Bearing in mind the limited width of the ITCZ in the area of AF447's demise, and given the considerable range (air to air) for a high altitude loitering Zephyr drone, it should be possible to keep the drone out of any nasty weather's harm's way (see below). For polar duty, the "out of season" lack of insolation could well be a downing discrepancy for any solar-powered winged beastie. So for high latitude on station polar radio-relay duties, a helium-filled solar-powered (and -thrusted) blimp may prove to be a better solution. This one see link is capable of months on blimp-station at 60,000ft. Its solar panels can be on its sides.
.
The ITCZ is a region of light winds, which lends it the name the doldrums. The convergence of the Southeast and Northeast Trade Winds, within the doldrums, creates a zone of Cumulus clouds and attendant shower activity. Cumulus clouds often build up to great heights. Aircraft reports have estimated tops of Cumulonimbus to be as high as 12,000 m. The ITCZ varies from 20 miles to as much as 300 miles in width, and typically has an undulating conformation.
.
Seasonal Meandering of the ITCZ. We are interested in the ITCZ because, under certain circumstances, tropical depressions on the ITCZ intensify to hurricanes. It may seem puzzling that the ITCZ can produce cyclones, when the Coriolis force is at its weakest near the equator. The answer to this puzzle lies in the fact that the ITCZ is not stationary on the equator, but migrates north and south with the seasons. The ITCZ moves north during the high-sun season of the Northern Hemisphere, and south during the high-sun season in the Southern Hemisphere. These movements are not perfectly symmetrical above and below the equator, because of the influence of land masses, among other factors.
http://www.newmediastudio.org/DataDi...ITCZ_fig02.jpg
.
from this link

Everybody talking at once......avoiding that annoying superheterodyne squeal
 

Murphywasright addressed the problem of mutual interference if aircraft were to be broadcasting their data on the one V/UHF frequency. This has been resolved within "link" technology. i.e. no mutual interference. I imagine that it utilizes the same (or basically similar) handshaking protocols used to avoid interference/data collisions on the internet's pipes.

In principle you are right. The problem is that the ACARS transmission uses low speed data rates and consequently occupies a narrow bandwidth channel. You will have noted that each ACARS message took on average 6 seconds from initiating until the receipt confirmation was received. A different data protocol and more bandwidth would be required to transfer meaningful amounts of flight parameters even in an emergency situation.

Basic GPS data including position and altitude sent every 10 seconds with the remaining unused period in each 10 second interval used for selected flight parameters would be of use. It should be remembered that the position data is already being broadcast (by most aircraft) on ADS-B, and if means can be found for receiving and recording that data, then the ACARS channels flight data upload can be increased proportionately.

I am not against the promotion of various alternate means to get all or some of this information from flights over oceanic areas, but I am mindful of the BEA's Flight Data Recovery Working Group, and the expertise they accumulated for that project. Change happens slowly, especially when the infrastructure doesn't exist, or where industry standards/protocols need to be changed and approved by statutory authorities.

mm43

Hello mm43.

In emergencies, things need to get simple. I agree with you of course that change can be glacial in the industry.

Nothing focuses one's attention more than execution at dawn. It is tempting to rely far too much on ACARS in this specific accident. It was rather a fluke the data was made public. Without it, the several searches would have been even more broad and haphazard.

A more intensive data link triggered on Pilot/A/C thresholds could of course be route specific, the equipment made modular, and training would be somewhat straightforward. It is too much to ask, even with a fully cooperative roster of players.

Beyond this is the capability of displaying absolutely essential flight data to the cockpit as well. No offense intended.

bear

Weewinkywilly, there are some nice HF transmission tools that chiefly work via NVIS, Near Vertical Incidence Skywave. This depends on common properties of the ionosphere over the HF spectrum. It can be reduced to virtually a telephone technology using ALE, Automatic Link Establishment. It is claimed the military squeezes as much as ISDN level bandwidths out of HF, 128kbps. Link establishment time is small. And for data transmissions of low data rate aircraft information these might do well.

