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

AF 447 Thread No. 5

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

AF 447 Thread No. 5

Old 29th Jul 2011, 15:39
  #921 (permalink)  
 
Join Date: Apr 2008
Location: London
Posts: 195
Likes: 0
Received 0 Likes on 0 Posts
The CVR (assuming, complete) is at the end of the 3rd report published in French now on the BEA.aero site. My French isn't great, but it looks like complete confusion all the way down.
Lord Bracken is offline  
Old 29th Jul 2011, 15:48
  #922 (permalink)  
 
Join Date: Oct 2009
Location: berlin
Posts: 152
Likes: 0
Received 0 Likes on 0 Posts
2:12:44 C’est pas possible
grity is offline  
Old 29th Jul 2011, 15:50
  #923 (permalink)  
 
Join Date: Jul 2011
Location: usa
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Pitot tube blocked

Anti icing system is not certified for LSD larg supercooled droplets , freezing rain , freezing dreezle. LSD is probably what they encountered.

Blocked pitot tube including moisture drain hole if the AC was put in climb will read high erroneously and if you fixate on IAS and not flying pitch/power the reaction would be NU input and going into stall.

Here is what happened to North West B 727 in 1975

,,Investigators found that the pitot heads had ce damage which caused the crew to receive the wrong readings. The crew, believing the readings where true, raised their nose and pulled back on the control column, which caused the plane to stall,,

,,The aircraft had descended from 24000 feet to 1090 feet in 83 seconds,,

Full NTSB report

http://libraryonline.erau.edu/online...s/AAR75-13.pdf
STICK N RUDDER is offline  
Old 29th Jul 2011, 16:16
  #924 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,182
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by glenbrook
OK, this is the real report. It is very clear that PF was confused from the start and disbelieved airspeed. PNF kept telling him to descend, at one point saying "all three say you are climbing so descend";.
At one point PNF says ";we still have engines so whats happening"; presumably referring to the low airspeed.
2:12:27 PNF You're climbing (Stall warning), Descend descend descend descend
PF I was descending then?
PNF, Descend
Captain: No, you're climbing
PF: There I am climbing, ok now descend
...And tellingly, the Captain says :

Originally Posted by AF447 CVR Transcript
2 h 12 min 19 -> 2 h 12 min 45 : Horizon Horizon - Standby Horizon
Shades of Birgenair indeed:

Originally Posted by Birgenair CVR transcript
0346:00 (46:22) CAM-3 *ADI
...
0346:31 (46:53) CAM-3 *ADI*
Admittedly this is from a Google Translate of that particular section of the document, but the question in my mind is the same as in Birgenair - why did the PNF (who appeared to have a better understanding of the situation) not take control earlier?

One question for our Gallic cousins - do I interpret "Tu montes" and "Tu descends descends" as literally climb and descend, or could the PNF be referring to attitude (nose-up/nose-down) here?

[EDIT : Corrected Captain's statement - thanks for the catch! ]

Last edited by DozyWannabe; 29th Jul 2011 at 18:10.
DozyWannabe is offline  
Old 29th Jul 2011, 16:46
  #925 (permalink)  
 
Join Date: Sep 2004
Location: Frankfurt
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Copilot´s training

Who can please shed some light on the copilot´s deficient training the BEA report states.

"The copilots had received no high altitude tr aining for the "Unreliable IAS" procedure and manual air craft handling".

I find it hard to believe this. Isn´t this training absolute standard in any simulator training of any serious airline?
Am I missing anything?

