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AF447

Old 9th Jun 2009, 18:02
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Originally Posted by Rockhound
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
We have no idea if AF447 stayed on track. All we have is their last position report at INTOL. That is their last known position.

Everything else is speculation.

Correction: The last known position would have been when they went out of radar coverage approximately 15 minutes past INTOL.
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Old 9th Jun 2009, 18:05
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golfyankeesierra;
Sorry Guys, you have to stop.
I agree with you if you mean those who extrapolate small amounts of evidence into broader theories/conclusions about what occurred.

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.
Why does it "get annoying" for you? A comment about the level of training and relative absence of experience in high-performance transport aircraft is not about offending or annoying, it is about informing and even challenging the present circumstances in which both airlines and new pilots find themselves. Who is going to come to this profession for sixteen-thousand a year and the kind of training regimes new pilots must accept from their employer who themselves are only trying to make a buck and stay in business? This is much, much more than about stars in one's eyes about aviation, that wonderful love of flying that drives many to arrest all other activities in their lives to follow their dream.

This is a complex matter about the present practicalities of the career which I and other poster have dealt with thoroughly in other threads and which, if you haven't, I kindly invite you to read and consider. We cannot and should not deal with it here.

This was an experienced crew!
No disagreement there given that this was Air France. I have already stated (in bold font), that "my comments do not apply to this crew".

And even after and despite this tragic accident, aviation still remains safer then it has ever been.
I and all who fly (past tense in my case) professionally understand this very well and would agree, so I'm not certain what you're trying to convey. The larger message from the post you're quoting from is, while you're observation is correct, the accident trend and issues outlined elsewhere are not pointing to a continuance of that trend, (low accident rates, safest means of transportation etc etc), and a lot of safety specialists "have their radar on" as it were and are speaking out, loud and clear. The issues I describe above and more thoroughly in other threads are serious, immanent issues in this industry which, if left unaddressed, have the potential to turn the industry's admirable safety record around.

Let me ask in the face of the accidents since the tragic and avoidable MD80 one at Madrid, where are the "Sully's" of professional transport aviation? Such a statement is perhaps quite a direct and pithy way of stating the issue, but there it is - sometimes "pithy" is the shortest way to communicate overarching concerns. We have three accidents, (Madrid, Buffalo, Amsterdam) which have resulted from basically stalling an airliner and which have killed a lot of our passengers. That's unacceptable.

PJ2
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Old 9th Jun 2009, 18:17
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already done at Air France Flight 447 - Wikipedia, the free encyclopedia
But makes me wonder who considers themselves authorised to write in there.
There is a nice diagram of a pitot/static probe and a description of how it works, despite the fact that the A330 has pitot probes, and separate static ports. The guy that wrote it should have twigged it when he wrote 3 pitot/static probes and 8 ADMs.
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Old 9th Jun 2009, 18:19
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could you comment on this

Transcription: "In relation to the Rudder Travel Limiter (RTL) if the violent storm theory holds then it is probably as a result of structural failure due to massive yawing forces induced by turbulence. The F/CTL RUD TRVL LIM FAULT message has been generated due to the NAV ADR DISAGREE message and NOT due to a fault in the Rudder Travel Limiter itself NOR due to a failure/separation of the rudder. If the problem lay in the unit itself, a F/CTL RUD TRVL LIM 1 / (2) FAULT would appeaer. This is due to the Rudder Travel Limiter requiring an airspeed input from the ADR’s to function properly."
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Old 9th Jun 2009, 18:19
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This information below was just posted 7 hours ago and thought it might be of useful information to a few experts here.

Engineer decodes Air France Flight 447 emergency messages
@NSXTASY:

From the link:
Then the rudder exceeds the limits of normal flight.
This is utter rubbish. The message sent by the central maintenance computer was that the limiter was flagging itself - most likely due to the lack of airspeed data (ADIRUs) and nothing whatever about any rudder limits that had been reached as this 'engineer' suggests.

@727GM

Once again we have no indication that any of the ACARS messages were
related to a loss of VS. To say otherwise is not helping this thread. The
aircraft in question would not have suddenly started wagging its tail for lack
of ADIRUs, nor has there been any demonstrated sane reasoning shown so
far that would support our PF to have suddenly had an urge to start
stomping away at his rudder pedals.
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Old 9th Jun 2009, 18:25
  #906 (permalink)  
 
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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

I'm implying that we don't really know what path they took after their report at INTOL. To my knowledge the ACARS transmissions don't include location and the position of debris found in the ocean means very little with respect to the specific track flown, particularly after days of drift.

Regarding communications, HF radio in oceanic airspace is not like you experience with VHF over land. At times atmospheric conditions can make HF communication impossible and it varies from place to place. Just because comms were good at the last position report doesn't mean they'll work 20 minutes later. If deviating without a clearance oceanic procedures would have required a broadcast on 121.5/123.45 but there is no record of anyone having heard one. Again, that doesn't mean that a broadcast wasn't made (severe electrical storms can interfere with VHF reception). So, that a request to deviate wasn't received does not prove that a request wasn't transmitted or that a deviation from track didn't occur.

