Umm...

[not sure JD-EE is still around to correct, but see e.g. http://www.pprune.org/tech-log/44963...l#post6437226] ] :)

The PNF may have been absolutely wrong. The PF sensed an odor he did not recognize. Having an answer to a question is not sufficient to close the topic if it may have been wrong. JD-EE was not present, thankfully. PF was, and his question got an answer.

You are easy to please, if it matches your goal. I suggest that more common by far are electrical faults, overheated defrosters, motor spark, and hot wiring, than a smell an experienced pilot cannot identify, and wants input from his partner....

Have electrical problems been eliminated by anyone other than you? Not by BEA.

I'm pretty inclined to accept whatever JD-EE (female) says about electrical matters and the production of ozone. However I suspect many of us will not be able to reliably distinguish the smell of ozone from the smell of an electrical fault/short. A common misconception is that the this "electrical smell" is a result of ozone production. So did the pilots really smell ozone, or did they smell an electrical problem that they (incorrectly) ascribed to ozone? What may be easily distinctive to JD-EE may not be to many of us.

The timing seems suspicious, and I would not be inclined to dismiss an electrical fault just because this fault should not have produced ozone. It might have produced something that the pilots believed was ozone.

At the same time that both pilots suddenly perceived that the cockpit had suddenly become uncomfortably warm. A sudden updraft of warmer air from below, which was sufficiently rapid to temporarily "overwhelm" the ability of the climate control system to compensate? Maybe. Or maybe something else.

Somehow, I missed JD-EE's post on electrical smells.

As a long-time Hammond Organ fixer (over 40 years), I can tell you that the so-called "electronic smell" is often the smell of:
a) burning/melting plastic (often insulation)
and/or
b) over-heated transformer components, such as wax, oil, and the like.

Ozone itself is a different smell. Lyman's speculation can never be verified as truth or not. We weren't there; we can't smell it. But it walks like a dog, barks like a dog, etc. etc.

OTOH, burning plastic is generally extremely toxic, so now we can add fuel to the fires of speculation: PF was maybe poisoned by toxic fumes(???). :ugh:

Off to search for JD-EE's post.

@Lyman, slats11,

The lack of secondary evidence in terms of items recovered, no cascading series of failures consistent with arcing or fire and no reference to unusual smells, temperature changes (or, indeed, smoke) after the initial query leans heavily towards discounting the possibility, does it not?

@Organfreak - you can click the little arrow next to JD-EE's name in my initial quote above and it will take you directly to her post.

Yes indeedy, DW, and thanks for that. A post from last year; who knew?

And, I meant to include this photo in order to bolster my own credentials: :hmm:

http://www.organfreak.com/images/contpanel.jpg

;) (I 'spose this will be removed)

Perhaps Dozy. However so much of this still doesn't quite make sense. I am certainly not insisting there was a electrical fault. But I am wondering if it is possible.

I just find the timing odd. Confusion about whether PNF had adjusted the A/C. An ozone smell. A significant rise in cockpit temperature. And then a minute later UAS and autopilot drops out.

Yes the explanation could be an updraft of warmer air associated with Cb. This could have produced an ozone smell in the cockpit, and may conceivably have resulted in a transient rise in cockpit temperature. No comment about an updraft or turbulence at that time however.

Any idea what PNF is saying here? Radar??

Was PF worried about something at that time?

What in particular is bothering you? I've been hanging around these threads so long I could probably dig up some stuff to help.

I am not sure I would put much weight on an electrical fire situation, on board the aircraft that is. But outside, think St. Elmo's Fire. A quote from a B757 FO flying from LAX to ATL in high clouds:

@Organfreak
The organ of my church is a traditional organ, but for some months "they" did important work of "renovation" (no need !). The air is blowed with an electrical engine, but they connected the whole to... the speakers already connected on an electronic organ...

the organist found something sounded wrong wenn he played the great organ : his nightmares and earmares are finished : the engine burned last week doing much damage in the church...:E

Nice cockpit !

