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

AF447 Thread No. 3

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

AF447 Thread No. 3

Old 1st Jun 2011, 18:12
  #1021 (permalink)  
 
Join Date: Dec 1999
Location: Ottawa, Ontario, Canada
Posts: 330
Likes: 0
Received 0 Likes on 0 Posts
Can we settle this question of who was PF and which seat he was occupying?
According to press reports, the junior FO (800 hrs on type) was PF, having been designated as such by the captain. But where does this idea come from?
According to BEA's 27 May update, "at 0155 the Captain woke the second co-pilot and said '[...] he's going to take my place'".
The 'second co-pilot' presumably was the junior FO.
Who was 'he'? Presumably, it was the junior FO and it seems highly likely that he was going to physically take the place of the captain in the LHS. However, that does not necessarily mean that he was PF.
I would instinctively think, as they were approaching an area of turbulence, the captain would designate the more experienced, senior FO (4400 hrs on type) as PF.
Yet, one minute before they impacted the sea, "the PF said 'go ahead you have the controls'. It seems unlikely that a more experienced pilot would hand off to a less experienced one.
So I would think the junior FO was PF and the senior FO was PNF.
Of course, there's also the possibility that, after he returned to the flight deck, the captain changed places with the senior FO in the RHS...but that's hardly likely.
I suppose the question can easily be settled by the BEA.
Rockhound is offline  
Old 1st Jun 2011, 18:18
  #1022 (permalink)  
 
Join Date: Aug 2010
Location: j w d
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Question

No AB exp hence the question.

What does the FD give if TOGA is selected at altitude ?

On our current bird one gets standard pitch up and wings level as default. All other lateral modes are canceled.

One then sees time to time (in the sim), if the trainees forget to select a lateral mode after TOGA selection and follows the FD, a constant deviation of course if there is some assemetric present that looks pretty similar to last track of AF.
Isobars is offline  
Old 1st Jun 2011, 18:23
  #1023 (permalink)  
 
Join Date: Dec 1999
Location: Ottawa, Ontario, Canada
Posts: 330
Likes: 0
Received 0 Likes on 0 Posts
The 32 year old co-pilot did not have a license to take over from the captain. He did have 807 hours on type

JD-EE,
Would the junior FO not allowed to have been PF? After all, he was qualified to operate the A330, just not as PIC.
Rockhound is offline  
Old 1st Jun 2011, 18:28
  #1024 (permalink)  
 
Join Date: Jul 2009
Location: UK
Posts: 133
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jcjeant
Hi,

Those people have the answer to your question:
Mary Schlangenstein and Mary Jane Credeur
And what makes you think the French BEA chief spoke to these two Americans? They did have help from 3 staff in Paris that is closer to the BEA offices - but the article also contains other unattributed 'facts' that are not confirmed by the BEA statement i.e. who was at the controls when so don't believe all you read on the net, and this conflicts with other leaks "from sources close to the investigation" that were reported in Australia!

The CNN report Air France crash pilots lost vital speed data, say investigators - CNN.com basically repeats the BEA report correctly, but the pilot journo Miles O'Brien reliably informs "You push down on the wheel to gain air speed"- nuff said.

Last edited by sensor_validation; 1st Jun 2011 at 18:46.
sensor_validation is offline  
Old 1st Jun 2011, 18:33
  #1025 (permalink)  
PJ2
 
Join Date: Mar 2003
Location: BC
Age: 75
Posts: 2,482
Likes: 0
Received 0 Likes on 0 Posts
JD-EE;
I also note plaintive requests for experience flying ALT2 - I wonder how often A330/A340 aircraft fall into ALT2, how often they train for it, and, in only a semi-serious tone, is ALT2 survivable? It is apparently rare. (And, yes, some people appear to have survived it.)
From experience and from the paucity of responses regarding Machinbird's request for "Alternate Law" (1 or 2) experience, it is indeed a very rare event.

Alternate Law itself, like Direct Law are, (or certainly should be for A320/A330/A340 crews), non-events, especially if one is accustomed to and has practised one's craft by manually flying the machine.

