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

AF447

Old 9th Jun 2009, 16:32
  #881 (permalink)  
 
Join Date: Jul 2007
Location: Here
Posts: 52
Likes: 0
Received 0 Likes on 0 Posts
hot rising air in thunderstorms

@ PJ2
I read in the Air Caraibe (ACA) Report which was posted here that actually the rise in air temperature is due to ice build-up on the pitot and the TAT probe. The TAT probe picks up the temperature of the ice, which is higher, rather than actual air temp.

Last edited by Config Full; 9th Jun 2009 at 16:46.
Config Full is offline  
Old 9th Jun 2009, 16:32
  #882 (permalink)  
 
Join Date: Apr 2008
Location: London
Posts: 26
Likes: 0
Received 0 Likes on 0 Posts
There has been a lot of attempts to decode the ACARS messages. The messages that have been sent are normally then fed into the companies version of AIRMAN which is a maintenance tool. The ACARS transcript is raw data.

This data would then take the look of the Post Flight Report. In fact it looks exactly like what you get out of the flightdeck printer with cockpit effects on the left and maintenance messages on the right.
jimpy1979uk is offline  
Old 9th Jun 2009, 16:41
  #883 (permalink)  
PJ2
 
Join Date: Mar 2003
Location: BC
Age: 76
Posts: 2,486
Received 2 Likes on 2 Posts
Config Full;

Thanks - taking a look at the report - my French is poor but one can get a gist of it.

I see the fin is ship-board so perhaps soon we'll see a photo of the area where the attach points are.
PJ2 is offline  
Old 9th Jun 2009, 16:47
  #884 (permalink)  
 
Join Date: Jun 2009
Location: cannes
Age: 68
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
for interflug

hi interflug.
yes the term severe is standard.as they gather their information with sat survey or any other informations sources.

like this one.
http://www.star.nesdis.noaa.gov/smcd...y/TIAVN18a.GIF
.
but it s obvious that we don t received any messages from them if we re crossing the ITZ or the the bengal gulf during the monsoon.cause it will be useless .
gilot is offline  
Old 9th Jun 2009, 16:48
  #885 (permalink)  
 
Join Date: Jun 2001
Location: East of the Sun & West of the Moon
Posts: 286
Likes: 0
Received 0 Likes on 0 Posts
@DC-ATE

DIESEL, not DEISEL... absolutely right, thanks for the correction.

Well, I don't know everything, but I know/knew enough to avoid areas such as the one in question by enough margin that I never really had to worry about it. .... This is far from an exact science and the sooner some pilots realize that, the better off we'll all be.
And what makes you think the AF pilots didn't think the same? We really don't know what sort of deviation they chose except that there's no record of them making a request to ATC. But, on a bad night with HF communication that in itself means nothing. Until data proves otherwise it's unfair to suggest that these pilots were using any less diligence than you would have. Remember all the plotted tracks we've seen are assumed, not actual. And, as you say this is far from an exact science, which means that even when you are certain you are making prudent choices there is the chance you may still be wrong, no matter how smart one may be.

One could make the argument that, possibly, the incident might have been avoided if only the aircraft.....had avoided the area completely.
Which area? The entire South Atlantic in the vicinity of the ITCZ as my last taxi driver suggested? Perhaps they should have just stayed in RIO until the weather was better, but then if they did they'd probably still be there wouldn't they? The ITCZ's a fairly continuous phenomena. Without knowing what route they took through the area and where they were relative to what they could see of the weather (visually and/or on the radar) we don't know enough to draw any conclusions as to the wisdom of their choices.

ELAC
ELAC is offline  
Old 9th Jun 2009, 16:53
  #886 (permalink)  
 
Join Date: Mar 2002
Location: EU
Posts: 644
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by PJ2
411A;
Quote:
the above statement I suspect is indicitive of a present day general lack of swept-wing aircraft aerodynamic knowledge...IE: if dutch roll conditions should develop (especially, at higher altitudes), the last thing a pilot would want to do, is have pilot applied larger rudder inputs, because....this will make the dutch roll conditions much worse, not better.
A known fact, decades ago, but I now suspect...totally forgotton, or never taught.
Concur, 411A. Seen it in major carriers as well and not just the smaller outfits. It's barely bread-and-butter training all the way down.
Sorry Guys, you have to stop.
It really gets annoying that after every accident someone needs to point out that younger pilots can't fly and and training isn't what it used to be.

This was an experienced crew!

