Quote:
"@HN39 - Understood, and it wasn't a criticism, I just wanted to make sure that as the thread meanders to its late stages we got as many of our facts in a row as we can."

IMO, that has to be one of the most patronising comments I've seen on this thread - from someone who is inclined to bluster in areas of which he understands little.

Believe me, it wasn't meant to sound like that! Honest and heartfelt apologies if it came across that way.

I felt it was important to make the distinction because, as I've learned from you all, a simulator's behaviour around the edges of the flight envelope will usually be approximate, whereas doing it for real would give a more accurate picture.

As far as I'm aware, I knew it was Bechet who flew the reconstructions at Toulouse because he said he did on the ACI/Mayday programme on the subject.

Thank you, Doze. What I wanted to confirm. I feel we are on the same page, and I have actual experience flying the "limiters" or "protections" in a FBW system.

???!!!what!?

Today all the airline pilots are type rated on these simulators for all their training and formation!!!!

That's true today, but not on the A320 at Blagnac in February/March 1988. The Thomson-CSF flight simulator was very unreliable, and certainly not approved for zero-flight-time type-ratings! Admittedly, it would have been a bit better 6 months later.

Bonsoir Chris,

Thank you for your time reference.

Asseline said he trained his 100 FT height flight on the Thomson simulator (with sealed software) used to train AF first A320 pilots. Isn't ?

Which informations and simulator quality had Asseline, Bechet, the BEA, about AoA in Alpha protection and flight laws ?

So You were type rated by Test pilots who had to do instruction and qualification ?

roulis!

More of a history reference, after 26 years! Sorry, I should have explained better, so today I have been looking at the Aeroformation course information, the schedule (with many amendments), and my own notes annotated on them.

Capt Asseline was, I now understand, to be in charge of A320 flight training for Air France, and would have been on Aeroformation (later renamed Airbus Flight Training) A320 course #1 ("FC1"). I was one of two ordinary line captains (each of us paired with a line first-officer) on course FC2 - the first BCAL/BA course - a week behind FC1. (It is sometimes forgotten in French aviation circles that there were three launch-customer airlines for the A320, and Air Inter was the lowest in the pecking order.) The rest of my course members were training and management pilots, and two pilots from the CAA. We did not mix socially with the AF pilots, which I now regret; but we would occasionally meet them briefly at the simulator platform on handover, or at the drinks machine.

After a couple of weeks of self-tuition on the VACBI, and passing the technical exam, we started the FBS (fixed-base simulator) - originally planned to be 14 three-hour sessions - on the third Monday in January. The two FBSs were hors-service (u/s), so the first half of the series was cancelled and we started at FBS session #8, using the FFS (full-flight simulator). I cannot remember if we used one or both FFSs, but I think only one was available most of the time. It or they were unreliable - throughout our 7 FBS and 7 FFS sessions. Neither of my two instructors for the 14 FBS and FFS sessions was A320 type-rated, as far as I know. We lost 1h40 on the first two FFS sessions, and regained 0h45 on the next three; lost 0h45 on the sixth, and regained 0h10 on the seventh.

We then went home to England to wait for the A320 to be type-certificated, returning to Blagnac in March for our type-rating training. The latter consisted of one FBS session for re-familiarisation; 3 FFS sessions with instructors who were A320 TRE/IRE-rated, during which we did our instrument ratings; and one base-training sortie on the a/c for our type ratings.

Quote:
"So You were type rated by Test pilots who had to do instruction and qualification?"

Most of the TRE/IREs were Aeroformation trainers, not test pilots. There were, however, two or three test pilots who were involved in our refresher sim sessions in March. They may not have been TRE/IRE-current, but I'm not sure. They included GC, UE, and maybe NW. (Later, GC and NW were closely involved in our line training from Gatwick.) My single sortie on the a/c for base-training and type-rating was with an Aeroformation training captain, Dick Steele (who later conducted my "final" line check out of Gatwick). We reached alpha-max at an altitude of 4000 ft...

Quote:
"Asseline said he trained his 100 FT height flight on the Thomson simulator (with sealed software) used to train AF first A320 pilots. Isn't?"

That's quite possible, as he would have been able to negotiate extra sim time in his capacity as chief trainer for AF. But I cannot comment on "sealed software". What is that?

Quote:
"Which informations and simulator quality had Asseline, Bechet, the BEA, about AoA in Alpha protection and flight laws?"

