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AF447 wreckage found

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AF447 wreckage found

Old 1st Jun 2011, 18:30
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ECAM: this is the first time I have understood that feature of the system, Low Speed Stability.

Low Speed Stability will attempt to pitch the nose down to maintain just above Vls, but the pilot *CAN* override this (maybe that is why the PF was pulling up - he was stopping the nose from dropping in the belief they were flying and the systems thought they weren't due to the low airspeed reading?).

I'll post a link to your post in the Tech Log discussion, since I have yet to see this man-machine interface issue raised in the deluge of posts on that sub forum. It may have been mentioned, but not in the concise way you just did.

PF is in ALT Law, so hand flying, which means flying a bit by "feel" (is this right, AB drivers?)

I have flown conventional aircraft in out of trim conditions, so I think I know what "feel" might be in his hand, and induce a pitch up that it takes a bit of scan to realize is happening. This might explain that initial "zoom" at 7000 fpm and initial "correction" to about 700 fpm climb ... thanks for switching the light on for me.
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Old 1st Jun 2011, 18:44
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Cool

Hi,

Yes. If your pitch rate is too fast, you can change your AoA too fast and either create a stall, or an accelerated stall, while pulling out of a dive.
This ... ?

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Old 1st Jun 2011, 18:51
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Aquadalte,

At 1 h 31 min 44 s, the RECIFE controller gave it [AF447] the ATLANTICO HF frequencies: 6649 or 5565 kHz, then 6535 kHz after the TASIL point. The crew read back the three frequencies. Note: TASIL is on the boundary between the ATLANTICO and DAKAR Oceanic FIRs.

At 1 h 33 min 25 s, the crew contacted the ATLANTICO controller on the 6649 kHz frequency.

At 1 35 min 15 s, they informed the controller that they had passed the INTOL point at 1 h 33, at FL350. They announced the following estimates: SALPU at 1 h 48 then ORARO at 2. They also transmitted their SELCAL code: CPHQ.

At 1 h 35 min 26 s, the ATLANTICO controller coordinated flight AF447 with the DAKAR controller. At 1 35 min 32 s, the ATLANTICO controller transmitted the following items to the DAKAR controller: TASIL estimated at 2 h 20, FL350, Mach 0.82.

At 1 h 35 min 38 s, the ATLANTICO controller sent a SELCAL call.

At 1 h 35 min 43 s, the crew thanked the controller.

At 1 h 35 min 46 s, the controller asked them to maintain an altitude of FL350 and to give a TASIL estimate.

Between 1 h 35 min 53 s and 1 h 36 min 14 s, the ATLANTICO controller asked the crew three times for their estimated time passing the TASIL point. The crew did not answer.

[There was no further contact with the crew.]
The recent BEA note indicates that the PF briefed the PNF who had arrived at the cockpit that at some time before 1 h 59 min 32 s that logon with DAKAR had failed. (At least 21 minutes before estimated changeover from ATLANTICO to OCEANIC DAKAR which was at 2 h 20 at the TASIL waypoint.) LH507 (believed to be the flight with AMDAR) monitored 121.5 the entire flight and never heard any communication from AF447.

The PF also briefed the PNF at 2 h 00 that the ‘little bit of turbulence’ just experienced would be similar to what would be experienced ahead.

Tim Vasquez concludes, “Based on the soundings above, my conclusion is that the maximum cumulonimbus tops were 56,000 ft with an equilibrium level of 47,000 ft, representing the tops of most parts of the MCS except near the edges.”

So CVR transcripts of any conversation on what they were seeing on their radar displays will be interesting.

I'll leave it to others to comment on jumping ahead on a frequency change 21+ minutes before one arrives at the boundaries of the FIR.
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Old 1st Jun 2011, 19:03
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xcitation

I seem to remember that the flight plan for AF447 did not list Paris as it`s final destination but something closer along the way (toulouse?) and Paris as an alternate. The logic, so it was said, would be that filing Paris would have left them with less than the allowed contingency fuel and that through this trick, they could safely go with the amount of fuel on board and decide closer to French shores to use the contingency fuel to go to Paris.
Can anyone confirm that that was the case? And if so, what would that say about their ability to deviate around the cell and still make it to Paris. A refuelling stop in Toulouse would certainly be an embarrassment.
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Old 1st Jun 2011, 19:03
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Speaking of Tim Vasquez: If you browse over to his web site you'll note that he has made some data modifications, today as a matter of fact, which uses some of the data supplied by BEA on 27 May.
As usual it makes for some very interesting reading.

However, and again using data provided by BEA, he corrlelates that data with weather data available at the time.

