org/forums/showpost.php?p=3715118&postcount=168)

Rule #1 in accident investigation - take your time, don't destroy evidence
That's the way it should be ... but in that BEA / Airbus love story, things may work quite differently.

[barit1]

...a 30 kt ram into a concrete wall with no fire is hardly going to render them unreadable!

Of course not - but first things first. The external condition (including pre-existing anomolies) needs good documentation - to see if any internal or data defects can be correlated with external condition.

At least that's the way it's supposed to work.

More of concern I'd think - to ADAT (GAMCO) anyway - is permitting French authorities to read out the recorders. Remember the Cameroun accident w/Kenyan 738 jurisdictional issues?

[GearDown&Locked]

How many seconds are needed by those engines to spool down to idle?

[N1 Vibes]

G,D&L,

suggest 5 seconds maximum, at the EPR they were at probably producing between 100-150K lbs thrust total.

Brgd's

N1 Vibes

[old,not bold]

I've scrolled through most of the thread...lot's of stuff about why it happened, physics, chocks, etc etc.

But I didn't see any comment about why the fuselage seemed to more or less snap like a broken twig, slightly aft of the flight deck.

Can anyone enlighten a non-structural engineer, non-physicist, non-most things person?

I always thought that the fuselage structure is supposed to withstand quite severe unexpected and unusual forces. And this one didn't.

[lomapaseo]

I've scrolled through most of the thread...lot's of stuff about why it happened, physics, chocks, etc etc.
But I didn't see any comment about why the fuselage seemed to more or less snap like a broken twig, slightly aft of the flight deck.
Can anyone enlighten a non-structural engineer, non-physicist, non-most things person?
I always thought that the fuselage structure is supposed to withstand quite severe unexpected and unusual forces. And this one didn't.
The initial aircraft motion was parallel to the ground. Eventually it contacted a hard immovable object which now changed the motion to about 45 degrees to the ground. This force appears to have been applied directly to the underside of the fuselage located forward of the wing and main gear.
Thus a significant bending moment coupled with significant impact forces resolved through the 45 degree change in direction.
Not exactly considered in the normal operational design of an aircraft

[EDML]

The fuselage was going up the slope of the blast wall. At this moment
there was not a lot of deceleration as the plane was only pitched
around the CG.
A short moment after the Cockpit area went over the edge the main
gear started climbing the wall. At this moment the whole plane was
slowed down quite heavily because now there was real deceleration.
This created a forward-down momentum around the CG. This momentum
smashed the forward fuselage on the sharp edge of the blast wall cutting
it through up to the main deck. As the integrity of the lower part of the
fuselage was completely destroyed the down momentum bend down the
part of the plane forward of the edge.

[ATC Watcher]

I was just shown a photograph of the aircraft taken from an helicopter after the accident, and the braking marks on the concrete are clearly visible, but curiously only on one side ( left) and it is a very straight (double) mark.

[Tediek]

you never know what has happened, but i guess when things really go belly up, people panic, do weird things, maybe breaking with one foot as it's different due to the dual function etc. etc. Do weren't pilots I guess, so the routine fails there.

[bsieker]

I always thought that the fuselage structure is supposed to withstand quite severe unexpected and unusual forces. And this one didn't.

Among other things, an airframe also has to be lightweight. This is not only achieved by using lightweight, strong materials, such as aluminium, composite materials, and, in highly stressed places, even titanium alloys.

It is also achieved by designing it for a very precisely defined type of loads and forces, so it is in fact made to withstand only expected forces. It is the designers' and engineers' job to think of all the forces to which the structure could reasonably be expected to be exposed. Scaling a concrete wall is most likely not on their list.

The design must clearly state what types of loads and at what magnitude are expected, and how these maximum loads were derived, and must be demonstrated to break no earlier (in the case of the wings, at least) than at 150% of that load. For the wing this means, an actual production model must be bent until it breaks. This Youtube-Video (http://youtube.com/watch?v=6Uo0C01Fwb8) shows what it looks like.

The certification authorities must agree with the calculations for the maximum design load and certify that the structure has met the test for the aircraft to receive airworthiness.


Bernd

[CONF iture]

I was just shown a photograph of the aircraft taken from an helicopter after the accident, and the braking marks on the concrete are clearly visible, but curiously only on one side ( left) and it is a very straight (double) mark.
Any chance to see that picture ... ?
Please !

[ATC Watcher]

I have an electronic copy now but do not know how to paste a photo to a reply here.
If someone can help, or give me an e-mail address in PM and I'll send it.
ATCW.

[aerotransport.org]

http://www.myaviation.net/search/photo_search.php?id=01220767&size=large

[carholme]

This helicopter photo clearly shows the arrow in the centre of the pan, indicating that the a/c did not wind up at the red line position as described in post # 108. Looks like it travelled almost directly across the pan.

carholme

[forget]

Correct carholme The blue arrow is the first useable reference point we've seen here. These will show actual positions.

http://i21.photobucket.com/albums/b270/cumpas/pad.jpg

http://i21.photobucket.com/albums/b270/cumpas/pad2.jpg

[bsieker]

Correct carholme The blue arrow is the first useable reference point we've seen here. These will show actual positions.

Incorrect.

This helicopter photo clearly shows the arrow in the centre of the pan, indicating that the a/c did not wind up at the red line position as described in post # 108. Looks like it travelled almost directly across the pan.

I have inferred the correct position as early as post #118 (http://www.pprune.org/forums/showpost.php?p=3711858&postcount=118). Markings on the wall were perfectly usable references to the position. My post seems to have been largely ignored, except by CONF iture, maybe because I did not draw a big colored bar to indicate the aircraft position. I left that exercise to the readers.

The skid marks seem to be consistent with the ones seen in post #250 (http://www.pprune.org/forums/showpost.php?p=3726121&postcount=250), where they have been compressed by an long telephoto lens. On both photos they seem to end under the wing between the innermost and the second pylon.

Judging the offset from the engine scratch marks they appear to have come from the center gear.


Bernd

[BillS]

"they appear to have come from the center gear."

the two lines appear to converge - indicating gear turning?

[somepitch]

looks like the skid marks are from the nose gear, which as BillS pointed out would have been turning according to the position of the rudder...

[Good memories]

I remember the accident in Madras with one of the first 320's delivered to Indian Airlines. I believe the towback truck sheered the wiring on the nose strut of the ground/air sensor. The acft. ended up with its nose in the terminal .

I think there could be a clue. Maybe the Alpha floor protection sensed a in flight condition with zero IAS and commanded the engines to GA thrust. I never flew an Airbus , but I'am sure many of you pilots out there know the logics of this machine. Q. Do the brakes get signals from the ground/air sensor. Could it be they had a T/O warning as the flaps were up and somebody tripped the ground/air cb to silence the warning. I realise there are a lot of maybe's and if's , but it could be a good starting point.

I like to hear your comments on this.


Good Flying!



John

[MD11Engineer]

This might indeed be a possibility. I have no experience with the A340 but on the MD-11, if during an engine run the AOA vanes stand in a high alpha position and due to some reason (e.g. the upper torque link being disconnected and hanging down, thus putting the NLG air/ground switch into "flight" position) the air ground system gets put into air mode, the stall protection system will activate, extend all leading edge devices and autothrottle will push all throttles to full power.

Jan

[bsieker]

I think there could be a clue. Maybe the Alpha floor protection sensed a in flight condition with zero IAS and commanded the engines to GA thrust. I never flew an Airbus , but I'am sure many of you pilots out there know the logics of this machine.

An involuntary activation of Alpha Floor protection is exceedingly unlikely. It is inhibited before take-off, and below 100ft RA during approach, and is triggered by angle-of-attack (as a function of IAS and high-lift device configuration).


Q. Do the brakes get signals from the ground/air sensor.


Yes, they do. Normal braking is only available (among other things) if the main landing gear is in ground condition. In the air, alternate braking is active.

Either way, brake pedal deflection will give braking action, and antiskid is available with both normal and alternate braking, unless explicitly turned off by releasing brake pedals, flipping the "A/SKID & N/W-STRG" switch, and pressing the brake pedals again, or because of a number of fault conditions.

(FCOM 1.32.30, P5, SEQ 100, REV 14,
FCOM 3.02.32, P13, SEQ 001, REV 24)


Bernd

[Good memories]

Hi Bernd,

Thanks for your quick reply. If somebody pulled the ground/air senser CB in the cockpit, could that trigger the event that happened.

John

[Good memories]

Hi Bernd,

Obviously you are well informed in to the logics of this acft. Suppose the crew makes the power check but the acft. is not in the T/O configuration. The Parking brakes are set >The acft is not in the T/O configuration> the T/O warning sounds, >somebody in the cockpit wants to silence the warning and pulls the ground/air CB. Q? Do the parking brakes remain set or not.

John

[hetfield]

If somebody pulled the ground/air senser CB in the cockpit

I'm not Bernd, but on Airbus it isn't that simple......

[Jetjock330]

Only 2 C/B's in an Airbus cockpit, one under each pilots chair, for electrical protection of movement of the each pilots chair. The overhead panel are just COMPUTER RESETS, although they resemble C/B's, as we would all know them to look like.
The C/B's are in the avionics bay, protected by a big dog from the engineering company, hence the reason I never get near them.

[bsieker]

Good memories,

I'm merely an academic, and this may be more authoritatively answered by pilots or engineers, but here's what I can see:

- The Parking brake is not part of the ECAM Takeoff-Memo, neither is it in the Before-Takeoff or Takeoff standard procedures. It is, however, in the Taxi procedure, as is calling-up (if not already displayed) and checking the ECAM T.O Memo.

(I do not have appropriate documents on engine test runs, so cannot comment on the procedures at all.)

- T.O Config test button will not trigger the warning for parking brake set, setting take-off power will. The engine test here apparently was nowhere near full or reduced take-off power, so it would not have been triggered. (FCOM 1.31.15, P5, SEQ 001, REV 08)

- I cannot see any condition other than simultaneous blue hydraulic and hydraulic accumulator failure that would disengage the parking brake when it is set to "ON".

- As Jetjock330 mentioned, there are no circuit breakers in the cockpit proper, so only any of the number of engineers on board could have pulled one. Would be rather silly, but humans are known to act like that sometimes, so only official publications will tell.


Bernd

[CONF iture]

That picture is a dynamite (http://www.myaviation.net/search/photo_search.php?id=01220767&size=large) Thanks !

So let me go for this:
http://i13.servimg.com/u/f13/11/75/17/84/tls_1010.jpg
Yellow: 340 position when it strikes
Green: Final position
Tailstrike 1 due to the nose climbing the wall
Tailstrike 2 when left engines reach the wall

they appear to have come from the center gear."
the two lines appear to converge - indicating gear turning?
looks like the skid marks are from the nose gear, which as BillS pointed out would have been turning according to the position of the rudder...
No other choice than to agree with you guys!
And NO BRAKING ACTION AT ALL !

[BillS]

And NO BRAKING ACTION AT ALL !
Don't think we can conclude that.
The main gear did not lock - it appears the nose gear did and there appears to be no turn.

There appears to be a shadow where you mark tail stike one - is this a vertical marker? see other shadows to right.

[CONF iture]

The main gear did not lock
And it did not have to lock if antiskid was working properly, but an antiskid operating at its optimal capacity (as it should have before this crash) would still produce 3 double parallel, light at least, rubber print ...
None to be seen ... ?
it appears the nose gear did and there appears to be no turn
I don't think nose gear locked ... it just did skid ... and could it be a strong asymmetric thrust preventing that ship to turn right ... ?

I see the shadows, but I'm talking on the much larger mark on the ground, the one the same color the 340.

[tubby linton]

I seem to remember that the anti-skid is only active above 30kts so any braking below this speed would lead to a locked wheel.

[bsieker]

I seem to remember that the anti-skid is only active above 30kts so any braking below this speed would lead to a locked wheel.


As has been mentioned before, the limit is 10 kts on the A340 (FCOM 1.32.30, P 2, SEQ 001, REV 17)


Bernd

[CONF iture]

What's more from that picture (http://www.pprune.org/forums/showpost.php?p=3742414&postcount=307) ...


So in yellow the initial tail strike
And in green the tail mark as forward fuselage section + left engines drift to the right on wall upper section

http://i13.servimg.com/u/f13/11/75/17/84/tls_0110.jpg


Also the foam shape around the aircraft makes me think that #3 ENG did not shut down right after the crash and probably produced enough thrust to displace the tail in its final position ...