And even after and despite this tragic accident, aviation still remains safer then it has ever been.
golfyankeesierra is offline  
Old 9th Jun 2009, 16:56
  #887 (permalink)  
 
Join Date: Jun 2008
Location: Dubai
Age: 64
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
WXR training

PJ2

r. In a recent conversation with colleagues, I am informed few know how to use the B777 radar either, with recent, "interesting" results in the same ITCZ.
Until recently I used to run the engineers through the FFS (747/A320/777) showing them Radar Operation typical screens & failures.
I used to teach radar maintenance for one of the OEM's
I have never done it or had it requested by the Crew, or the airline

This thread has had a few drivers knocking on my door over the last week that awareness HAS to be a plus
avspook is offline  
Old 9th Jun 2009, 17:04
  #888 (permalink)  
 
Join Date: Mar 2006
Location: california, usa
Posts: 79
Likes: 0
Received 0 Likes on 0 Posts
Rudder break-out forces and Pedal travel

Back in the aftermath of the JFK AA accident, it was interesting to read in Aviation Week the article comparing the various manufacturer's philosophies on cockpit design & rudder force limitation.

I don't have a link, but as I recall, the Airbus design included both a relatively small breakout force to get the pedal to move, coupled with an surprisingly small displacement(travel) and low (additional) pedal force required to reach full input.

Imagine a loss of autopilot in severe turbulence/IMC/at altitude coupled with a loss of rudder load-limiting.......with a cockpit rudder control that requires very little pedal force and travel to apply maximum inputs. The means of load limiting vs. airspeed at the control surface varied between manufacturers, I don't recall the Airbus system.

If this were the case, the tail departing the airplane may be the cause of all the other error messages. The engines would depart shortly after.......
727gm is offline  
Old 9th Jun 2009, 17:05
  #889 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by golfyankee
Sorry Guys, you have to stop.
- well said.

One mention of 'Dutch Roll' and out come all the gum-bashers from under the stones - "ee - when I were a lad....".

Did they get any? Possibly.
Did they not get any? Don't know.
Is it really pertinent? No.

NEXT! Relevant posts would be nice.
BOAC is offline  
Old 9th Jun 2009, 17:18
  #890 (permalink)  
 
Join Date: Jan 2008
Location: UK
Posts: 266
Likes: 0
Received 0 Likes on 0 Posts
Even the media have backed off. Given that there's NO new electronic messages, NO new met, NO CVR, NO FDR and precious little new evidence it will be interesting to see the next relevant post that has something new to say.
worrab is offline  
Old 9th Jun 2009, 17:19
  #891 (permalink)  
 
Join Date: Jun 2009
Location: Barcelona(Spain)
Age: 49
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
This is reaching a point where it is becoming apparent that the information available at this time does not offers any answers. For every theory there is another one that goes in the opposite direction and is as good as the first one.

Why don't calm down a little bit a try to piece together what we really have so we have a place to start when new evidence shows up?

Anyone cares to try?
Joss is offline  
Old 9th Jun 2009, 17:23
  #892 (permalink)  
 
Join Date: Aug 2007
Location: inmysuitcase
Posts: 209
Received 0 Likes on 0 Posts
Sorry Guys, you have to stop.
It really gets annoying that after every accident someone needs to point out that younger pilots can't fly and and training isn't what it used to be.

This was an experienced crew!
Is a F/O with (ar.) 3000 hours, experienced in wide-body long-haul?
If I look back to myself now, sorry, i was not......

I teach/exam in the sim and the real-a/c, crm-thing I use the last 3 months is the bufalo and the amsterdam; they both stalled a perfectly good airplane..........(i do agree a little with the (not-so-)-old guys)
testpanel is online now  
Old 9th Jun 2009, 17:37
  #893 (permalink)  
 
Join Date: Sep 2008
Location: MI
Posts: 570
Likes: 0
Received 0 Likes on 0 Posts
ELAC -
Without knowing what route they took through the area and where they were relative to what they could see of the weather (visually and/or on the radar) we don't know enough to draw any conclusions as to the wisdom of their choices.
Fair enough. However, other flights apparently got through that area, not only that night but other nights as well, without problems. As we keep saying, we'll know when we know and even then, we probably won't !!
DC-ATE is offline  
Old 9th Jun 2009, 17:43
  #894 (permalink)  
 
Join Date: Jul 2008
Location: UK
Age: 69
Posts: 475
Likes: 0
Received 0 Likes on 0 Posts
The messages also showed that the autopilot was off, though it was impossible to say whether it had disengaged itself, as it is designed to do when it receives suspect data, or whether the pilot had decided to turn it off, Arslanian said.
Can we now stop the uninformed chat about manually disengaged autopilots not appearing on ACARS or are the investigators also badly informed?

It would be far more useful if people would investigate rather than opinionate
Safety Concerns is offline  
Old 9th Jun 2009, 17:43
  #895 (permalink)  
 
Join Date: Sep 2005
Location: No one's home...
Posts: 416
Likes: 0
Received 0 Likes on 0 Posts
BIg surface.. big forces.
The roll was due to yawing a swept wing - not the rudder.
I understand the aerodynamics of roll solely from rudder and I had demonstrated to me in the tanker that one could be in 60 degrees of bank and roll out on a heading when starting only 5 deg from the desired roll out heading.