This is the new, updated, weather chart and the flight path of AF447:

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Old 1st Jun 2011, 19:13
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Guys.... a little knowledge is a dangerous thing:

Saturn

that logon with DAKAR had failed. (At least 21 minutes before estimated changeover from ATLANTICO to OCEANIC DAKAR
I'll leave it to others to comment on jumping ahead on a frequency change 21+ minutes before one arrives at the boundaries of the FIR.
Why are you claiming they're "jumping ahead on a frequency"? They are talking about their datalink or CPDLC / ADS, not radios. That comment in the handover means that haven't yet got CPDLC logon with Dakar ATC (possibly because it's too early for Dakar to "accept" them). As far as HF frequencies are concerned they may well have still been on SELCAL watch on the Atlantico frequencies...the fact that Atlantico couldn't raise them could just mean they were in an area of poor HF reception.


ap08

The logic, so it was said, would be that filing Paris would have left them with less than the allowed contingency fuel and that through this trick, they could safely go with the amount of fuel on board and decide closer to French shores to use the contingency fuel to go to Paris.
I think capital punishment should be re-introduced in the judicial practice. The management of the airline that tolerates (encourages?) such tricks deserves no less.
It's called a reclearance operation....been done for years in Longhaul.....I plead guilty to doing this, as I guess do many of the grey haired Longhaulers here. It's no big deal as long as you don't reclear onwards beyond your enroute alternate without the fuel to do so.

Last edited by wiggy; 1st Jun 2011 at 19:34.
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Old 1st Jun 2011, 19:28
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Originally Posted by iwrbf
Hi there,

german news outlet "Der Spiegel" has an interesting story about a german aerospace engineer (Professor, that is...) who experienced some strange (disturbing) behaviour in the simulator. Read yourself (english version):

Air France*Catastrophe: Victims' Families Propose Grounding All*A330s - SPIEGEL ONLINE - News - International

Kind regards,
Peter
I'm not able to find details of his simulation a year ago online - I wonder if it includes the zoom-climb to FL380 ?

Did find in here picture of the Professor suggesting a position for the captain?

AirFrance.pps
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Old 1st Jun 2011, 19:40
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Devil

so if they filed for Toulouse, intending to go on to CDG, I assume that a deviation might have put them into a situation where they would end up having to refuel before getting to Paris?
could this have begun as a severe case of get-homeitis?
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Old 1st Jun 2011, 19:43
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Wiggy, although it did not affect the flight, Brazilian ATC had omitted DAKAR from the AF447 flight plan. (Whether it affected the search is probably an open question at this point.)

At 1 h 46, the DAKAR controller asked the ATLANTICO controller for further information regarding flight AF447 since he had no flight plan. The ATLANTICO controller provided the following elements: A332, from SBGL to LFPG, SELCAL: CPHQ.

The DAKAR OCEANIC Regional Control Centre created the flight plan and activated it. {No time given for when this was done.] The result of this was to generate a virtual flight following the planned trajectory in the DAKAR FIR between TASIL and POMAT. There was no radio contact between AF447 and DAKAR, nor any ADS-C connection. The flight remained virtual.

At 2 h 47 min 00 s, the DAKAR controller coordinated flight AF447 by telephone (ATS/DS) with the SAL controller (Cape Verde) with the following information: passing the POMAT point (leaving the DAKAR FIR) estimated at 3 h 45, FL350, Mach 0.82.

At 2 h 48 min 07 s, the DAKAR controller told the SAL controller that flight AF447 had not yet established contact with him.
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Old 1st Jun 2011, 19:54
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could this have begun as a severe case of get-homeitis?
It could equally have been a pragmatic approach to getting out of GIG in the first place. I haven't seen the performance figures for the flight but they may not have been able to lift the planned payload and "full" GIG-CDG fuel out of GIG...they might have been able to carry fuel for GIG-CDG plus a little bit of extra, but not enough to give them the legal amount of contingency, or buffer fuel, needed at the start of the flight. One option would be to come back on a windier cooler day, another dump freight or passengers... , another one would be to fill up as much as possible, file a plan for say GIG-TLS - which given the shorter track could then mean you have full legal contigency fuel for that sector, so all legal, above board, a recognised procedure and safe.

Once you approach TLS you look again at fuel on board and decide wether you have enough in tanks to overfly TLS and continue to CDG with legal reserves or wether you don't, in which case have to do a tech stop.

It's not a technique used as much these days as it was 20-30 years ago but it still has it's uses if you're short of performance, and it's perfectly legal, the critical thing is you don't press on beyond the en-route alternate without fuel to so so....sadly the crew of AF447 never got to make that decision.

