Simplest ideas are usually the quickest to deploy, and often the most reliable.

Place one or more blocks of bog-standard marker dye under seats or behind panels.

The passenger compartment invariably breaks up on striking the sea surface or is crushed by depth pressure, thus exposing the dye to water and starting a trail in the sea current.

Any airline could do this right away as a voluntary measure. Very little design required, no airframe changes, no type approval or certification.

The extra weight? Probably no more than a couple of bottles of booze.

Sallyann1234,
Do you know any technical details about the stuff (I don't, which is why I ask)?
How much would you need for a really big stain that persists for a couple of days in a heavy swell?
And wouldn't it be affected by wind and current in the same way as debris?

And talking debris, how often does an aircraft end up in the water without leaving at least some debris on the surface anyway?
In the case of AF447 there was an entire tailplane... it still did not help in finding the sunken wreckage, leave alone the FDR and CVR.

CJ

I hope the Brazilians have finally gotten around to doing the forensics on the bodies. This would give some idea of the speed at impact, and what happened to the fuselage, and what to look for. My guess is the speed wasn't that fast and the plane broke into several large chunks.

To give you all an idea of what is being sought, this is how small the FDR is.....

This one is still attached to the ROV that recovered it.http://i23.photobucket.com/albums/b3...lack_box_c.jpg

HamishMcBush,
Even shorther than some I've seen and handled......
Do we know the type of the FDR on AF447?

This is assuming the FDR broke free of the fuselage which it probably didn't. That's why they couldn't hear the pinger - it is enclosed in a piece of the plane which is lying on the seabed, like the Titanic.

In response to the following:-

-@UA
-Juste wondering if you could comment about the order of magnitude of the -cost involved in operating such vessel ? Also what would be the typical -mission for this type of equipment ? Telecom cables ? (very) deep offshore -rigs ? scientific ?

Not willing to go into costs at this stage other than to say that the whole spread (vessel, WROV, deep tow sonar & personnel is considerably sub £100k per day.)

Typical workscope for such a sonar spread is pretty much as you state above, scientific, deep wreck search, deep telecoms cables, pipeline route survey, not rig related however at those depths.


-@UA
-I don't know either, whether you can comment on some of the issues?

-Do we even know where the debris field is?

-What's the resolution of the sonar? How easy or difficult is it to distinguish -a piece of 'man-made' debris from the rock next to it?

-It's unlikely the FDR and CVR were thrown clear from the rest of the -wreckage... more likely they're still stuck in some of the aircraft structure. -So much the same question... you're not looking for rectangular boxes, but -for the most likely parts of the wreckage. Can the kind of sonar you mention -find those?

-You obviously would not send a ROV down until you had at least some kind -of target, no?

A working group is currently in place to identify the search area.

Typically, given the length of cable behind the tow vessel (upto circa 10,000m) a series of runs will be made within a box, once the box is complete any targets identified by the sonar passes will then be investigated by the WROV.
It is not a case of differentiating between simply 'black boxes' and rocks, any wreck be it aircraft or ship will leave a debris field, usually over quite a large area. Such an area would be rather obvious and would warrant further investigation with the WROV using both video and hi-res multibeam sonar to map the debris field. Such a hi-res multibeam system can pick out items as small as a coke can.

@christiaanJ
I have seen marker dye deployed from a liferaft during a maritime exercise. The distance that it could be seen from the air was amazing - long before the raft itself was seen. The size and profile of the raft was not too dissimilar to the floating debris from an aircraft.

I'm suggesting that the dye capsule would be secured within the airframe, so that the marker train originates from the seabed location rather than from the floating debris.

I was fortunate to be involved in a conversation with a senior manager at the company where I work today. I am told that the company I work for is putting pressure on the airline industry to update the 30+ year old technology used by the pinger system and to aim to have FDR's use a transponder system, so they will not transmit until interrogated. This will mean that the battery life will increase, to up to 5 years.
We can do with support from those in the aviation industry to take this further, I am sure.

Sally Ann,

Thanks, sounds like another halfway sensible idea worth exploring?

As you said, the equivalent of a few bottles of booze spread through the aircraft might do the job.

Still, I'm less convinced that a "marker trail" from a wreck 4000m down wouldn't totally diffuse before it got to the surface, or wouldn't be so far displaced by currents, that it would not be any rel help.

CJ

But better than no help, surely...

It is simple and probably effective and better than not having that capability, no?

RE: Tracer Dyes. These are often designed so that even if the dye isn't visibile to the naked eye by exposing a sample of water to UV light the dye glows in a way that can be detected electronically.

In this way the dye can still be detected when it is diluted down to levels way below is being visible to the naked eye. In fact in some situations where they are used this is the preferred method. For example releasing the dye into a stream at the start of a cave network and sampling the rivers coming out of the caves to see if they are connected. The locals tend to get funny if you turn the whole rivers purple, hence using dyes at levels to be invisible to the naked eye, but still detectable is standard practise.

So in the AF scenario by taking samples of surface water and testing for presence of the dye over a very wide area you could find traces and focus the search in to the areas with the highest concentrations.

How long would this take in this search?

Agreed. Chemical analysis would not be practical.

