Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

AF 447 Thread No. 7

Tech Log The very best in practical technical discussion on the web

AF 447 Thread No. 7

Old 16th Mar 2012, 17:50
  #841 (permalink)  
 
Join Date: Oct 2011
Location: Lower Skunk Cabbageland, WA
Age: 70
Posts: 354
Mssr. Hollandaise:
Scaning vario 4 times in 4 minutes : Yes it is very schocking !
Please pardon my non-flying ignorance (again), but what is "vario?"

And, was your remark sarcastic, or serious?
Organfreak is offline  
Old 16th Mar 2012, 17:53
  #842 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 63
Posts: 1,809
Cool

Hi,

Vario ....
Variometer - Wikipedia, the free encyclopedia
jcjeant is offline  
Old 16th Mar 2012, 19:05
  #843 (permalink)  
 
Join Date: Aug 2011
Location: Grassy Valley
Posts: 2,123
ly

Organfreak

Howdy. For context, imagine a human being in free fall, terminal velocity is about 120 miles per hour. This aircraft, at 15 thousand feet per minute descent, would pass our skydiver at 60 miles per hour! DOWN. Probably close to the jet's terminal velocity. Compare that picture with the apparent calm on the flight deck. Do you sense a disconnect? With an angle of attack of 40 degrees, the a/c is presenting an enormous amount of drag to the airmass, hence the : "I feel like we have some crazy speed". The noise must have been loud, and of course, unusual.

Even at the more consistent 10 thousand fpm descent, that is 120 mph. Even as a non-pilot, would you be concerned?

So I am expressing some surprise that others don't clamor for some more CVR.
The Flight deck was more animated, and noisy, than BEA would have us believe, No? Yet without a solution, the three pilots patiently await, what? In virtual silence? Nerves of steel? Ice water in the veins. I doubt it. "We are going to crash, this cannot be..." "Four spades? Double".

Eh?
Lyman is offline  
Old 16th Mar 2012, 19:40
  #844 (permalink)  
 
Join Date: Jul 2009
Location: France - mostly
Age: 80
Posts: 1,689
Originally Posted by organfreak
... what is "vario?"
In the A330 the vertical speed indicator is to the right of the altitude tape and counter on the PFD. See for example page 48 of the second interim report. It consists of (1) an analog pointer that points to a vertical speed scale in white on a grey background graduated at intervals of 500 ft/min and (2) if the V/S is greater than 200 ft/min, a digital window showing the V/S in hundreds of feet per minute.

The analog pointer and the digital indication are normally green, but if the V/S is greater than 6000 ft/min they become amber and the pointer stays at the end of the scale.
HazelNuts39 is offline  
Old 16th Mar 2012, 20:01
  #845 (permalink)  
 
Join Date: Feb 2001
Location: UK
Posts: 647
Vario

Vario, short for variometer, is usually used in English AFAIK only in gliding terminology. Our glider varios are sensitive to small changes in vertical velocity. The equivalent instrument in powered aircraft, from small single engine to airliners, is usually called a VSI (again, AFAIK) – Vertical Speed Indicator.

I suspect the same term for both is used in France – vario. If my surmise is correct, we have a translation from French to English of “vario” to “vario”, whereas it would be more usual to translate vario as VSI.

Hope that helps. If I have it wrong, and English usage in airliners is to call it a vario after all, I shall stand corrected (and have learnt something!).
chrisN is offline  
Old 16th Mar 2012, 22:10
  #846 (permalink)  
PJ2
 
Join Date: Mar 2003
Location: BC
Age: 72
Posts: 2,429
HN39;

Re, "In the A330 the vertical speed indicator is to the right of the altitude tape and counter on the PFD. See for example page 48 of the second interim report. It consists of (1) an analog pointer that points to a vertical speed scale in white on a grey background graduated at intervals of 500 ft/min and (2) if the V/S is greater than 200 ft/min, a digital window showing the V/S in hundreds of feet per minute.

The analog pointer and the digital indication are normally green, but if the V/S is greater than 6000 ft/min they become amber and the pointer stays at the end of the scale.
"

The following image may assist:

Pitch: 10deg ND
Altitude passing: 33580
IVSI 20,100fpm

PJ2 is offline  
Old 16th Mar 2012, 22:53
  #847 (permalink)  
 
Join Date: May 2011
Location: BOQ
Age: 75
Posts: 489
AOA: approx 28-29 degrees (+,- ambient wind, on the FPV)

FPV: barely visible with no trend information associated with it.

KIAS: 187 and increasing, trending to 209.

I would think that picture, itself, would sell a stand alone AOA gage for trend indentification (and possibly an ALT Law PLI, before the fact).