Until those facts are known it's not really possible to conclude whether they attempted to deviate, and if so by how much, or whether they flew directly through the MCS shown in the satellite image or not.

ELAC
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Old 9th Jun 2009, 18:30
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ELAC wrote:

Until those facts are known it's not really possible to conclude whether they attempted to deviate, and if so by how much, or whether they flew directly through the MCS shown in the satellite image or not.
Point taken and much appreciated. The mystery deepens.

Did we ever confirm whether or not the crew sent a text message about turbulence? I'm confused by recent posts on that subject.
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Old 9th Jun 2009, 18:33
  #908 (permalink)  
 
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Some facts,

?? asked this question: (deleted)?

If speed indication fails (for whatever reason) then rudder limitation stops. Am I right? if that's the case, how on earth (on air) a pilot would know how much rudder could apply without breaking it? Even more, in FBW a/cs, where pumps and fluids can creat a LOT of force, wouldn't this become super critical? Same question applies to the case of using "alternate law".
Because besides the RTLU (Rudder Travel Limiter) there is also a PTLU (Pedal Travel Limiter) - limiting mech(cable) pedal input to rudder servo jacks - in this 'classic' Yaw control system.

In the 'Enhanced' version there is no mech(cable) backup so also no RTLU/PTLU.
Art feel and Trim is directly on Pedals by a PFTU.

RTLU/PTLU in this 'classic' version and also PFTU 'in the enhanced version' are driven by SEC1 (SEC2 as backup) an this has nothing to do with - LAW- configuration.

Rudder Travel Limiter is mounted on the VS rear spar above the upper servo jack (so is retrieved within the VS and last position soon to be known by the investigators)

The Pedal Travel Limiter however is mounted in the THS compartment.

A330 tech.

Last edited by A33Zab; 9th Jun 2009 at 19:40.
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Old 9th Jun 2009, 18:37
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PJ2

has taught passengers to expect and demand $1.49 fares in exchange for on-time,
I always read your post with great attention because are part of the few ones with some meaning on most threads in PPRuNe.
However let me disagree on the PAX demanding $1.49...they are offered such fares and they will take it, note that I am not a LCC PAX therefore my mindset on the topic might be bias.
What disturb me is inferring that low fares are lowering the safety standards....where are the Control Boards?
Could be that competition have brought to the flight systems ways to save costs and become more efficient? Following your rational we could also state that the special fares for the crews and employees of an airline are the cause of the lower safety standards.
Thanks for your great contribution
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Old 9th Jun 2009, 18:41
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Last edited by Config Full; 9th Jun 2009 at 19:46.
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Old 9th Jun 2009, 18:41
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Apologies again if this is silly or off-topic.

There is a possible chain of events, being discussed, that starts with the failure of the Pitot probes. Does this imply that at least two probes must have failed (almost) simultaneously? I saw mentioned "EFCS PROBE 1+2/2+3/1+3" sitting next to "F/CTL RUD TRVL LIMIT FAULT". How exactly is it determined if a probe is failing: is it some low-level status related to the probe itself (heating?); or is it determined e.g. by comparison with the other (one or two) probes? Also, I assume that power for the 3 Pitot heaters comes also from different buses?
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Old 9th Jun 2009, 18:44
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New info

FYI again:


As reported in AIT reference "AF447 Issue 3 June 8th 2009", there are 3 standards of pitot probes in
service on the A330/A340 family aircraft:

- Thales (ex Sextant) PN C16195AA and PN C16195BA
- Goodrich (Rosemount) PN 0851HL

It is reminded that the 'BA' standard probe was made available to address low altitude water ingress
events that generated a number of RTO on the A320 family program.

AF447 aircraft was equipped with Pitot PN C16195AA.

The intense speculation regarding these pitot probes has led many Operators to contact Thales or
Airbus to:

- request an immediate replacement of the Thales 'AA' probes with 'BA' (Service Bulletins A330-34-
3206, A340-34-4200, A340-34-5068)

- report recent and past (previously unreported) events of Unreliable airspeed.

These events, after analysis and confirmation, will allow to determine if any corrective action is
warranted by the findings.

In this context, all Operators, equipped with Goodrich (Rosemount) or Thales (Sextant) pitot probes,
are requested to report all confirmed in-flight Unreliable airspeed events.


2/ TYPICAL SIGNATURE OF UNRELIABLE AIRSPEED

To be sure that Unreliable airspeed events are correctly identified, please report events corresponding
to the criteria as follows:

- Crew report indicates loss or discrepant IAS (Indicated Airspeed) on CAPT and/or F/O PFD and/or
Standby Airspeed indicator (ISIS).

