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Air France A330 accident

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Air France A330 accident

Old 5th Jun 2009, 05:50
  #21 (permalink)  
 
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Also, I'd note that the new, clean, thread in R&N has a good and legible version of the ACARS messages, and while I'd echo the statements made there that we don't know enough about the details (yet) I will note that not one message is ATA 24 - Electrical. Which seems to at least make the various electrical power failure scenarios less likely at this point. (Indeed, that thread has become almost TechLogish right now)
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Old 5th Jun 2009, 06:26
  #22 (permalink)  
 
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The problem with either a MayDay or ELT activation is that they don't actually help right now while everything is going to Hell. They had their hands full (and then some, I suspect) doing the "Aviate" part of the response - "Communicate", especially where they were a long way from help, shouldn't have been anywhere on the priority list.

I do not agree with your opinion. There are some common sense issues here.
"Avigate, Navigate, Communicate" The priority is well defined, but not in regards to a "MAYDAY" call, that is straightforward and we do it in the sim every 6 months!

To me the answers/speculation on the 2 questions I put are absolutely significant in building the total picture. I keep thinking over the last 24 h waht would prevent me from doing the MAYDAY call. What would prevent you? The PTT is on the sidestick, you know...
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Old 5th Jun 2009, 06:43
  #23 (permalink)  
 
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dessas

Whilst I agree a Mayday or ELT activation would be nice, and the PTT is right there on the sidestick, we do not know if the radios were tuned to guard, I suspect there was plenty going on around them that precluded setting up a frequency on the radio. Even tx-ing blind on whatever frequency they were on might not be heard if as is thought, they were in an area of an electrical storm.

Just my two rupees worth.

KW
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Old 5th Jun 2009, 07:10
  #24 (permalink)  
 
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As far as I am concerned in remote areas w/o VHF coverage VHF1 is set on Guard, VHF2 - IFB (123.45 or 126.9) and VHF3 ACARS.
So a MAYDAY call is REALLY straightforward...
VHF is not affected as much as HF by thunderstorms.
The ELT manual "on" is on the overhead panel right next to APU Fire push-button or somewhere thereabouts...
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Old 5th Jun 2009, 07:17
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dessas

Whilst I appreciate your reasoning and the settings on the radios, as I understand it, events started to evolve shortly after the last radio contact. I suspect the flightdeck was somewhat chaotic and events overtook the norm.

KW
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Old 5th Jun 2009, 07:32
  #26 (permalink)  
 
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Try to think of other accidents and recall whether there were 'Mayday' calls that weren't a request for ATC services but were a simple announcement of the situation. I can think of a couple off the top of my head where no calls were made.

I can entirely relate to 'no Mayday call' from an emergency I had in a smaller plane with just a few passengers. The scenario is you have a crisis in the cockpit, you need to hustle and solve the situation that appears to have the upper hand over you. You really can spare no thoughts or movements that don't address the situation. You realize a Mayday call brings you no benefit whatsoever and the needs an desires of prospective listeners are their problem, a lack of understanding on their part becomes no concern to yourself.

Furthermore, we're all aware of how car-drivers get distracted when using their cell-phones. Spending too much time on the radio, splitting your mind cycles between flying and talking, will tend to reduce your critical emergency handling performance.

Last edited by ttcse; 5th Jun 2009 at 08:17.
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Old 5th Jun 2009, 11:15
  #27 (permalink)  
 
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Jigsaw!!!

Capt PitBull,

I agree with you on the failures never seen before.....But we should never forget that here we had fully operational a/c in cruise with no reported failures.....and the chances of an Essential bus collapsing before a fully serviceable AC Bus is extremely rare,

Which Aircraft you had those failures on???

I know A320s were very susceptible initially but then Airbus came with mods to rectify those problems and in the A330s these were dealt with right from the beginning,

I have only ever seen a major electrical failure on A330 was after both engine startup the AC Bus1 and AC Bus 2 wont tie up.......fault came down to ACMU and BTB.......but still not accepting the fact that how can it just fail on its own and probing in detail led to a very interesting finding.....Aircraft on stand was powered by the Mobile GPU and not by the external power.....and just by reading the frequency meter showed that the generator on this particular unit was generating AC with frequency jumping all over the place which was the extremes of limits......and Aircraft systems however powered were put into max stress and just after engine start both computers gave in.......

There is always a reason for everything........we can only help by learning from these things!!!!!
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Old 5th Jun 2009, 11:21
  #28 (permalink)  
 
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Mad (Flt) Scientist,

With no message related to ATA 24........goes back to contradicting everything which was mentioned everywhere right from the beginning....that a severe lightening strike caused a "short circuit"........wonder where all this info comes from?????? People imagining things....
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Old 5th Jun 2009, 23:19
  #29 (permalink)  
 
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"For example, on a 747 the throttle is pushed by hand. You feel it move in turbulence. On recent Airbuses, this throttle is fixed. You look at the dials. You don't feel anything."

This is an extract from a Reuters news article. Can someone please explain why the 747 throttle levers move during turbulence?

Genuinely curious, why would turbulence effect throttle position? is it down to a pre-set thrust or speed requirement?