OK465 is offline  
Old 16th Mar 2012, 23:37
  #848 (permalink)  
PJ2
 
Join Date: Mar 2003
Location: BC
Age: 72
Posts: 2,429
OK465;

Re, "FPV: barely visible with no trend information associated with it.

KIAS: 187 and increasing, trending to 209."

For clarification, "209" in ten seconds at that specific moment - the trend arrow is a real-time indication that changes as rapidly as the energy of the aircraft does and that varies with pitch, power and even external forces should there be any. Not saying you're not aware of this, I think you are but just for all who examine this..., caution is advised in concluding too much from a snapshot. As you're likely aware, the FPV is partially below the bottom limit of visibility for all PFD information. The "FLY UP" arrows, advising of a very steep ND pitch, are just coming into view. Clearly the AoA is greater than the FPV can fully display.

Regarding "AoA" indications etc, as a former A330 captain I don't know what to "recommend" anymore in terms of making this better. Clearly we can't just focus on "loss of airspeed" as 'cause' simply because when that's fixed, something else will arise. What would you advise we could learn from Islamabad, or Tripoli? Other than "understand the airplane", "fly the airplane", I truly don't know. And more automation?! Heaven deliver me, but I read that that exact solution is being touted and even planned, and it is SO wrong! I understand that a serious discussion is taking place next week at the RAeS, (The Aircraft Commander in the Twenty-first Century?) on these topics.

The discussion on these nine AF447 threads has been so varied, so rich and so populated with perceptive thinking and suggestions that address the exact problem (how do we solve "loss of airspeed?") and the broader problem of human factors and automation, (I have written on this as well) that I think some 'distance' is needed from solutions to percolate and filter through to practicality, enhancement to safety and to cost including certification, training and so on.

Last edited by PJ2; 16th Mar 2012 at 23:53.
PJ2 is offline  
Old 17th Mar 2012, 01:36
  #849 (permalink)  
 
Join Date: Sep 2009
Location: Around the World
Age: 70
Posts: 88
CVR Transcript: FD1 + FD2 Availability

Hello,

A
FPV barely visibe
yes, at # 847 above.

but Nr3 Interim Report En CVR transcript (p 89 to 100) points this:

FD 1 and 2 become --------- FD 1 and 2 become ------------ Comment
unavailable at ---------------- Available again at
=========================================================
2:10:08 ------------------------------ 2:10:17 -------------------------HDG & ALT CRZ modes
2:10:21 ------------------------------ 2:10:26 -------------------------HDG & VS modes
2:10:36 ------------------------------ 2:10:42 -------------------------Transitionally available (how ?)
2:10:45 (may be ?) -------------- 2:10:47 -------------------------HDG & VS modes
2:11:40 ------------------------------- 2:12:52 -------------------------HDG & VS modes
2:12:58 ------------------------------- 2:13:57 -------------------------Temporary (that is to say ?)

During more than half the time of the four minutes event, the two FD were not available. A graphic would give an easier visualization.
I have done it, but unfortunatly i don't know how to insert the picture.
Who will again dare to say that the pilots were stupid?

Last edited by Jetdriver; 17th Mar 2012 at 03:38.
NeoFit is offline  
Old 17th Mar 2012, 02:47
  #850 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 63
Posts: 1,809
Cool

Hi,

but unfortunatly i don't know how to insert the picture.
Easy way to post a image
imgur: the simple image sharer
jcjeant is offline  
Old 17th Mar 2012, 14:50
  #851 (permalink)  
 
Join Date: Jun 2011
Location: france
Posts: 759
Scaning

Originally Posted by Organfreak
was your remark sarcastic, or serious?
Very very serious !
Normaly your eyes come to the variometer (VSI) (in french variomètre) every two seconds great maximum. Not only to put your eyes on it, but to correct your altitude and your speed , that you scan in the same frequency, and as well as your heading . When you have seen any of these three informations, you come back to look and correct your attitude (pitch and roll). You have also to look outside with your other eyes (!) and to crosscheck the other pilot in the crew, to look the other instruments, manage the warnings, cautions, cabincrew, hijackers, fire, doc. etc.
roulishollandais is offline  
Old 17th Mar 2012, 14:52
  #852 (permalink)  
 
Join Date: Jun 2011
Location: france
Posts: 759
(Following : I had to many smilies for only one post !)

If anything is wrong, you have to say it to the other pilot. The two pilots (or three in AF447) are not independant.

In AF447, altitude, attitude , heading , vertical speed (vario) ... and speeds were wrong, and the CVR shows a crew totally disconnected from these basics .

The crew managment in normal flight says that any of the two pilots has two main functions maximum and two subsidiaries functions maximum, under these four functions :
-pilot
-navigation
-radio-com
-mechaniks.