Again, two problems exist, frequency allocations and polar regions.

Frequency allocations can be squeezed out, perhaps. While HF broadcasting is in severe decline squeezing out more bands for amateur radio has proven very difficult. Were these inactive or no longer needed HF broadcasting frequencies no longer needed obtaining new ham bands should, logically, be easy. So I suspect this will be a serious problem even for aircraft safety issues. A lot of frequencies will be needed and significant weight additions for the new transceivers, antennas, and computers will exist. These can all be dealt with.

Polar regions remain the tough spot. I am not well versed in the ionosphere's configuration at the magnetic poles. I'm not sure it has been studied. It WILL be vastly different due to the interactions with the Earth's magnetic fields. And we have auroras in the polar regions. Auroras shred and spread signals. Most transmissions, AM, FM, or CW sound more like they've been fed through something for audio like shredding is to junk credit card offers. SSB works, in so far as it is "understandable", amazingly so compared to CW. AM and FM are generally unintelligible unless the power is very high. Since SSB can get through that suggests that somehow data should be able to get through at about the bit rate for vocoded speech, 100 to 200 bps, using brute force techniques. Maybe an off the shelf technology to deal with it exists. I'd expect it still would be classified if it does. How many wars do we fight in the polar regions?

Maybe this can be done. But the proposal needs more polish performed by people with more current experience with recently unclassified systems than I have at this moment.

From the NTSB/Rudder thread, a question for 330 pilots. RTLU fail/prior limit is reported as 7.9degrees, full sweep, by inspection. The Limit in a/s> 272knots is the last one before Law switch, but even at 4degrees each direction, with no modulation of rate of deflection, and a fully powered Rudder, what is the effect of rapid cycling of Rudder: at m.82, at m.82 with a stop @4degrees, and with a 7.9 degree deflection (stop to stop) ? Under what conditions would the Rudder be used at that velocity?

JD-EE, For purposes of this discussion, and a proposed fit of enhanced Comm over areas of low likelihood of FDR/CVR recovery, wouldn't ice be considered a similar deck as land?

If you are referring to the AF447 rudder, the recovered RTLU provided a limit function based on a +/- deflection of 7.9° either side of the centered position, i.e. a total "sweep" of 15.8°.

http://i36.tinypic.com/2zi4im1.jpg

The best description on the design criteria and in service use I have seen can be found at:-

http://pilotlab.net/aircraft-manufacture/airbus/rudder-loads.pdf

mm43

mm43

Thank you for the link, it is most helpful. Help me with some nomenclature if you would. My reading of both the second report and the initial one tells me that "Rudder Angle" (a singular) to me has historically meant the angle between the longitudinal line of the Fuselage and the angle described by the Rudder face.relative to same. Sweep describes the arc between stops (or input, as the case may be. They are two different things. The Graph likewise shows a ~4degree angle consistent with RTLU default after Law Change for the assumed speed, 272 knots. Since the angle available on each side is certainly not necessarily utilized, the descriptor it seems to me would relate to a single condition, (deflection) independent of (though certainly made possible by) the restriction (Mechanical stops). Here to learn.

bear

Rudder travel
 

Doesn't the A332 have a larger VS than the A333? (due to the -200 being shorter ie to provide the same stabilising moment). Is the rudder the same between the -200 and the -300, with the same deflection limits? or is the rudder larger on the -200 with different deflection limits?
thanks
Ian

Bearfoil

I'll get back to you on the substance of your question, but I think you should have a look at the FCOM for the A330. You can download it, or just view it at:-

A330 - Flight Controls

FluidFlow

I haven't got the precise dimensions of the V/S for the A333 series, but am aware that the height of the A332 V/S is about 55cm greater than the A333. The rudder limits are the same, and I am assuming that the rudder area has been varied to match the different V/S designs.

mm43

Thanks, I look forward to your reply. Meantime, and without the "Bird", a pilot has no heading (crab) reference, and if Rudder is used to return 447 to "En Ligne de Vol," he has a critical need to know the response his control input has had. Should he stop too soon, or too late, the Rudder gets rapidly out of sync with the Fuselage direction, and each subsequent Rudder input puts the machine more out of whack, until shock loads rip off the VS. This assumes that the Rudder has mechanical stops, but no rated deployment; the Rudder slams to its stop each time he applies any Rudder at all..And below 272 knots, as 587 shows, the engines are scraped off.