Notwithstsanding 'only partially-serious', talk of "survivability" is like saying is walking down an escalator that isn't functioning "survivable", or crossing the street without traffic lights? These things do have risks associated, but one simply responds appropriately.

To pilots new on the airplane it would take a few moments to get used to the directness of the controls but it would be nothing they wouldn't be familar with from earlier, conventional controls say on the B737.

There is no mystique, no mystery about this "Alternate Law" thing...and if we think about it, no airliner would ever be certified if such reversions were difficult to control or had a propensity to diverge into unstable flight.

These are fundamental design and engineering notions and expectations. In Direct Law, (not the case here), the airplane has all flight controls with NO failures. The pitch trim is manual and in the simulator at least, one simply trims the airplane the way its always done with conventional flight control systems.

All control "feel" in the control column is, and has been for fifty years, artificial feel which is "built into" the system to approximate the feel of the need to trim...there is NO direct feedback from any flight controls on any airliner flying today that provides feedback to trim the aircraft. It's usually done with springs and whatnot.

On the A330, when flying in direct law, one must be careful with the rudder, (due no limitations) and one must trim the aircraft - to do that, one simply rolls the hand wheel fore or aft to trim out the forces, just like one did on the B727 or DC8...trim...wait...trim...wait, etc. There is rudder trim but no aileron trim.

Every simulator session I've had, has practised Alternate Law due to various system failures which we practise. Once in a while with a dual hydraulic failure or the emergency electrical config the aircraft reverts to Direct Law. Again, it is a non-issue.

In certification work by the FAA, the A320 as been flown and landed using only differential engine thrust and only manual trim...not using the stick at all. I've done that in the sim on the A320 as part of the initial check-out on the airplane...you can land the airplane on trim...its a mess but that is where I would use the term "survivable".

That can't be done on the A330/A340...too much mass, too difficult to anticipate pitch changes and the exercise becomes an out-of-sync PIO until the "firm" touchdown or other such "arrival".
PJ2 is offline  
Old 1st Jun 2011, 18:37
  #1026 (permalink)  
 
Join Date: Feb 2005
Location: Correr es mi destino por no llevar papel
Posts: 1,435
Received 0 Likes on 0 Posts
Originally Posted by Rockhound
Can we settle this question of who was PF and which seat he was occupying?
Untill we get sidesticks displacement plots, no.
Clandestino is offline  
Old 1st Jun 2011, 18:43
  #1027 (permalink)  
 
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 6,364
Received 31 Likes on 18 Posts
PJ2:

A point on cognitive factors, raised by ECAM Actions on the other thread.

http://www.pprune.org/rumours-news/4...ml#post6487657

In short, Low Speed Stability in pitch channel Alt Law may be trying to move the stick one way (senses slow speed from FUBAR AS system) which is nose down. This can be overridden by the PF pulling ("back stick") the other way, which could have been overridden by a bit too much force initially?

My idea, perhaps dead wrong, is an initial reaction was response to that perceived stick load (nose down) with an overcorrection (see 7000 FPM zoom climb) initially corrected to 700 fpm climb ... but that doesn't answer all of the mail. Given my own experience in flying out of trim aircraft (now and again in ham fisted fashion) I can see how this might play out.

What my own instrument flying experience -- both my own episodes of making a hash of flying on instruments, and watching pilots under instruction or on a check ride do similarly -- tells me is that if that feel was a factor, an inextricably linked factor is (I am on the cognitive theme here) likely a scan breakdown away from primary scan instrument -- attitude indicator (artificial horizon) -- early in the event. All my previous posts down rabbit holes of partial panel and tumbling gyros aside (sorry about all that) it is isn't that uncommon in instrument flying, even with a working attitude reference, for cognitive mismatch to occur when tasks and stimulations add up. (Aside: playing the SOB sim instructor allows you to find any pilot's task saturation point. *Insert Evil Cackle here *).