SoaringTS...you beat me to it, Rgds.
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Old 1st Jun 2011, 20:00
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A weather deviation decided in time (not in a panic) costs peanuts in fuel. Cut that idea.
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Old 1st Jun 2011, 20:01
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wiggy

I understand the idea and yes, it does make sense when you're streching it a bit. my question was: how long a deviation could they have made before TLS would have been their guaranteed next stop?

We've seen many cases where pride made people make bad decisions.
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Old 1st Jun 2011, 20:47
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Looks like a lot of posters do not have a clue about CPDLC operations, hence the comments about jumping ahead on a frequency, no CPDLC log on yadda, yadda, yadda.

Agree with wiggy, a little knowledge is indeed a dangerous thing. With the data released in dribbles, I cannot help but think that we are all being led into posting things which will help interested parties to cover their arses.

We might be doing the dead crew members a great disservice in our rush to pontificate and show off " armchair " style our great flying skills and systems knowledge.
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Old 1st Jun 2011, 21:04
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Training Training Training...

There is no mystery.

1/ a pilot nose up
2/ he stalled his plane and didn't alert the captain nor did he communicate
3/ he didn't recognize his fault although his instruments gave him all the necessary information (the lack of speed data is a consequence of the stall not the cause)

That's all.
Pilots are here to pilot the planes that are given to them (OK : their opinion is welcome).

I play golf : every 3 month I need 3 hours of practicing my 3 iron to be able to do something with it.

To pilot is a sport : it needs training and training and training.

That's why there are captain and cadet. Champions and losers.
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Old 1st Jun 2011, 21:21
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Bluesideup

Just as a caveat, I have read most but not all the approximately 1300 posts on this thread. I have yet to read anything concerning the “Thrust Lock Mode” of the autothrust system. If it’s been previously addressed bear with me. For continuities sake, I’m starting at square one of how the system is supposed to work. As for my background, I flew the A-330 for a year and a half as a Captain prior to my retirement (60th birthday) about 1 year ago.

The problem with the autothrust system being inop is the way they interface with the thrust levers. When autothrust is in use the thrust levers are selected to one of 4 detent positions (TOGA, FLX/MCT, CL and IDLE) and don't move even though the engines may be delivering different amounts of thrust to maintain the selected mach/airspeed number. During cruise, they are in the CL or climb detent and have a power range from idle to max climb thrust. CL is the detent the thrust levers stay in 99% of the time. It is used for climb, cruise, descent and approach. To manually control the thrust levers you need to take them out of the CL detent, match the EPR setting with the thrust levers (there is symbology on the engine instruments which show you the position of the thrust levers and the actual EPR setting so that you can match them up before you disconnect the autothrust system). This provides a smooth transition between manual and autothrust use (no power surge). When the autothrust system failed on AF447, the thrust levers were in the CL detent. There is a difference if the system is turned off manually or due to a system failure. If the autothrust system is turned off manually using the pushbutton's on the thrust levers, the system will go to the max power setting of the CL detent unless the thrust levers are manually set as previously described. If there is a system failure the autothrust system goes into the "Thrust Lock Mode" and freezes the engine power at whatever thrust was being developed at the time of the failure. Thrust lock indications are a MASTER CAUT light, an amber flashing ENG THRUST LOCKED and AUTOFLT A/THR OFF,THR LEVERS.......MOVE ECAM messages, a single chime, and a STATUS page message. The chime is repeated every 5 seconds until pilot corrective action is taken. As you can imagine, when you have multiple failures, there's a lot of blinking lights, chimes, bells, whistles and other distractions not to mention a rather long list of ECAM and STATUS messages on the screens. The important thing to remember here is unless you reference the engine instruments, you don't know at what power setting the engines were actually producing at the time of the failure. The autothrust system on the Bus is OK, but remember the thrust levers never move so you lose one of the subtle cues normally found in the cockpit of most other aircraft. The autothrust system is normally very aggressive in trying to meet the speed demands placed on it. By this I mean you can get very large reductions or additions to thrust in order for the system to meet target speeds/mach settings. They are even more sensitive when turbulence is encountered and I've seen large variations in thrust setting in an attempt by the system to maintain target speeds. If you’ve ever ridden in the back of the A-330 in turbulence you will definitely notice the power changes. You also have to remember that power changes at max operating altitudes are very sluggish and it takes time to regain the target speed especially if the speed is bouncing around rapidly. In the AF447 situation, the PF (pilot Flying) slowed the aircraft from .82 to .80 mach. During this time he also encountered increasing turbulence and within a minute or so lost his instrumentation, autopilot, and autothrust. Until BEA releases the Flight Data Recorder readings and we know at what thrust setting the thrust lock mode froze the power, we won't know to what extent the autothrust system was responsible for possibly contributing to this accident. I hope this gives you a better understanding of how the system is supposed to work.
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Old 1st Jun 2011, 21:39
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JJFFC:
1/ a pilot nose up
2/ he stalled his plane and didn't alert the captain nor did he communicate
3/ he didn't recognize his fault although his instruments gave him all the necessary information (the lack of speed data is a consequence of the stall not the cause)
Is it your position that the airspeed indicators did NOT react to ice on the pitot tubes?
I play golf : every 3 month I need 3 hours of practicing my 3 iron to be able to do something with it.
To pilot is a sport : it needs training and training and training.
That's why there are captain and cadet. Champions and losers.
I play golf as well, and still use my 3 iron. The 1 and 2 iron have been retired.