I think the problem warranted a look see at the logs of GZCP. Look for squawks, fixes, and any repetitive maintenance. I'll just go find it in the report.


Sure.

And since when has any accident report contained maintenance logs for the aircraft when there was no obvious maintenance problem relevant to the accident?

Back when we started this merry dance you expressed a desire to make sure the crew were not held solely responsible for the accident if there was any doubt. The crew have not been held solely responsible. What, ultimately, are you trying to achieve now?

If you think the logs were not gone over with a magnifying glass, you would be mistaken. Are you always satisfied with what is obvious? You do not consider that which may be hidden?

I am not and may never be comfortable with the finding's accuracy.The conclusion is beyond belief. It stretches the imagination that it could be true.

Lyman, you're confusing the BEA going over the records (which I'm sure they did) with said records' inclusion in the report (which in all likelihood was unnecessary).

What is it about the conclusion that you find so hard to believe? It fits aspects of several previous accidents and known HF problems. Most pilots aren't supermen and even the best are as prone to bad days in the office as anyone. Combine this with organisational entropy on the part of their employer and the chances of something serious happening increase exponentially.

Contrary to the beliefs of some, the BEA have never hidden anything or covered for Airbus, and I'll cheerfully debate anyone who disagrees.

Cocophony
 

Hi Lyman,
It makes perfect sense.
All the holes in the Gruyère cheese simply lined up that night.

At time 2.10.03 the flight deck loud speaker warns of autopilot disconnect, and is heard and acknowledged.
From time 2.10.09.6 the Altitude Alert deviation warning "C Chord" sounds and continues to sound until impact.

It is only interrupted by "Stall Stall", ECAM "dings", crickets, "Priority Left / Right", "Dual Input" etc.

No one on the flight deck mentions hearing anything. No one thought to cancel the "C chord".
The only device attempting to warn them that were stalled was lost amongst the cacophony of other aural warnings.

On previous aircraft, we had both the vibrator noise (unmistakeable) and the tactile feel through the control column.
Why was something similar not thought to be necessary?

Revisiting the yoke-stick problem
 

From the final report:
From the CVR:
So .. the PNF made remarks (give orders) to the PF to go back down and the PF give a positive verbal answer
Anyways .. the PNF can't see if the PF make good actions on the stick ...
How he can be sure that his orders are really followed by PF actions ?
By checking the instrumentations ?
Maybe by looking at the instruments and seeing that these would not show what he expected of them (because his order to the PF" back down" and the positive answer by PF) he began to believe that the instruments were no longer reliable
That can be a additional trouble for the PNF ... and alter momentarily is judgement of the situation ..

jc, just to let you know:

When I used to teach instruments, and I gave a flight student a correction, I rarely if ever "rode" the controls, unless the student was badly over controlling.

What I did do, however -- and I suspect that the PNF something similar -- was that after I gave a corrective input to the flight student, I watched the flight instruments to see if he put the correction in or not.

In the fleet, I took that same approach when I was a C/P flying with a pilot who was having trouble while flying instruments. I'd make an oral input and watch the instruments to see if he complied with my suggested correction. A number of my copilots did the same for me, and one talked me out of a slight case of the leans.

(Granted, at night near a the deck of a ship, however, I did tend to guard the controls when the other pilot was flying just in case my call for "power" went unheeded, in which case I'd make the input).

Put another way, I'd say that your line on "watching" the controls may not fit with the primary concern that pilots focus on to see if their suggested correction is acted upon or not.

He migh guard the controls, or ride them. Depends.

PNF doesn't make any reference to his instruments (other than speed) being out. Remember it was the instruments on his side being recorded, and the report makes no mention of instrument failure. Also, his rising alarm regarding the Captain's return could suggest that he could see exactly what the aircraft was doing and didn't like it one bit.

Dozy, that does not relieve a copilot from staying in the problem until the Captain returns.

But it does speak to a problem with "cockpit gradient" that we have only a little to work with.