Did you notice the nose gear just forward #4 ENG ?
http://i13.servimg.com/u/f13/11/75/17/84/tls_0111.jpg

[CONF iture]

The A345/6 has the parking brakes powered by the blue hydraulic system. The parking brake selector valve, when set, acts as a pressure reducing valve and drops the upstream pressure in the brake lines to 175 bar ( 2535 psi ), this being the pressure that holds the brakes on. The system is designed to hold the aircraft with one engine at full power provided the others are all at idle. All this of course pre-supposes that you have ample blue system pressure to start with !
Actually the capacity of the brakes/tires assy being able to hold the aircraft in position at high thrust is proportional to the load of the aircraft, the capacity of the brakes, and the state of the surface (and some other minute parameters)
Normal park brake is only applied to wing gear
The park brake applies pressure only to the main gear and not the center gear ...
The brake pedals apply wheel and center gear brake pressure. The left pedal applies left main brakes plus forward center gear brakes, the right pedal applies right main brakes plus aft center gear brakes.
Given this, the main and center gear wheels would be turning even under maximum pedal deflection, just above the skid point. On-site, there would be signs of heavy braking if indeed it was applied through the pedals, but there would not be skidding.
If the park brake remained set throughout the accident sequence, the wheels would essentially be locked and not turning however.
If park brake was selected on and aircraft moved forward with 4 or more wheels rotating, pressing the toe brakes would have no effect as normal brakes are not avail in said condition.
These are few of the very interesting comments in this thread.

First post on that list mention 2500 PSI regarding the parking brake ... but watching at the BRAKE and ACCU PRESS indicator I cannot see anything much more than 2000 PSI with PARKING BRAKE ON ?
If I well understand, there were only 8 wheels fighting 4 engines set at about 70% N1. How possible would it be for these wheels to be turning and not skidding under a continuous PARKING BRAKE action ?
Is it possible it would not even leave any braking mark ?

Thanks for your further comments.

[Tediek]

Good morning, does anybody know the latest status of the plane? Has it been scrapped already or parked up somewhere?

[barit1]

It's being delivered next week to an Indonesian airline. :}

[glad rag]

Hillarious repy, RIP the fatality.....:ugh:

[ChristiaanJ]

gladrag,
AFAIK, at least two people were seriously injured.
As usual with this sort of thread, getting "follow-up" info is almost impossible.
But some people here do still think about what happened to them, and would have liked some more news....
In my case... I did not know any of them personally.... but they were still colleagues.

[Wizard]

Heard from a senior insider at Toulouse "they did everything wrong, ran all 4engines at 80% max power for engine run up instead of one at a time, overloaded parking brakes, pointed the aircraft at a building instead of towards open areas, after it got away on the brakes it was allowed to run and accelerate uncorrected for 13 seconds, finally engines throttles were closed and power reduced 2 seconds prior to impact, by then it was too late - aircraft total write off police investigation continues as is standard procedure in France".

[Bus429]

In accident investigation there is a notion known as the "hindsight bias". This is the understandable inclination to say (of those involved): "Why did they do this?" or "why didn't they do that?" etc.
While an accident is evolving - all the holes are lining up - those involved do not appreciate they are involved and often take the "best" steps to resolve the situation, often falling back to "knowledge-based" rules.
Virtually every accident comprises a sequence of events; each sequence is an "opportunity" to prevent the accident - assuming you know the accident is happening.

[GearDown&Locked]

Virtually every accident comprises a sequence of events; each sequence is an "opportunity" to prevent the accident - assuming you know the accident is happening.

...or about to happen if this or that stays the same. It's like leaving a glass jar on the floor with small kids in the house. They can run into it or not, and if they do they can hurt themselves or not, and you can assume they're on another room and the chance is minimal, etc... but the "opportunity" is there isn't it?

[Terry McCassey]

http://www.pprune.org/forums/%5BURL=http://i253.photobucket.com/albums/hh73/TerryMcCassey/A345.jpg%5D%5BIMG%5Dhttp://i253.photobucket.com/albums/hh73/TerryMcCassey/th_A345.jpg%5B/IMG%5D%5B/URL%5D

CONF iture, found the information on the brake pressure from my A345 Technical Training notes.

[Terry McCassey]

http://i253.photobucket.com/albums/hh73/TerryMcCassey/th_A345.jpg (http://i253.photobucket.com/albums/hh73/TerryMcCassey/A345.jpg)

Oops, forgot this . .

Terry

[CONF iture]

Thanks Terry for that Technical Training note, and as you said, 175 bars is about 2500 psi.
Also, from your document, I've been very interested in these other notes:

"The PRK BRK SEL VLV is operated by two (electrical) motors ..."

"It also sends an electrical signal to the BSCU and EBCU in order to inhibit other braking modes. This signal is disabled within the BSCU if blue system pressure, monitored by the pressure transducer, falls below 1450 psi."

I won't comment on these now ... but keep them on the side.

Heard from a senior insider at Toulouse
"they did everything wrong, ran all 4engines at 80% max power for engine run up instead of one at a time, overloaded parking brakes, pointed the aircraft at a building instead of towards open areas, after it got away on the brakes it was allowed to run and accelerate uncorrected for 13 seconds, finally engines throttles were closed and power reduced 2 seconds prior to impact, by then it was too late - aircraft total write off police investigation continues as is standard procedure in France".


http://i24.servimg.com/u/f24/11/75/17/84/tls_0212.jpg (http://www.servimg.com/image_preview.php?i=7&u=11751784)

Obviously, there is something very "strange" with these 13 seconds !?

How that senior insider from Toulouse manage to squeeze 13 sec for that airplane to travel at the very most its own length knowing than 2 sec before impact the boat had already reached its cruising speed of 15 meters per second ?

Then how that senior insider from Toulouse explains the boat did not follow the crew order to turn away from the wall ? (BTW he even does not mention that ...)

And how that senior insider from Toulouse explains the absence of braking marks if "it got away on the brakes" ?


That late inconvenient picture (http://www.pprune.org/forums/showpost.php?p=3742414&postcount=307) publication is very tough on BEA credibility ... just one more time !


Thanks to forget (http://<font color=) for letting me know how to do the trick with the image.

[bsieker]

CONF iture, Wizard,

From what information given in the snippet you posted did you get the position of the aircraft as seen in your picture? Pointing the aircraft at a structure is not the same as putting it directly in front of it. It only means that if it moves directly forward (although for an unspecified distance) it will hit that structure. The posted quote implies that it is standard procedure to point it into an open area, in this case here that would be towards south-east.

The information given was not only heard from an unnamed "senior insider", but was also in the Accident Information Telex from AI, which all A340-600 operaters will have received; cf. FCS Explorer's post from 21st November, 12:04CET. The information in said AIT was based on examinaction of the DFDR, and approved for release by the BEA.


Bernd

[barit1]

Shouldn't the FDR tell us the aircraft's heading during the static runup?

FWIW, for a performance check (called MPA once upon a time, not sure about today), setting high power (at least 50% thrust, usually) is required for a specified stabilization time of a few minutes. If this were the case at TLS, and the work crew were not aware the ship was moving, then the reason for the 11 seconds delay in retarding T/L's might be understood.

[Yankee Whisky]

Maybe I am old fashioned, having been part of a 50's airforce, but has Airbus become so modern that the use of wheel chocks before an engine run-up, or even being parked, is no longer considered "cool" ?
Does full engine power cause the landing gear to "bend" and that's the reason for not using chocks?

[forget]

Yankee Whisky. The matter of wheel chocks during high power runs has been discussed here. If you were pushing chocks under your wheels then you were doing it wrong - as is half the world according to this thread :ugh:
http://i21.photobucket.com/albums/b270/cumpas/CHOCK.jpg

[The Bartender]

...and with that image and text in mind, why use chocks at all....? If what the image says is true, and the aircraft moves forward to touch the chocks, friction will be lost and the aircraft will accellerate even further...?:hmm:

Just asking... :rolleyes:

[go-si]

I suppose it comes down to what chocks are supposed to do, stop an aircraft if the parking brake has failed or is not fully operative.
Probably not designed to halt an aircraft with N engines pushing amount X newtons of thrust.

[forget]

If what the image says is true, and the aircraft moves forward to touch the chocks, friction will be lost

Nowhere near as much - because the tyre is already distorted against the brakes before it reaches the chock - and so will not try to ride up the chock.

[IFixPlanes]

@ forget
I guess you are working on B737.
Prevent Airplane Movement During Engine Operation At High Power
...
- You must set the parking brake.
...
- Make sure the ANTISKID switch, on the center instrument panel P2, is in the OFF position.
...
- Put the wheel chocks 6 to 12 inches (15 to 30 cm) in front and aft of the nose gear tires and all the main gear tires.
...

A320 Fam. AMM do not mention any space between wheel and chocks:
...
If high power is necessary (above 1.20 EPR) aircraft must be immobilized by wheel chocks and brake pedals. Do the following procedure:
...
- On the LANDING GEAR CTL & IND PNL 402VU select "A/SKID NOSE WHEEL" switch in ON position.
- Fully depress brake pedals and hold.
- Release parking brake handle
...

Normally the parking brake is able to hold the A/C at its position with 1 engine at high power setting. (even by the A320 Fam.) :zzz:
I prefer the space between wheel and chocks not in conjunction with friction. As i mention above the parking brake is all i need and when she fails during high power you feel a bump when the wheels touch the chocks. It is like a wake up call to retard the throttle(s). ;)

[punkalouver]

It is wise not to do a high power run toward solid objects, however some planes have a limitation that if the wind is over a certain speed, the aircraft is to be into or within a certain number of degrees of the wind direction. Running all four at the same time, especially if at a light weight is something to avoid if possible. Perhaps symmetrical engines only. Was there a specific reason to do all four at once? One person should be looking outside at all times to see if there is any forward movement. And of course, consideration of ground conditions such as slippery surfaces among other things.

[CONF iture]

From what information given in the snippet you posted did you get the position of the aircraft as seen in your picture? Pointing the aircraft at a structure is not the same as putting it directly in front of it. It only means that if it moves directly forward (although for an unspecified distance) it will hit that structure.

It all comes from this (http://www.pprune.org/forums/showpost.php?p=3726121&postcount=250) and this (http://www.myaviation.net/search/photo_search.php?id=01220767&size=large) !

Position in precedent post (http://www.pprune.org/forums/showpost.php?p=3801882&postcount=337://) is the one at the initial nose impact

… and below is the position 55 meters before impact :

http://i28.servimg.com/u/f28/11/75/17/84/tls_0211.jpg (http://www.servimg.com/image_preview.php?i=9&u=11751784)

Considering the pad setting, initial engine test position, from where all started, was pretty close, I would say MAX an additional 20 meters back in direct line or not.

Official information published on November 20th by Airbus (http://www.flightglobal.com/blogs/flightblogger/2007/11/etihad-a340600-preliminary-tim.html) and BEA (http://www.bea-fr.org/francais/actualite/com20071120.html) (and lately forwarded by unidentified senior insider from Toulouse) does NOT quite tell the same story than those pictures which surfaced … 10 days later !?

As I said earlier everything is known already, why so many obvious discrepancies ?

What else is purposely retained that could prevent to exclusively blame the guys seated in front ?

[ChristiaanJ]

What else is purposely retained that could prevent to exclusively blame the guys seated in front ?
I'm not interested in "BLAME".

But as an engineer, I still simply cannot get my mind around running up all four engines against the parking brakes to the earlier quoted thrust, and then NOT slamming all throttles shut the very instant the aircraft started to move, rather than ELEVEN seconds later.

OK, I'm a dinosaur, because I still know Concorde at T/O power plus reheat could NOT be held against the brakes. But I would have hoped some of our experience would have filtered down the ages.....

[glad rag]

Yes, I also cannot understand the lack of SA

+1

glad rag

[CONF iture]

In one of the late BA038 thread
As for those critical of the AAIB it is amazing arrogance for some of you to think you know better about how they should be handling it
Such a statement would be harder to pronounce regarding … the French BEA

[Dysag]

Re: "I would have hoped some of our experience would have filtered down the ages....."

No chance, Sir, there's no mechanism for that, and no-one wants to learn from the old farts.

[HarryMann]

I prefer the space between wheel and chocks not in conjunction with friction. As i mention above the parking brake is all i need and when she fails during high power you feel a bump when the wheels touch the chocks. It is like a wake up call to retard the throttle(s).

I think this is the correct reasoning for chock positioning fwd of the wheels.

I note the procedure don't specify a 'lookout' dedciated to warning of unexpected movement at all times...

4 engines at once saves time (but that's cynical).. once again, no lives lost thankfully

As for old farts being listened to... they should always be an integral part of operating procedures! - you don't get old by being particularly stupid :)

[PAXboy]

Dysag No chance, Sir, there's no mechanism for that, and no-one wants to learn from the old farts.How beautifully put. :(

I have been in telecommunications for 25+ years and my friends and I find that our experience is often considered irrelevant as it is from so long ago. As in IT, as in aircraft, the fundamentals do not change. And one of those fundamentals is that we do not listen to men that are old enough to be our fathers. :hmm:

When I was 20 something, I'm sure that I knew it all. :rolleyes:

[saman]

A senior German chap in Toulouse once said to me "I wish I was 17 again! I knew absolutely everything then - but now I feel I know so little"

I know what he means!