And as I remember the tanker dash 1 said that a hard rudder could put the airplane beyond 90deg bank in less than 3 seconds. That is a very big force.
wileydog3 is offline  
Old 9th Jun 2009, 17:44
  #896 (permalink)  
 
Join Date: Dec 1999
Location: Ottawa, Ontario, Canada
Posts: 330
Likes: 0
Received 0 Likes on 0 Posts
ELAC,
Correct me if I misunderstand you, but it seems to me that you're implying the AF crew did deviate from track? Doesn't the evidence (comms from the crew, ACARS transmissions, location of wreckage and debris) indicate that AF447 stayed on track and flew into, or found itself in, a major storm cell?
Rockhound
Rockhound is offline  
Old 9th Jun 2009, 17:48
  #897 (permalink)  
 
Join Date: Aug 2008
Location: Finland
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
FAQ compilation

So many questions/theories flying around anyone interested to compile some FAQ with possible threads and at least some facts which has been surfaced so far. In any cases major accidents this forum discussion comes easily bloated with various sides and opinions and only by reading whole thread you can follow thru what's the opinions / findings.

Any volunteers who has followed thru things along this thread to do some FAQ for things to look for ?
ketuomin is offline  
Old 9th Jun 2009, 17:52
  #898 (permalink)  
 
Join Date: Jun 2009
Location: London
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
So many questions/theories flying around anyone interested to compile some FAQ with possible threads and at least some facts which has been surfaced so far. In any cases major accidents this forum discussion comes easily bloated with various sides and opinions and only by reading whole thread you can follow thru what's the opinions / findings.

Any volunteers who has followed thru things along this thread to do some FAQ for things to look for ?

already done at Air France Flight 447 - Wikipedia, the free encyclopedia
kbootb is offline  
Old 9th Jun 2009, 17:55
  #899 (permalink)  
 
Join Date: Jun 2001
Location: East of the Sun & West of the Moon
Posts: 286
Likes: 0
Received 0 Likes on 0 Posts
And you do know the weight was 210 t? Also you do know what the precise temperature was?

Could you just for fun do the math again with 220 t and ISA+15 ?
@Interflug

See, this is my point about uninformed comment & questions. These questions reflect a lack of understanding about the aircraft and the nature of its indicating systems.

No, I don't "know" that the weight 210T, and I don't know what the "precise" temperature was.

What I do know, however, is that the MTOW of this A330-200 was 233T, and that according to my handy-dandy FCOM 3 the initial fuel flow at FL350 at 230T and ISA+15 is 6730 K/hr. and at 210T is 6165 K/hr. (actually slightly different due to different engines, but only slightly). As the aircraft was, according to the records, airborne for at least 4:11 (22:03-02:14?) I can deduce that its weight at the time of the accident was no greater than 233T - (4.2*((6730+6165)/2) = ~205.9T. Probably it was less than this, but I don't know the actual TOW nor do I have the desire to try calculating a climb fuel burn, but in any event 210T is a conservative value, unless you want to revive the baseless overloaded aircraft theory again.

I also know that the speeds I quoted to you for the weight are KIAS (Knots Indicated Air Speed), so they themselves will not change with a change in temperature.

As per the above calculation the aircraft's weight could not be 220T after 4 hours of flight unless the aircraft was very grossly overloaded, and the speeds I quoted do not vary with temperature. So what I do know is that there is no meaningful answer to your questions.

A question you didn't ask, but which might be relevant is the aircraft's altitude capabilities at its assumed weight at the time of the accident. For my aircraft with slightly different engine performance they are:

@ 210T and M.80

Optimum Altitude = FL360
Max. Alt. @ ISA+20 = FL370
Max. Alt. @ 1.4G Margin = FL378
Max. Alt. @ ISA+10 = FL385
Max. Alt. @ 1.3G Margin = FL394

So, again, given that the weight was if anything less than 210T, the choice of FL350 was an entirely reasonable one from a performance perspective and, in fact, probably below the optimum altitude (which as displayed to the pilots would also be modified by temperature, wind speed/direction and cost index) for the aircraft at that weight. This would go some ways towards explaining why I find suggestions that they were flying too high in a coffin corner so ludicrous.

ELAC
ELAC is offline  
Old 9th Jun 2009, 18:00
  #900 (permalink)  
 
Join Date: Dec 2008
Location: SoCal
Age: 65
Posts: 31
Likes: 0
Received 0 Likes on 0 Posts
Deep search capabilities

There had been some talk earlier that we as humans did not have the capability to search to the depths where this incident occured. This has recently changed. Woods Hole Oceanagraphic Institute demonstrated 6.8 Miles at the bottom of the Mariana Trench on May 31, 2009.

link to press release

News Release : Hybrid Remotely Operated Vehicle “Nereus” Reaches Deepest Part of the Ocean : Woods Hole Oceanographic Institution
etesting2000 is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.