Cheers, mini (obviously a non driver)
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Old 5th Jun 2009, 23:48
  #30 (permalink)  
 
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The throttles (thrust levers) on the 747 will move IF the auto-throttle is engaged. And, if you're in turbulence, the airspeed will be fluctuating quite a bit.
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Old 6th Jun 2009, 02:52
  #31 (permalink)  
 
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mini

Very basically the aircraft's autothrottle is "programmed" to fly the aircraft at a certain speed..as DC-ATE has said in turbulence the aircraft's speed could be varying quite rapidy as the headwind/tailwind effecting it changes. The result is the autothrottle will be changing power to try and maintain the programmed speed. On most, if not all Boeings, that in turn means the throttle levers physically move fore and/or aft to reflect the power changes demanded by the autothrottle.
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Old 6th Jun 2009, 06:32
  #32 (permalink)  
 
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ACARS Messages

A summary of the final messages from Flight 447 is as follows:

(AP) French and Brazilian officials have described a "burst" of messages
from Flight 447 just before it disappeared.

A more complete chronology was published Wednesday by Brazil's O Estado de
S. Paulo newspaper, citing an unidentified Air France source, and confirmed
to The Associated Press by an aviation industry source with knowledge of
the investigation:

_ 11 p.m. local time The pilot sends a manual signal saying the jet was
flying through CBs towering cumulo-nimulus thunderheads.

_ 11:10 p.m. A cascade of automatic messages indicate trouble: The
autopilot had disengaged, stabilizing controls were damaged, flight systems
deteriorated.

_ 11:13 p.m. Messages report more problems: The system that monitors
speed, altitude and direction failed. The main flight computer and wing
spoilers failed.

_ 11:14 p.m. The final message indicates a loss of cabin pressure and
complete system failure catastrophic events in a plane that was likely
already plunging toward the ocean.
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Old 6th Jun 2009, 09:08
  #33 (permalink)  
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Handyman -
a loss of cabin pressure and
complete system failure catastrophic events in a plane that was likely
already plunging toward the ocean.
- do you have some information that we do not? Where do you see the loss of cabin pressure?
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Old 6th Jun 2009, 09:22
  #34 (permalink)  
 
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BEA press conference

Hi,

Right now a BEA press conference is broadcast on France 24 TV channel.
If skilled members of this forum could watch it they might gather useful information.

Cheers !
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Old 7th Jun 2009, 19:32
  #35 (permalink)  
 
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Originally Posted by Jetstream00
Something that boggles me is that in todays news they are hinting towards pilot error for stalling the airplane, which does not make sense as these airplanes have alpha floor protection ( stall Protection) which with all its PRIM's and SEC's working would not allow it to reach that situation.
If Airbus flight control is in "alternate law" mode, alpha floor protection is lost.
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Old 7th Jun 2009, 19:39
  #36 (permalink)  
 
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ACARS details wiki

Originally Posted by Handy Man 01
ACARS Messages
A summary of the final messages from Flight 447 is as follows:
A detailed and relatively complete overview of ACARS messages and some conclusions are on the AF 447 wikipedia page in the automated messages section.
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Old 7th Jun 2009, 21:58
  #37 (permalink)  
 
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Tim Vasquez has posted a fantastic weather analysis for the AF744 flight here Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data . At the same time some pilots have posted observations of temps within cells climbing with 30 degrees within seconds and on the R&N live thread this is currently being discussed.

I have asked Tim his opinion on the likelyhood of this and below is his reply. Unfortunately I am not able to post on R&N, perhaps pilots reading this thread may wish to report it there.

Sorry for the thread drift. I felt it was necessary given the circumstances.

I do not agree that a bubble of warmer air (that is, any warmer than about
5 degrees compared to the environmental air) would have made it up
to flight level. This requires exceptionally high equivalent potential temperatures at some
lower altitude. The atmosphere has a tendency to overturn bubbles of hot air as soon as they
start becoming significant because "absolutely unstable" lapse rates are unsustainable.
We do see thunderstorm heat burst phenomena on the Great Plains at night, but this occurs due to
the downward forcing of a low-level inversion, and I can't picture a mechanism for
this to occur at flight level given the conditions shown.
But in regard to the above mention of an aircraft's "coffin corner"
(<a href="http://en.wikipedia.org/wiki/Coffin_corner_(aviation)">Wikipedia</a>) it is
possible that wind values alone could greatly affected airspeed -- on Doppler radar we often
see anomalies of 40 to 80 kt at flight level within storms (Google "storm top divergence" for
some examples).

Tim
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Old 7th Jun 2009, 23:40
  #38 (permalink)  
 
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off thread - apologies

Thank you flybywife for reposting, it was at the recommendation of a mod that I asked the question
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Old 8th Jun 2009, 00:05
  #39 (permalink)  
 
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Hi Van Horck,

Yeah, I read Tim's piece and thought a lot of it, so I thought his reply to your question should get an airing on the R&N thread.

Dunno how lon it'll last though - the mods seem pretty hot on deleting stuff! Gets a bit confusing sometimes when you read somthing that makes seems to make sense and when you go back it's gone!

What did you do to not be able to post on R&N?

FBW
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Old 8th Jun 2009, 00:24
  #40 (permalink)  
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R&N is subject to some control at present to keep things on an even keel. If the discussion is more technical, you might find it easier to run the information in Tech Log.
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