[falcon12]

As an older fart and engineer used to running four far less powerful engines than either the Olympus or the CFM56 on ground runs, to retract the throttles from full power was an instinctive action if the aircraft moved, wall or no wall in front of the aircraft!

As to experience and youth, I suppose it can depend on who taught you in the first place. As an RAF Apprentice, there were hords of old boys in brown dust coats that droned on and on for hours followed, once on a squadron, or in this case, a manufacurers working party, more old farts in overalls. It certainly stopped me being cocky until I should have known better!

Today, the youth are not interested in listening whether you in a suit or overalls.

[PAXboy]

Continuing thread drift but not altogether away from the seat of the topic ...

Whilst working in the financial district of London in the late 1980s, I noticed the process of pensioning off the 'old farts' and promoting those in their 20s. It was done to save money and the idea that the new boys would have new ideas. What actually happened was that the companies lost the people who remembered what happened the last time it all went wrong.

Those times when the old geezer (RAF or commerce or politics) would scratch his head and say something like, "The last time that happened, we found that the <ITEM> had failed and there is no warning light on it because it is supposed not to fail and just be replaced every 10,000 hours." Thus the problem was fixed and the new boy learnt a lesson.

In the mid 1990s, I heard a most interesting discussion about this from the head of Personnel (probably called Human Resources :rolleyes:) of a major UK finance group say on BBC R4, "We realised that, in letting go so many senior people, we had lost our 'corporate memory' of what happened before and we were having to learn lessons all over again."

QED.

[goudie]

If you get rid of the 'old farts' the re-invention of the wheel becomes an original idea!

[BEagle]

Those 'old farts' in brown overalls were worth their weight in gold!

As a pilot under training, one day when I turned on the battery master in my Jet Provost, the AC inverter didn't respond. Cycling the battery didn't help and the young lad outside hadn't a clue..... So he sensibly went and fetched help.

Out came an elderly chap in a brown coat. He opened up the nose, reached inside and gave something an almighty clout with his fist. I felt the aircraft actually move.

"Try it now!"... Click, whiiiiizzz - and the inverter started up as normal. After I got back from an hour scaring myself over the Bardney sugar beet factory, I spoke to the line chief. It seems the old boy had remembered that trick - he said he hadn't seen it for a few years though; in fact it must have been about 12 years since he'd last seen that particular snag when some even older fart in a brown coat had taught him the trick.

Old age and treachery will always outfox youthful enthusiasm!

[old,not bold]

ChristiaanJ

But I would have hoped some of our experience would have filtered down the ages.....You and me both. But as others have pointed out, there are people of fewer years who know it all, so who needs experience?

What Airbus have managed to suppress successfully so far is that a note was found sellotaped to the remains of the nose of that aircraft. It was short and simple. It said;


Gotcha.

I'm still around.

Yours till hell freezes,

Murphy.

[ChristiaanJ]

What Airbus have managed to suppress successfully so far is that a note was found sellotaped to the remains of the nose of that aircraft. It was short and simple. It said:
Gotcha.
I'm still around.
Yours till hell freezes,
Murphy.Thanks....
I've met Murphy a few times....

[Chris Scott]

Quote from ChristiaanJ:
But I would have hoped some of our experience would have filtered down the ages.....

Something about those ignoring the lessons of history being condemned to watch it repeating itself?

http://www.pprune.org/forums/showthread.php?t=313707&page=4

27 years ago, an empty rear-engined passenger jet was doing high-speed taxiing trials, following a nosewheel-steering malfunction. The aircraft had not been prepared (or configured) for flight, but there was (one) pilot on the tiller. You can guess the rest...

We must be just about due for the next one?

[Fly380]

Yeh don't tell me. The pilot got promoted and became fleet manager on another fleet and then nearly ran out of fuel in West Africa on one of his new twin engined airbus aeroplanes. Did he get promoted again - I can't remember.:confused:

[Chris Scott]

You can say that if you like, Fly380 (whoever you are); I couldn't possibly comment...

He wouldn't have been the first ex-short-haul pilot to get caught out in West Africa with lousy weather-forecasting in the Harmattan season. The Airbus... is immaterial!

[Fly380]

Well Chris Scott - it seems we both remember the event and as a direct result the system changed. Any high speed taxi checks had to be crewed and prepared for a normal flight with a load sheet and 2 pilots. For anyone interested in this particular event the aircraft became airborne when the flaps were selected (don't know why). It was out of trim and the pilot managed to stay airborne narrowly missing the Gatwick control tower - the old one! - before completing a very hairy circuit and landing safely. A very narrow escape. I am not aware of a similar occurence since - fortunately.
Oh and by the way I didn't think The Hamattan reached Libreville.

[Chris Scott]

Yes, Fly380, you are spot-on.

I hope the Moderators will accept that this discussion is not entirely off-topic. When maintenance procedures suddenly turn into what equates to an operational incident/accident, lessons have to be learned (or, sadly, relearned) and, if necessary, new procedures worked out:
a) by those intimately concerned, the fleet, and the company;
b) by the whole industry, via the MOR system;
c) the lessons must be handed down from generation to generation. There is nothing new under the sun.

Unfortunately, every generation thinks that its predecessors were (a) idiots and (b) operating archaic kit that bears no relevance to the latest miracles of technology.

What happened was, I think, unprecedented on a jet airliner at the time, and the gentleman concerned was no fool. Normal practice had been to park the A/C after flight with the TPI (stab trim) at a nose-up-trim angle suitable for T/O well-laden, rather than zero. The A/C was naturally tail-heavy when empty. The flaps would have been at zero. The aeroplane rotated spontaneously, like even a B707 can do, but at a low speed... The flaps were, I think, selected deliberately to stop the aeroplane stalling when it was already well airborne.

The revised procedure for high-speed taxiing, as you say, was effectively to prepare the aircraft for flight. Will this concept be handed down the generations?

We have all learned a lot from reading on this thread about Airbus's mixed fortunes at Blagnac, and the way they could have avoided losing an aircraft. We understand a lot more about the role of chocks on large aeroplanes. Let's hope the next generation, somewhere in the world, doesn't make history repeat itself. Can't say I'm confident...

[jfill]

There is a email rumor circulating on the internet which seems to come from someone with inside knowledge of this accident. Anyone hear of a possible "official" report?

I have cleaned it up a bit.

--------------------------------------------------------------------

Employees of the airline were in the aircraft, but no employees from the manufacturer were on board.

All four engines were set to takeoff power in this virtually empty aircraft. The run-up protocol prohibits this.

No chocks were set. Brakes will not hold aircraft at full power.

Takeoff warning horn was sounding in the cockpit because all four engines were at full power.

The flight computer thought they were trying to takeoff but the plane had not been configured properly (flaps/slats, etc, etc).

One of the crew pulled the 'Ground Sense' circuit breaker to quiet the alarms.

The aircraft now assumes it’s in the air.

The flight computer automatically releases the brakes. This is a safety feature to prevent the brakes from operating before landing.

The throttles were not retarded by manual control until about 2 seconds before impact.

[ChristiaanJ]

jfill,
Would need several holes in the cheese lining up.
But, ye know, it sounds plausible... !
CJ

[Chris Scott]

Could they have been frustrated aviators, like some of our fellow posters? And facing towards the ramp was all part of the cunning plan... :E

[ChristiaanJ]

Chris Scott,
I like that one....
"If they can do it with a Harrier, then why not us..."

[peebs24]

quote " But, if you're going to do run up tests surely the manual states the braking/anchorage requirements.

Were these requirements met?"

I think the manual probably says only run-up one engine at a time in which case the brakes are adequate to hold the a/c

[Good memories]

Hi JFILL,

This could be the cause imho. Have a look at posting 312.

Good Flying!

John

[jfill]

Post #312 by "Good memories" previously raised a similar focus on the cause. The email source is thought to be an active pilot who doesn't follow internet forums. Maybe we are closely circling around the actual events.

These types of post get to be massive in size and a little hard to follow. Some argue let's just wait for the "official" report but that would take all the fun out of it. But more importantly there is significant educational value in many of the well thought out and insightful post.

I think it is the nature of pilots to want to troubleshoot problems real time. When flying, you don't have the luxury to wait for the "official report."

[TyroPicard]

Chris Scott and Fly380
IIRC the flaps were selected to silence the T/O Config Warning - Flap extension happened about 80 kts. and with the TPI nose-up (set after landing to allow water to drain?) the aircraft was destined to fly...
TP

[punkalouver]

Was it flight crew doing the runup or maintenance crew or both?

[spannersatcx]

Employees of the airline were in the aircraft, but no employees from the manufacturer were on board. I find that very hard to believe. I doubt very much Airbus would allow anyone to go off in an aircraft, that still belongs to them, unsupervised.
There is a email rumor circulating on the internet Exactly that, a rumour.:eek:

[Chris Scott]

Thanks for setting me straight on that one, TP. Your memory seems to be better than mine. We did indeed leave the TPI (tailplane) parked at 3deg nose-up (trim) for water draining. [Why did we not do the opposite, i.e., leave the trailing edge down? That would have kept the nosewheel on the ground.]
But we three are at risk of running a parallel topic here...

[Wodrick]

Post #46 Spanners confirms your thoughts (and mine !)

[Jet II]

Some argue let's just wait for the "official" report but that would take all the fun out of it.

As this aircraft was not officially 'in service' and this was just really a factory accident then you may never get an 'official report'

I can't really see the French releasing something that officially shows Airbus in a bad light - but we live in hope :E

[GobonaStick]

Employees of the airline were in the aircraft, but no employees from the manufacturer were on board


That's cobblers.

There were nine people on board. Two from Airbus, the other seven from ADAT - formerly GAMCO. None from Etihad, afaik.

Both Airbus employees were among the five taken to hospital afterwards.

[epicfco]

Hi, As far as i know, looking the photos from different sides i could not see any chocks around on ground.
To my knoledge choks should be fitted on, in testing engine area.
Also the aircraft is facing the testing area, instead been backwards.
Really i'im very interested to know if chocks were on, as is an important matter on my job.
Thanks , Alex

[barit1]

See post #345 (http://www.pprune.org/forums/showpost.php?p=3805861&postcount=345)for prior discussion - namely crosswind limits

[Lone_Ranger]

"Obviously, there is something very "strange" with these 13 seconds !?" Very strange indeed, I find the 2 "facts" 1. it took 13 seconds to travel across the pan and 2. it was doing 30mph on impact .....totally unreconcileable

[CargoFlyer11]

It appears to me that the tire mark in the photo :MyAviation.net - Aviation Photo Gallery (http://www.myaviation.net/search/photo_search.php?id=01220767&size=large) is from the nose gear as they tried to turn away from the wall - if you look at it you can see that it goes from a double mark to a single mark as it approaches the wall; apparently as the nose steering is turned more, the tires begin to scrub more - then when the nose gear breaks off from impacting the wall, it moves more to the right, and ends up near #4 engine...:rolleyes:

[EDML]

I do not believe that the fligth computer will release any brakes.

Firstly that might be very dangerous in specific situations and secondly
there where two incidents recently that shows us that it cannot be true:

1. Some months ago a A319 or A320 landed with the parking break set.
The outcome where a hard nosewheel touchdown, blown tires and control
problems. The report is available on the internet (I suppose it happened in
the UK).

2. The Iberia A340-600 Crash landing in Ecuador: Due to a very hard
touchdown they lost the Air/Ground logic. That left them with no Groundspoilers,
no Reversers but WITH THE Brakes. - And that also was an A340-600.

Marcus

[SPA83]

unidentified origin. So, true or not ?

Nine employees of the xxx airline were in the aircraft, but 'no
> > employees' from Airbus were present.
> >
> > The xxx taxied out to the run-up area.
> >
> > Then they took all four engines to takeoff power with virtually an empty
> > aircraft. (They obviously didn't read the run-up manuals.)
> >
> > No chocks were set, (not that it would have mattered at that power
> > setting).
> >
> > 'Brakes will not hold it back at full power anyway'.
> >
> > As it turns out the takeoff warning horn was blaring away in the cockpit
> > because they had all FOUR engines at full power.
> > Th e aircraft computers thought they were trying to takeoff but it had
> > not been configured properly (flaps/slats, etc, etc).
> >
> > Then one of these xxx decided to pull the 'Ground Sense'
> > circuit breaker to quiet the alarms.
> >
> > This fools the aircraft into thinking it is in the air.'A big, big
> > mistake'!
> >
> > As soon as they did that, the computers automaticlly 'released' all the
> > brakes. ('this is a Safety feature so that pilots don't land with the
> > brakes on'.)There was No time to stop and no one smart enough thought to
> > reduce
> > the max power setting.....
> >
> > So the rest is xxx.
> >
> > No one is talking, so who knows if there were survivors.