In case the other pilot cannot assume his functions, you have to do the four functions.

We pilots may be masochist ? We like that !

This eyes training does the pilot look so attractive !!! Your friends like to be looked by you really : they are indeed (here I am happy but it is real) ! hum... It was the case before the FBW and his seemingly sleeping on the control ! - (here I am sarcastic) Also the BEA #3 says the A330 cannot stall (p.26 french version)
roulishollandais is offline  
Old 17th Mar 2012, 15:11
  #853 (permalink)  
 
Join Date: Sep 2009
Location: Around the World
Age: 70
Posts: 88
jcjeant
Thank you very much.

Here is the picture, and I hope it's correctly resized

In my sens, ite missa est
@ 02:11:40
disapearence of the FPV (bird),
with FLAG ON (both) CPT & F/O PFD FD ( Interim #2 - Acars).

NeoFit is offline  
Old 17th Mar 2012, 15:14
  #854 (permalink)  
 
Join Date: Oct 2011
Location: Lower Skunk Cabbageland, WA
Age: 70
Posts: 354
OF in over his head

Thanks to all who answered my ignorant questions so kindly and clearly. What a great forum this is. I've learned so much about flying from you.

Lyman asked me a bunch of questions about what I think/assume, many posts ago. I was going to give him a detailed answer, but by simply being away from the computer for a while, the time has come and gone. Suffice to say, yes, I agree, there must be more to the story than what we have been told. And to your closing remark, "Four spades? Double," I simply say, "Redouble!"
Organfreak is offline  
Old 17th Mar 2012, 15:51
  #855 (permalink)  
 
Join Date: Aug 2011
Location: Grassy Valley
Posts: 2,123
flying s

NeoFit

Thanks for the graphic, it is instructive. I consider this wreck to have two discrete phases, if not more. There is #1 the uncoupled a/p, manual control, and wild climb, leading to #2: STALL. Once STALLED, the a/c was in completely unknown territory, it was not "flying". It is fodder for endless speculation and dozens of "What ifs". Though these a/c have STALLED, they do so in other than NORMAL LAW, contrary to my friend ruolishollandais's statement that in French, the Report says STALL is impossible. Any a/c will STALL, and most have, with variable results.

One cannot fly this machine without instruments to inform. Not in these conditions. The Pilot Flying had none of his screen recorded. BEA does not go further. Was there anything to record? Did PNF call for Captain to sort a political discussion between the two seated pilots? That's provocative, but Occam would have it that Captain was called to help fly. There was no Captain referee, only Captain in attendance. "I have lost my vario" says Bonin, "Okay" says Captain.

No orders as to authority from Captain DuBois. None that are given us, in any case. So we are left with a narrative that I believe is lacking in data that would put in context what the conclusions are, or certainly at least suggested.

Mistake? BEA inadvertently included only pilot comment that leads to a definition of Pilot Error? Sure, pigs fly.

IR #2 has a description of previous UAS events to contextualize what happened to 447. It is instructive, and to me, estblishes that any UAS is fraught with risk, unaddressed SOP, and quite frankly, ignorance of the dangers by both manufacturer and line.

How do I know this? Because BUSS was not selected, and was "Optional" to the extent that pilot polling helped decide to deselect its presence in the cockpit.

An opinion poll to determine if pilots want to save their asses with a system that addresses a dangerous Condition? Blase? Perhaps, but it is so telling that UAS was not given the sort of attention it required.

Read IR #2 re: UAS. It describes a crapshoot, not a serious problem/address.

The conditions 447 found that night were severe, but not rare. To arrive at safety, risk is mitigated, not ignored.

Organfreak. Howdy, I mostly wanted to reframe the velocities for you. !5k fpm is 180 Miles Per Hour. That means in one minute, half of 447's altitude will be lost, and recovery will not be likely. That is why postSTALL events are not germane, imho. Once in the climb, and probably very quickly, the odds go sour for recovery. CRM is a relatively newly quantified concept, and arguments that say "Well,, PNF needed to...." Fine. However, if the last chance to live depends on politics, not command, well.........

adios.
Lyman is offline  
Old 17th Mar 2012, 16:18
  #856 (permalink)  
 
Join Date: Jul 2009
Location: Not far from a big Lake
Age: 77
Posts: 1,458
VSI Scan