Thanks
levelvibes is offline  
Old 29th Jul 2011, 16:47
  #926 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 66
Posts: 1,810
Likes: 0
Received 0 Likes on 0 Posts
Cool

Hi;

One question for our Gallic cousins - do I interpret "Tu montes" and "Tu descends descends" as literally climb and descend, or could the PNF be referring to attitude (nose-up/nose-down) here?
Methink it means
literally climb and descend
jcjeant is offline  
Old 29th Jul 2011, 16:58
  #927 (permalink)  
 
Join Date: Jun 2009
Location: VA, USA
Age: 57
Posts: 571
Received 0 Likes on 0 Posts
2 h 11 min 32

je n’ai plus le
contrôle de l’avion là
J’ai plus du tout le
contrôle de l’avion
Google Translate gives me:

"I have no control of the plane there
I am over the whole control of the plane"

I'm pretty sure there is a more accurate translation, but so far the story from the CVR is one of confusion and disbelief at what the instruments were telling them, rather than a systematic approach to understanding the situation and appropriate recovery. I have been through the entire CVR transcript, but since my French is iffy and my clumsy attempts using Google translate (particularly since the document is columnized) are hard to follow, I'll leave it at that.
GarageYears is offline  
Old 29th Jul 2011, 17:35
  #928 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 6,364
Received 31 Likes on 18 Posts
It is very clear that PF was confused from the start and disbelieved airspeed.
What did he see on his attitude indicator?
PNF kept telling him to descend, at one point saying "all three say you are climbing so descend";.
Note: when talking a pilot out of vertigo or scan breakdown, I learned the hard way that an effective technique is to do what I think the Captain was trying to do. The Captain appeared to be trying to get the PF to use his attitude reference, or was pointing out a problem in the attitude.

What I found works is to make recommendations or commands based on the monkey skills required to remedy the siuation.
Examples.

"Lower nose to horizon." "Raise nose to five degrees nose up. Lower nose to three degrees nose down.

Roll right. Stop roll. Wings level.
Left wing is down, roll right. Stop roll.
Add power. reduce power.

What that does is help the other pilot make corrective actions and re-establish his scan. Not sure what others have experienced in this regard.

My aircraft commander once talked me out of a horrific case of the leans doing just that. I used the technique more than once later on in life.
At one point PNF says ";we still have engines so whats happening"; presumably referring to the low airspeed.
2:12:27 PNF You're climbing (Stall warning), Descend descend descend descend
PF I was descending then?
PNF, Descend
Captain: No, you're climbing
PF: There I am climbing, ok now descend
Looks like someone got behind the aircraft.

I was descending?
No, you are climbing.
Chills up my spine.
Lonewolf_50 is offline  
Old 29th Jul 2011, 17:39
  #929 (permalink)  
 
Join Date: Mar 2001
Location: us
Posts: 694
Likes: 0
Received 0 Likes on 0 Posts
The turbulence recorded between 0207 and 0210 was near but did not exceed 0.5G

There are several pages of presentation on the on-board radar, its limitations, etc.

Le radar de bord ne détecte donc pas directement les dangers à éviter et présente certaines limitations qui nécessitent de la part des pilotes une surveillance active et une interprétation permanentes des images présentées pour limiter le risque de sous-estimation du danger de la situation. Il est à noter que, au moment de l’accident, la présence de cristaux de glace à haute altitude n’était pas considérée comme un danger objectif et que les équipages n’y étaient pas sensibilisés.
Just before the captain leaves to go on his rest, there is four minutes (0148 -0152) of turbulence at 0.3-0.4G. Moderate turbulence but nothing to indicate there was any conversation about adjusting the radar. And as the captain takes his leave, no discussion about the weather at all.

BEA comment on an AF A-320 flight that ran into a Cb enroute Geneva.

The top of the cumulonimbus being mainly made up of ice crystals, their detection by the onboard weather radar required an active search with changes to the gain, tilt and range, to be able to detect humid zones. This must be done in sufficient time to allow avoidance. In addition, the rapid formation of these clouds requires frequent repetition of the search. During this flight, the radar [2] was in WX mode, gain on AUTO, the tilt set at -2° and the distance selected on the ND at 160 NM on the Captain’s side and 80 NM on the co-pilot’s side. The Captain expected to encounter storm activity on arrival at Geneva, but not in cruise. The copilot focused his attention on programming the FMGS for the arrival. The crew did not carry out any particular search for storms with the aid of the radar.
Turbulence at the top of cumulonimbus
SaturnV is offline  
Old 29th Jul 2011, 17:47
  #930 (permalink)  
 