[DozyWannabe]

Internet rumour mill:
> > As soon as they did that, the computers automaticlly 'released' all the
> > brakes. ('this is a Safety feature so that pilots don't land with the
> > brakes on'.)
Ridiculous on the face of it - landing is precisely when a pilot *does* need the wheelbrakes.

Sounds to me like some bright spark has decided to cherry-pick the debate about the Hamburg and Conghonas incidents and tried to apply it to a completely unrelated scenario. Added to this the language has all the hallmarks of the most poorly-informed Airbus bashing ("fooling" the computer, the computer "thought" it was in the air or taking off). It doesn't even differentiate between spoiler braking (which is affected by the ground sensor, but is not relevant in this case) and wheel braking (which to the best of my knowledge is either not, or only marginally affected by the ground sensor and is very relevant in this case).

Finally - if you're going to pop a CB to shut the alarm off (unwise, but for argument's sake plausible), why would you waste time second-guessing the computer logic and pop the ground sensor when you could just pop the alarm? I'm committing a bugbear of mine by making an assertion of what a pilot would or wouldn't do there, but it just doesn't seem to follow to me.

The closest wild guess I would make is that the big hole in the cheese was human error of some kind, whether that error was in the cockpit (CRM's just as important in a test environment as in line flying), or a communication error on the ground.

[Ptkay]

Ridiculous on the face of it - landing is precisely when a pilot *does* need the wheelbrakes.


You have no idea.
This is the same scenario that crashed the Lufthansa in Warsaw.
The brakes will not deploy until the status "on the ground" is reached !!!
(as stated before, to protect from landing with brakes on)
Hence once the status "in the air" is faked to the computer by pulling the breaker,
the brakes turn off.

As simple as that!!!

[DozyWannabe]

Yes, and Airbus changed the logic in the face of the (decade old) Warsaw incident. The unfortunate TAM crew at Conghonas were getting wheelbraking to some degree, but minus the spoilers the braking action was insufficient.

This still doesn't answer the question of why one would pop the ground sensor CB (if there is such a thing) rather than the alarm CB, if one were simply trying to silence the alarms.

I'm quite prepared to accept I might have the logic wrong, but I think it's a bit unfair to state that I know nothing...

[EDML]

Hi,
that is simply not true - the Aircraft systems will not block using the brakes when the plane is in "Air mode".

Even in Warsaw that was not the case.

After the Warsaw accident they did not change the logic - only the
sensitivity and logic of the Weight on Wheels sensors was changed.

The brakes can always be used (see the accident in Equador - they had
brakes but no Ground spoilers and no Thrust reversers).

Only Ground Spoilers and Thrust reversers are locked out while aircraft is
not in Ground mode. - And that makes sense: Braking in the air is no problem
while the use of Reversers or Ground Spoilers surely is.

Marcus

[ChristiaanJ]

This still doesn't answer the question of why one would pop the ground sensor CB (if there is such a thing) rather than the alarm CB, if one were simply trying to silence the alarms.To me, what really makes this whole scenario more and more unlikely... :

In the supposedly chaotic environment, with alarms blaring, would the non-expert non-Airbus personnel doing the engine test:
1) immediately realise what the alarm was... ?
2) instantly know which CB to pull to silence it... ?

I personally admit to a sneaky liking for the scenario as the ultimate SNAFU, but I don't really believe it happened that way.

CJ

[bvcu]

First observation there are no c/b's on a 346 flight deck. Only resets. To silence the horn the c/b is in th e/e bay. Dont think someone is going to climb down the hatch during a ground run !!! Only thought is if they pulled both LGCIU resets ?? Have to look at the schematics to see what that would do. Having said that you would probably have c/b pulled as part of checklist for high power runs as on most other airbuses and boeings . Be interesting to know the REAL story , if it ever comes out.

[Chris Scott]

I agree with much of what has been said above. We can speculate endlessly on "crew" errors of commission or omission in the above accident, but we shall always run into the twin hurdles of (a) our incomplete understanding of systems logic in this scenario and (b) our ignorance of what was actually done in the cockpit.

This inevitable conjecture has done little to enhance Airbus's reputation, as it emits more heat than light. It may even lead to misunderstandings in the Airbus operational community, with possible safety implications.

Perhaps it is time for Airbus, in the interests of themselves and the industry, to volunteer the results of their own investigations into this matter, and any lessons they may have drawn – and others might be advised to draw – from it.

[ChristiaanJ]

Perhaps it is time for Airbus, in the interests of themselves and the industry, to volunteer the results of their own investigations into this matter, and any lessons they may have drawn – and others might be advised to draw – from it.I agree with Chris. This time it was a brand-new, unflown aircraft, still on the factory site. But nothing tells me so far, that the same scenario couldn't be reproduced elsewhere.

[Jetjock330]

First observation there are no c/b's on a 346 flight deck. Only resets.

bvcu,

Allow me to correct you. There is more than 1 c/b on the A346 flight deck, including A332/A343/A345. There actually two c/b's!

They are located beneath each pilots seat, one under each pilot's seat for electrical, forward aft travel. FACT, 2 c/b's on Airbus flight deck!

[Admiral346]

JetJock, you are right!

Someone would have had to open the hatch behind the Captains seat and crawl down into the E&E compartment, then go looking through racks and racks of computers and c/bs and find the right one. No way under time pressure, unless you are the engineer who knows exactly where everything is located.

[ChristiaanJ]

JetJock, you trying to get this thread moved to JetBlast? :rolleyes:

[bvcu]

touche jet jock !!!!!! forgot about those !!!

[DozyWannabe]

ChristiaanJ:
I agree with Chris. This time it was a brand-new, unflown aircraft, still on the factory site. But nothing tells me so far, that the same scenario couldn't be reproduced elsewhere.
Gabby Johnson is right! ;)

But in all seriousness, it could just as easily be Etihad that have requested the results of any investigation to be kept between the two companies, which would put Airbus in the distinctly difficult position of having a bunch of interested parties wanting to know what happened, and a large customer who would rather they didn't tell them.

[Huck]

What would it have cost to put a couple of trained flight test pilots in the front seats.....

I do full power runs all the time, conducting maintenance test flights on MD-11's. Seatbelts tight, hand on throttles, only two engines max at any one time, big chocks, and lots of space in front of the nose. And never, never let go of the throttles.

[Chris Scott]

Quote from DozyWanabee:
But in all seriousness, it could just as easily be Etihad that have requested the results of any investigation to be kept between the two companies, which would put Airbus in the distinctly difficult position of having a bunch of interested parties wanting to know what happened, and a large customer who would rather they didn't tell them.
[Unquote]

Very much hope that is not the case, DW. Surely Etihad's reputation is not predicated on a small part of its engineering department?

In view of the fortunate lack of fatalities, plus a lack of video footage; would the press release not be relegated to a paragraph in the inside pages of large-circulation newspapers; and fail even to be reported on CNN, Al Jazeera or BBC?


Huck and ChristiaanJ,

I agree. A lot of useful stuff has been posted in the pages above. Including lessons (not always) handed down.

[ChristiaanJ]

Surely Etihad's reputation is not predicated on a small part of its engineering department? Hummm...
You would not expect a major airline to send the teaboy and a few junior spanner-wavers to do acceptance testing on a new aircraft....
So yes, I think it would reflect on their engineering department, and in the present 'cut-back' atmosphere that might not be such a good idea.

[precept]

Deo Gratias. That all are alive is thanks enough. The rest shall sort itself out in due course.

[LedZeppelin]

Huck: "What would it have cost to put a couple of trained flight test pilots in the front seats....."

What's the answer to this question?

[PJ2]

LedZeppelin;
Re "What's the answer to this question? "

If I may, hard to say exactly as it depends on rates but hypothetically, at 4hrs minimum per day x 2 type-qualified pilots x $200/hr each, roughly $1600.

[Valcon]

http://i508.photobucket.com/albums/s329/beagle44/a340.jpg
Its time to cheer those poor guys up and put and put a smile back on there faces!

[patkinson]

I've seen a Handley Page Hastings jump the chocks and have done it myself in a Provost... golden rule off engine runs..Brakes 'on' and adequate brake pressure available ! Carried out engine runs at max power on many other big jet types ..
power equalised across the aircraft and feet on brakes ..usually never causes problems!!
Hope these guys are ok!!!:ok:

[cockney steve]

Post # 404
" fool! that's [B]not[B] what was meant by "do a run-up" "

[LedZeppelin]

.... mm, that is less than I thought.

Thanks PJ2

[armchairpilot94116]

Any chance Airbus will start doing these max power engine runs while the plane is positioned on an unused taxiway? Just in case of another run away?

[ChristiaanJ]

Any chance Airbus will start doing these max power engine runs while the plane is positioned on an unused taxiway? Just in case of another run away?I doubt it....
I think Airbus would prefer not to have brand-new out-of-control aircraft careening across Blagnac airport.
Loose cannons and bulls in china shops come to mind.

Not to mention noise issues....

CJ

[ATC Watcher]

Question from a novice in Aircraft testing : Are there any benefits of testing /running all 4 engines at the same time at max power ?
Looking for vibrations ? Testing the brakes ?

[jimtherev]

Testing the brakes ?...

Well, they got their answer, didn't they! :zzz:
Jim

[Machaca]

PDF of full report available here (http://www.bea.aero/docspa/2007/f-cj071115/pdf/f-cj071115.pdf) (French).

Article at Flightglobal (http://www.flightglobal.com/articles/2008/12/10/319969/violation-of-test-procedures-led-to-toulouse-a340-600.html) re findings include:
...power of the Rolls-Royce Trent 500 engines was increased to an engine pressure ratio of 1.25 - with the thrust levers corresponding to a position between maximum continuous thrust and maximum take-off thrust.

All four engines were operating. While the parking brake was on, registering 2,600psi, the inquiry says the applied thrust was around the limit of the parking-brake capacity.

At the time of the accident an Airbus employee was occupying the right-hand seat of the jet while an Abu Dhabi Aircraft Technologies technician was in the left-hand seat.

Flight-recorder data shows that, shortly after 16:02, the person in the left-hand seat warned that the aircraft was moving. The ground speed began gradually increasing to 4kt over the next few seconds and, after a second call that the aircraft was moving, the recorder registered pedal-braking and the deactivation of the parking brake.

Brakes on the A340-600 are linked to two hydraulic circuits: the 'green' normal circuit and the 'blue' alternate. The parking brake is on the blue circuit and only applies to the left- and right-hand main undercarriage bogies, not the centre bogie.

If the parking brake is released and the brake pedals applied, the 'green' circuit comes into play. The pedals act on all three main bogies.

Recorder data shows that 'green' circuit brake pressure on the A340 rapidly rose to 2,500psi while the 'blue' circuit pressure dropped.

About seven seconds after the first movement warning the nose-wheel was turned sharply right. Activating the nose-wheel steering inhibits braking on the central bogie, becoming completely ineffective past 20° of steering.

The aircraft swung 37° to the right but continued to accelerate, its speed increasing from 4kt to 31kt in seven seconds, before the aircraft struck the test-pen wall, demolishing its forward fuselage.

[NotPilotAtALL]

Hello,

lomapaseo (http://www.pprune.org/members/48942-lomapaseo) write ages ago ....

Why can't you just chop the engines in 5 secs or so and that would be enough to keep it from going that far over a barrier in front of you.You have now the answer at your very good question in the report !

Valcon (http://www.pprune.org/members/264965-valcon)
Its time to cheer those poor guys up and put and put a smile back on there faces!This cartoon is so true .....

Regards.

[blueloo]

Activating the nose-wheel steering inhibits braking on the central bogie, becoming completely ineffective past 20° of steering.

Another little "gotcha". Presumably a good reason for this in normal ops...but when the proverbial hits the fan surely you want all stopping capabilities..... usually if you are swerving to avoid something that would be an indication you need a large stopping force....

A lot of these Airbus features which generally are pretty good seem to have major ramifications at rather inconvenient times.

A couple of caveats before the usual B vs A debate: Neither manufacturer is immune from these "gotchas", and is this incident clearly a few protocols were overlooked and lastly reducing the thrust might have seemed like a good idea too.

[RatherBeFlying]

The observer in the jump seat was a licensed pilot with AB type ratings but was leaving the conduct of the flight test to the guy in charge (who unfortunately got fixated); so, did not pull the throttles until he saw the wall coming up [and self preservation instincts took over].

