Thread: Habsheim
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Old 3rd Mar 2014, 23:39
  #585 (permalink)  
DozyWannabe
 
Join Date: Jul 2002
Location: UK
Posts: 3,182
Originally Posted by CONF iture View Post
[*]At most, the audio track of the video could tell when the engines accelerated, but not when the thrust levers were advanced.
So to get that information, the CVR audio (which includes the sound of the thrust levers being set to TOGA) and the audio track from the video recording can be synchronised using audio processing techniques (primarily spectral analysis).

That is in fact precisely what the BEA did, and they then synchronised the result with the engine data from the DFDR. Again, please forgive the poor Google Translate grammar:

Originally Posted by BEA report Section 1.16.2.1
1.16.2.1 . Restitution [of] engine parameters during the overshoot

The characteristic parameters of acceleration engines after delivery of gas were returned from three independent means :
- The engine parameters recorded on the DFDR ;
- Spectral analysis of the final seconds of the CVR , the characteristics of engine speeds frequencies being recorded by the micro environment of the cockpit ;
- Spectral analysis of the soundtrack of a made ​​by a viewer on the ground video.
The results of these operations are perfectly consistent and show that the engines are reassembled [regaining] power [normally] from the control overshoot [TOGA thrust setting] .
The last engine speeds returned by the CVR and D.F.D.R. are 84.4 percent respectively . 1 100 N on C.V.R. , 83 and 84 p . 100 N 1 on the D.F.D.R. The soundtrack of the video can reproduce a few extra seconds after the impact on the trees (when the flight recorders stopped working ) : the last value of the maximum speed , clearly identified with this method is 91 percent . 100 N1.
Originally Posted by gums View Post
Until the commercial dudes have a checkout that shows the limits of the FBW systyems or even the "conventional" ones, we will likely see another crash like this one.
Sorry gums, I've got to dissent a bit there. For one thing, we're talking about a crash that happened almost 24 years ago and there hasn't been one like it since. For another, the manufacturer had zero input on the conduct of this flight - this was an AF aircraft with an AF crew flying an AF special charter operation. If we make the reasonable assumption that the "early adopter" line crews were given a demonstration and handling training akin to what was on the Gordon Corps video, then it is also reasonable to infer that the sales bumph should not have influenced them.

As I alluded to earlier, Airbus's own demonstrations appear to have been performed *either* at higher altitudes with persons other than crew (e.g. pilots in training, press, VIPs) aboard - *or* at lower altitudes with only crew aboard. I can find no evidence that they ever combined low altitude demonstrations with non-essential people on the aircraft as this AF sortie did.

On top of this discrepancy in approach, there is also the sense that the unexpected deviation from the briefed sortie led to rushed decision-making and a level of improvisation that many would consider unacceptable, particularly given the crew's unfamiliarity with the airfield.

Regardless of what CONF iture seems to have interpreted the details around Alpha Max to mean, the undeniable fact is that the EFCS did not point the aircraft at the trees, nor did it command the excessive reduction in thrust which necessitated such a drastic escape.

[EDIT : I'm not demonising or casually disregarding Asseline here, and as I said I do sympathise with the guy. However, the sympathy tails off somewhat after a point because as far as I know he has not publicly acknowledged that there were several points where he could have done things better - maybe because that requires at least entertaining the notion that there was no cover-up and conspiracy. That he apparently continues to refuse to at least entertain the thought is troubling to me. After a while, it just seems to come across as making excuses. ]

Last edited by DozyWannabe; 4th Mar 2014 at 00:34.
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