Join Date: Jan 2008
Location: Herts, UK
Posts: 748
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by HarryMann
an well positioned AoA instrument, with green and red areas
Of course you need to have valid airspeed to set the green/red correctly.
Not at the -ve and +ve extremes, as with a revcounter, we have an Orange area

But yes, its not all so simple... but nothing is, What is simple and the Captain could have pointed straight at it.. would be a large simply calibrated AoA instrument -
We are supposed to be cruising at about 3.5 °
So WIHIH
i.e. What in Hell Is Happening, that looks like 15°

Last edited by Jetdriver; 2nd Aug 2011 at 00:38.
HarryMann is offline  
Old 29th Jul 2011, 17:49
  #931 (permalink)  
 
Join Date: Jan 2008
Location: uk
Posts: 861
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by GarageYears
2 h 11 min 32

Google Translate gives me:

"I have no control of the plane there
I am over the whole control of the plane"

I'm pretty sure there is a more accurate translation, but so far the story from the CVR is one of confusion and disbelief at what the instruments were telling them, rather than a systematic approach to understanding the situation and appropriate recovery. I have been through the entire CVR transcript, but since my French is iffy and my clumsy attempts using Google translate (particularly since the document is columnized) are hard to follow, I'll leave it at that.

- GY
I read it as "I no longer have control of the plane". My french isn't that good either though. Hopefully english translation will be along soon.

I believe they definitely had _some_ pitch info, but what:

Les ailes à plat
l’horizon l’horizon de
secours
- that is capt. at 2.12.19

Shouting for wings flat I think (too late - wings needed to be a lot below flat by then ?). But "l’horizon de secours" - is that the standby (ISIS) ? If so, was PF/PNF seeing something else on main attitude display ?

Mostly, like you say, it looks like complete confusion. No verbal acknowledgement of stall or recovery from. Unless "Im in TOGA eh?" is indicating "I'm in TOGA so can't be stalled can I ?". Previous stall training emphasised TOGA, not nose down, didn't it...

Still, at least we got data to look at now.
infrequentflyer789 is offline  
Old 29th Jul 2011, 17:53
  #932 (permalink)  
 
Join Date: Jun 2009
Location: VA, USA
Age: 57
Posts: 571
Received 0 Likes on 0 Posts
The amplitude of the SS inputs are also pretty disturbing...

Here's the beginning;
2 h 10 min 05 Altitude=35024
The P/A2 disengages.
The roll angle from 0 to 8.4 ° in 2 seconds while the handle is in neutral.
The pitch is 0 degrees.
Cavalry charge (Alarm: disconnection autopilot)
2 h 10 min 06
The flight control law passes from normal to alternate. PF: "I have control"
During the period 2 h 10 min 07-2 h 10 min 18
The SS is positioned:
- To pitch between neutral and ¾ stop
- Left half and then stop right half-stop, 2 times, alternating left until it stops then right to the half-stop (period 4 seconds).
The pitch increases to 11 °.
The vertical acceleration varies between 0.9 g and 1.6 g.
The roll angle is between 11 ° right and 6 left.
The vertical velocity increases up to 5200 ft / min.
So the first SS input at 0.8M/FL350 is 3/4 of the SS travel NU, with an equally significant full-left and then 1/2-right alternating inputs over a period of 4 seconds... pitch started at 0 degrees at 2h10m05 and is 11 degrees at 2h10m18

<snip>

2 h 11 min 32:
OPL is the handle:
- Set to pitch, reached the
stop after 6 seconds and there
remains up to 2 h 12 min 15
etc...

Apologies for the Google Translate.

- GY
GarageYears is offline  
Old 29th Jul 2011, 17:53
  #933 (permalink)  
 
Join Date: Oct 2009
Location: berlin
Posts: 152
Likes: 0
Received 0 Likes on 0 Posts
jcjeant, send you a PM
grity is offline  
Old 29th Jul 2011, 17:57
  #934 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 6,364
Received 31 Likes on 18 Posts
Garage years:

A couple of threads back, either Chris Scott or Confiture posted a link to a small video of a pilot flying a sidestick (in turbulent weather? at low altitude?) that he opined as being in the realm of over controlling. Is what you described in the same ball park, or do you think it's larger control deflections?