Of course there are now new procedures: High power runs on two (not four) opposite engines at a time Chocks always to be used -- people stopped using them because they tend to get jammed and the a/c has to be subsequently pushed back to retrieve the chocks.

[forget]

Chocks always to be used -- people stopped using them because they tend to get jammed and the a/c has to be subsequently pushed back to retrieve the chocks. :ugh:

We've been through this before. Chocks should not be placed against wheels during engine run-ups. Boeing warns against this in their Maintenance Manuals. Airbus doesn't. Boeing has my vote.

[ATC Watcher]

The first sentence of the report recommendation :L’enquête a mis en évidence des dérives répétitives par rapport aux procédures opérationnelles écrites au sein de la direction des essais pour la réalisation des essais au sol

Basically saying that repeatedly test technicians were not following the written procedures , but this must have been known by their superiors as everything was taped.Commercial pressure is mentioned in the report.
Anyway lessons have been learned as those procedures have since been re-written , ( max 2 engines at a time, chocks in place.etc.. ) according the report, and now even the ground controllers have to verify on the R/T that chocks are in place before giving authorization to start an engine test run .

[lomapaseo]

We've been through this before. Chocks should not be placed against wheels during engine run-ups. Boeing warns against this in their Maintenance Manuals. Airbus doesn't. Boeing has my vote.

Agree, but might it still get jammed if you do 4 engine run-ups at high power ?

[forget]

.......... and now even the ground controllers have to verify on the R/T that chocks are in place before giving authorization to start an engine test run.

And do these ground controllers know the correct 'in place' for the chocks? I'd guess no.

Thanks to Spanner Turner, Post 213. :D

Quote below is from the Maintenance Manual. (a 747 manual, but you get the picture).

C. Prepare for Engine Operation.

(1) Check that airplane is parked in clean area with wheels on areas that are free of oil, grease, or other slippery substances.

(2) Make sure the wheel chocks are installed at the main landing gear wheels and ground locks are installed.

(a) Do these steps if you will operate the engines for a high power engine run.

1) Make sure that the forward wheel chock is six to twelve inches in front of the tires.

NOTE: This will cause the thrust of the engine to be held by the frictional force between the airplane tires and the ground, and not the wheel chock. The wheel chocks do not have the same frictional force as the tires. If the tires touch the wheel chock, some of the frictional force between the tires and the ground is lost, and the airplane can skid. The wheel chocks are only used to prevent the airplane from rolling if the airplane brakes were accidentally released before or after the engine run.

[glad rag]

There are sections of it's fuselage at the 380 section delivery bay at lagaderre on the back of low loaders today..........................................yesterday two A380 section 19 lowers, guess it's spring clean time.......

[Huck]

All the procedures in the world will not help them if the person that has his hands on the controls is not smart enough to wipe off the power.....

[ChristiaanJ]

Huck,
Grossly unfair remark....
Count off thirteen seconds, and tell me what you would have done in that time.

Twenty-twenty hindsight doesn't count.

Three seconds to get the message the aircraft is moving, after a three-minute engine run.
Two seconds for " oh *****, the brakes ", and starting to stamp on them.

Eight seconds left.

The pit wall looming up, so you try to turn.
Somehow chopping the throttles gets left out....

Read the report for the rest.

CJ

PS: For those with sufficient technical knowledge, the somewhat warped translations being provided by babelfish and similar, should be enough to get the essentials. Others shouldn't be commenting here in the first place.
And no, I'm not going to translate the entire report either, unless somebody pays me.

[captplaystation]

I'm sorry to contradict you but what they did was THICK, plain and simple. If your car is accelerating towards something out of control you are expected to have the presence of mind to take your foot off the accelerator before jamming on the brakes, this is really no different.
If the person(s) in the cockpit didn't appreciate the relationship between the thrust lever position ( that THEY had set ) and the forward motion taking place then they had no bloody business to be sitting there in the first place.

Is that not the crux of the matter ? ? :ugh:

[CONF iture]

Des traces de freinage symétrique des deux trains principaux sont présentes depuis environ soixante mètres jusqu’au mur.
... Where did I put my glasses (http://www.myaviation.net/search/photo_search.php?id=01220767&size=large) ... ?

[Luap]

If your car is accelerating towards something out of control you are expected to have the presence of mind to take your foot off the accelerator before jamming on the brakes, this is really no different.

There is a difference: in a car, you use the same foot for the accelerator and the brakes, so if you brake, you have that foot not on the accelerator. While on the aircraft, braking doesn't cut the throttles.

I think the crew really didn't expect the aircraft to move, so the crew hadn't thougt what to do in case the aircraft would move. If you have to think first, you are too late..............

[HotDog]

Not only did they fail to follow SOPs for ground runs, they were plain stupid and incompetent. Maybe they'll roster a qualified pilot to assist engine runs in future?

[wildadv]

The issue is not about putting a "qualified pilot" at the controls during engine runs, the issue is ensuring that those at the controls have the necessary training to carry out those tasks and that they follow the procedures necessary for the task concerned. Start shortcutting procedures and sooner or later, something will happen. You would be amazed how much different a high power engine run is from an aircraft during a takeoff run. I can't comment on a 340 engine run, but I can assure you 320's and 767's bounce all over the place, and thats only two engines. In a restricted run bay such as at Toulouse (I've been there so I know what it's like) you have very little time to react if something is going wrong.

The biggest problem a lot of engineers face is that a lot of companies don't want to train us in simulators. We learn "on the job". So training to recognise things like brake failure and aircraft movement after jumping chocks may never be carried out. It's always in the back of your mind if you are aware of it's possibility. It all comes down to being competent at what you are doing, following procedures and maintaining situational awareness. Some of these things can never be learnt out of a book.

[whatbolt]

There doesnt seem to be any mention of any ground crew in all this.

[ciampino]

CAPTPLAYSTATION You are right there run procedures were very poor.Engineers running engines can become pretty complacent after doing up-teen runs and nothing ever going wrong and thats when it bites you.

[Swedish Steve]

Maybe they'll roster a qualified pilot to assist engine runs in future?
What a good idea. Next time I need an engine run, I can send the pilots off to do it and they can come back and tell me what needs changing!
I have run engines for 35 years. Small engines are easy. Run a Jt8D in a B732 and its like being in a simulator. No noise or vibration.
But go out and run a B777 Trent up to take off on the brakes. Its mostly guess work with the whole aircraft leaping around. You have to take a print out of the readings because there is no way you can read the figures. Luckily here we can use the runway for engine runs. Feels much safer looking at 8000ft of tarmac. We used to have a run bay where you were 50ft from a wall. I hated it in there, felt very unsafe.

Also running engines for maint, they are usually faulty. There is a reason for running them and it is not like a normal take off, you are on edge looking for a defect. And with todays reliable engines, we don't do it very often.

[Daysleeper]

The biggest problem a lot of engineers face is that a lot of companies don't want to train us in simulators.

EU operator I know does just that, engineers have a sim conversion for ground running, about 4 hours between 3 people, brought up a lot of good issues.
Able to practice things like brake failures and engine fires, helped people understand some of the risks, including using too few people. You really need someone in a front seat who is not doing the test or the readings , just there to be the safety net.

[Silver Spur]

Is everybody OK though??

[cockney steve]

above from post #414.

Have you considered that there would be an enormous side-thrust generated on the leg?....Perhaps the design enginers decided there was a better chance of control without the tyres rolled off the rims /sidethrust exceeding structural strength of wheels/sidewalls being ripped through by tarmac.

It's unrealistic to expect a/c landing-gear to be designed to take stresses beyond the max sustainable by the airframe......in this case, the limiting-factor is the friction between tyre and runway...unless you propose "grooves" for the bogies to slot in and treat grounded a/c as trams!


wonder if the company will give the crew a christmas bonus this year :E

[ChristiaanJ]

There doesnt seem to be any mention of any ground crew in all this.There is a mention in the report, but they had moved well out of the way of the jetblast and the dust blowing about.
Not that they could have done anything to prevent it happening, actually.

They did manage to stop one of the engines after the crash, though, by smothering it with water and foam. Two engines had already stopped by themselves (damaged). The remaining one was up against the blast wall, and thet couldn't get enough water and foam in to stop it, so it ran on until the feeder tank was empty.

[lomapaseo]

They did manage to stop one of the engines after the crash, though, by smothering it with water and foam. Two engines had already stopped by themselves (damaged). The remaining one was up against the blast wall, and thet couldn't get enough water and foam in to stop it, so it ran on until the feeder tank was empty.

Presumably the engines were at idle at this point, else it would be difficult to get enough water/foam inside the engine compressors to stop it.

[nuclear weapon]

Is this aircraft insured? Does Ethiad get a replacement without paying anything from airbus? And who takes the fall for this?

[Smilin_Ed]

It's hard to understand why the person who put the throttles forward didn't KEEP HIS HAND THERE, ready to pull the power back in the event of a problem. :ugh: :mad:

[Huck]

Huck,
Grossly unfair remark....
Count off thirteen seconds, and tell me what you would have done in that time.



I am a maintenance test pilot on MD-11F aircraft. I execute max power ground runs about twice a month.

What would I have done? Same thing I always plan on doing - Throttles idle, max manual braking, shut down one or more engines if things don't get better.

If you're cinched down hard in your seat with your hands and feet on the controls (and you damn well should be) I can do all that in a second or two.

In other words, if you're not a pilot, you better be prepared to act like one if you ever start moving during a high power ground run.

I have absolutely no concept of what distraction or thought process could delay these vital reactions. I could give the same scenario to a 10-hour private pilot student in a Cessna 150 and his/her reaction would be the same - wipe off power, max braking.

What happened here? I have no concept whatsoever. Unless both front-enders fell out of their seats, somebody should have been on the throttles within 2 seconds. If not them, the jumpseater.

[bvcu]

Simple basics need to be applied . Ignore the rubbish spouted about Boeing V Airbus in previous posts ref chocks , both manufacturers procedures specify chocks for high power runs . The difference is you leave a gap on Boeings as you have full parking brake pressure and if the aircraft moves it will slide into the chocks and enable them to grip properly . Because all the Airbus widebodies use a lower park brake pressure you have specialist large chocks which are used differently. And basically commercial pressure is the biggest problem as you need a heavy a/c with ballast or fuel which makes the job much easier as the aircraft doesnt bounce around and you can read the gauges !! The basics of high power runs as i was taught and insist on when running is the guy in the left seat has his hands on throttles any time power above idle. Man in right seat is experienced and when at high power keeps lookout for a/c moving and feet ready on pedals. If you're on a type with complex figure recording to be done then you need someone on the jumpseat to assist with that. This incident had diferent people from diferent companies , how comprehensive a brief was given before?

[ChristiaanJ]

Smilin_Ed, Huck,
Have you read the report?
If not I can try and pull out the relevant bits and translate them.

In brief, they had been running all four engines for about three minutes already, waiting for the oil to get warm enough to check for a leak.
So by that time their hands would have come off the throttles, thinking the parking brake was holding the aircraft adequately.
In reality, the engine thrust equated almost exactly the holding power of the brakes for those three minutes, and then (possibly because the fuel burned, hence a/c becoming lighter) overcame the brakes.

CJ

[RatherBeFlying]

I could give the same scenario to a 10-hour private pilot student in a Cessna 150 and his/her reaction would be the same - wipe off power, max braking.The problem is that the ground tech performing the test from the right (also the guy in charge) never had the training that one would expect out of said 10-hour private pilot student in a Cessna 150.

Just learning to start the thing is some orders above the same task in a C-150. I suspect that some of the basics of taxiing that we expect out of said 10-hour private pilot student in a Cessna 150 fell out of AB's ground test tech syllabus.

[forget]

I suspect that some of the basics of taxiing that we expect out of said 10-hour private pilot student in a Cessna 150 fell out of AB's ground test tech syllabus.

And how do you suppose they got to the run up pad?

[ChristiaanJ]

And how do you suppose they got to the run up pad?You've heard of tugs, I presume?
Saves fuel, and noise.

CJ

[forget]

You've heard of tugs, I presume?

Errr, yes. But this thread has already told us the aircraft was taxiied to the run up pad. Do keep up.

[RatherBeFlying]

OTJ Training -- works acceptably for normal procedures; less so for handling emergencies:ouch:

[lomapaseo]

OTJ Training -- works acceptably for normal procedures; less so for handling emergencies

who was the trainer and who was the trainee:confused:

[ChristiaanJ]

forget,
Sorry, I didn't re-read all 23 pages, and I don't think it's mentioned in the report.

But one does forget, occasionally....

CJ

[golfyankeesierra]

In my company ground runs are only performed by a select group of (senior) AMT's who have trained it in the sim.
I'm not sure how often (only initial or recurrents as well), but I see them every once in a while in the simbuilding.
So I can't beleive AB won't train their people (and after this one they really will).

