AF447
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A330 fuselage...
@ Romani
Most of the A330 is of conventional metal construction, with composite vertical and horizontal tail surfaces, so behaviour on contact with the sea would probably (sea states and other factors unknown, of course) be similar to the A320 "Sully" event ...
Most of the A330 is of conventional metal construction, with composite vertical and horizontal tail surfaces, so behaviour on contact with the sea would probably (sea states and other factors unknown, of course) be similar to the A320 "Sully" event ...
Last edited by Jig Peter; 15th Jul 2009 at 15:14. Reason: Typo ... sorry !
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Fortes turbulences
@thermalsniffer
No one has answered the question regarding the purported crew report of "fortes turbulances" (see posts 574 and 628 and underlying source material), and that it is not mentioned in the BEA report.
No one has answered the question regarding the purported crew report of "fortes turbulances" (see posts 574 and 628 and underlying source material), and that it is not mentioned in the BEA report.
2. an automatic position report triggered by the FMGS was issued at 0200, which should include:
- from waypoint xxxx, time and FL
- current position (lat, lon), time and FL
- to waypoint yyyy, time and FL
- next waypoint zzzz, time and FL
- Wind (heading, speed)
- SAT (deg C)
- Icing (manual field?)
- Turbulences (manual field?)
- Airspeed (kts/mach)
- Ground speed (kts)
- Vertical speed (ft/mn)
- Heading
- Track angle
3. press reports are to be considered unreliable until cross-checked with official investigations sources.
A second question is if the report by the crew did happen at 2:00, why would the A/THR be on at 2:10:46??
2. turbulences automatically reported at 0200 but none at 0210...
@ LeandroSecundo
Sorry, you were right, I wrongly noted 2C check at 6,000 hrs when it was actually 1C (beside, this document you linked doesn't give the answer for A330 but it may be infered from A320s checks). Thx MROJunkie for the correct table.
S~
Olivier
Last edited by takata; 15th Jul 2009 at 15:27.
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Meteo
RE: rgbrock1 (#3634) and BOAC (#3631)
Quote:
But, again, do these images tell the entire story?
/Unquote
No they do not. But there is verbal explanation that goes with it. While the meteorologist specialist stuff is at places difficult to follow for a layman like me, they did more than just look at those images. From what I understand, there are two sets of data that permit them to say something about the probability of extreme updrafts at the time of AF447.
The first is the vertical temperature profile of the atmosphere as obtained from radiosonde ascents on that day in the area, combined with the temperature of the seawater. Convective air currents derive their energy from the fact that the rising air is warmer and hence lighter than the surrounding air. The greater this temperature difference, the greater the speeds that upward moving airmasses are likely to attain (probably a gross oversimplification on my part). An analysis by Tim Vasques available on the Web compares these temperatures and concludes from them that extreme updrafts are unlikely.
The second is the apparent "overshoot" in the convective cells as can be seen in the satellite infrared images, as discussed in the BEA report. The rising air, after penetrating the tropopause, will reach an altitude at which its temperature is equal to that of the surrounding atmosphere. At that (equilibrium) level it no longer experiences an upward bouyancy but since it is moving at a certain speed it will not suddenly stop there, but will continue upwards, gradually losing momentum, until it stops. At that point it will be cooler than its surroundings, and that temperature can be seen in the satellite IR images looking at cloud tops. The greater the upward speed, the greater that overshoot beyond the equilibrium level, and hence the lower the temperature where it stops. That analysis, done by Meteofrance in the BEA report, also shows that there is no evidence pointing towards extreme updrafts.
I repeat that this is a layman's account, trying to help fellow-laymen understand the meteo lingo. Hope it helps.
regards,
HN39
Quote:
But, again, do these images tell the entire story?
/Unquote
No they do not. But there is verbal explanation that goes with it. While the meteorologist specialist stuff is at places difficult to follow for a layman like me, they did more than just look at those images. From what I understand, there are two sets of data that permit them to say something about the probability of extreme updrafts at the time of AF447.
The first is the vertical temperature profile of the atmosphere as obtained from radiosonde ascents on that day in the area, combined with the temperature of the seawater. Convective air currents derive their energy from the fact that the rising air is warmer and hence lighter than the surrounding air. The greater this temperature difference, the greater the speeds that upward moving airmasses are likely to attain (probably a gross oversimplification on my part). An analysis by Tim Vasques available on the Web compares these temperatures and concludes from them that extreme updrafts are unlikely.
The second is the apparent "overshoot" in the convective cells as can be seen in the satellite infrared images, as discussed in the BEA report. The rising air, after penetrating the tropopause, will reach an altitude at which its temperature is equal to that of the surrounding atmosphere. At that (equilibrium) level it no longer experiences an upward bouyancy but since it is moving at a certain speed it will not suddenly stop there, but will continue upwards, gradually losing momentum, until it stops. At that point it will be cooler than its surroundings, and that temperature can be seen in the satellite IR images looking at cloud tops. The greater the upward speed, the greater that overshoot beyond the equilibrium level, and hence the lower the temperature where it stops. That analysis, done by Meteofrance in the BEA report, also shows that there is no evidence pointing towards extreme updrafts.
I repeat that this is a layman's account, trying to help fellow-laymen understand the meteo lingo. Hope it helps.
regards,
HN39
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No, unlikely a composite component would shatter-like-glass, as it's a matrix of fibres within a substrate.
Although a lot of strain-energy would be released when a component does break, that then would release the strain throughout much of the rest of the component.
The fin was not found in a thousand pieces, nor would that be expected !
One hypothesis, is that it failed due to inertial loading, when the fuse entered the water (in line of flight - read axially in this case), decelerating at a very high rate, as it's(the fin's) supporting structure progressively buried itself under water, with the fin still in free-air (little balancing drag)
No doubt BEA have already calculated the deceleration required, in round terms, to fail the fixings through forward bending in this manner... from its mass and vertical mass centroid. I would imagine this would be many tens, maybe 20 ~50g or more (but don't shoot me unless you've done some sums as well
Although a lot of strain-energy would be released when a component does break, that then would release the strain throughout much of the rest of the component.
The fin was not found in a thousand pieces, nor would that be expected !
One hypothesis, is that it failed due to inertial loading, when the fuse entered the water (in line of flight - read axially in this case), decelerating at a very high rate, as it's(the fin's) supporting structure progressively buried itself under water, with the fin still in free-air (little balancing drag)
No doubt BEA have already calculated the deceleration required, in round terms, to fail the fixings through forward bending in this manner... from its mass and vertical mass centroid. I would imagine this would be many tens, maybe 20 ~50g or more (but don't shoot me unless you've done some sums as well
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rgbrock1
Tim Vasques detailed analysis of the weather for AF447 can be found here.
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data
Crudely speaking he concludes that the weather system was not unusual for that area.
But best to read his site yourself.
Tim Vasques detailed analysis of the weather for AF447 can be found here.
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data
Crudely speaking he concludes that the weather system was not unusual for that area.
But best to read his site yourself.
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mm43:
I've prepared a graphic which shows the ETO times SALPU, ORARO and TASIL calculated from the 0150z ~ 0200z GS of 464KT. On passing SALPU the SBFN-SSR would have received the last squawk from AF447 - at about 254NM from the radar. The 0214z Ultimo Reporté and the now discredited 0214z ACARS position are also shown.
I've prepared a graphic which shows the ETO times SALPU, ORARO and TASIL calculated from the 0150z ~ 0200z GS of 464KT. On passing SALPU the SBFN-SSR would have received the last squawk from AF447 - at about 254NM from the radar. The 0214z Ultimo Reporté and the now discredited 0214z ACARS position are also shown.
It is nice, but:
- 0214 position doesn't exist.
- 0150 & 0200 exact positions are still yet unpublished,
If extracted from the BEA flightplan reconstitued, due to its scale, it is not possible to make any precise position within a margin of error of 3-5 NM.
So, it is actually not possible (for any one of us) to figure out if any flight plan deviation occured already before 0210, nor to compute the aircraft airspeed at all these points, including the last one.
On the other hand, the BEA should be able to do it from the vectors recieved at 0150, 0200 and 0210 (see my post above) and it should be able to verify precisely the distance actually flown (with airspeed, temp, wind, and heading) between those points, including the final vector after 0210.
This is what I found seriously missing in the preliminary report, as they only published the last position, and previously also the altitude (FL350, during June 6th conference). My opinion is that F-GZCP airspeed was already reported erroneous in this last position report.
S~
Olivier
press reports are to be considered unreliable until cross-checked with official investigations sources
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Fortes Turbulences
Takata, you already answered the questions at Post 2125. Sorry for the repetition, but I missed it in my thread search.
The BEA pointed that she was flying at cruise settings Mach 0.82 @ 0210Z and autothrust was ON (self-disconnected at 0210Z); unlikely a 'fortes turbulences' mode which would be at reduced speed to Mach 0.80 and autothrust OFF (like in Air Caraibes case). See my first hypothesis post about the so-called 'fortes turbulences' report issued at 0200Z.
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DJ777:
takata, with all due restect, it may also apply to forum reports. Frankly, I doubt the auto position report at 0200 contained all this info and the BEA did not mention it. Is it not possible that what you describe is an ADS full position report, not a simplified company one ?
takata, with all due restect, it may also apply to forum reports. Frankly, I doubt the auto position report at 0200 contained all this info and the BEA did not mention it. Is it not possible that what you describe is an ADS full position report, not a simplified company one ?
So, wait and see, I'm pretty sure they are one step beyond us in this case because they have much more data on hand than published yet. I asked someone to get the exact format used by Air France for its long haul position reports and I'll get his answer soon.
S~
Olivier
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Airspeed anomaly?
Is it possible the reduced airspeed ( calculated and shown a few posts ago) after 0200 is really due to a dogleg having been performed and track nearly regained??
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Hyperveloce
You cannot know the "speed" of the a/c point to point without knowing its route (Miles covered). This is where speculation gets out of control. My point is that the "line" between the last two reporting points is "straight", it may not have been, it hasn't been published if it is known. The line is itself speculation, onto which you have heaped additional (speed) speculation. What is "known" is the 3nm separation a/c from "flight path"
(per BEA).
You cannot know the "speed" of the a/c point to point without knowing its route (Miles covered). This is where speculation gets out of control. My point is that the "line" between the last two reporting points is "straight", it may not have been, it hasn't been published if it is known. The line is itself speculation, onto which you have heaped additional (speed) speculation. What is "known" is the 3nm separation a/c from "flight path"
(per BEA).
Last edited by Will Fraser; 16th Jul 2009 at 02:01.
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takata
As I pointed out in the accompanying text, the original 0214z so-called ACARS position first reported by the media was discredited.
I accept that the 0150 and 0200 positions have not been published, but with diligence it is possible to derive them to a reasonable degree of accuracy which assumes that the BEA used Google Earth to construct the graphic in the first place. The BEA graphic provided the first evidence that the 02:10:34 position was not on the ORARO ~ TASIL track, even before I found the French SHOM report and 2.98°N 30.59°W.
Similarly, the 0130 and 0140 positions place the a/c overhead INTOL at 01:32:32.
All that can be deduced so far is that the a/c essentially flew the UN873 center-line plus or minus the plotting error, but that irrespective of that error the 02:10:34 position was 3NM left of track. When the deviation occurred is unknown. It certainly isn't a SLOPS offset (left?).
mm43
It is nice, but:
- 0214 position doesn't exist.
- 0150 & 0200 exact positions are still yet unpublished,
If extracted from the BEA flightplan reconstitued, due to its scale, it is not possible to make any precise position within a margin of error of 3-5 NM.
- 0214 position doesn't exist.
- 0150 & 0200 exact positions are still yet unpublished,
If extracted from the BEA flightplan reconstitued, due to its scale, it is not possible to make any precise position within a margin of error of 3-5 NM.
I accept that the 0150 and 0200 positions have not been published, but with diligence it is possible to derive them to a reasonable degree of accuracy which assumes that the BEA used Google Earth to construct the graphic in the first place. The BEA graphic provided the first evidence that the 02:10:34 position was not on the ORARO ~ TASIL track, even before I found the French SHOM report and 2.98°N 30.59°W.
Similarly, the 0130 and 0140 positions place the a/c overhead INTOL at 01:32:32.
All that can be deduced so far is that the a/c essentially flew the UN873 center-line plus or minus the plotting error, but that irrespective of that error the 02:10:34 position was 3NM left of track. When the deviation occurred is unknown. It certainly isn't a SLOPS offset (left?).
mm43
You cannot know the "speed" of the a/c point to point without knowing its route (Miles covered). This is where speculation gets out of control. My point is that the "line" between the last two reporting points is "straight", it may not have been, it hasn't been published if it is known. The line is itself speculation, onto which you have heaped additional (speed) speculation. What is "known" is the 3nm separation a/c from "flight path"
(per BEA).
(per BEA).
Last edited by DJ77; 16th Jul 2009 at 07:52. Reason: Smily added
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Sorry I didn't have the time to read all the thousands of posts prior to commenting. You folks are a bit testy.
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Anut and other newbies to this thread: If you can't find the time to slog though all the posts on this thread as many of us have, then please do a search of posts with a keyword that interests you. You, for example, might do searches on Vertical Stabilizer, VS and Rudder.
GB
GB
AircraftNut;
Well then, ask yourself why you feel that way after just one post. A lot of people here have done a lot of work with a great deal of varied expertise and thought behind their contributions. They are no more special than anyone else except they have put in some time reading what others have said. You put the word "experts" in quotation marks. That is disrespectful to those here who, like yourself, have both a long list of qualifications and lots of experience to speak from. The contributors here who post the most useful and helpful information do their research first or they are reminded, sometimes politely even, that this is a serious discussion with some 3600 contributions which just may have touched upon the obvious items you posted. I hope this is of some help. The place is definitely worth the effort.
Thanks. I don't feel very welcome among all of these "experts".
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Review the Thread
Excellent advice Graybeard and my addition to this advice is to review the thread very carefully. Even after careful searches of "fortes turbulences," I missed that my question had been asked and answered. I had a lingering concern in my lurking mind regarding the purported report by the crew of strong turbulence (not mentioned in the BEA report) and that the auto thrust was disengaged. After Takata's response, I went back and indeed I had assumed the crew report was from an original source---it was a media quote allegedly made by a BEA official.