To be simple:
You are PNF in an C172
You see (instruments) that with no doubts the aircraft is climbing
You ask the PF to stop climbing or more you ask him to go down
The PF answer you "yes ok i go down"
Again you check the instruments .. and see that the plane continue to climb .. and of course as nothing indicate an instrument failure .. you become concerned
For the demonstration only (as you can check your own yoke :) ) .. you check the PF yoke and see he pull the yoke in his stomach ...
In the A330 ...
It was already an instrument failure (unlike in the C172) ... it was a positive answer of PF (like in the C172) ... and when you check again instrumentation .. the instruments show the aircraft continue climbing
You check your stick ?
You check the stick of PF ?
You put handcuffs on the PF ?

Either we are looking at another dazzling display of inability to understand what was written or strong tendency to falsify other folk's posts. Shaker is not installed on aeroplanes that have natural pre-stall shake. BEA did flight tests with A330 with similar weight and C.G. as AF447. While they didn't push it all the way to stall...

Repeat after me: shakers are devices fitted to aeroplanes with natural pre-stall buffet too weak to comply with certifying regulations.

See previous entry.

Good grief, Gums, where would the energy for overspeed come if you are at practical ceiling and pulling up like mad?

Maybe, but if he was, he was dead wrong and consequently just dead.

It was not. Read the report, please. AP was off and by the time descent started it was blocked off by ADR rejection due too to low forward airspeed. Capt was unable to grasp the situation so he thought it would be good idea to press the non-function AP button, without explaining it, either for the benefit of co-pilots or CVR.

Bravo sierra perpetuated on PPRuNe. Read the report. Page 87. Slamming the stick from full back to full forward in ALT won't kill or even hurt you, if the average of pitch gyrations is centered on cruise pitch.

Who said I regularly fly Airbus? I was just a line jock, warming the RHS of 319/20 for a bit less than two years. Who gives a rat's stern about me? It is all in the certification standards!

Every fault recorded on DFDR came from just two sources: 1) blockade of pitots in cruise 2) stall. No fault that could be consequence of shortcut or fire was detected. Of course, there is also a dissenting opinion on Egyptair 990 that claims there are faults that go completely unrecorded on FDRs yet render the aeroplane uncontrollable in seconds. We must examine every option, must we?

That would leave massive trace on Nz. Read the report.

I'm a bit late into the ozone discussion, but you're going to get my dimes worth anyway.

St. Elmo's fire and Ozone smell can be found from sea level and upwards when the conditions are right. On ships passing through tropical zones, St. Elmo's fire is often seen attaching itself to a yardarm of a mast, or even the outer corner of a bridge wing. The Ozone smell comes with the event.

Having had a lot to do with Ozone generators in a former life, I do know the smell of Ozone, and the linkage of St. Elmo's fire to that of the Ozone smell is also one I know well.

The PNF had crossed the ITCZ many times and was well aware of what he saw and smelled, and any conjecture that the smell was of electrical origin is just that - conjecture.

@ Clandestino
Then why do all Boeings & L1011s etc. have stick shakers, despite having natural pre-stall buffets?
Belt & Braces perhaps?

Beats me. Where did you get the reference about Anyboeing and 1011 having natural pre-stall buffet? Now we know 330 has it and 1g amplitude at cockpit is not what anyone would call "light buzz".

Anyway, what would have happened to flight controls of the aeroplane with synthetic pitch feel that suddenly got fed with low speed signals in cruise?

On every conversion course in the simulator. "Cobble stone" turbulence can feel similar.
The controls would feel lighter than normal - just like roll in ALT LAW

Buffet was not noted on CVR. Buffet was determined by analyzing accel. The aC did not pitch nose down at Stall.

The pilots were not privy to recorded data on flight recorders. The Shaker vibrates the stick with no net effect on Pitch. Most installs include a very loud and disconcerting clatter, there is virtually no chance to miss the warning, though of course a possibility exists that it will be ignored or misunderstood. Marvin Renslow proved an exception.

I think any agreement on these points may be impossible, except to agree to disagree.

