Air France plane missing?

[Passion for flying]

Thank you for opening the dialogue in this direction. The problem with terrorism is that it is a perversly cowardly act, to make the debate simpler and get away from any kind of racial angles here, Terorists are by all means killers. They kill and so called suicide killers in any shape or form are killers, full stop. There are a lot of gaps on the AF 447 here and we all know that. Unfortunately we will always have to live with a risk of having killers aiming at civil aviation. Now in this case we all can observe an obscure reporting by all elements around France, their timing, their initial speculations, there so called interim report. A killers strike can not be ruled out and I wonder what would it take to render an AB330 inop, not controllable, what would be the minimal device be? Not all of the bodies have been found as we know, so we can not say, uh, we have not found any explosive traces or blast marks on bodies, the same goes for the mostly still not recovered wreckage and of course the ace, the FDRs. How come an Atomic submarine with the most sensitive sensory equipment is unable to locate the wreckage, it is also clear that that kind of sub has depth limitations, but its sensors can go wide and deep. We know also that Pitot failures were not the initial cause. ACARS messages lead us all to start calculating and trying to reading them to a possible conclusive result, we were not able to and, I think others mentioned that here before me, why would AF or any airline post crash release such vital data to the media? Or was there an agenda to do so to point in the "wrong" direction. Journalists must print so they can eat, they are not paid to do serious investigative reporting, a few only of those, but mainstream is under pressure to print otherwise a pink slip is on their desk. I also belive that determined killers, if they then would be organized and equied with some cash can if they then really want stll neak through controls. Airports in my view have become a lot saver but at some places where security is overdone, I suspect the routine can provide failure. Worst, Rio is no Doberman pit...like, say, Dulles Intl where we have to take shoes off and depose our a bit too big After shave, or matches that we wanted to bring home as a souvenir etc. I do no know if it is possible to take a step back and filter all again and take the big mostly probable facts and reassemble, maybe prioritize them 1 2 3 style. But then we will find out that all of a sudden 3 becomes 2 and 1 becomes 3 and that is where I smell a rat. Evan, thanks for your patience and I also do never want to offend anyone, sorry if sometimes emotions come out, this one is sad and something went terribly wrong, condolences again for all the families and loved ones of the victims. SR

Swissair,
Just to give you an alternative to your theory about terrorists causing the crash of AF447, this rather wild speculation is about as good;

What if the crash was a result of a collision causing at least one of the aircraft to become uncontrollable (as with the Embraer and the "Sol" Boeing 737 over Amazon)? There is reason to believe that some non-announced air traffic could be going across between the South America northeast corner and the Africa north west corner, transporting high value illegal goods. Such a flight would not be announcing itself (transponder off, low altitude when within radar coverage near each coast, then climbing to high altitude to fly economically enough to actually make it across). If the transponder was switched off, the TCAS would be inoperative, and not warn other oncoming aircraft of the impending meeting. Whoever involved in such flights would never admit to anything.

This is probably about as far-fetched as a terrorist bombing given the evidence analysed so far.

I line up with everyone else wishing for the CVR and FDR to be recovered. That would provide some real opportunity to build a scenario and understand the accident.

[SYDCBRWOD]

The sub I was on had active sonar, but it was "forward looking", and I don't think it would be sensitive enough to delineate anything "small" lying on the bottom from anything else. More importantly, large naval subs don't go that deep, and don't ask me how deep (classified). Add to that the fact that no-one would want to maneuver a huge sub around those mountains.

Precisely why I didn't mention it. Active sonar fitted to subs is a bit like your standard radar fitted to most aircraft - it will be able to distinguish things that are flying, but the 'picture' it will return of the ground (the equavalent of the sea floor in this scenario) would just be a jumble of shapes. To distinguish shapes on the ground you need a very special type of radar like that fitted to the E8C Joint Stars aircraft. It has the necessary side scan radar (40 foot long) and more importantly the software to enable it to distinguish what it 'sees' on a battlefield.

The equivalent systems in an aquatic environment are sophisticated sidescan sonar units http://en.wikipedia.org/wiki/Side_scan_sonar that to my knowledge are not mounted on SSN's. Even if they were, unlike radar operating in a nice thin atmosphere, Sonar operates in a much thicker medium (water) that can interfere with sonar returns due to changes in temperature (thermoclines) and salinity. As such the sidescan units need to employed much closer to the seafloor - and whilst I respect your point that you cannot tell us the maximum operating depth of a USN submarine,
even the soviet Alpha class with its titanium hull has only been to 1300m depth - its safe to say the french SSN cannot get below this depth without catastrophic results. Given the sea floor can be up to 6000m deep in the search area, that's not much good for any active sonar scan. Add to that topography described as 'mountainous' and any active sonar on the sub will be fairly useless.

[SYDCBRWOD]

And the high profile solid engines? wont they be spotted by ultra secret sensory?

As you seem to know more about what sensors are fitted to french SSN's you tell me if they will be able to find them.

[SYDCBRWOD]

The Turbines are large, alloy and hardened and most probably lie in tact in one piece offering a rather echo........

If you are again harping on about why the french SSN has been unable to find the aircraft then let me offer some reasons:

1. The active sonar fitted to the sub is operating up to 5 km above the seafloor. Sonar returns will be affected by changes in temperature and salinity over that distance.

2. Even if the SSN was fitted with a fairly advanced type of sonar and was getting a solid non corrupted return from the sea floor, sonar only 'paints' an outline of returns from the sea floor. Given that this seach may be from a depth of 5000m's the equivalent would be flying slowly at 15,000 feet at night and looking down for the faint outline of something that may not still be in the shape of an airliner. As such shapes that are easy to distinguish may be the first things recognised - the straight leading edge of a wing, the length of a piece of fuselage, or perhaps if the engine has landed the right way, the circular shape of an engine inlet. Of course these shapes may be disrupted by being buried in silt, or maybe the airframe either wasn't in as good a shape as the investigators think, or it may have broken up further in the water.

3. The search area has many underwater canyouns and mountain ranges. The captain of the SSN is not going to risk damage to his vessel or risk the lives of his men going too close to these.

4. How large is the search area? Hundreds or thousands of square km's? It's not like AF447 just came down in a small lagoon or bay. From the debris recovered on the surface, and using wind and current data the searchers can infer some results, but we are still talking a massive area. Added to that is that the airframe probably didn't sink straight down, but may have floated for a short while, been subject to currents on the surface or subsurface, and may even been able to 'glide' underwater (the USN is investigating remote underwater autonomous vehicles that move by altering their bouyancy and gliding on wings).

When searching for lost shipwrecks it generally takes weeks to months to find them using devices that just aren't on SSN's. And these are solid steel ships that are likely to have largely hung together on their way to the sea floor. This search will take time when they get the right equipment out there (search starts in a few days).

Please get away from the theory that the french sub is there to destroy or protect evidence. It's most powerful tool was its passive sonar arrays - they rely on the pingers to be operating, or if they are operating, for the sub to be somewhere nearby to distinguish the sounds from the background clutter of noise. The sub was unable to find the pingers, so I'd guess it will be recalled or retasked, as any active systems are not suitable for an underwater archaeolgical search.

so where are they?

Somewhere on the ocean floor.

[Evan]

From the Aviation Herald:

At 01:33Z flight AF-447 did forward an estimate of 02:20Z for waypoint TASIL (the BEA states in their report, that that estimate was not provided despite three repeated requests by Brazil's Atlantic control). The position estimates were immediately phoned to Dakar ATC, the receipt of the estimates were acknowledged by Dakar (the BEA states, that Dakar requested such data at 01:48Z as they did not have a flightplan).


On Jul 8th The Aviation Herald received additional information to a possibly related incident. The information states, that data collected by Delta Airlines since 2006 support the theory of blockages of the pitot tubes rather than icing. About 1 in 83,300 flights have been affected by unreliable airspeed encounters since 2006, all events occuring between FL330 and FL400 in moderate or stronger turbulence. All events took place between May and December (none between December and May) and all events took place on latitudes between 3 degrees North and 37 degrees North. See: Incident: Northwest A333 over East China Sea on Jun 23rd 2009, unreliable airspeed.

Q: What is this theory of blockages? Ice crystal blockage rather than icing?

[Window-Seat]

Evan, and there can be very large forms of ice crystals in the atmosphere. As an admittedly very rough form of speed sensor back-up, how about an external flexible strip of metal or composite that could be viewed out a side window or by camera? Even without other inputs, the amount of bending would directly relate to drag and potential lift, while the amount of bending plus atmospheric density would correlate to speed, no? Or perhaps something like that could be incorporated into a refined instrument. I think a piston and spring in a wind chamber would have the potential for sticking, but maybe it could work.

[Theoddkiwi]

Q: What is this theory of blockages? Ice crystal blockage rather than icing?

A really high flying bug or swarm of bees? ..... sorry

[Fear_of_Flying]

What is this theory of blockages? Ice crystal blockage rather than icing?

I find this to be an interesting question, and it's not really explained by the Herald update. Naively, I see the distinction as one between tiny ice crystals in the air "clogging" the tubes being one scenario, and water freezing on contact with the sensors, blocking the airflow that way, as a second possibility. In both cases, we have "blockage", so the term isn't very instructive.

But it is an important question for a couple reasons that I can think of. First, which conditions in the atmosphere could have led to one or the other of these situations? My understanding had been that we were mostly considering icing, supercooled water droplets freezing on contact with the pitot tubes, as opposed to ice crystals in the air. Second, the modifications of the upgraded pitot tubes explained in Evan's post #1100 talk about drainage of water and preventing icing, but not explicitly about this type of ice crystal blockage.

[WhiteKnuckles]

I hate to admit it, but it is gonna be lots less fun following this thread when they find something that rules out most of the possibilities raised. Right now, with the inability of ruling most stuff out, it is more educational as people raise different possibilities.

Since there seems to be agreement that a military sub would be awfully lucky to find the critical stuff on the bottom of the ocean, I'm wondering (again) whether the research vehicles which can submerge to great depths to study sea life wouldn't be a better choice. Too **ing bad the pingers aren't narrowing the search, but is the search by these military subs just a futile delay in the search for the key pieces?

How awful for the families of the people whose bodies are lost forever. Nothing is going to soften that pain.

[Window-Seat]

Without pinging, large military subs in this case are useless.

[SYDCBRWOD]

I hate to admit it, but it is gonna be lots less fun following this thread when they find something that rules out most of the possibilities raised. Right now, with the inability of ruling most stuff out, it is more educational as people raise different possibilities.

Since there seems to be agreement that a military sub would be awfully lucky to find the critical stuff on the bottom of the ocean, I'm wondering (again) whether the research vehicles which can submerge to great depths to study sea life wouldn't be a better choice. Too **ing bad the pingers aren't narrowing the search, but is the search by these military subs just a futile delay in the search for the key pieces?

How awful for the families of the people whose bodies are lost forever. Nothing is going to soften that pain.

Tell you what, I'll rephrase your question and you answer it:

"Is the search for the pingers which are incorporated into the 'black boxes' to assist in them being located and should be operating for at least 30 days after a crash, by a vessel with very sensitive listening equipment
just a futile delay in the search for the key pieces?"

Answer:___________________________________________

[WhiteKnuckles]

Tell you what, I'll rephrase your question and you answer it:

"Is the search for the pingers which are incorporated into the 'black boxes' to assist in them being located and should be operating for at least 30 days after a crash, by a vessel with very sensitive listening equipment
just a futile delay in the search for the key pieces?"

Answer:___________________________________________

This plane dropped out of the sky on 6/1. It is now 7/8. Is that enough of an answer? I'd say "listening" at this point may be past its useful life.

[TeeVee]

and i re-raise the question: how is it that equipment designed to detect that whis is designed to undetectable cannot even locate that which is designed specifically to be detected???

i smell french rat!

[swissair]

Can you share, elaborate further please?

and i re-raise the question: how is it that equipment designed to detect that whis is designed to undetectable cannot even locate that which is designed specifically to be detected???

i smell french rat!

Hi TeeVee, can you share more of our thoughts, your take, your direction on this so far futile search? Thank you.

[SYDCBRWOD]

and i re-raise the question: how is it that equipment designed to detect that whis is designed to undetectable cannot even locate that which is designed specifically to be detected???

i smell french rat!

Or the pingers aren't working - not the first time that has occurred....

Or they are searching in the wrong area...

Or there was a thermocline that deflected the sound...

Now, your proof of this french rodent?