Since we don't know what he was seeing, and apparently can't from the way FDR data is recorded ... how can one get to the root cause of his control inputs?

Last edited by Lonewolf_50; 1st Jun 2011 at 18:55.
Lonewolf_50 is offline  
Old 1st Jun 2011, 18:48
  #1028 (permalink)  
PJ2
 
Join Date: Mar 2003
Location: BC
Age: 75
Posts: 2,482
Likes: 0
Received 0 Likes on 0 Posts
LW_50...yeah, that's a big displacement to be accounted for by that response from the AFS...hm. Another research item but just heading out...I'd have to ask the question whether or not the AFS would behave that way in Alternate 2 Law. I don't think so, but will take a look when back. PJ2
PJ2 is offline  
Old 1st Jun 2011, 18:51
  #1029 (permalink)  
 
Join Date: Jun 2009
Location: I am where I am and that's all where I am.
Posts: 660
Likes: 0
Received 0 Likes on 0 Posts
HN39, your plots make sense to me with regards to AoA. If, as has been shown, the plane hit with approximately equal forward and down velocities the AoA for a dead level plane (0 degrees pitch) would be 45 degrees. So I'd think the AoA would have gone up over 50 if the plane hit with a pitch of 16 degrees up even with a head wind.

Your data makes good sense for "what". That still leaves why, which apparently has BEA puzzled, too.
JD-EE is offline  
Old 1st Jun 2011, 18:56
  #1030 (permalink)  
 
Join Date: Mar 2001
Location: us
Posts: 694
Likes: 0
Received 0 Likes on 0 Posts
Tim Vasquez has updated his meteorological analysis, dated June 1, 2011.

Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data

This study was significantly updated on June 1, 2011 in memory of the 2nd anniversary of the crash. Also it was precipitated by the renewed interest in the fate of the flight with the data recorders having been recovered a few weeks ago. Interestingly it appears that almost all of the conclusions in my earlier study were correct. The purpose of this update is to introduce some new information, make corrections where necessary, edit extraneous theories that can now be disregarded, and clean up the text a bit.
SaturnV is offline  
Old 1st Jun 2011, 18:57
  #1031 (permalink)  
 
Join Date: Oct 2001
Location: Germany
Age: 62
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
@ rgbrock1:
have you ever yourself experienced pitot tube icing and, if so, what happend and how did you react?
No. only some spurious A.ICE pitot and static-warnings while passing cloud layers (me thinks: heating momentarily overwhelmed). Just worked though the ECAM-procedure, but it cleared every time on its own...
RealQuax is offline  
Old 1st Jun 2011, 18:57
  #1032 (permalink)  
 
Join Date: Feb 2001
Location: The Winchester
Posts: 6,445
Received 3 Likes on 3 Posts
Rockhound

"at 0155 the Captain woke the second co-pilot and said '[...] he's going to take my place'".
The 'second co-pilot' presumably was the junior FO.
Not necessarily, the transcript says "le commandant de bord réveille le second copilote" which seems to me to read he woke the second, or other P2.

So reading the BEA transcript it's quite possible that the junior P2 was in the RHS from takeoff. The captain woke the other (or second) co-pilot by some means and then commented to the junior pilot in the RHS that:"he's going to take my place". i.e. the senior P2 simply replaced the captain in the Left hand seat.
wiggy is offline  
Old 1st Jun 2011, 18:58
  #1033 (permalink)  
 
Join Date: Jul 2007
Location: uk
Posts: 769
Received 0 Likes on 0 Posts
Graybeard: It certainly was investigated! Aug 1995 and resulted in the fitting of pitot heads with increased heating and a software change to increase the time line before ALT2 was latched. A/P and ATHR initially lost but were restored once out of icing conditions however the lateral twitchy aileron response was very evident for the landing.
Meikleour is offline  
Old 1st Jun 2011, 19:02
  #1034 (permalink)  
 