End of shaker discussion pour moi.

Training and "feel"
 

@ Cland..... my comment to Doze was a "barb" about the almost perfect flight control laws and reversion sequences, especially WRT to stall warning/avoidance. And with respect to energy required to overspeed at the limits of the envelope, I stand my ground. With even a "limit" of "x" gees above gee=one, kinetic energy is enough to do exactly what the dweeb did - pull and pull to the limits and run outta energy while transitting the stall protection limits, then get to new territory. pushing forward would have equally bad outcomes if the "overspeed" "protections" ( how I hate that term) are FUBAR due to invalid speed inputs to HAL.

Thanks, Wolf, for the IFR training comments. I followed the same procedure for many years when dual, and when in a chase plane for the single-seaters I watched and talked a lot on the inter-flight radio. In the Viper, we were in a back seat and the control stick did not move or reflect what Joebaggodunuts was doing up front. So watch the gauges and feel the jet, then take over if things are going to hell.

Back to Cland..... From the CVR fidelity ( could detect switch changes) and the comments by the troops, doesn't sound as if the AB330 has pronounced buffet in the stall regime. On the other hand, the older designs many of us flew from the 60's and on had distinct pre-stall indications. In my case, we had vastly larger margins from stall-onset to actual stall, as well as immensely larger speed margins before reaching VNe.

An example presented was to have a shaker or pusher when the jet had no clear pre-stall buffet or warning. So I flew the VooDoo, which fit the description when supersonic. But sub-sonic, the thing shook and wobbled and such that only a hamburger would have pulled harder. You could also feel "stick lightening" ( also feel it supersonic, but no buffet). I will bet a hundred bucks I could fly with you in a pre-AB330 heavy and show you the buffet or buzz indicating an approach to a stall.

I read the CVR again, and the experienced pilot is telling the other guy to stop climbing and to be "gentle". After a minute of fruitless talk, he calls for the aircraft commander. All the while the stall warning doofer is going off. I never wished to fly a "crewed jet", and what we saw in AF447 confirmed my fears. " I got it, no, you got it........" Least in the Viper we could completely cut out the student's stick very easily.

Thanks to JC for reviewing the CVR comments for first minute or so.

And the abruptly increased temperature in the cockpit?

There are still some details that appear to be without explanation.

It is easy to overread or under read a CVR transcript. Human behavior psychologists believe that 10% of communication is the words themselves, 30% is the tone and the way the words are said, and up to 60% is nonverbal cues. I expect the exact words used account for > 10% when considering technical and procedural matters. On the other hand, we don't have a complete transcript (for understandable reasons) and so we may be missing some information which would help put things into context.

Why did the Captain not get a useful handover when he returned to the cockpit? Had things already degenerated that much. He got garbled bits if information plus lots of warnings and alarms plus a feeling that things were not right ( abnormal pitch attitude). It would have been perplexing to understand what had gone wrong in the brief interval since he had left the cockpit.

@ Clandestino,

Quote:
Originally Posted by Turbine D
very gentle adjustments of the sidestick are required?
The reference you mentioned is the TAM incident. What I referred to in the BEA Final Report was in Appendix 6, Page 1.
Airbus "Unreliable Speed Indication" Procedure, A330 Air France FCOM:
Guess the TAM folks proved the Air France FCOM wrong?

Quote:
Originally Posted by Turbine D
And finally, would the pilots who have or do regularly fly Airbus aircraft, such as Clandestino, be clamoring for sidestick shakers if it were of true benefit?

I am sorry Sir, that I gave you credit for something that didn't deserve credit. I was just going by your previous information (Bio) that very recently changed including your location...

GPS and INS integration
 

dCLbydalpha


There is a lot of work in this area - and QANTAS and Honeywell are in the lead on it: See this ICAO document one of many - https://docs.google.com/viewer?url=h...%2F6104_en.pdf

I never saw a jet I didn't want to fly. :)

from BEA: "Control of the flight path does not correspond to what is expected. The amplitude of the actions may doubtless be explained by the highly charged emotional factors generated by the unexpected autopilot disconnection in the context of the flight."