I think the simulator(s) had been increased in number and reliability by the end of June. I know little about the working of sims, but all the necessary information would surely have been available from the Aerospatiale EFCS design team to create the necessary algorithms? Perhaps someone else can comment.

You have clearly no idea what would be to reproduce such a flight for real with the necessary required level of detail, accuracy, and fidelity, to have any value. The flight over the Toulouse runway was not meant to be a "reproduction" but was merely a wish by members of the commission to personally assess the behavior of the aircraft during maneuvers near the ground, to see if the switching of control laws could cause difficulties for a pilot.
HN39 is referring to the 'graph' on page 63 of the PDF which refers to a simulated flight not a real one.

As you seem ready to give any value to those graph, how Bechet and Asseline would still keep the same speed after obtaining so different alpha ?
According to the poor quality ... graph we are presented, not if he had started the maneuver at the same altitude that Asseline did, and not 10 ft lower ...

Some remaining outstanding issues
 

Bonsoir Chris Scott,

Thank you for your long description of the A320 launch-customers pilots type rating. I could compare it to my own MD-80's TR at the same moment. Despite the MD-80's were already "old" aircrafts our TR had many similarities, but of course no flight with test pilots, not alphafloor flight. But like you, only one base-training sortie on the a/c, after VACBI, FBS and FFS. That only one flight was around 1 hour or less, verifying that the real plane felt still easier than the FFS, and to say we did a real flight !

I wanted to point that flying alpha prot or alpha floor on A320 FFS is reliable, as the FFS has the exact reproduction of the EFCS rules. That is very different from trying to test i.e. stalls who have never been done in flight, and whose behaviour is still unknown and could not be "reproduced" on the FFS.

My purpose was to say to DozyWannabe that the FFS simulation from BECHET/BEA was totally reliable, and consequently too that the Hazelnuts39's demonstration perfectly applies (about "sealed software", see (1)).

Continuing the demonstration, it suggests that the fact that pulling the stick three seconds later and getting in alpha prot which had not been previewed by Asseline -and missing in the short "briefing" (gums You are right, that was a very poor "briefing" !) - modified seriously the pitch control reponses.

I don't forget that Hazelnuts39's conclusion reminds that it was not enough to replace the late thrust of Asseline.

Asseline is writing many times in his book that he surely was wrong to trust his altitude. we know from the crash itself and the videos that the plane's real altitude was nearly the same that the RA. The question seems still to be open : did Asseline read 100 FT on his baro-altimeter, when the DFDR records an altitude complying with the Radar altitude, and Mazières telling him clearly about RA ?

The BEA report is saying too that the crew did not contest the FCS (at the time of the enquiry, which is some years earlier than Asseline's book).

(1) re:"sealed software" : Asseline said that working with Thomson they first asked to AI -or AS ?- they needed the copy of the EFCS software. Asseline said they recieved a negative answer, but AI-or AS?- accepted to give them an original EFCS software in a box they could not open or read or copy

I see no reason to doubt the accuracy of the simulator used by Bechet. He gained less than 10ft height in the five seconds after he went to full throttle and full back stick. That is equivalent to less than 1 kt of airspeed. In the accident flight the wind was light and variable (5 kt +/- 2kt headwind component), and in those last few seconds the airplane entered the lee of the forest. Those wind varations were evidently not represented in the simulator.

P.S.
Just before hitting the trees, the DFDR recorded RA was 24 ft, possibly even less because the recorded values are rounded to the nearest 2 ft. The average tree height is reported as 12 m (40 ft).

Thanks roulis,

My main purpose was to explain to anyone interested in these matters that - at the time Capt Asseline was doing his conversion course - the A320 sim was unreliable, and that zero-flight-time conversion was impossible.

Quote:
I wanted to point that flying alpha prot or alpha floor on A320 FFS is reliable, as the FFS has the exact reproduction of the EFCS rules. That is very different from trying to test i.e. stalls who have never been done in flight, and whose behaviour is still unknown and could not be "reproduced" on the FFS.

I think the a/c would have been stalled during the test programme. But it would not be necessary to incorporate any stall data into the FFS, because the aerodynamic stall is not part of the training syllabus. And, of course, it did not occur at Habsheim.