Yes, one needs practice to stay proficient.
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Old 1st Jun 2011, 22:05
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Pitot tubes reacted to stall rather than to ice after AP disconnected

Lonewolf_50


JJFFC:
Quote:
1/ a pilot nose up
2/ he stalled his plane and didn't alert the captain nor did he communicate
3/ he didn't recognize his fault although his instruments gave him all the necessary information (the lack of speed data is a consequence of the stall not the cause)

Is it your position that the airspeed indicators did NOT react to ice on the pitot tubes?
It is my opinion that after the plane had stalled, the pitot tubes didn't reacted to ice but to the stall and to the fact that the plane was really below 60 and inclined.

Maybe the AC disconnected because the Pitot tubes iced, but the BEA has never written this in this report : nobody knows why the AC disconnected.

Maybe the PF wanted to climb because of the weather (somebody already mentioned that in this topic).
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Old 1st Jun 2011, 22:14
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The plot unthickens.....
If there is any shred of truth in the above posts - i.e. filing for LFBO but intending LFPG (all above board and as per regs, one assumes) - then a marginal fuel mentality scenario for lack of adequate CB avoidance cannot be dismissed. I checked the BEA report again for RTOW vs MTOW.... ah, suddenly it starts to make sense. I still maintain pts 1 to 11 on p49 for what happened subsequently. Whatever law it was in, the scenariio holds. Commercial pressure vs airmanship leading up to it? We shall one day see....

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Old 1st Jun 2011, 22:27
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If you look at the findings of crash AF358 a lack of training, missing procedures and improper judgement seem to be the case. Of course this was a different situation than AF447 but it might indicate a not perfect safety culture and lack of or improper training within the airline.

]Conclusions (Wikipedia) AF358
The TSB concluded in their final report that the pilots had missed cues that would have prompted them to review their decision to land.[33] In their report[14] the TSB cited that
Air France had no procedures related to distance required from thunderstorms during approaches and landings
After the autopilot had been disengaged, the pilot flying increased engine thrust in reaction to a decrease in airspeed and a perception that the aircraft was sinking (spatial disorientation). The power increase contributed to an increase in aircraft energy and the aircraft deviated above the flight path.
At 300*feet above ground level, the wind changed from a headwind to a tailwind.
While approaching the threshold, the aircraft entered an intense downpour and the forward visibility became severely reduced.
When the aircraft was near the threshold, the crew members committed to the landing and believed their go-around option no longer existed.
The pilot not flying did not make the standard callouts concerning the spoilers and thrust reversers during the landing roll. This contributed to the delay in the pilot flying selecting the thrust reversers.
There were no landing distances indicated on the operational flight plan for a contaminated runway condition at the Toronto / Lester B. Pearson International Airport.
The crew did not calculate the landing distance required for runway 24L despite aviation routine weather reports (METARs) calling for thunderstorms. The crew were not aware of the margin of error.
The topography at the end of the runway beyond the area and the end of Runway 24L contributed to aircraft damage and injuries to crew and passengers.
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Old 1st Jun 2011, 22:34
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Thrust Lock

drkraft

If there is a system failure the autothrust system goes into the "Thrust Lock Mode" and freezes the engine power at whatever thrust was being developed at the time of the failure. Thrust lock indications are a MASTER CAUT light, an amber flashing ENG THRUST LOCKED and AUTOFLT A/THR OFF,THR LEVERS.......MOVE ECAM messages, a single chime, and a STATUS page message. The chime is repeated every 5 seconds until pilot corrective action is taken.
You raise another good point. Having read up some more on TOGA thrust lock incidents I can see that this issue alone has led to pilot overload and overspeed in the A330.
A330 experienced an uncancelable toga lock thrust condition following a predictive windshear go around
Are we reaching the point of over automation?
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