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AF447 wreckage found

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AF447 wreckage found

Old 1st Jun 2011, 19:43
  #1261 (permalink)  
 
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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
  #1262 (permalink)  
 
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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
  #1263 (permalink)  
 
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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
  #1264 (permalink)  
 
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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
  #1265 (permalink)  
 
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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
  #1266 (permalink)  
 
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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
  #1267 (permalink)  
 
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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 ďThrust Lock ModeĒ of the autothrust system. If itís been previously addressed bear with me. For continuities sake, Iím 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 youíve 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
  #1268 (permalink)  
 
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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
  #1269 (permalink)  
 
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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
  #1270 (permalink)  
 
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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....

Last edited by Pininstauld; 1st Jun 2011 at 22:45.
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Old 1st Jun 2011, 22:27
  #1271 (permalink)  
 
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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
  #1272 (permalink)  
 
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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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Old 1st Jun 2011, 22:38
  #1273 (permalink)  
 
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spatial disorientation after a stall

Log22
Posts: 1


]Conclusions (Wikipedia) AF358

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).
Very interesting your mention of the "spatial disorientation"

PS : But for your "AF bashing" it is not necessary ; AF has not to prove it knows how to operate planes since the 1930' ; and the Paris - Rio route is one of the oldest !
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Old 1st Jun 2011, 22:58
  #1274 (permalink)  
 
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Flight Plan

The AF447 flight plan on the Vasquez site clearly states destination is Charles De Gaul (LFPG). So we can debunk the Toulouse destination theory if that is a reliable facsimile.

Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data
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Old 1st Jun 2011, 23:37
  #1275 (permalink)  
 
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Barnyard Logic II

Lonewolf50
For Graybeard and about AoA Probes and indications
Graybeard, in re "better" AoA indicators. I'll suggest to you that the US Navy has been using one "better" (actually, I doubt it's any better) from before I started flying which functions reilably at airspeeds below 60 knots. (There is one on the T-34C Trainer that works as you describe ... a weather vane in the horizontal plane. See also AoA probes on various Navy jets).

I don't think it's the probe that's the issue, but a software decision on signal processing. You could do what you need to (no stall chirp on the ground) with a WoW switch (already have one on the bird, yes?) without artificially clipping the AoA signal when in flight.

Your comments, sir?
The real measure of AOA is degrees, not knots, of course, although everybody has been shouting for a Stall Warning below 60 knots, not a specific AOA.

I don't have the numbers, but it appears that onset of stall of the A330 at that MAC and flap is less than 20 degrees. The report shows AF447 achieved AOA in excess of 40 degrees, double the onset of stall. How much AOA does it need to measure, 90 degrees, 120 degrees? What's the point?

You have to balance Stall Warnings in extremely rare events with far more common nuisance stall warnings, in order to maintain confidence in the system. In fact there was no doubt a point in the zoom climb to stall that airspeed was near zero, and the AOA vanes would fall with gravity, probably showing a negative AOA.

Last edited by Graybeard; 1st Jun 2011 at 23:38. Reason: typo
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Old 2nd Jun 2011, 00:24
  #1276 (permalink)  
 
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Saturn,
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.

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.
SaturnV,
The notification from ATLANTICO to DAKAR, (contrary to what happens now), was not automatically done from one ATC to the other at that time, once the CPDLC/ADS FANS system was not fully operational at that time. According to FANS procedures, one should try to notify/(log-on) between 10 to 40 minutes before reaching the boundary. Further, there are normally two HF radios on A330's. Therefore, it was common practice to call DAKAR, at least 10 minutes before reaching the boundary on HF2, while maintaining a SELCAL watch with ATLANTICO on HF1.

But I'm with you. I'm very curious on what CVR transcripts may bring to light.
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Old 2nd Jun 2011, 00:31
  #1277 (permalink)  
 
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Greybeard reminds us:

The AOA sensor is just a high priced vertical weathervane,
...but like the weathervane, shouldn't it too be statically balanced? And if so, why would it be unreliable below 60kt?

The balance weight would not need to be out in the airstream; it could be internal, behind the aircraft skin.

Just askin'.
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Old 2nd Jun 2011, 00:52
  #1278 (permalink)  
 
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Static Balance

Every AOA sensor I've seen on ground has been full stop down (neg AOA), which indicates no static balance. Don't believe I've ever seen one in flight.

I don't know a lot about AOA vanes, which I why I asked for someone really knowledgeable to speak up. You can peruse pix on airliners.net to get a good sample.
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Old 2nd Jun 2011, 01:23
  #1279 (permalink)  
 
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TheShadow:

Your prescience is unparalleled on this thread. We have only been provided with a sou-son of data but I believe you have nailed it. The THS situation was, I also believe, the lethal factor.

I thank you for your insights. As a current 330 pilot I will now be paying a lot more attention to its position. Especially if things ever get convoluted!

I wondered who you were. I see from a basic search you may be an ex-Viet chopper guy. How do you know about all this Airbus stuff? And especially in such detail? Please tell us more?

Your erudition is also commendable.

Please keep up this extraordinary work.
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Old 2nd Jun 2011, 02:03
  #1280 (permalink)  
 
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The aviation industry may have just found their spokesperson. Notice his emphasis on proper training and having AoA displayed . We should all be grateful he landed that plane safely on the Hudson and became a hero. It seems his time has come....

Sully: Training is key to avoiding air accidents - CBS News Video
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