- Typical ECAM Warnings were seen:

NAV ADR DISAGREE
NAV IAS DISCREPANCY
F/CTL ALTN LAW
F/CTL RUD TRV LIM 1(2) FAULT
AUTO FLT AP OFF
AUTO FLT A/THR OFF
STALL WARNING (audio call-out)
AUTO FLT REAC W/S DET FAULT


- Fault Message "PROBE-PITOT 1+2/2+3/1+3" was possibly also seen.
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Old 9th Jun 2009, 18:47
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Any probe heating issue would have been flagged by the PHC's. (PROBE HEAT CONTROLLERS) They are able to determine whether a probe is being heated or not.

Any issue with probe heat and you would have a different selection of messages although there would be some overlap.

The probes have their own independent PHC.

Manual autopilot disconnects are logged on acars as well just in case some haven't seen post #915
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Old 9th Jun 2009, 18:48
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Airbus Rudder

A lot of talk about the rudder on AF447. I asked this in the Tech Forum but got no reply. What indication is given the pilot when they are in other than 'Normal Law' on an Airbus as to how much rudder to apply or NOT to apply, if needed, to keep the rudder attached to the airframe?

Is the Airbus of such a design that one needs to accually use the rudder in flight, even in turbulence? I only flew Lockheed, Douglas, and Boeing aircraft (Transport-wise), but don't recall ever using the rudder except on the ground. Oh, maybe during crosswind take-offs and landings, but NEVER enough to cause any kind of problem, with or without boost. Thoughts anyone?
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Old 9th Jun 2009, 18:55
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Static discharger

Interesting little detail on the picture lifting the fin onboard: The top of the fin / rudder seems intact, but only one static discharger remains attached. At least 3 are missing.

Of course, they could have gone during impact (but looks not damaged), or during handling by the Brazilian team in the water, or due to lightning...
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Old 9th Jun 2009, 19:13
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Simply no evidence regarding VS/rudder

DC-ATE,

My thoughts are that AA587 cannot be compared with AF447 with regard to the rudder use. AA587 was flown on a A300-600 and according to the NTSB investigation this type of aircraft, in comparison to others, has the lightest pedal forces as well as among the shortest pedal travel, making it harder to gauge the right force applied to them.
To my knowledge no Airbus A330/A340 have reported issues similar to those that eventually brought down AA587.
Instead I have read a report by a AF Concorde pilot who said that in its early tests the A300 displayed weaknesses in the rudder, and I always wondered whether that was somewhat related to AA587. But nothing with the A330/340. And there is no evidence to tell here at this time. Simply wait for the investigation.
If I find the AF pilot quote I'll post it here.
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Old 9th Jun 2009, 19:17
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Brazilian Air Force AF447 Website

:: FAB - Força Aérea Brasileira ::
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Old 9th Jun 2009, 19:20
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to chefrp:

That's unlikely but possible. Static dischargers are here to discharge static electricity, and when you get a lightning strike (can be anywhere on the fuselage, sometimes one or more "burn away", that's what they are installed for. So this could be a sign of (very) intense lightning action, if the 3 were gone due to lightning. But as I mentioned above, could also be during the water-impact or during handling later.
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Old 9th Jun 2009, 19:26
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One very obvious difference between AA587 and AF447 that I haven't seen mentioned is that in the former, the rudder and VS had separated at some point prior to discovery, while in the latter the entire assembly has been recovered intact.

Significant? I don't know.

FBW
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Old 9th Jun 2009, 19:27
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09/06/2009 - 10h49
Press Release- English
PRESS RELEASE 21

The Brazilian Navy Command and Aeronautical Command inform that, from the beginning of the search until now, the total of bodies recovered from the ocean is 24, all now aboard Brazilian ships.
The last eight bodies recovered, in a joint effort of the Brazilian Navy and the French Navy, will be in due time be sent to Fernando de Noronha, where they will receive initial preparation and afterward transport by plane to the city of Recife (PE).
The Frigate Constituição is around 400 kilometers from the Archipelago of Fernando de Noronha, with the 16 bodies previously rescued. The meteorological conditions have not interfered with the search and rescue operation this day, still there are meteorological formations that indicate bad weather in the proximity of the Archipelago.
Currently the Operation counts with 255 military personnel from the Brazilian Air Force, moved to Natal (RN), Recife and Fernando de Noronha (PE), and 14 aircraft, with 12 being Brazilian Air Force and 2 from France. The H-34 helicopter (Super Puma - FAB) flew from Natal to Fernando de Noronha, in order to directly support the rescue operations.
The Brazilian Navy now has 570 military personnel on board the ships. The Patrol Boat Guaíba substituted the Patrol Boat Grajaú that returns to Natal (RN) to resupply. Thus, five Brazilian Navy ships and one French Navy Frigate, continue in the area of operation.
The search and rescue missions continue, without interruption, and are concentrated on the areas where the bodies were located. The search for other clusters of wreckage continues to be carried out by the R-99 aircraft, and during the night, visual search aircraft work on the transport of supplies to Fernando de Noronha.

NAVAL SOCIAL COMMUNICATION CENTER
AERONAUTICAL SOCIAL COMMUNICATION CENTER
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