Join Date: Jun 2009
Location: LSZG
Age: 51
Posts: 86
Likes: 0
Received 0 Likes on 0 Posts
wiggy wrote:
So reading the BEA transcript it's quite possible that the junior P2 was in the RHS from takeoff. The captain woke the other (or second) co-pilot by some means and then commented to the junior pilot in the RHS that:"he's going to take my place". i.e. the senior P2 simply replaced the captain in the Left hand seat.
BEA says AP2 was active. PF must have been sitting on the RHS
MartinM is offline  
Old 1st Jun 2011, 19:03
  #1035 (permalink)  
 
Join Date: Jun 2009
Location: I am where I am and that's all where I am.
Posts: 660
Likes: 0
Received 0 Likes on 0 Posts
Rockhound - I read that handover as one thoroughly confused pilot deferring to the other who might have a fresh idea. (Of course, if the surface had come into view, somehow at night under a heavy storm, with the Moon set or very nearly set, your view makes more sense.)
JD-EE is offline  
Old 1st Jun 2011, 19:07
  #1036 (permalink)  
 
Join Date: Feb 2005
Location: Correr es mi destino por no llevar papel
Posts: 1,435
Received 0 Likes on 0 Posts
Originally Posted by Lonewolf50
Since we don't know what he was seeing, and apparently can't from the way FDR data is recorded ... how can one get to the root cause of his control inputs?
By sitting on one's hands and refraining from extensive theorizing until such time when BEA releases DFDR plots and CVR transcript. From DFDR data we can 99.99% reliably conclude what were the indications in the cockpit. 0.01% refers to freak CRT (or LCD) failure undetected by ECAM.
Clandestino is offline  
Old 1st Jun 2011, 19:09
  #1037 (permalink)  
 
Join Date: Oct 2001
Location: Germany
Age: 62
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
@MartinM: The plane flies like a charm with the PF in the RHS on AP1: It is just a procedure to use the onsite-a/p. In my company for instance, in MNPS-airspace flying with CPDLC, procedure is to fly on AP1, irrespective of who is PF.
RealQuax is offline  
Old 1st Jun 2011, 19:13
  #1038 (permalink)  
 
Join Date: Jun 2009
Location: I am where I am and that's all where I am.
Posts: 660
Likes: 0
Received 0 Likes on 0 Posts
Clandestino:
Quote:
Originally Posted by Rockhound
Can we settle this question of who was PF and which seat he was occupying?

Untill we get sidesticks displacement plots, no.
I'm starting to mumble to myself we haven't a clue where either of the two co-pilots was sitting. Was takeoff captain and 37 or captain and 32 unless 32 was not licensed to take off the plane with captain sitting in the left seat.

There is no record yet released saying PF in right seat handed off to the new person who moved into the left seat. So it appears the person at the controls as the plane upset was the person at the controls for basically all of the flight.

We do have a lot of news report "assumptions", "presumptions", and rumors. But I discount that.
JD-EE is offline  
Old 1st Jun 2011, 19:16
  #1039 (permalink)  
 
Join Date: Jun 2009
Location: LSZG
Age: 51
Posts: 86
Likes: 0
Received 0 Likes on 0 Posts
I just had a chat with one of my Bus driving colleagues. Let me drop in one of his ideas.

Highspeed stall at FL350

Pilot reaction would be. Pitch up to reduce turbulences over the wing. This reduces speed of course and pitches up momentarily till you begin to enter into low speed stall. If you get a too high AoA at that point, you may generate an unrecoverable deep stall.

This would somehow explain, why the PF initially pulled the stick, then did some nose down to slow down the vertical speed. And unfortunately it ended up in a deep stall.

Which immediately would have required throttle IDLE and THS to 0°

BEA report says that IDLE throttle was much later at around FL100

What do you think on this theory?
MartinM is offline  
Old 1st Jun 2011, 19:20
  #1040 (permalink)  

Dog Tired
 
Join Date: Oct 2001
Location: uk
Posts: 1,688
Likes: 0
Received 1 Like on 1 Post
No, on several counts, I don't think so...
fantom is offline  

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.