Quote:
re:"sealed software" : Asseline said that working with Thomson they first asked to AI -or AS ?- they needed the copy of the EFCS software. Asseline said they recieved a negative answer, but AI-or AS?- accepted to give them an original EFCS software in a box they could not open or read or copy

Thanks - that is interesting, and would make sense commercially.

Regarding the test flights at Toulouse, I'm going from Captain Bechet's interviewed statements on the ACI programme, and he at least seemed to be confident that it was close enough to the actual event (though obviously with some variation) to be useful. Other than that I make no claims whatsoever, other than HN39 (as usual) seems to be on the money regarding the effect of earlier vs. later application of full back-stick.

As for the software in the original simulators, it would have been standard practice at the time to provide complete and working hardware/software combinations as a unit - as long as the interface of the simulator and that of the aircraft was the same it should have been like-for-like. As such, the behaviour of the EFCS would have been one-and-the-same on the simulator and the real aircraft, but the simulator's flight model behaviour would still likely have been undergoing refinement. The "black box" (in engineering terms, i.e. meaning a 'sealed unit') was and still is for commercial considerations only - Airbus's competitors would have likely been very interested in the implementation of their systems, and - especially at that time - the fear of industrial espionage was a real one.

I know that the flight model was essentially fed with the data gleaned from the flight testing performed on the A320 prototypes, and I've been told that those prototypes were the most heavily instrumented and monitored machines of their type at the time. I don't know whether they were flight tested beyond the stall boundary, but wouldn't be surprised if they were at least taken as close as possible in order to gather data on airframe characteristics.

From my brief experience, I can say that modern A320 simulators do provide a plausible representation of behaviour going into stall and recovery, but can't vouch for how precise a representation that is.

In 2 sec the airplane gains 5 deg of AoA without altitude gain and without losing speed ... That A320 is a very special bird indeed ...

Yes, the atmosphere was calm.

Not what is in the report text and not what is on the graph you're commenting ...
How do you explain again such confusion in the report ... ?

The reports states that the wind was 5kt at the time of the accident. Comparison of the recorded airspeed and groundspeed shows variations of +/- 2kt of airspeed that can only be explained by variations of the wind speed.
The last value of 34 feet is obviously a typographical error and should read 24 ft as shown in the CEV print of DFDR data. In addition, the recorded accelerometer data show that the airplane cannot possibly have climbed 10 ft in one second between TGEN 333 and TGEN 334.
http://i.imgur.com/jOmWmjz.jpg

I thot Doze or another contributor tried to duplicate the stall/recovery for AF447 in the sim.

Unless early flight tests showed a poor pitch co-efficeint at a high AoA, as we had in the Viper, then an approach to stall at 20K would seem to provide great data for the simulator. No need to reach the AF447 complete stall conditions, but at least show the ability of the alpha protect and such to help the pilot. From the AF447 data, seems to me that the 'bus has poor nose down authority once past 15 or 20 degrees AoA. Our problem in the Viper was similar, in some ways. We had plenty of nose up, but our AoA limiter would not let us use it. Nose down was FUBAR due to the design of the jet and its pitch co-efficient at 40 - 50 degrees AoA. Hence, we had the manual pitch override switch that would only work if AoA was above 30 degrees.

I still feel the accident, if you can call it that, was the result of poor planning and practice, and improvised changes in the "plan". I won't comment any further on the airmanship of the pilot.

1. If it was one they would not have used it for the graph drawing
2. Tome 2 is more inclined to depict 34RA for TGEN334 than 24 ...

http://i55.servimg.com/u/f55/11/75/17/84/image12.jpg

Still nothing new here gums - We still all agree - But what we're looking for is the FULL story not only the part on the crew.
As HN39 is avoiding the question, you probably could bring your thought on that :

That is not what I said in post #622 based on the graph in the report. In the simulation the airplane gained 10 ft and that is equivalent to 1 kt of airspeed.The graph is a computer/plotter generated record of the simulated flight. How accurately were the plotter pens aligned with the millimeter raster on the paper ? The scales and the Habsheim points have been handwritten on that plot with lesser accuracy. The wind at Habsheim was variable. Thus a difference of one or two knots is easily masked by other factors. It is ridiculous to dismiss the simulation for no other reason than that you can't see a difference of one knot on that plot.

"It's a special bird indeed"

Well… Maybe.

During that time was it gaining thrust? If so, then increasing the angle of attack, and thus drag, keeping the potential and kinetic energy constant, but matching the increasing drag and thrust? That doesn't seem an unreasonable proposition.