[ChristiaanJ]

It starts to look as if more and more people could do with a French > English translation of the full report.

Anybody willing to have a go, even with a raw babelfish translation?
I'd be willing to tidy it up, but I do not have the means to do-and-save a full raw translation.

CJ

[punkalouver]

Perhaps a phone call by you to the BEA mentioning how many people are interested in the report that don't speak French.

[Hot Rod]

My guess is that BEA dont want people to know what happened so they publish it in frog language only :sad:

[RatherBeFlying]

After a theoretical phase of familiarisation with the aircraft systems, trouble-shooting and functional tests, ground test technicians take training courses for cabin crew, courses in radiotelephony and taxiing. The next phase is practical while the trainee works with an instructor.

The following points are notably addressed: low speed taxi
conduct of ground test participation in accelerate-stops production flights
conduct of tests in Customer Acceptance Manual and associated tests use of technical documentation and software training in pressurisation tests.
Practical parts of this training are accomplished in the airplane and in the simulator.

A refreshment session is performed in a simulator every two years for ground test technicians.

[captjns]

In accordance with the Maint. Ops. Manual at my former airline engineers had to complete a training course before they were allowed to ride the brakes when the aircraft was towed, taxi the aircraft, and perform engine runs.
One week of ground school, time in the simulator, observation, instruction, aural emination, and a check ride.

I find it hard to believe that Airbus would not have similar requirements for their engineers.

[ChristiaanJ]

I find it hard to believe that Airbus would not have similar requirements for their engineers. Capt'n, they do.
The post by RatherBeFlying before yours is a translation of the relevant section in the BEA report.

CJ

[CONF iture]

My guess is that BEA dont want people to know what happened so they publish it in frog language only
Not sure every one read French in Abu Dhabi … but nothing like french French de France to cook la cuisine française.


Here is the contest :
Symmetrical braking traces from the two main gears are present since about sixty meters to the wall
First one to identify them ... Top chrono !

BTW, where is that (http://www.myaviation.net/search/photo_search.php?id=01220767&size=large) picture in that final report ?

[ChristiaanJ]

CONF iture,
Good point.
On "that" photo the traces from the nose gear are clearly visible, but not those from the main gears.

I would expect that the nose gear was already skidding sideways by that time, leaving a clearly visible trace, while the main gears were braking "normally" rather than skidding, so there would be far less in the way of traces.
Also, the water and foam would have washed some of them away, making them difficult to see from the air. They were probably still identifiable on the ground.

Re the tyre marks, the report says:
Traces de pneumatiques au sol
Pour les descriptions qui vont suivre, la référence en distance est prise au
point d’impact avec le mur, en remontant la trajectoire.
Une première trace de pneumatique correspondant à une des roues internes du train principal droit est visible à partir de cent vingt mètres sur une longueur d’environ dix mètres. La trace des pneumatiques externes
est présente mais moins marquée. Ces marques sont orientées suivant un axe au cap magnétique 330°. Aucune trace des pneumatiques du train principal gauche n’a été observée.
A quatre-vingt-trois mètres, on aperçoit les premières marques laissées par le train avant. Elles s’orientent vers un cap nord, sont d’abord parallèles puis, à cinquante mètres, convergent pour ne plus former qu’une trace. Le train avant n’est alors plus du tout directif.
Des traces de freinage symétrique des deux trains principaux sont présentes depuis environ soixante mètres jusqu’au mur.

This tallies with what Page 16 posted.

CJ

[Smilin_Ed]

ChristianJ: I repeat, I can't imagine why someone didn't have his hands on the throttles the entire time. It doesn't matter how long. :ugh: :mad:

[ChristiaanJ]

ChristianJ: I repeat, I can't imagine why someone didn't have his hands on the throttles the entire time. It doesn't matter how long.Complacency? Even the report says as much.

CJ

[CONF iture]

I would expect that the nose gear was already skidding sideways by that time, leaving a clearly visible trace, while the main gears were braking "normally" rather than skidding, so there would be far less in the way of traces
CJ, very surprising to only apply a "normal" braking when you’re gonna smash a wall !?
Do the same in a car, even as a passenger, and you will push as hard as you can on your both feet … I believe that’s just an instinctive reflex.

If the braking was just "normal" since 60 meters before the wall, how was it between 110 and 60 meters, as there is no mention of any braking traces ?

Many many questions to be asked to the BEA … Many discrepancies between the text and the graphs ...


But to me the main curiosity is here :
A first trace of rubber corresponding with one of the internal wheels of the Right Main Gear is visible starting from a hundred and twenty meters over a length of approximately ten meters. The trace of the external tires is present but less marked. These marks are directed along an axis with the magnetic course 330°. No trace of the tires of the Left Main Gear was observed.
How is it possible 3 wheels out of 12 left sideways marks with an angle of 18 degrees ???

My only explanation is Right Main Gear was mainly delested, and Left and Center Main Gears did not touch ground anymore, as a consequence of the turbulence created by the engine thrust on the wall behind and lifting the tail.
In the same time obviously the three oleos were fully extended, long enough to put the aircraft in the flight mode logic with the possible requested sequence for the braking to be authorized, just like after any regular touch down.

[mivens]

CJ, very surprising to only apply a "normal" braking when you’re gonna smash a wall !?
Do the same in a car, even as a passenger, and you will push as hard as you can on your both feet … I believe that’s just an instinctive reflex.Actually, I don't believe that's strictly true.

You might like to read the Wikipedia entry on Brake Assist (http://en.wikipedia.org/wiki/Brake_Assist):

Research conducted in 1992 at the Mercedes-Benz driving simulator in Berlin revealed that more than 90% percent of drivers fail to brake with enough force in emergency situations. Brake Assist detects circumstances in which emergency braking is required by measuring the speed with which the brake pedal is depressed. Some systems additionally take into account the rapidity of which the gas pedal is released, pre-tensioning the brakes when a "panic release" of the gas is noted. When panic braking is detected, the Brake Assist system automatically develops maximum brake boost in order to mitigate a drivers tendency to brake without enough force.

[lomapaseo]

Quote:
CJ, very surprising to only apply a "normal" braking when you’re gonna smash a wall !?
Do the same in a car, even as a passenger, and you will push as hard as you can on your both feet … I believe that’s just an instinctive reflex.

Actually, I don't believe that's strictly true.

You might like to read the Wikipedia entry on Brake Assist:


Quote:
Research conducted in 1992 at the Mercedes-Benz driving simulator in Berlin revealed that more than 90% percent of drivers fail to brake with enough force in emergency situations. Brake Assist detects circumstances in which emergency braking is required by measuring the speed with which the brake pedal is depressed. Some systems additionally take into account the rapidity of which the gas pedal is released, pre-tensioning the brakes when a "panic release" of the gas is noted. When panic braking is detected, the Brake Assist system automatically develops maximum brake boost in order to mitigate a drivers tendency to brake without enough force.


So for an A340 braking system (not a car) how does pedal force relate to braking force? I mean there are certainly hydraulics and other systems involved aren't they?

[Giolla]

CJ: Trace de pneumatique = bandenspoor/remspoor maar geen rubber!

[ChristiaanJ]

CONF iture, lomapaseo, Giolla, et al.

Apologies, I used "normal braking" as the opposite of skidding. Sorry if I wasn't clear enough.

"Traces de pneumatiques" is ambiguous, since it could refer equally well to skid marks as to visible traces of hard braking without skidding.
One would assume the antiskid was active.

CJ

[Koll]

Part of the check list prior to engine running is alway to select anti skid to the off position. Generally the anti skid will be inactive anyway below a certain speed, definately in the case of a static aircraft.

[Giolla]

There is a full report available - in French.from BEA,

If it is of any help, I can translate the document.

[ChristiaanJ]

Giolla,
I've already read it, and quoted from it.
I'm pretty well bilingual English-French, so I have no problem with it.
If you're willing to translate the nearly 30-odd pages of text for free, youre welcome.
It's the kind of job I would expect to be paid for....

CJ

[Giolla]

It is too cold to go sailing......I grab your point:cool:

[CONF iture]

So for an A340 braking system (not a car) how does pedal force relate to braking force? I mean there are certainly hydraulics and other systems involved aren't they?
Some malfunctions inhibit the antiskid which implies to limit the brake pedals action in a way to obtain a max brake pressure of 1000 psi as indicated by the gages and not risk to lock the wheels. Actually that limit is very easy to exceed if not carefully monitored.

[CONF iture]

Taxiing up to 30 knots in straight line is part of the everyday operation but I’ve never felt hitting something even would it be a wall could imply so much destruction. All the photos reveal a phenomenal energy dissipation and I would easily conceive the speed and/or thrust was much higher than 30 knots and/or idle thrust.

Nobody yet dared to comment on the fact that obviously the three Main Landing Gears took an in flight status for a while ?

There is even a possibility here that the protections played another unconceivable trick :
If the turbulences were able to lift the tail up they could be well able, in the same time, to disturb the Angle of Attack censors and set them beyond the ALPHA FLOOR threshold which would have triggered the ALPHA FLOOR protection by applying TOGA thrust.

A lot to consider … Let’s see if anyone is willing to comment ?

[GobonaStick]

would have triggered the ALPHA FLOOR protection by applying TOGA thrust


But it didn't because the FDR traces clearly show the EPR on all four engines not rising above the test level of 1.25 at any point, and only changing after the moment of the collision when all engines suddenly reduce thrust.

[balsa model]

... phenomenal energy ...
Just a thought: some of the aircraft kinetic energy would have been stored in its rotational inertia - it was turning, not just moving forward.
Perhaps you could explain why you find the damage unbelievable for a 30kts collision. Isn't the nose section relatively lightweight structure?

[ChristiaanJ]

CONF iture,
I don't really get your point.
The blast wall was not vertical, but angled, so of course the airframe would go up and over, and would have done so even at less than 30kts.

CJ

[Koll]

If you drove your car into a wall at 30 knots the front bumper would be somewhere around the windscreen. It's hardly surprising that a "vehicle" the weight of an A340 would be damaged to this extent after impacting and mounting the blast fence. Plus the blast fence would have acted like a knife cutting into the fuse as it went over it. The fact they were at near take off power while all this was going on would have helped too.

[Huck]

May have been somewhat tail-heavy, as well....

[CONF iture]

Such aircraft is usually nose heavy when empty, 40 tonnes of fuel … probably not much in the tail, but with 26% CG anyone with the graph will tell ?
Also the aircraft was in straight line as shown by the nose gear marks.

Pictures clearly show multiple impacts, multiple structural deformations and failures.
Initially nose tip collides, impact visible just below ENG 2, which provokes immediate major structural failure just behind cockpit area, then another major structural failure about 10 meters further aft before ENG 1 and 2 finally contact the wall. In the same time nose landing gear detaches and flies away + major tail strike occurs.

To this point it is already a lot of energy dissipation … but that’s far from over.

Look at these left side engines, they just want to climb the wall, a 20 meters fuselage section is now on the other side of the wall, MLG is suspended in the air.
Then under ENG 3 and 4 thrust the tail moves 15 meters laterally …

Anyway, very lucky these nine persons on board … No mention if seat belt were fastened in the flight deck or in the cabin ?

Another point of interest from the CVR :
« euh… cabin is… aircraft is moving forward »
« Aircraft is moving forward »
« parking brake off »
13 seconds … and that’s it ?

The full event is on video tape … no chance to see it ?


Still not many to comment on the absence of braking marks contrary to what is reported by the BEA ?

And still nobody to comment on the early crab movement of the aircraft 120 meters away from the wall, and so with only 3 tires marking the ground ?

[CONF iture]

http://i65.servimg.com/u/f65/11/75/17/84/hud00110.gif (http://www.servimg.com/image_preview.php?i=20&u=11751784)

Crowd record as long it is brand new ... but no one in sight when report is out ...

What's Going On !?

[atakacs]

What's Going On !?

Business as usual....

[punkalouver]

http://i65.servimg.com/u/f65/11/75/17/84/hud00110.gif (http://www.servimg.com/image_preview.php?i=20&u=11751784)

Crowd record as long it is brand new ... but no one in sight when report is out ...

What's Going On !?

What is going on is that the French have decided not to publish their report in English. So the vast majority of pilots, you know, the people who could read and learn from this, can't read and learn from the report. Politics or cheapness or pride or whatever, ahead of safety again.

[ChristiaanJ]

punkalouver,
I'm not BEA, so don't quote me.

So the vast majority of pilots, you know, the people who could read and learn from this, can't read and learn from the report.

- Pilots? IIRC there weren't any pilots there...

- It wasn't an 'accident' in the aviation sense, since no flight was intended, the aircraft never was airborne, and there were no fatalities. A serious 'incident', yes (injuries and hull loss).