If the plane can be in Alt 2 at altitude, and thus need to be hand flown in tha tmode, should not the training syllabus include such tasks and skills be mastered, or at least demonstrated?
Lonewolf_50 is offline  
Old 29th Jul 2011, 17:57
  #935 (permalink)  
bearfoil
Guest
 
Posts: n/a
Lonewolf

I see your quoted exchange differently. Rather than being behind, I see a PF asking for help from someone who (he thinks may) have accurate reads, his being 'duff'.

If so, it is absurd, and calls for an exchange of ss? PF should not even think of asking his question "I was descending then?" If going on feel, he's barking up the wrong tree, and if he is unaware, his question should have been a statement, "your aircraft".

bear
 
Old 29th Jul 2011, 18:01
  #936 (permalink)  
 
Join Date: Jul 2011
Location: Northern Hemisphere
Posts: 195
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Lonewolf_50
....

.Tarom, Orly 1994, ..
I doubt that aircraft developed a 10,000 fpm rate of descent. (And good thing, the pilots reacted promptly! Overcoming that 10,000 fpm from first unstalling, then getting knots on, then recovering with a nice firm pull without heading toward accelerated stall, since you are not in Normal Law ... how much altitude that takes is a question worth thinking through.
The Tarom guys were with their sticks full ND, during the ascent already, before the Stall, at 60 pitch, as they understood what they need to do, long before the Stall, they just could not stop the ascent. The problem was that the THS was full UP, in spite of elevators full DOWN. They were able to get the A/C back from a 60 degree pitch,....

All was needed was to change the pitch.... take that 10000ft/min descent rate from a NU, to a ND....

Easy to say....

Interestingly, the PF had a Glider Pilot License, since 2001.
airtren is offline  
Old 29th Jul 2011, 18:02
  #937 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 6,364
Received 31 Likes on 18 Posts
bear, one way to resolve a pilot who is confused by his displays, in a multi crew aircraft, is to pass the controls to the pilot who isn't. Yes. That is a technique. Would that have helped in this instance? If done early enough, likely so.

Don't know what AF SOP is for such things, nor the corporate culture, nor the norms in its pilot community.

I thus won't comment on what should, or should not have been done, or what is or isn't absurd.

I learned the "helpful copilot" role in CRM and via experience. It sometimes precedes "I have controls" as the order of actions. Depends on the situation.

Last edited by Lonewolf_50; 29th Jul 2011 at 18:12.
Lonewolf_50 is offline  
Old 29th Jul 2011, 18:10
  #938 (permalink)  
 
Join Date: Jun 2009
Location: VA, USA
Age: 57
Posts: 571
Received 0 Likes on 0 Posts
Lonewolf_50:

My take is the reported stick inputs of the magnitude stated are wholly excessive for the altitude/speed, turbulence or otherwise. At the start of the sequence small corrective inputs would have been expected (what I read in the report was entirely different, almost as if the PF was behaving as if they were low and slow).

- GY
GarageYears is offline  
Old 29th Jul 2011, 18:14
  #939 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 6,364
Received 31 Likes on 18 Posts
GY, your comment on "reacted as though he were low and slow" puts the "recency of training" issue back on my screen as a significant training issue among other training issues.
Lonewolf_50 is offline  
Old 29th Jul 2011, 18:24
  #940 (permalink)  
bearfoil
Guest
 
Posts: n/a
lonewolf

With your emphasis on scan (kudos), and your teaching experience, the question asked by PF can mean only a couple things. With a nod to possible translation and linguistic issues, "Was I descending then?"

1. From your PFD, can you tell? (poor technique?)

2. Did you feel a descent? (not the proper time for flight by butt cheek?)

3. A student asking for direction, rather than a PIC?

All are unacceptable?
 

Thread Tools
Search this Thread

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

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.