Normaly your eyes come to the variometer (VSI) (in french variomètre) every two seconds great maximum. Not only to put your eyes on it, but to correct your altitude
Well I am a bit ancient I guess, and the VSIs that I remember were not IVSIs.
We had to hawk the pitch attitude very carefully and note any trends on the altimeter, then apply a correction to pitch to hold altitude. There was too much lag in the VSI to use it for altitude maintenance. All I used the VSI for was to verify I had set pitch and power about right for a descent rate or climb rate.
It is interesting to learn that there has been a change in scan patterns as a result of new technology.
Machinbird is offline  
Old 17th Mar 2012, 16:27
  #857 (permalink)  
 
Join Date: Oct 2011
Location: Lower Skunk Cabbageland, WA
Age: 70
Posts: 354
Lyman claimed:
Once in the climb, and probably very quickly, the odds go sour for recovery
Please cite an authorative source or support your contention with known facts. There have been hundreds of comments in these forums stating that the stall may have been recoverable. Is it just that you enjoy being a maverick?

Last edited by Organfreak; 17th Mar 2012 at 16:30. Reason: HTML typo
Organfreak is offline  
Old 17th Mar 2012, 16:58
  #858 (permalink)  
 
Join Date: Aug 2011
Location: Grassy Valley
Posts: 2,123
Hey Organfreak

My comment comes from a point of view. It has to do with a body of facts, data, and evidence, plus the commentary of those here.

The Interim Report #2 discusses a foundation, a reference for the type of problem 447 had, and what others did, as well as the a/c reactions.
There could not be a worse place to lose instruments. There could not be a more lackadaisacal approach to AD, to training, and to command, by SOP and by culture.

From the OUTSET, something was wrong. Here, the evolution of opinion has landed on PE. I don't buy it. Neither pilot by CVR only, had the kind of demeanor one expects in such a situation, and for this I offer "Where is the Captain?". The entire contents of the releaes re: CVR could not have been better written by a soap opera show. Drama, personality, deviations from the expected, etc.

The two pilots were in trouble, and not because they did not get along. Here on thread, the popular drill is to claim discord, and incompetence. NO PROOF of either, merely a parsed verbal record, VERY parsed. What is missing? How about, "Where's the skipper, this bird is effed up, and we need him NOW." People have jumped, no, leapt to conclusions without listening for tone, volume, and idiom. Have you? Are you content with things as they are, without more data? Would your wife and kids be satisfied that you are painted as an incompetent dilettante, without as much as a complete record of events?

Three trained pilots, with a descent unarrested by any, with a mere position change on a stick. What DRAMA?

OPINION, MINE. It isn't for me to write the report. It was one thing when there was no evidence at all. Since recovery, what is available is parsed, limited, and censored. Should I get access to the CVR, I may have to apologize to BEA.

In the meantme, My opinion is not countered by evidence. Is it supported? I suggest it is, merely by noting the lack of evidence provided, when there is no reason to prevent its assessment. What gets no attention, seemimgly, is the utter lack of a case on which to rest Pilot ERROR, in the absence of a complete record. This is not obvious? Each of the actions can be explained, both to condemn and to clear. Is it odd that the context is lacking for any defense?

Not given what is at stake. Especially not now. BEA will never release any data that serves to condemn their actions. That became apparent when they caused to be released a PRESS memo, exonerating any "NEW" mechanical issues, and that language from the Airframe company. Of all the blatant political hand crossing, that was laughable.

In the absence of a complete record, neither of us can claim a conclusion, it is impossible.

be well.
Lyman is offline  
Old 17th Mar 2012, 17:09
  #859 (permalink)  
 
Join Date: Oct 2011
Location: Lower Skunk Cabbageland, WA
Age: 70
Posts: 354
Lyman, to be honest, I don't disagree with much of that. BUT, your claim (the one I quoted in my previous post) is the one I'm asking you to defend. "Odds"? I dunno about that, but I am of the impression that many/most pilots here would have sussed this stall and flown out of it, possibly without even spilling any peanuts. Any others want to jump in here?
Organfreak is offline  
Old 17th Mar 2012, 17:27
  #860 (permalink)  
 
Join Date: Aug 2011
Location: Grassy Valley
Posts: 2,123
Sorry Goose, I got a little carried away.

"ODDS". Hmm....Odds are hard to quantify, but I'll try. Here on thread there have been Bus drivers who claim to have Simmed this ride, and the reason I believe at least some of that is that a fair number admitted they couldn't recover. KNOWING what was happening. Air Caraibes had a potentially deadly zoom, uncommanded. Can you tell me from the evidence 447's climb was not at least partially commanded by the computer? You can't, simply because the evidence is not available. The g up was 1.65 in a 1 g command control, how's that? I know pilots who have experienced anomalous behaviour in this equipment: "It started to turn...we selected HDG/ALT and corrected, but no one could ever say why she behaved that way."

Mind of her OWN? By definition, my friend.

mind how you go.
Lyman is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.