Sounds a lot like some folks here.... Conclusion, doubtless correct, no need for explanation or analysis.. "Trust us, this is a government opinion."

Eliminated are ham handed tendencies persist, despite busts on sim, rote obedience to Stall Warn on TO, palsy, or bad curry from flight kitchen.

On the other hand, maybe it is a quote from one of Dozy's posts... There is a familiar ring to the rhetoric...

What possible significance is the temperature in the cockpit?
Why was there not a proper handover to the captain when he returned to the cockpit?
When he entered, he asked "What are you doing?" The PNF (in the LHS), the much more experienced of the two copilots, responded: "What's happening? I don't know...I don't know what's happening". The captain didn't even resume his place in the LHS where he could assume control, he got into the jump seat behind the console. Ten seconds later, six stall warnings sounded in the space of four seconds. No reaction from any of the three pilots. Seventeen seconds on, at FL250+, the PNF asks: "What do you think? What should we do?". The captain replies, "I don't know. It's going down". He's been on the flight deck a full minute, during which time neither of the two copilots has been able to explain what's been happening, yet he makes no effort to assume control.
In his book Erreurs de Pilotage 5, Otelli points out that STALL was verbally annunciated 75 times, taking up a total time of 54 seconds; the stall itself lasted 4 minutes and 24 seconds.

Obviously it has no significance whatever, it is not covered in the "analysis".

On the other hand, evidence of absence is not absence of evidence.

"why should anyone give a rip?" is your question rhetorical, rock hound?

What are the odds the report is a fiction?

Rockhound, I have absolutely no idea what the significance of the cockpit temperature is. I am asking a question, not posing an explanation. Likewise I don't know what the PNF turned to maximum just before. He denied he had touched the A/C, so maybe the radar range (they were discussing a possible deviation to the left at the time).

All I am saying is that it may possibly be of significance. Out of the blue. In the middle of an 11 hour flight. Just one minute before other problems quickly unfold.

Obviously the PNF can't explain what he can't understand. But I would like to think he could have given the Captain a reasonably coherent account of the events that had transpired.

The Captain seemed very slow to act. Given he had only left the cockpit 11 minutes earlier, it is unlikely he had been asleep and was suffering from sleep inertia. So why?

Well in fairness, what was he expected to make of the following?

A quick explanation that the autopilot dropped out and they climbed and then entered a stall may have been sufficient to give the Captain the required situational awareness.

Although we don't have the audio, it is likely that PF and PNF were somewhat agitated (or more) when the Captain returned. Lack of clear handover. And then confusion, lack of assertiveness, and likely increased agitation.

slats11;That's the problem, they didn't know they were "stalled".

You're right though, a quick briefing by the PNF may have helped, but on the other-hand he probably thought the PF would do it. :sad:

They were pitched up 15 degrees at FL350 and when the stall warning went off they didn't know they were in a stall? Sorry I guess we have covered this many times before. Unbelievable.

Ok. You are correct. I really meant that a coherent explanation from the PNF ( who seemed to have the better SA) that the AP had dropped out and they had climbed together with the Captain noting the pitch up attitude followed by the stall warning ...... Surely this would have been enough to make sense.

Nothing coherent (crew wise) happened in that cockpit from the A/P disconnect through to the end. It would seem that the BEA's Human Resources Group were not able to format a reasonable explanation for this behaviour either.

Hi Rockhound,
It's a clue that you've just entered a region of much warmer air suddenly.
If the outside air temperature has risen faster than the hot air trim valves can respond, then you may have just entered the warm rising air of a big CB.
Best recheck the OAT for possible engine anti icing.

The two copilots were maxed out when the Captain returned to the flight deck. I don't understand why he didn't ask for the Altitude Alert deviation warning ("C chord") to be silenced so he could think straight. It was constantly filling in all the gaps between the other aural warnings until impact.