- The BEA would not have any legal obligation to produce a translation, and hence would not do so, if only to avoid arguments about the exactness of the translation, or even legal issues.

- Anybody who'd want to read and learn from the report (I'm now talking about those who would be directly and seriously interested, not the typical wannabee) can commission a professional translator. Do a word count and get an estimate. The report is now in the public domain.

BTW, don't ask me. I've done some, but I've now retired.

CJ

[punkalouver]

punkalouver,

- The BEA would not have any legal obligation to produce a translation, and hence would not do so, if only to avoid arguments about the exactness of the translation, or even legal issues.

- Anybody who'd want to read and learn from the report (I'm now talking about those who would be directly and seriously interested, not the typical wannabee) can commission a professional translator. Do a word count and get an estimate. The report is now in the public domain.



In other words, as I said(slightly modified), the vast majority of people won'tread the report and learn from this.

Politics or cheapness or pride or whatever, ahead of safety again.

[punkalouver]

punkalouver,

- The BEA would not have any legal obligation to produce a translation, and hence would not do so, if only to avoid arguments about the exactness of the translation, or even legal issues.

- Anybody who'd want to read and learn from the report (I'm now talking about those who would be directly and seriously interested, not the typical wannabee) can commission a professional translator. Do a word count and get an estimate. The report is now in the public domain.



In other words, as I said(slightly modified), the vast majority of people won't read the report and learn from this.

Politics or cheapness or pride or whatever, ahead of safety again.

[CONF iture]

Politics or cheapness or pride or whatever, ahead of safety again
And the correct answer should be somewhere between "politics" and "whatever"
The less visibility, the more chance people will stay away from the stuff.

Habsheim and Ste-Odile have never been translated. It is true that both happened to French carriers on French territory, but many all over the world would have liked to read and learn from the work of the "experts" in this time of new technology introduction.

Bangalore is another case, the second 320 to crash (http://en.wikipedia.org/wiki/Indian_Airlines_Flight_605), two years before Ste-Odile. Indian authorities with participation of Canada took care of the investigation. The accident report is not a widely known document either.

To me, it is obvious the Etihad 340 "incident" report should have been published in English as well ... I will translate what I think is the most intriguing part in that report.

[punkalouver]

Thank you so much. It could save millions of dollars or lives in the future. In your opinion, how long would it take to do a whole report like that?

[shortfuel]

Just a copy-past of my post on the same subject done in Middle-East section on Dec. 14th:


What we've learned:

- Run-up test was performed at high ENG thrust setting on 4 engines to detect an oil leak (procedural violation)
- No chocks in place (procedural violation)
- Braking system was normally operative giving full efficiency
- 3 technicians in the cockpit, 1 AI tech on the right performing the test, 1 GAMCO tech on the left as a client observer only, 1 AI flight test engineer (A320, ATR42 type rated though), observer as well on a J/S.
- 6 other people, in the cabin.

What happened:

During run-up, A/C started to move due to:
-high vibrations
-decrease of GW due to fuel burn during test (1270 kgs)
-slight brake pressure decrease on one wheel

Gamco technician noticed that first and spoke out.
AI technician focused on an altn braking problem and deactivated the park brake while pressing the pedals (not enough in a first stage...) to recover normal braking.

As the A/C continued moving, AI tech tried to steer the A/C to the right to avoid the wall...doing so, he inhibited braking on central wheels.
A/C accelerated, 4 to 31 kts in 7 sec.
About 2 sec before impact, the engineer on the rear J/S retarted the THR levers to idle.


That's facts.

That was just to give a reply to that racist story we read about this event.

So long'

If you really need any additionnal specific details (i.e translation), I can try to help, but sorry I will not translate the whole document.

[CONF iture]

If you really need any additionnal specific details (i.e translation), I can try to help, but sorry I will not translate the whole document.
Am working on that ... slowly but almost surely.

[ChristiaanJ]

CONF iture,

Since you're located "W of 30W", I don't know how good your French is...
As I said, I'm not willing to translate the entire document for free, but if you're doing so, I'm certainly willing to do a read-through of the translation with the original next to it, to nitpick on any details that might cause confusion.

Cheers,
Christian

[dvv]

CJ, I've asked around, and it looks like it would be something like $800 to use a professional translator's services. And it's before proofreading…

[ChristiaanJ]

dvv,
I'll dig out the report and do a wordcount.

CJ

[dvv]

CJ, no need, I've done that already :cool:

[punkalouver]

CONF iture,

As I said, I'm not willing to translate the entire document for free, but if you're doing so, I'm certainly willing to do a read-through of the translation with the original next to it, to nitpick on any details that might cause confusion.

Cheers,
Christian

And how much would you charge to translate a report like this?

[ChristiaanJ]

dvv,
What word count did you get for the French?

punkalouver,
If you want a professional translation, done by somebody working in the field and familiar with the subject and terminology, you're looking at something in the order of €0.10 to €0.15 a word before tax et al.
If you want a 'quick-and-dirty' translation done by a 'general purpose' translator, it's in the order of €0.05 a word net..

CJ

[punkalouver]

So for a 10,000 word report, all the BEA would have to do is pay perhaps 1,000 to 1500 Euros and they can't be bothered. Perhaps losing an opportunity to prevent a future accident by cutting off the vast majority of pilots who can't understand French.

I'd call that a potential hole in the old Swiss cheese theory, or a link in the chain toward an aircraft accident.

CONF iture is doing us all a great favour. Thank you and please do not rush. Quality is more important than haste.

[CONF iture]

As English is not my first language, but French is supposed to be ... I had a pretty good idea of what I had to translate, but probably not how to put it right.
Hope it won't sound too Chinese to too many ... but welcome any comment to improve the final result.
There is in the following about 85% of the BEA report (http://www.bea.aero/docspa/2007/f-cj071115/pdf/f-cj071115.pdf)

LAST EDIT 2009 FEB 04 :
Thanks to your inputs I did some corrections.
I also did add the paragraph translated by RatherBeFlying, I hope he won't mind.




SYNOPSIS

On 15 November 2007, the Airbus A-346 F-WWCJ was undergoing static engine ground runs on the Toulouse-Blagnac airfield. The purpose was to test systems with technicians of the airline that had ordered the aircraft. No wheel chocks were used. On completion of these tests, after having stopped and inspected the engines, technicians have started them again for another run at high-power to find the origin of oil seepages.

Approximately three minutes after power up, the aircraft began to move forward. The technician on the left seat perceived the motion and informed the Airbus technician on the right seat. The latter acted on the brake pedals and then released the parking brake. DFDR then indicates a partial release of the brake pedals. The aircraft continuing to move forward, he tried to modify its trajectory by using the nose wheel steering. The nose wheel gear quickly skidded sideways as the aircraft accelerated.
The aircraft struck the slope of the anti-blast wall. Forward fuselage broke and flop on the other side.

There were thirteen seconds between the aircraft early move and the wall collision.


1- GENERAL INFORMATION

Information on staff

The ground tests during customer reception phase are performed under the responsibility of only one ground test technician, an Airbus employee. He was usually accompanied by one or more persons representing the client, and sometimes by other Airbus employees. Airbus had no special qualification requirement toward the client representatives attending testing. The representatives of the customer sitting in the cockpit had normally observer roles, but it could happen that the ground test technician involves a representative of the client, for example by allowing him to taxi.

During this test, the technician in charge of ground testing was on the right seat, an aeronautical technician representing the client was on the left seat and a flight test engineer was on the jump seat.
The client representative and the flight test engineer had no specific function in the aircraft handling. The role of the client representative was to observe the parameters during testing to ensure compliance with expectations.


Persons on the flight deck

Ground test technician on the right seat
Male, 41 years old, Airbus employee, responsible for the test


Track technician since 1992
Ground test technician since 1998
RR Trent 500 familiarization course in May 2000
Attached to the Flight Test Department / Reception since 2004
Flight test engineer since 2004
Recurrent training for A-330/340 engine test in October 2006


Aeronautical technician on the left seat
Male, 36 years old, employee of a maintenance company (GAMCO), which receives and maintains the Etihad Airline fleet.


Technician for the GAMCO company since 1997
Courses at Lufthansa Technik and Airbus in 2002
A-346 static engine ground run training in 2006


Flight test engineer on the jump seat
Male, 42 years old, Airbus employee


Flight test engineer in 2000
Attached to the Flight Test Department / Reception since 2000
Authorized to perform engine tests on Airbus family
Airplane commercial pilot in 1998
A-320 type rating in 2004
ATR-42 type rating in 2006


Engine parameter reference

The thrust of the A-346 engines is measured with the EPR (Engine Pressure Ratio) which represents the ratio of pressure between the total output of the turbine and compressor inlet. This ratio varies approximately between 1 (ground idle) and 1.41 (full thrust, or around 28000 daN).


Weight and balance

The aircraft was at 223 tons including 40 tons of fuel, and the CG was at 25.8%. Ground tests are usually performed with 80 tons of fuel. The maximum certified take-off weight is 380 tons.


Braking system

The A-346 has two Main LG, one on the right side and one on the left, one Central LG and one Nose LG.
Each MLG and the CLG have 4 wheels each. CLG is slightly behind both MLG. Each MLG wheel and CLG wheel is equipped with a braking system, and each brake is powered by two independent hydraulic systems. The NORMAL braking is controlled through the green system. The blue system powers the ALTERNATE braking.

When the parking brake is set, the blue system pressurizes both MLG at 2500 psi. The CLG brakes are not pressurized by the parking brake.

When the brake pedals are pressed, the green circuit is pressurized on both MLG and on CLG with a record depending of the pedals position. The green circuit pressurization is inhibited as long as the parking brake is activated.

If you release the parking brake and simultaneously you press the brake pedals, the system allows both circuits to be pressurized together, while the ALTERNATE circuit depressurizes. This applies only to both MLG and the total amount of pressure from both circuits is limited to 2770 psi.

In addition, the braking of the CLG wheels is automatically reduced when the nose wheels are steered. From a turning order of 20 degrees, the CLG braking is completely inhibited.

Regulation for certification indicates that the parking brake must be designed to prevent the aircraft from moving on a dry runway with one engine at maximum thrust, the others being at ground idle. In these circumstances, the A-346 parking brake must develop a minimal braking force of 28000 daN or 3500 daN by braking wheel. The system was designed to develop a braking force of 8500 daN by braking wheel with a brake pressure of 2500 psi.


Weather conditions

Wind 330/16
Temp 5C
Dew point –5C
QNH 1019


Aerodrome information

The accident occurred on the BIKINI ramp. The area dedicated to testing, is part of the manufacturer's facilities.

No grip data for the surface of the test area was available before the accident. To enable a quantitative analysis of braking performance, it was necessary to undertake measures of slipperiness. These measures were carried out in conditions close from the day of the accident. The friction coefficients were measured between 0.65 and 0.68. These values correspond to the coefficient of a dry track in good condition.


Data recorders

The CVR and FDR have been synchronized using the UTC time registered in the FDR and the “Master Caution” “Single Chime” identified on the CVR.

The aircraft arrived at the BIKINI area around 14:19
It was at a magnetic heading of 312 degrees. The parking brake is set and active.

During the tests between 14:19 and 14:58 the maximum EPR values are between 1.04 and 1.22

The last static engine ground run is started at 15:58
The aircraft is still at full stop.

Between 15:58:10 and 15:59:03 the thrust is increased from idle to a steady value of 1.25 EPR. This engine thrust setting corresponds to a position of thrust levers between MCT (Max Continuous Thrust) and MTO (Max Take Off Thrust).

The ALTERNATE pressure values are close to 2600 psi for the wheels 1,2,5,6 (left gear) and 3,4,7,8 (right gear). They are at 64 psi for the wheels 9,10,11,12 (central gear).

At 16:02:06 the person on the right seat starts talking but is interrupted at 16:02:08 by the person on the left seat who announces :
“euh ... cabin is ... aircraft is moving forward”

The first significant LONGITUDINAL ACCELERATION values showing a forward acceleration of the aircraft are observed around 16:02:07
The recorded ground speed starts to increase at 16:02:09

Between 16:02:08 and 16:02:13 the ground speed increases from 0 to 4 kt.

At 16:02:11 the person on the left seat repeats :
“Aircraft is moving forward”

An action on the brake pedals is recorded from around 16:02:11

The parking brake is deactivated around 16:02:13
The person on the right seat announces :
“parking brake off”


From the moment the park brake is released:


brake pedals are briefly released on two occasions

the ALTERNATE braking pressures go below 192 psi

the NORMAL braking pressures from MLG are consistent with the brake pedals position on both right and left sides, and increase from 300 to 2500 psi in one second

the NORMAL braking pressure from CLG reach a maximum of 192 psi at 16:02:14 and then decreased to 64 psi and stabilizes at that value

the wheels speed values which were still recorded to zero (sensors do not work until a wheel speed of 3 to 5 kt) become positive and are consistent with recorded ground speed and aircraft movement

recorded ground speed increases rapidly from 4 to 31 kt in seven seconds

Between 16:02:13 and 16:02:15 the order given to the right NWS (Nose Wheel Steering) goes from 0 to 75 degrees (full right order). The evolution of the nose wheel angle until impact is consistent with that order. From 16:02:15 the magnetic heading of the aircraft begins to increase; it goes from 312 to 349 degrees in seven seconds.