Bearfoil, "JD-EE, For purposes of this discussion, and a proposed fit of enhanced Comm over areas of low likelihood of FDR/CVR recovery, wouldn't ice be considered a similar deck as land?"

Ice is going to be very pure water, which is an insulator. It will have a different dielectric constant. So there will be some reflection. It also is not a very good insulator so there will be dissipation. I do know that you can speak by radio, sometimes. from Antarctica to the US on amateur radio. But that's using techniques for low angle radiation rather than NVIS, which has a design range of a couple hundred miles. In practice it works fairly well from ONT up towards Portland, Or. and Seattle at night. In the day time other modes with far longer ranges seem to predominate. But there will always be a workable frequency for NVIS modes if you have enough freqeuencies available. (And ALE is a good tool for passively discovering this based on control station's beacon transmissions. If you hear something like turkey gobbling on HF when listening for SSB that's ALE.)

My sticking point is that I have absolutely no idea how NVIS works very near the poles. But at those locations working via longer range modes might be workable with several master stations in strategic locations around the world. The South Pole would be miserable to setup. The North pole has a good land ring around it that could support 1000 mile single hop communications in a pseudo-NVIS mode.

I'm not advocating scrapping the idea over the South Pole. I've not heard of any planes having difficulties let alone dropping down there on flights from Oz to South America. So it would be a lot of expense for modest reward. The plane would leave quite a splash on the white surface, I'd imagine. Surveying for it would not be nearly as difficult as the AF447 case.

"the height of the A332 V/S is just under 3 meters greater than the A333"
 

mm43, the difference in VS height is around 50cm, not 300.

kwateow

Thanks for correcting me. I've corrected the original post.

mm43

bearfoil;
Not quite...the PFD and the ND have a full-time (green diamond) "track" symbol on the compasses so that the pilot can compare track with heading (blue triangle) and thus derive drift. Also, there is a full-time wind symbol on the ND, top-left.

Clearly, (when not in NAV mode), in HDG/VS mode the Heading/Track symbol overlays the heading, (yellow lubber line at the top of the ND) and in TRK/FPA mode the Heading/Track symbol overlays the green diamond track symbol and lines up with the green track line, (4th graphic in HDG-VS, 5th in TRK-FPA). One can see the drift in either mode or even if the FD's are off as in this case. In NAV mode, the Heading/Track symbol is removed.

The presentation is visible at all times no matter what mode the FD is in, even if it's off. The bottom graphic shows the relationship between the Bird and the Track.

Here are three graphics which illustrate the symbols:

http://i277.photobucket.com/albums/k...-09_203718.jpg



http://i277.photobucket.com/albums/k...-09_231923.jpg





http://i277.photobucket.com/albums/k..._2010-03-3.jpg


http://i277.photobucket.com/albums/k...-10_005039.jpg


http://i277.photobucket.com/albums/k...-10_005039.jpg


Hope this helps. Thanks for your note on the other thread.

PJ2

Scientific Report from the BEA Drift Group available
 

A report describing the BEA effort to model the tracks of the AF447 debris field prior to the Phase 3 at sea search is now available...

http://www.bea.aero/en/enquetes/flig...oup.report.pdf

PJ2

Thank you for the excellent post and graphic. From memory (different computer), I recall an ACARS entry Re: FPV. Was it not selected and reported by the Flight Computer as unavailable? My assumption then is that the crew wished to select The FPV (bird) due to some need for it, in a cockpit that had become if not unintelligible, at least highly demanding? If flight data was displayed, and serviceable, augmenting the available cues with duplicative data might have been extraneous? The crew would have wanted to simplify the screens and distill the cues to regain control, no? The FPV u/s record fits with a screen that was either too busy or unavailable and a crew who were attempting a recovery from upset? The other possibility would be that the A/P trip happened after loss of control and the pilots may have been incapacitated due to the loads of uncontrolled flight and the computer volunteered an admission of degraded control/available instrumentation?

bear

bearfoil;
You're welcome - glad it's of use. Even though retired, the questions remain engaging.
I wouldn't place too much emphasis on the FPV selection or loss of the information, (which was likely due to loss of other systems). This is a relatively small piece of information which a crew, wrestling with rapidly unfolding occurences and a rapidly degrading situation, would not reach for.
No, I can't see this as part of any crews' thinking. "Screen clutter" is not an issue nor would one resolve this by de-selecting the FPV, (which re-selects HDG/VS).
AFAIK, with one exception, the DMUs do not become "too busy", (over-loaded) and thereby struggle to display information. That one exception is, (and I have seen it), when "Navaids" or "Waypoints" is selected for display and the scale of the ND is on 320nm. If there are a lot of these in the database, the display will sometimes flicker, but I think it is a non-issue in these circumstances.
Abnormal Attitude laws disconnect the A/P at 25degNU, 13degND and 50deg Bank, (if I recall correctly - not near my FCOM at the moment). Such attitudes are a long way from causing an incapacitation of the crew "due to the loads of uncontrolled flight". IOW, while such attitudes are extreme, they are still within the realm of crew controllability, while upside-down or pitch-vertical (up or down), would become a far greater challenge.

In terms of upset, "wings level" would come first, even before pitch, primarily because of the potential for spiral dive if wings are not first leveled. The exception, some will argue, may be in very high pitch angles where a "roll-off" to get the nose down first, may be more successful than a maximum-effort push-over. In any case, the FPV is not the information to be sought regarding these priorities as the primary guidance is attitude (closely followed by speed), in the moment, not trajectory which is what the FPV displays - in short, one uses as much sky as is necessary and available to return to controlled flight.

I think another way to put it might be, these are not moments where fine-tuning the response is a priority and such selections (or even paying attention to) lateral 'g' loads as indicated by the FPV, is not going to happen - unless heavily trained for and often (and we as an industry don't do this), the reaction (once past "startle") is more instinctual than measured.

I believe the crew had both PFDs (horizons) but stand to be corrected given the time that has passed since I read the reports.

Regarding rudders and fins, parts of the Canadian TSB Report on the Air Canada upset is worth reading I think.

Cheers,

PJ2.

bearfoil - in reply to Post # 1847

RUDDER ANGLE
The acute angle between a water or airborne craft's fore-and-aft line and the current longitudinal center-line of the rudder.
Wrong! The graphic shows 7.9° of rudder angle at 272KCAS - the value that is "locked in" (when the flight law changed to Alternate) until slats extension, when it reverts to that available in Normal Law.

The 4.0° angle is that available at 350KCAS and beyond when in Normal Law, and would be the value "locked in" if an overspeed event had resulted in a change to Alternate or Direct Law. The 4.7° angle was included as a reference as to the angle at FL350 and M0.86 / 330KCAS.

Maximum rudder travel is therefore automatically limited as a function of aircraft KCAS to prevent structural overloading. In this respect, the "travel" is the angular deflection from the fore-and-aft line as described above. I haven't seen a schematic for the RTLU, but I suspect that a worm screw driven device creates a "feedback" position that inhibits hydraulic pressure to the operating rams beyond the set point. In this respect, the RTLU position is utilized by both port & starboard rams.

mm43

cc45

Thanks for posting the link to the BEA's extensive report on how they determined the area to be searched during Phase 3. The report is complex and shows the difficulties that were faced in backtracking debris. For those who wish to wade through it, the link to the PDF file is:-

Phase 3 Search Zone Determination Report

Be warned - the file is large - 37MB.

mm43

mm43;
RTLU schematic below.

There are six "stops":

Rudder Pedal Stops - non-adjustable, which limit pedal maximum travel
Pedal Travel limitation unit - PTLU - limits maximum pedal command
Servocontrol input linkage fixed stop - limits masimum servocontrol command
Rudder travel Limitation Unit - limits the masimum input to the servo controls
Rudder Travel Stops - non-adjustable servocontrols stroke-end stops
Rudder Structural Stops - when servo controls are not installed

Note - There is no special stop between the rudder and the structure of the vertical stabilizer.

http://i277.photobucket.com/albums/k...0_143738-1.jpg

http://i277.photobucket.com/albums/k...mechanical.jpg








http://i277.photobucket.com/albums/k...stallation.jpg

PJ2

Thanks for posting the drawings of the RTLU. Turns out the device is similar to what I had envisaged.

mm43

The following is an extract from the Phase 3 Search Area Determination Report:-

On June 2 2009 at 8h16, a possible pollution spot was detected near 30°30.5’W 2°43.4N by the synthetic aperture radar (SAR) on board the COSMO SkyMed 1 satellite.

Figure A7_1 below shows the cusp shaped spot detected, which does not have the characteristic elongated form of an oil spill coming from a ship. CLS and CEDRE experts were not able to understand its origin. Report by G. Hajduch, P. Lozach & F. Collard gives other SAR images with well-identified signatures from ship tracks and oil spills.

http://i37.tinypic.com/1h7ytg.jpg

Figure A7_1

A 330 m wavelength swell (propagating southward) is also visible (the SAR resolution is 30 m). We have seen in chapter II (section on particle trajectories), that the back track (to June 1 at 2h15) of this pollution spot falls (within one or two kilometres) under the plane flight line roughly 10 nautical miles south southwest of LKP (one minute of flight time). This prompted us to check if such a spot could correspond to some kerosene (aviation fuel) released by the plane.

Within a few minutes after release, kerosene spreads on the sea surface as a very thin layer of the order of 1 µm (actually between 0.05 and 5 µm; the uncertainty is large). After 30 hours kerosene will have evaporated and dispersed[26] almost completely: with an initial amount of 50 m3 there would remain (with a 10 knots wind) roughly 0.5 m3 for a SAR detection. The estimated area of the spot on Figure A7_1 is approximately 0.5 km2 and that would correspond to a layer 1µm thick at most. Knowing that some 43 000 kg of kerosene were still in the plane tanks after its 3h 40 mn flight (Rio to LKP), thus roughly 54 m3 (kerosene density is 0.8 kg dm-3), it is not impossible that this pollution spot may be the remnant of a kerosene release by the plane (be it voluntary or not). Of course it is difficult to tell which quantity is precisely involved (it may vary between 3 m3 and the whole 54 m3).

A last point concerns the wind drag on the spot as a whole: generally, 3% to 4% of the wind speed is assumed for oil (CEDRE, 2004). On Figures 25 and 27 we took 0% and 2% respectively (kerosene is light and volatile and has possibly a smaller wind drag than oil). The greater the windage the nearer the back tracked position to LKP since winds were northerly, but the nearest to the plane track is obtained with a 2% wind drag (whence our choice). Over only 30h we could expect a small distance between positions estimated with a 1% drag difference: there is however a 5 km distance (slanted in a SW-NE direction, see Figure A5_2) because the wind was strong then.

We have been unable, however, to relate this pollution spot to any impact point of the plane as determined from the debris and bodies found and the velocity fields estimated (whatever the methods). But, all our calculations, are based on the assumption that the plane hit the sea surface intact (following BEA expertise of the recovered plane remains).

NOTE:[26] breaking waves can drive small droplets into the water column. This process is called dispersion (Lehr & al., 2002)
-------------------------------------

This "oil-slick" can not be discounted, bearing in mind that the modeling which resulted in the Phase 3 Search Area, has so far not provided a result. My initial reaction to this information was that if it wasn't kerosene, it could possibly have been a short-lived algae bloom. Those blooms are more likely to be found in coastal waters where land based run-offs provide nutrients to trigger them.

Machinbird and GreatBear have both postulated (with different reasons) that the crash spot may be closer in to the LKP than had been assumed. Obviously, further research and modeling may bring this oil-slick and its location into sharper focus.

EDIT:: "... experts were not able to understand its origin" - that alone is cause for further investigation?????

mm43

MM43
Thanks! A very interesting piece of information. Logically, droplets of Jet fuel would be emitted by the wreckage for a few days after the fact (and maybe even now) and would rise up through the water before spreading out on the surface to finally evaporate. I wonder if anything was detected at a future date from the same area?. Any evidence of a focal point near the LKP emitting hydrocarbons for a period of days would be almost conclusive evidence of AF447's location..
Detection of any currently emitted jet fuel would likely require a different method of detection, probably a "sniffer".
The BEA 3rd Phase search area determination site was not responding when I tried it over the weekend.

Oil Slick
 

Thanks MM43.
This slick is about 1 knot south of the first possible sighting of A447 debris by a merchant ship on June 5 (which corresponds to the 1 knot north movement of the debris field stated from 7th June). Given a slow release of fuel into the ocean from the tanks, and a 30m resolution, one wonders if some of the black spots in this slick (appear to be darker than the background 'noise') taken 30 hrs after the event are the first photos of debris of AF447? I cant see why the group have rejected this postulate in their report.
regards
Ian
PS. This is a radar image - the darker areas are smoother than lighter areas.

Gentlemen, would there be any information available from the decent profiles from swiss111 and or china airlines 006 that might assist in determining the possible location of the impact. Is it not fair to say that if the crew had no or little opportunity to recover the aircraft that it would most likely have been in a spiral dive, commencing almost as soon as control was lost and most certainly near the LKP. Whilst i know like every thing else that is being explored it only hypothetical, but the "experts" can't seem to find it, maybe this could be considered. It seems to me time and time again during these investigation that big long complicated explanation are devised to try and explain how and why something happened, and when the investigation is complete and the "truth" comes out that it was just the most simplest of things that caused it, i wonder if this isn't the case when trying to look for the place that the aircraft now rests, for me i would have said "start where we last knew where it was and work outwards", all this talk of the wind was doing this and currents was doing that, it flew off in this direction or that direction is just fanatical and has been proven to be wrong, ie. it's not where they thought it should be. South African 295 was located in 16000 ft of water and the "experts" search for 2 months and found nothing the real experts then showed up and found it in 2 days. Perhaps the wrong people are looking.

"Pollution spot"
 

It is highly interesting to note that the Drift Group puts the back tracked position of the pollution spot picked up by COSMO Skymed1 right under AF447's flight path, approx. 10 nm (1 minute of flight) S/SW of LKP. If the pollution spot were indeed to be kerosene, it seems that the Drift Group assumes that AF447 must have lost that in flight, "be it voluntarily (fuel dump?) or not". The Drift Group's logic is based on BEA's assumption that AF447 hit the ocean in tact and that the drift models deployed point the wreckage area all well north of LKP. Remember also BEA's earlier statement that "AF447 has never been south of LKP".

The Drift Group report contains two further intriguing statements, which with hindsight (since in the original search area nothing was found) may point to a wreckage location near the 40nm perimeter of LKP, to the NE of LKP (see also my post # 1383):

One statement is on page 102, under the final remarks of the report: [/SIZE][/FONT][FONT=Verdana]"It is possible we have underestimated the wind drag on human bodies. If so, this would push the wreckage area towards the northeast, closer to Ursulla sighting and to the original flight track."

The second statement is on page 101, under the objective discussion of the different models, where for the INNOMC models it is stated that: "If we add the Stokes drift contribution the crash point is now found outside the 95% confidence rectangle, slightly east of the Ursulla sighting (at 42 nm from LKP, not shown on the Figure). We have excluded this last possibility."

Best,

Dutch

P.S. In my post # 1383 I referred to the overview map of retrieved items on page 37 of the 1st BEA interim report. In the French version there are three items depicted east of LKP; in the English version (same page) there is no trace of those items.

Photo Image
 

Any ideas as to why the supposed slick should have that bifurcated shape ?

The only way I can see is the a/c hit hard and quite fast, possibly with one low wing.
Lost a whole wing in a bounce, which altered its trajectory. The wing with its fuel diverged over orders of hundreds of metres (1 or more) from the rest of the aircraft.

There would be fuel at the initial impact point plus two streams diverging.
Subsequent drift and dispersion of these two fuel trails, resulting in the pattern you see, which covers a spectrum up to tens of hundreds of metres (30 hours later?)
:confused:

If this was the case, one could perhaps imagine the a/c direction being from NNE towards SSW ? The smaller pattern to the West would be the separated wing...

If so, it impacted across rather than along the swell?

==== ===== ==== ==== ==== ==== ===== ==== ==== ====

We are now a long way from the current evidence, probably even further from reality, but experiments and computation of a modelled situation could show whether this sort of pattern is likely or even possible.

.. and if so, which direction it was travelling at impact.

Appendix 7
 

Thanks MM43for posting the Appendix 7 extract, I’m surprised it hasn’t provoked more reaction, so perhaps I will start it off.

Having read through the 37mb of pdf analysis, most of it mathematically whey beyond my understanding, I like you am confronted by a credible piece of evidence (Appendix 7), which when you consider the Emeraude re-analysis data (or has that been dismissed) makes me wonder what (or who’s) guidance the searches so far were based on.
I accept your comment, it may be an algae bloom but they in themselves may be generated by an increase in minerals in the area, which when you consider this is almost mid Atlantic and there were few if any other ships around, where did that come from ?

I’m beginning to think there is either a lot of political wrangling going on here or somebody has something to hide.

The autopsies were comprehensive enough when it came to those seated.

As far as the others? There's a large hole in the report, eh? Why leave the other bodies to be a mystery? Inquiring minds want to know.

Brazil had the medical work, then BEA claimed they were sitting on it. When Brazil was queried about holding the medical stuff, what did they say? Wasn't it something like, "The French didn't ask."

I remember commenting on this sometime ago, and came to the conclusion that the items you have mentioned were probably removed from the English version due to them positively being identified as not belonging to AF447. Meanwhile, the French version update got forgotten.

In the rehashed French version of the graphic below, those items are circled in cyan, while there is an item marked "07" in the same color near the LKP. That item has been queried by me in the past, and I am now of the opinion that its position had been mistranscribed by someone mistaking a handwritten 3.66 for 3.11 (or more likely - 3,66 for 3,11), which would place its position close to that of the V/S and other debris recovered on 07 June 2009.

http://i35.tinypic.com/5wyrls.jpg

The Port Outer Spoiler's position is also noted, though I have expressed doubts previously and believe it is the Starboard Outer.

The Pollution Spot is also identified, and I'd make the comment that even though there has been discussion in Appendix 7 on the wind-drag, no mention has been made of the effect of surface currents in the area during the previous 30 hours. The shape of the "oil-slick?" could also be as a result of kerosene escaping under increasing pressure as the remnants of the aircraft sank. I believe the nature of the impact was such that the wings may have remained substantially intact, and the fuel tank bladders though probably ruptured only gave up the majority of the fuel as the aircraft sank. This could well account for the "cusp shape" formed when the kerosene made it back to the surface - bearing in mind that the trajectory of sinking wreckage could be extremely variable.

Having said that, no one has conclusively determined what the surface current was doing in the immediate area of the LKP at or shortly after the crash, and evidence presented in the Report provides tracks for a number of surface drifters, but for different positions and times. The surface currents in this area have been found to be extremely variable and what may happen to similar objects placed in the water at the same time but say 10 NM apart can be "mind boggling".

So in summary, there is nothing to positively identify this Pollution Spot as being related to AF447, and my comments should only be taken as conjecture.

mm43

Because they couldn't reconcile its position with the other backtracked bodies and debris positions.

BTW, a knot is a measurement of speed, i.e. 1 knot = 1 nautical mile per hour.:ok:
The SNA "Emeraude" saga was probably due to some local politics. With regard to the determination of the Phase 3 Search Area, I don't believe there has been pressure on anyone, rather the Drift Group worked to establish what they believed, and with the information they had at their disposal, was the most probable area in which debris would be found on the bottom.

mm43

Exactly MM43. My post was obviously not well written or too succinct.:ugh:
Distance from the slick to where the merchant ship first sighted debris divided by the difference in time = velocity = approx 1 knot = the velocity the report stated on page 5 "After June 7 all the floating remains were entrained to the North by an approximate 1 knot (or 0.5 m s-1) current."
The report basically shows the backtrack could not be done due to insufficiently accurate data for this area so my point was why reject this slick when it fits in with their accurate data although it is in conflict with their extrapolated (ie possibly incorrect and at least inconsistent) model results. IMO they assumed a sudden release of fuel which gave a different expectation so rejected this on an (incorrect?) assumption then also because it didn't fit in with their (inconsistent) modelling. I am not criticising their modelling effort as it was mammoth and they found this satellite image, simply saying they found the modelling was unable to yield reliable results so, on that basis, the slick should have been given more weight.
respectfully, Ian

That seems to be the reason for rejecting the Pollution Spot, though they have offered that it may be as a result of a fuel dump (or implied that). My reaction is that any fuel dump wouldn't have left the evidence the radar produced, and would probably have not been detected. For kerosene to have accumulated on the surface in a similar fashion to that in the radar image, it would be as a result of a sustained leakage on the surface or subsurface.

mm43

I wonder what the buoyancy is of wing less engines. Could it have floated several hours before sinking?

HN39

HazelNuts39, please allow me to add a question, "If the leakage was "slow" how long might the buoyancy of the kerosene have helped the wing to float? (I am presuming that water would replace displaced kerosene leading to a heavier assembly.)

Could the shape of the possible fuel on the surface be a tight right hand turn??

Where?
 

Thanks, mm43 for that graph and your interpretation of the differences between the French and English version.

I’m inclined to see the “pollution spot” as a red herring.

As for the Drift Group report, it is laudable of BEA to put that online, but the only conclusion I can sensibly draw from its 100+ pages, combined with the fact that the search has remained fruitless until now, is that, despite all the modeling, the few real data available at the time of and immediately after the crash do not permit to draw any other conclusion than that 447 can be anywhere within the 40nm radius from LKP except:

1. In the area that has been searched so far, and
2. (very) close to LKP.

The first seems obvious. And I realize that the second one goes against what some other participants in this forum have suggested (e.g. the adepts of a “deep stall” scenario). But I base myself on the 02:14 ACARS Advisory Cabin Vertical Speed message. Assuming that 447 @ 2:10 at LKP was still at its FL350, it took still four minutes of flight from there before the CVS + 1800 ft/min message.

I stand to be corrected, but wouldn’t that imply that the V/S of 447 from LKP until then could not have been as such to make it end up (very) close to LKP.

Wouldn’t mind receiving some feedback on that.

Dutch

This interesting analysis of the Vertical Speed at impact has been published by Matthew Squair - an engineering systems analyst. Well worth a look.

HN39, JD-EE;

I tend to favour a scenario where the main wing spar remained substantially intact and attached to the midships section of the hull. The hull and the wings were of course ruptured, and the time for water to permeate where it could was probably in the order of a minute or two, then buoyancy was lost. Kerosene not already released would continue to do so as the craft sank. Remember, only a limited number of control surfaces were recovered, which would indicate that the remainder were possibly left attached.

mm43