Documentation discrepancy of Rad Alt datum at TGEN 334
 

Hello Confit,

I think many of us were already aware of the discrepancy between the figure of 34 ft in 1.11.4 of the BEA "Rapport Final", and the 24 ft shown in the DFDR "Tome 1" table of the same document.

Thanks for bringing to our attention that DFDR Tome 2 of the same document appears to show a figure of 34 ft, in line with the narrative. The version you show magnified in your post is, I presume, the PDF copy, the poor quality and assembly of which we discussed earlier on this thread.

Another curious aspect of this matter is that an HTML version of the BEA report - Habsheim F-GFKC - clearly shows a figure of 24 ft in both Tomes 1 and 2.

TGEN 334 seems to represent the last second of flight before the RA antennae (rear fuselage) reached the treeline. The ground between the northern extremity of the grass Rwy 34R and the treeline - a distance of about 70 metres - seems to have been flat, with minimal slope. One cannot, however, entirely rule out the possibility of a vehicle or other temporary obstruction being present within the wide, conical lobe of the aircraft's RA TRx. As the ground-speed of the a/c was slightly less than 60 m/s at that point, the RA values at both TGEN 333 & 334 could have been affected by vehicles or superstructure between the grass runway and the treeline.

Therefore, determining the precise RA datum at TGEN 334 would not in itself enable us to prove the trajectory of the a/c in the final second of free flight.

Confit,

I think you are wrong to argue that the wind was calm, if only for the reasons HN39 has pointed out.

Also, if you look again at the Andre Karsenty video, you will see a large balloon in the backround about 7 seconds before the a/c reaches the treeline. It is leaning slightly towards the south, suggesting some kind of headwind component for the A320.

And, as you and any pilot of any size of a/c know well, the proximity of trees is always associated with some degree of wind-shear.

Wind components (W/Cs) can, of course, be estimated from a comparison between the TAS and the GS. (Any error in the GS readings from the IRS are likely to remain constant for the short period of the straight-line flypast. In this case, allowing for pressure altitude and temperature, adding 3 kt to each IAS value gives the approximate TAS.)

Starting from level-off at TGEN 321 and finishing with TGEN 334, the estimated W/Cs at one-second intervals are as follows:
-7, -4, -8, -9, -7, -7, -6, -4, -6, -5, -7, -7, -3, -3.

The above variations are consistent with small gusts of a light headwind.

Good ... then from the 30 ft with a gain of 10 ft at 17 deg of alpha and speed at 119 kt the BEA and yourself agree that the airplane was surviving the 40 ft forest ...

I am certainly not looking for any kind of "one knot difference" or other 2 kt gust theory to dismiss such ridiculous simulation when they want you to believe that taking 5 additional degrees of alpha in 2 seconds to bring it to alpha max won't make a difference in term of altitude and speed compared to the same aircraft that remains between 14 and 13 of alpha as computed on the graph.

Where did I argue so exactly ... ?
The atmosphere was calm, and the wind less than 5 kt according to the Air Traffic Controller.

Here is the ultimate purpose of my concern. This Official Report has a typographic quality of the 60s at most but certainly not one of the 90s standards. All the "graph" as presented as they are, are a pure joke or an insult to the reader. Too convenient for blurring data and bringing confusion. One crucial Annexe is nowhere to be seen and manipulation in Annexe labeling is even created in an attempt to mask its absence. As the BEA is that unprofessional, we clearly do not need them.

I am concerned that a guy with your background seems to give more credibility to such piece of cr@p from the BEA than to Ray Davis ...

dragging it out, heh?
 

C'mon, Confit.

The jet and its FCS worked as advertised. And then the laws of physics and aero came into play.

It could be that 'bus folks did not do enough testing at altitude to examine all the "protections" and "floors" and such using flight idle, TOGA, etc. The jet did not have the pitch coefficient problem we had in the Viper, so it had plenty of nose down authority at high AoA ( although we saw with AF447 that the THS position had to be compensated for to get the nose down). Nose up is "limited" by the flight control laws WRT AoA, not the actual capability of the plane, and we had that in the Viper. You can command everything, but HAL is only gonna let the jet "obey" the laws, best it can.

Well, that's the risk you take with an unofficial publication. That document was probably derived from the BEA PDF, and transcribing those DFDR printouts must have been especially error-prone. I'd say that the evidence offered by CONF iture (the magnified scans, and the values as they appear in the narrative) is sufficiently convincing.

BEA Rapport Final
 

Quote from noske:
"Well, that's the risk you take with an unofficial publication. That document was probably derived from the BEA PDF, and transcribing those DFDR printouts must have been especially error-prone. I'd say that the evidence offered by CONF iture (the magnified scans, and the values as they appear in the narrative) is sufficiently convincing."

Yes, I agree with all of that. It is ironic, however, that the RA figure of 24 ft at TGEN 334 in the HTML version of Tome 2 is more plausible than the 34 ft figure in the PDF copy of the BEA report. The Karsenty video rules out any inference that the a/c might have climbed 10 ft in the last second.

Whichever of the two figures is correct, students of the report might expect that its final edition would have corrected an unnecessary anomaly that undermines the authority of the whole document. If that and other less imperative amendments were done, it is unfortunate that the BEA has not made the amended document accessible via their website.

In public transport, the Habsheim accident has unique aspects and complexities, and continues to provide a basis for the study of a broad range of aeronautics. In recent years, the BEA has published several very informative papers relating to flight safety matters in general. Its valuable contributions to the subject are somewhat undermined by the continuing deficiencies of the Habsheim document.

Hi gums,
Just a reminder to you and others that, in AF447, Pitch Alternate Law allowed the THS to continue auto-trimming to full nose-up trim. At Habsheim, starting with Pitch Normal law, the THS auto-trimming was disarmed first (briefly) by the premature, 2-second engagement of Flare mode at TGEN 313 (t -21) - triggered by flying over trees; and, secondly, when Flare mode was entered again at TGEN 317 (t -17). Finally, it remained disarmed when Alpha Protection mode took over from Flare mode at TGEN 330 (t -4). Earlier, in fact, it had had no need to trim between TGEN 306 (t -28) and t -21. So, to sum up, it remained at U04 (4 degrees nose-up trim) for about the last half a minute of flight. Full deflection in the nose-up trim sense is 13 degrees.

In France the official version is not the BEA file, but the "JOURNAL OFFICIEL" copy of the BEA file. Probably the BEA had two versions : 24 and 34 Ft. They have to verify and ask to the J.O. to register the true number. The J.O. would not modify such a number.

Bon soir roulis,

The Journal Officiel is the document, available via the BEA website, which Confit shows.

http://www.bea.aero/docspa/1988/f-kc...f-kc880626.pdf

Can you explain more? Are you saying that, once the document has been published as the Journal Officiel, the BEA is completely powerless to publish any necessary corrections?

The Ray Davis angle was covered earlier in the thread more than once - here:

http://www.pprune.org/tech-log/52803...ml#post8209613

and here (click the arrow to go to the original post):

One thing that I didn't mention before and may have some bearing is that Mr. Davis was hired by a UK TV production company making a documentary on the subject - not of the crash itself, but of Asseline's attempt to clear his name. The Airbus document explaining where Davis may have erred does not allude to this, but there is a distinct possibility that the information supplied him may have been missing some of the details mentioned in the above posts.

We also know that the Loral DFDR units fitted to the early A320s were later known to be susceptible to write errors when subjected to unexpected shock or vibration. The estimated value of +0248 RA at TGEN335, which CONF iture has helpfully provided in magnified form, is clearly erroneous - therefore it is within the realms of possibility that the previous value is also in error. That the video evidence clearly does not demonstrate an altitude gain of 10ft before impact with the trees supports this hypothesis in my opinion.

Hi Chris - I hope you find this interesting, though it's on a bit of a tangent. When we tested the AF447 scenario in an A320 sim (the best we could do as there were no A330 sims available), the autotrim was limited by the system well before we got into difficulties - to simulate the scenario, the TRE had to manually wind on full nose-up trim with the wheels. If such behaviour was consistent with the A320, it follows that autotrim behaviour on the A320 series is different from that on the A330/340.

@Chris Scott,
1. My last sentence was perhaps at a wrong place?
Once the document has been published in the Journal Official any necessary correction is possible in a similar form and level of law hierarchy, probably in a short but accurate description of the modification but with the signature of the original administration . If the modification is not published you may ask a Court to apply the wrong text. The Journal Officiel does the maximum to avoid such mistakes and many verifications are done and redone before publishing, to respect every comma or space, but in the JO typography, design , with absolute rules of registering, diffusion, existence of copy. It often needs much time which brings a delay between the BEA text who has its own design, and rules, published so quickly as possible and the JO tex
It is unusual that the BEA text provides a copy of the Journal Officiel which gets a BEA report.. Why, when was the original BEA report replaced in their files?

2. The numbers provided by the sensors must not be replaced, the BEA may only comment them in his report

Absolutely not - The advertisement is to do the necessary in order to expect alpha max 17.5 deg in this configuration, but certainly not to restrict it to 15 at most.
The law in this case is to permit 17.5 deg of alpha and not to restrict it to 15, or even 14 depending on where you look into that BEA Official Report ...

I'm not too sure how such document as you posted it is actually obtained ?
Don't you think the transcribing to obtain such format must be part of an automatic process ?

Then you should have said that that type of DFDR was also susceptible to write errors when anticipating a shock ... the emotion maybe.
BTW any data from TGEN335 has already no value has the tape is labelled as de synchronized.

Not more than it demonstrates an altitude loss of 6 ft the second before ...

Where does it say this? It doesn't say this in any of the documentation.

To my mind it's two separate pieces of information out of context that you have yourself combined to come up with this ludicrous theory that the FCS was to blame, and not the arrogant*, incompetent** and stubborn*** (on that day at least) Capt. Asseline.

* - In blithely assuming that he was skilled enough to take a greater level of risk with pax on board than Airbus's own test pilots
** - Thoroughly making a hash of the approach with very poor thrust management
*** - Going ahead with the flypast on the first attempt when it was obvious that the briefing was wrong (regarding which runway to follow)

Of course it does as already posted in #599 and #603.

Finally showing your true colors after initially playing false demagoguery by pretending "having some sympathy for Capt. Asseline".

Neither of those posts state 17.5deg as being a guaranteed swift response upon full application of back stick, and in fact the Airbus documentation does not mention 17.5 degrees at all. You're taking the absolute value given in the BEA report out of context and grafting it to the Airbus documentation in a way that is not consistent with the way the documentation is written in order to claim that there should have been an expectation of 17.5 degrees, when that doesn't seem to be the case.

And I *am* sympathetic to Asseline in some respects, particularly the lack of oversight and poor preparation materials given him by the airline. This does not alter the fact that the conduct of the flight seems to be consistent with the negative traits sometimes ascribed him, and *on that particular day*, as I said, he seemed to be displaying those traits during the conduct of the flight. The two positions are not mutually exclusive.

The DFDR recording offers three sets of data that can be used to reconstruct the trajectory:

-- radio altitude
-- pressure altitude
-- x, y, and z accelerations

When comparing these three sources, the different heights of the respective sensors must be taken into account. The radio altimeter antenna is on the lower rear fuselage, the ambient pressure is sensed by Air Data Modules close to the static pressure ports on the front fuselage, and the three-axis accelerometer is located near the center of gravity. The relative height of the three sources varies with the pitch attitude of the airplane, and for the radio altitude also with the elevation of the terrain. The following graph shows the height of the CG taking those factors into account. The elevation of the terrain can be taken as 781 ft at TGEN=334 with a downhill slope of 0.15%. The pressure altitude depends on the local pressure, given in the report as QNH=1012 hPa and QFE=984 hPa. If the pressure has been accurately measured and properly rounded the QNH must then lie between 1012.1 hPa and 1012.5 hPa. The graph shows the CG height based on the pressure altitude for both values of QNH.

http://i.imgur.com/4v6E9D3.jpg?1

Gotta tellya, Confit, that until I see the actual FCS charts/functions for modes and such, I'll stay with Doze and others that the plane gave everything it was "programmed " do.

My problem is with the "flare mode", which requires increasing back stick once the jet is "x" feet above the ground. Could it be that the "flare mode" prevents the jet from reaching the advertised max AoA?

I swear, the 'bus has more "laws" and functions and everything else that the space shuttle, the Viper or the F-22 do not have. For a pilot, I want to know exactly what to expect without having to go thru modes, sub-modes and then sub-sub-modes. Sheesh.

I am not an advocate of "direct" laws, as some have mentioned on our discussion. But you can only do so much to prevent/help some hamfist to fly the jet.