The angle of the nose gear reaches 77 degrees right at 16:02:19 and remains to that value until the end of recording.
From 16:02:18 we can hear on the CVR severe vibration noises followed by impact noises.

The thrust levers do not move until 16:02:20 when they are retarded in the IDLE detent. The EPR values of the 4 engines start to decrease immediately afterward.

The longitudinal acceleration becomes significantly positive, indicating an aircraft deceleration, around 16:02:20.5

FDR recording ends between 16:02:21 and 16:02:22
CVR recording ends at 16:02:23


Information on the wreckage site

The aircraft was involved in a collision with the anti-blast wall north of the BIKINI area. It came to rest leaning on the wall, heading north. The tail cone and the tip of the right wing are in contact with the ground. Only the right MLG touches the ground.

The aircraft struck the anti-blast wall at an angle of about 30 degrees. The underside of the forward cabin was torn on about fifteen meters and was folded to the ground when passing the anti-blast wall.

The cockpit was crushed against the ground north of the wall. The avionic bay including most of the flight calculators, below the cockpit, has been completely destroyed.

ENG 1 and 2 hit the wall and have many damages. The pylon 2 is twisted. ENG 3 and 4 kept running after impact and did not stop immediately. It was not possible to stop them by pushing the FIRE pushbuttons or by switching OFF the ENG MASTER switches.
Water and foam spray on ENG 4 managed to extinguish it at 18:48
Due to the proximity of the wall a similar scenario was not possible with ENG 3 which extinguished by itself only on November 16 at 01:25 when he had consumed all its fuel supply.

The NWG is broken and separated from the fuselage. The wheels are oriented to the right and have a steering angle close to the maximum value. The wheel tires are tapped and show signs of perpendicular friction to the tread.


Ground tire marking

For the following descriptions, the distance reference is taken from the point of impact on the wall, and up the aircraft trajectory.

A first trace of tire corresponding to one of the internal wheels of the Right MLG is visible at 120 meters over a length of approximately 10 meters. The trace of the external tires is present but less marked. Those marks are directed along an axis with the magnetic course of 330 degrees. No trace of the Left MLG tires was observed.

At 83 meters, we can see the first NWG marks. They curve toward a northerly course, are initially parallel then at 50 meters, converge to leave only one single trace. The NLG is no longer directional.

Symmetrical braking traces from both MLG are present at around 60 meters and down to the wall.


Video Camera

The recording of a video camera permanently filming the BIKINI area has been exploited. You can see the plane during the last test. At first there is a plane slow translation, then a sudden accelerating movement.
While the path begins to slowly turn right, the NLG starts skidding sideways. The plane continues on its path to the wall.
The forward section rises, falls back on the wall and the fuselage breaks. There are flames at ENG 1 and 2 level and on the aft section of the aircraft.
By looking at recorded shots several days before the accident,
we can see that some tests are carried out with wheel shocks and some others without.


Analysis of braking force and surface grip

Braking force

For each of the braking wheels, the maximum braking force created by the brake pressure is determined based on the specification of brakes, depending on the recorded pressure. The overall braking force is obtained by the total amount of braking forces from the 12 wheels. When the parking brake alone is used, the brake pressure on the CLG wheels is void and only the MLG wheels contribute to braking.

Slip resistance force

For each of the wheels, the strength of slip resistance is equivalent to the supported weight by the wheel multiplied by the friction coefficient μ tire/bitumen. The simulation is used to compute the limit friction coefficient value below which the wheels would slip, under certain mass distribution assumptions. In the same way, the forces of slip resistance for each of the wheels are added to obtain the overall slip resistance force.

Engines thrust

The engines thrust was calculated from the recorded EPR parameters and from manufacturer data, based on the day conditions (320 ft, nil speed, ISA -9C, no bleed air from engines).
It has stabilized at around 83500 daN.

Results

The model is used to calculate the theoretical changes in thrust, the maximum braking force developed by the braking system and compare the slip limit force from which the wheels start to slip.
For the aircraft to remain motionless, it is necessary that the thrust is less than both the maximum braking force developed by the system and slip limit force.

Throughout the last test, the engines thrust and the maximum braking force on the parking brake are very close. To obtain under the same conditions a slip limit force equivalent to the thrust force, a friction coefficient μ of 0.687 is necessary. Given the measured friction coefficient values, it is reasonable to believe that the aircraft was quickly on the edge of the slip.

The fact that a balance, even fragile, has existed for about three minutes confirms that the brakes were functioning in accordance with their specifications.

Therefore, modeling allowed to establish, with a reasonable confidence level, that during the last test the thrust and braking forces were neutralized, but that the balance of those forces was particularly precarious.

The aircraft remained motionless with 8 wheels through the parking brake, then started moving. Several factors may have contributed to the aircraft movement, notably :


the vibrations created by the engines
the reduction of weight due to fuel consumption (about 1270 kg)
a slight local brake pressure reduction on one of the wheels


When the parking brake has been released, the application of the brake pedals has never permitted to reach the same level of braking despite the fact that the 12 brake wheels became solicited. This is due to two factors: firstly, the actions on the brake pedals have not been sustained at the maximum level, and, secondly, the action on the NWS very quickly lead to inhibit the CLG braking. The resulting braking during the motion varied between 65 and 95% of the braking level obtained before the aircraft movement.


Information on organizations and management

In the manual delivery, the seat occupied by the representative of the customer during ground test is not specified. In practice, the representative of the customer is generally on the left seat. He takes note with the Airbus technicians of the parameters to be monitored.

The Aircraft Maintenance Manual (AMM) and the CAM (Customer Acceptance Manual)state that the engines tests must proceed with the use of wheel shocks for the MLG.

The CAM uses tasks listed in the AMM. Thus, there is in the AMM a procedure to search for oil leaks called “The Fuel and Oil Leak Test”. This procedure calls for testing with two engines in operation. These engines must be the symmetrical engines of each wing. For the engine on which the oil leak is sought, it must be applied the maximum thrust value of the day (1.25 EPR that day, corresponding to the maximum value for this type of test). For the opposite engine the ERP value to be applied is 1.145
These actions are carried out by memory.


Formation of the ground technicians

After a theoretical phase of familiarisation with the aircraft systems, trouble-shooting and functional tests, ground test technicians take training courses for cabin crew, courses in radiotelephony and taxiing. The next phase is practical while the trainee works with an instructor.

The following points are notably addressed:


conduct of ground test
ground taxi
participation in accelerate-stops
production flights
conduct of tests in Customer Acceptance Manual and associated tests
use of technical documentation and software
training in pressurization tests

Practical parts of this training are accomplished in the airplane and in the simulator.

A refreshment session is performed in a simulator every two years for ground test technicians.



Additional information

Testimonies

Ground test technician on the right seat
After conducting the ground tests, the client company technicians had noticed an oil seepage on the pipe of one engine. The ground test technician had decided to proceed for another test before leaving.
He increased the thrust in order to heat up the engine oil. After approximately three minutes, as he was looking inside the cockpit, he heard the person sitting on the left seat announcing that the plane was moving. He then noticed himself the movement. He removed the parking brake to use the normal braking. The aircraft continuing to move forward he thought having a brake problem. He then tried to change the trajectory of the aircraft using the NWS. He specifies to have often carried out that kind of test, but at a higher weight.

Aeronautical technician on the left seat
During a last test at high thrust, he perceived the motion of the aircraft by looking outside. He felt hiccups caused by the brakes, he believes. He noted the ineffectiveness on the NWS action. It did not touch any control.
He specifies the high thrust test was performed to loosen the oil in order to detect any seepage.

Flight test engineer on the jump seat
He attended as an observer for his first A-346 delivery. During the last high thrust test, he heard the person on the left seat announcing that the plane was moving. Given the vibrated environment generated by the high thrust setting, he was unable to perceive accelerations caused by the aircraft movement. He only remembers to have grabbed and retarded the thrust levers when seeing the wall very close.

The ground personnel
They watched the end of the tests. Before leaving the testing area, the technician on the right seat told them to move further as he was going to proceed for a last high thrust test. They positioned their car in front of the aircraft then moved further on the side when thrust was set. They then saw the plane moving, initially slowly then faster. They saw it hit the wall. They gave the alert.

The use of wheel chocks is not systematic because their use is binding. Sometimes, it happens they stay trapped under the tires after the tests. This requires to push back the plane to remove them.

Note: It is clear from discussions with other Airbus technicians that this kind of test, including on 4 engines at high thrust, are frequent. All confirm that the use of wheel chocks is not systematic. Finally many underline the pressure from the customers to go and check some details. This leads sometimes to conduct tests outside the scope of the CAM.


2- ANALYSIS

Test procedure

Although the reference documents require the establishment of wheel chocks during engine tests, the investigation showed they were not systematically used. Similarly, during the test for oil leaks detection, it often seems that the procedure to apply thrust on 2 engines only is not respected.

The industrial and commercial issues that are associated to the delivery activities may lead to induce timely pressure on testing technicians during this phase.

The presence of representatives of the customer on board during the delivery phases can create pressures inducing testing technicians to come out of their frame of reference.

Reactions in the cockpit

The ground test technician resources were mobilized for about ten seconds on the braking system. He did not think to retard the thrust levers. This can be explained by focusing on the braking problem, by the dynamics of the situation and by the lack of training in this kind of situation.

The persons on the left seat and jump seat were present only as observers. The aeronautical technician on the left seat did not intervene on the controls until impact.
The flight test engineer intervened, but late, to retard the thrust levers. This can be explained by its statute, the fear of interfering with the actions of the technician and also by the dynamic of the situation.


3- CONCLUSIONS

Findings of investigation


The aircraft, including its braking system operated in accordance to specifications

The accident occurred in the delivery phase of a not programmed test

The procedure was not conformed to the task “The Fuel and Oil Leak Test” listed in the AMM. It was carried out particularly at high thrust on all engines without the use of wheel shocks

Testimonies and video recordings indicate that engine tests without wheel shocks are regularly practiced

The thrust used on the engines was at the same level as the nominal braking capacity of the parking brake

While the aircraft began to move, the ground testing technician pushed on the brake pedals and released the parking brake

The ground testing technician turned the NWS to the right. This action, by inhibiting the CLG braking, has limited the braking effectiveness

The actions on the brake pedals were not sustained to the maximum level

The Flight testing experimenter has retarded the thrust levers when the plane hit the anti-blast wall


Causes of the accident

The accident is due to the realization of a run up on all 4 engines at the same time, without wheel chocks, and during which the thrust was close to the parking brake capacity.

The lack of a detection process and deviation correction in the ground test procedure, in a context of permanent industrial and commercial pressure, did promote the realization of a test outside of the established procedures.

The surprise led the ground testing technician to focus on the braking system; therefore he did not think to reduce the thrust of the engines.


Measures taken following the accident

Customer Acceptance Manual has been revised (May 2008) to strengthen
the instructions to follow when conducting a run up. This includes :


install wheel chocks to all MLG wheels (and all CLG wheels if applicable)

mandatory presence of two qualified persons to the controls during run up and taxing.

[jettison valve]

CONF iture,

Thanks very much for your effort! Merci!

J.V.

[punkalouver]

Thank you very much for translating the report. I have not had time to read it yet but will next week. I'm curious about the 15% of the report that was not translated though?

And remember that what you have done may prevent another similar incident but you will never be aware of it.

[RatherBeFlying]

See http://www.pprune.org/4587807-post452.html for my translation of training of ground test technicians.

[captplaystation]

Strange that no-one has yet managed to leak the video of the trip, that would make interesting viewing. :hmm:

[Joetom]

CONF, thanks for the report in english.

I like the last bit of the report, during eng run ups they will need two qualified people in the flt deck.

In the normal airline world, very often only one qualified engineer in the flt deck during eng run ups.

Just the same two cabin crew have to check/confirm pax doors in auto/man, but an engineer can do it alone when he is operating the door ?

[PositiveRate876]

Merci buku Confiture. :ok:

I'm surprised to hear of the three people there, none of them would think to pull back the thrust levers to idle or even use reverse. :ugh:

[Super VC-10]

Do I understand correctly that none of the crew on the aircraft were actually qualified to fly it? I thought that a flight technically began when the engines were started, or does this not count because there was no intention to actually fly that day. :confused: