Hi Bpalmer,
Nice description of IAS.
CAS is IAS corrected for instrument and position /installation errors.

CVR specifics
 

Hi, Everyone. Been reading these 11 threads from the beginning of this tragedy. Finally registered in order to ask what (hopefully) is not taken as a stupid question: is the CVR audio purely mic driven or are the C-chord, stall cricket and other audio alerts wired directly into the box? I doubt they are wired in, but if it were the case and the electronics were going haywire, it could explain why the crew never acknowledged the alarms (requiring speaker failure) while still existing on the CVR... Speaking of that, I do still wonder why the BEA neglected to include the "one hour sleep" reference and if there is more to the "privacy" excuses re CVR, legit or not.

BEA
 

If only the BEA would release the DCVRs in their entirety but they didn't having bowed to pressures by Unions.
I've put forward what indeed really happened in terms of human interaction on the AF447 flightdeck only to see my posts deleted by dark forces.
It's difficult to fathom for for those who haven't lived in France to understand the strained relations the Unions have had with AF as well as overly-politicised appointements that are rewards for the party faithful.
A much better read than the BEA's report is the Judicial Experts' report.
A new panel has been selected for a 2nd Judicial Experts' report at Airbus' behest even though they were 98% happy with the 1st but now want to be 100% blameless with the 2nd report as it lays the foundation for the trial proper.
No trial can go ahead before the 2nd Judicial Experts' report is completed but the road will be a long one and the Investigating Magistratre is set to retire at year's end which will again slow the wheels of justice.
French trials for aviation accidents are endless.
For example, a chopper crash in in 2004 with 5 victims will reach trial in Jan 2014 after 10 years! Crash de l'hélicoptère d'Héli Air: jugement le 30 janvier | Nice | monacomatin.com but wait then there are appeals and appeals...

I'm pretty sure (though not 100% certain) it's all mic-driven, with "hot mics" at the crew positions and one or more "cockpit area" mics. What I am sure of is that the electronics were not "going haywire", they behaved as designed throughout the sequence. The only technical issue was the icing over of the pitot tubes, and the ice melted, clearing the pitot tubes during the zoom climb.

CVR transcripts as appendices to investigative reports are routinely redacted. Redaction of material considered irrelevant to the actual conduct of the flight is commonplace, and the discussion of rest was part of a personal (i.e. non-essential) conversation. The talk of "one hour" rest did not, as I recall, refer to the total amount of rest the previous night, but to a different period of time. Another thing you'll routinely see redacted are expletives and unintelligible words.

@Winnerhofer - you do talk a lot of rubbish sometimes. First you claim the wife of the PF was present on the flight deck (for which there is no evidence), and now you're saying Airbus are aiming for a "blameless" report when there is no evidence to suggest that. What is suspect about the so-called "Judicial Experts" report is that it was performed at the behest of the SNPL.

Once again I must remember you (it's tiring at the end to make the parrot) that this expertise is not related in any way to any union .. but it was requested by the judge who heard the case .. as French law requires to do in such cases
Those experts are independent and come from a pool of the judicial instances (and so .. are not "so-called" judicial expert :rolleyes: )
They are as independent as those of BEA Experts :ok:
I hope this help :)

Yes, when it comes to technical part: we agree that HUDs and alpha displays are useful. No, regarding the human factors involved in AF447; I do not think HUD would make a difference. From technical standpoint, crew had everything they needed to deal with the situation successfully, they were just so shocked they couldn't use any of it.

Some might find description complicated but I find their operation very simple; just keep on flying as you were. It's not as if Airbus pilots use their protections daily.

Not just that: even wings designed for similar missions have widely diverging characteristics near the envelope edge. 737NG has mach trim, 320 doesn't. 330 radically changes critical alpha at high mach, 320 not so. What impact does it have on line pilots? None whatsoever. Know your limitations and procedures. If you are going too fast, slow down but not so radically you approach stall. If your alpha is to high, reduce it in reasonable and timely manner. Fly the attitude. I guarantee you it works on Stinson Trimotor, F-16 and 330 despite never having flown any of them.

Only in your imagination. In real world there were quite a few pilots losing control of their steam gauged aeroplanes and there are many modern pilots who successfully returned their glass cockpit wonders to earth after major technical malfunctions. Implying all pilots today (except quinquagenarian and higher) can't fly in critical situations flies in the face of safety records and is off-scale hypocritical.

Design such a system and you'll get rich beyond your wildest dreams.

Point with unreliable data is that they cannot be machine-recognized and no amount of computing power can help it. Have a look at Aeroperu accident; the kind of false alerts they got and tried to resolve in vain.

It's even more moot considering one of the few coherent and rational items on CVR is recognition that speed display has gone bad - from both sides of cockpit.

True! Especially bearing in mind it's one thing to consider the pitot blockade, reconfiguration laws, aeroplane energy state, warnings etc. sitting comfortably in front of the computer screen, quite another having it all thrown at you over the middle of Atlantic at 4 a.m.

I was trying to point out discretely that you haven't read the part of AF447 report dealing with TAM incident which puts "kid gloves approach" straight into "old wives tales" category - something that has some basis in reality but through misunderstanding and misinterpretation diverges rapidly and significantly from it.

Regular use of autopilot does not absolve the pilot from obligation to check instruments. Idea that you need to handfly to know your typical flight-phase-related attitude is so unrealistic it... sorry, I can't find the phrase in English.

This discussion needed not read across to other types if folks would only read the effing report and see that there were many similar incidents on 330/40 fleet, with every single one having far, far better outcome, therefore making long, elaborate and usually just plainly wrong discussions on FCS degradation laws unnecessary - if one's intent is to get to what made the difference in AF447 case.

Airbus did effing fly 330 to check buffet levels, both waaay before AF447 and after. 340 test was not part of official accident investigation and only confirmed that 330 and 340 have very similar approach to stall characteristics.

Judicial Experts: Legal
 

@ Dozy : jcjeant is absolutely right.
Only the Juge d'Instruction has the power to demand un rapport des Experts Judiciares.
The judge ordered this because she would need 3 months of A332 sim to understand the intricacies so the Experts Judiciares is an ham-fisted shortcut.
What would really throw a spanner in the legal works is mounting pressure to get rid of the status of the Juge d'Instruction altogether and move an to an adversarial system by ditching the inquistorial one.
This was done in Italy in 1988.
Just for the record, over the last 30 years, the power of Juge d'Instruction has been eroded by endless reform so much so that it really be hightime to axe it.
Its survival was further damaged by the Outtreau Affair which was led by an incompetent Juge d'Instruction.

BOAC: I said nothing about the WoW - ground issue, only a passing comment on a clipping/filtering of the AoA signal, and was making a different point, when Dozy chose to take a point out of context and run with it. Since he didn't bother to read the post for comprehension, I thank you for pointing out that step toward Oozlum land.
The Korean bash that I responded to was what the point of my post was, not AoA/WoW interface or any of that.

Again, thanks for pointing out how far afield things can go when not correctly understood ... gee, I wonder if that isn't a metaphor for AF447 and the concept of pitch and power ... :p

@ Winnerhofer, axe grinding noted. :cool: Did your ancestors fight in the Schlacht im Teutoburger Wald. :}:cool::8

@ Piltdown Man:
Isn't that already happening?
You are probably right.
Indeed. There is one small problem with the template: in these RTS games, or MOBA games, everyone on the team is involved and has their attention keyed and alert states at a high level. Quite the opposite of automation dependent pilots with lowered alert states. :suspect:

EDIT to add:

Automation dependence and cockpit gradient problems are not unique to Korean operations, which is why I dragged AF447 into the conversation there about Asiana. I apologize if that wasn't clear.

(my bold)

Clandestino,

Why was that unofficial confirmation of 340 similarity even necessary?

What type of info would be derived from this consumption of jet fuel that would be useful with respect specifically to the 330....that couldn't be derived from a 330 test?

(Apologies for the short post.)

I fail to understand the bickering about insignificant details. The flight we are discussing was not a test flight and is not part of the investigation. The comité d'experts (two A330 captains, one B777 captain, one aeronautical engineer, and one maintenance expert, all five pilots) asked for a demonstration and hands-on experience of some flight characteristics that are common to the A330/A340 family of aircraft. They were happy with what they got, and described their observations with the usual caveats.

As to whether the buffet they experienced was more severe or less severe than that occurring during AF 447, one only has to compare the accelerations recorded near the center of gravity on the DFDR in the BEA report with those recorded in the demonstration flight.

If Airbus carried out additional test flights in an area that hadn't been explored earlier, that would have been with a minimum flight crew wearing orange suits and parachutes, without judicial observers at the controls or even on board.

(my bolds)

I would still point to the same above phrase, questioned originally IIRC by Chris Scott.

That decel rate used is also used for the manual stall QTGs in the FFS, from which, among other things, the buffet levels are tuned. The entry rate dependent variation would seem to be of some 'significance'....at least training-wise if different in a 330.

One would think striving to avoid the training caveat: 'the same, except different' would not be unreasonable. Accuracy and fidelity for training or 'just' a 'gee-whiz' flight are not insignificant IMHO, especially if purported to apply over a broader range. Expert extrapolations with caveats, as valuable and as conducive to happiness as they may be, are still in this case, 340 to 330 extrapolations.

In 45+ years of flying, I have never discounted any detail.

For the duration, as for the intensity, I invite you to look at the traces in the BEA Final report. Furthermore, it is not obvious on what information that statement is based. Maybe it would have been better to write: "... it is possible that there was a significant and rapid decrease of the effects, which could explain ...".

OK, so my bad on the "Experts" - however my suspicions over objectivity remain, as the usual suspects when it comes to Airbus-bashing seem to consistently refer to the report in favour of the BEA material.

Dozy,

I don't think you would include me as one of "the usual suspects"; at least I hope not!
Thanks to HN39 I have just acquired a copy of the Experts Report, and although I have not had time to read it in detail I have seen enough to convince me at least that it is a careful and objective description and analysis of the events and at least as 'good' as the BEA report.

No worries OG - perhaps my innate distrust of lawyers is somewhat overactive! :ok:

Beats me - it was for judicial purposes and I have not a slightest idea how French legal system works.

Judicial Experts' Role
 

It is worth remembering that the the Judicial (Forensic) Experts' opinions are not binding on the judge.
Leurs avis ne s'imposent pas aux juges qui restent libres.

CVR
 

Dozy, I suppose I should have said "the flight directors going haywire" (which we all know should have been turned off/ignored. Anyway, someone should confirm if the alerts are/are not hard-wired into Cvr so as to eliminate a potentially major flaw/reason the crew did not acknowledge stall. There was "ozone" smell in cockpit - shame if that were speaker unit and therefore...

Yes, I know it's a long shot, BTW.

No, it's a short one; it went no further than your foot. Alerts were picked up by CAM.

Stick neutral, the THS would still have tried to compensate to maintain 1G
At the time the AP and A/THR did quit, a sane degradation to Direct Law would have provided a welcome alternative.