No - aircraft was not in flare mode from shortly (as in under a second) after it overflew the "copse"/"bosquet". Well out of flare mode when the trees were spotted, and as other A3x0 rated pilots have attested, flare mode can be cancelled simply with application of TOGA thrust*. As OG attested to (If I read him right, it's related to EFCS phugoid damping) - the Alpha Max command in High AoA Protection gives as much as it can, then likely waits a fraction of a second to stabilise before determining whether the remaining AoA is to be used for extra pitch or for bank input.

Oops - got the above regarding OG's post completely wrong - apologies!

EDIT : As I said earlier, I have a suspicion that the airspeed deltas have an effect on how long it takes to consider the attitude "stable", and in a case such as this one where the aircraft was decelerating almost right up to impact, the duration would likely be longer than if it had airspeed in reserve.

The 'bus systems have three primary laws only. Alternate Law has a number of sub-modes, but the overall performance isn't a great deal different between them - the sub-mode is determined by which of the myriad systems has suffered a failure. It goes without saying that this will be more complex than a fighter, possibly even the F-22, because an airliner is a much more complex piece of engineering mechanically.

* - This aspect is discussed in more detail earlier in the thread.

@Hazelnuts39
What is still unknown is the altitude read on the altimeter on the cockpit

I think this has been covered before, but if I may attempt to recap...

The only way to be 100% certain would be to have had a camera trained on the PFD, but since we don't have that, a degree of assumption will always be necessary. Folks, correct me if I'm wrong - but I think from recollection of the AF447 thread that the DFDR altimeter trace is fed from the ADIRU selected on the Captain's side (LHS).

As others have demonstrated, the DFDR trace seems to tally well with other data when it comes to actual baro altitude. QNH seems to have been correctly set, and all things considered the likelihood is that the baro alt on the PFD was showing the values recorded on the DFDR. For there to have been a discrepancy would mean a fault on the data bus between the ADIRU and the LHS PFD, for which no evidence seems to exist (though, admittedly, such evidence would be difficult to trace later on).

Asseline insists that the baro alt was reading 100ft throughout, and furthermore frames the possibility that it wasn't as tantamount to accusing him of lying. He mentions earlier baro alt misreadings on test flights and argues that may have happened in this case. I believe he states elsewhere that he was relying on the baro alt and external references because he found the digital RA display difficult to read.

I'm sure that Asseline believes fervently that the baro alt was reading 100ft, and if it wasn't, he may have still perceived it as such through confirmation bias - as the workload on the flight deck was significantly higher than anyone had anticipated due to the briefing errors. If the baro alt was in fact consistent with the DFDR, that doesn't make him dishonest - it just raises the possibility that he made a (completely understandable) mistake under pressure.

On the other hand, his own input raises further questions about the conduct of the flight as a whole - particularly with regard to the wisdom of relying solely on one instrument if you consider that instrument to be unreliable, with the only safeguard being external references at an unfamiliar airfield.

As 17.5 deg value for alpha max at CONF3 given by the BEA is not good enough for you ... where do you think the BEA got that value if not from Airbus ?
True I should always remember that you still don't know which config was used in Habsheim ... !?

Another nice piece of disinformation. Who should I credit it to, OG or you ... ?

Then Bechet in his simulator just proved your suspicion wrong ...

Sorry gums but I go by the book, now if the the plane behaved as per an unpublished program ... it was the BEA duty to detail it afterwords.

If you say it was CONF 3 and the report says it was CONF 3, then it was CONF 3. I've been aware of that for a while.

Of course the BEA would have got the value from Airbus. But the issue I have with your position regarding 17.5deg is not the value itself - it's your interpretation of combining the absolute value as given in the BEA report with the less-specific (regarding values and how they are used by the EFCS) documentation that Airbus provided to flight crew.

Your argument seems to be that Airbus - to use your own word - "advertised" that in CONF 3, 17.5 degrees AoA would definitely be achieved under any circumstance with the application of full back-stick, when the documentation says no such thing.

AZR said much the same thing to you a couple of pages back:



On what are you basing that accusation? There seems to be a definite short delay between acquiring 15 degrees AoA and going further. OG reckoned it was related to damping.

How so? Please elaborate. For one thing, you yourself said that Bechet's work in the simulator and real-world testing did not involve a precise reconstruction of the event - so I'm puzzled as to how they could disprove an assertion if that was the case.