I envisage a slick of dye emerging on the surface downstream of the wreckage on the seabed, which in clear weather would be visible to a wide-area search more quickly than pieces of floating debris. It only needs to be there long enough for the first search plane on the scene to record the GPS coordinates of the start and end of the slick, allowing a pretty good extrapolation to the seabed location.

I don't pretend for a moment that this would be foolproof, but it could be a valuable extra pointer to the location of the FDR.

Emergency Buoy
 

How about a really long tether fastened to the fin and fuselage:}

just how long do you propose this lanyard to be?






gs

Guys IT WILL NEVER BE FOUND !

It's in Airbus and Air France best interest for it NOT to be found.

Look at the BIG picture Luke :sad:

Oh come on Flyboy...

If you'd been following the story properly, you'd be already aware of the precursor events, and the amount of neglicence being demonstrated thereby....

Getting hold of the FDR and CVR would at least narrow down the story.
It might even allow the "perpetrators" to blame it all on the crew.

So put some more peanut butter on your tinfoil hat, and let it be.

CJ

Anyone have an idea about in how many cases, say in the last 30 years, the boxes have not been recovered or the data had been destroyed beyond being of any use?

By Simon Hradecky, created Friday, Nov 20th 2009 14:30Z, last updated Friday, Nov 20th 2009 14:30ZA US Airways Airbus A330-300, flight US-740 from Philadelphia,PA (USA) to Madrid,SP (Spain), was enroute at FL390 about 350nm east of Philadelphia overhead the Atlantic about 40 minutes into the flight, when the crew announced they needed to return and was cleared to turn to the left. About 40 seconds later during the turn the crew declared emergency and requested to descend. About another 5 minutes later while levelling at FL300 the crew reported, that everything had returned to normal explaining, that they had experienced computer problems they were unable to resolve and they had been "missing control". The emergency was cancelled, the airplane continued back to Philadelphia. The airplane landed safely on Philadelphia's runway 09R about 75 minutes after the onset of trouble.

Probably the biggest use-case for those ships is as cable ships; there's always a mad dash to charter them when there's a bad cable break. A few years ago, when there was an earthquake at sea in the straits between Taiwan and Okinawa which took out multiple cable systems, there were something like 6 vessels on station at once, and a lot of people hoping nothing else broke for a while.

The two biggest operators are Alcatel and Global Marine Services of London. Which should make the usual suspects wet themselves all over again. didja no it a FRENSH airplane with LIMEY wings?

RE: tracer dyes
 

Just make the fuel traceable. Wouldn't be too hard/expensive to do it.
Even in the event of an inflight breakup it would narrow down the search area quite considerably.

It's been already done when adding specific smell to gas for safety reasons.

NOT a simple idea.

Fuel discharged at altitude scatters over a large area and largely evaporates.

In the case of AF447 there was little trace of fuel. How would a marker within it have helped?

What sort of fuel additive could be produced in sufficient quantities to trace all fuel used in all trans-ocean flights, in sufficient concentration to show up immediately in a search, but without acting as a contaminant at any combination of environmental extremes?

No. A marker needs to be non-consumable, and close to the structure that is to be located.

.. it seems wikipedia already has a list of unrecovered flight recorders, though how complete it is is anybody´s guess:

List of unrecovered flight recorders - Wikipedia, the free encyclopedia

The boxes have been proven crash proof, fire proof and water proof. Making them easier to find in deep waters should be an immediate priority. Of course, retrofitting all airliners with improved pingers, for instance is not an easily accomplished task but what else is there?

Point taken.

Some underwater cameras use a calibrated compressible marker in the event of going under the max certified operating depth for warranty reasons. A simple dye marker bottle with a similar device (frangible in this case) on it's cap, attached to the boxes themselves should do the trick.

If we wanted to spend some good money, it could be possible to use some of the old missile technology, and fire/unlatch a very small and conspicuous boey attached to a thin and long wire from a small box on the exterior part of the plane. It could be used as the beacon antenna . Conditions to deploy it: depth and lack of movement.


There is already a similar system used for submarines today. Example here.

Come to think of it, if you need a marker that's detectable at low concentrations and remotely (for example, from a maritime patrol aircraft), isn't the answer a radioactive substance? It's been done for various purposes.

No point putting it in the fuel for reasons given above. But some kind of structure designed to breach easily could do it. Of course, using teh radiations would run into all kinds of other problems (just think what the chemtrail types would say - or is that a feature, not a bug?)

Posted here as the other threads re 447 seem to be locked. Mods please do as you see fit, just thought it an interesting incident, given possible similarities.

From November issue of Aviation International News.

http://www.ainonline.com/news/single-news-page/article/pilot-suspects-static-electricity-in-citation-x-pitot-failures

Pilot suspects static electricity in Citation X pitot failures

By: Vladimir Karnozov
November 1, 2009

Static electricity may cause pitot static probes to fail, according to a Cessna Citation X owner-pilot who survived a simultaneous failure of all three pitots during a flight earlier this year. Kirill Minovalov, a Russian entrepreneur and private pilot, was flying in stormy weather conditions when the incident happened; he managed to land safely at Moscow’s Domodedovo Airport.

Minovalov, 38, was quick to take advantage of Russia’s economic reforms in the early 1990s. In 1994 he formed Bank Avangard and still serves as its president and CEO. He was urged by the Russian Business Aviation Association to discuss the serious safety incident and spoke exclusively to AIN.

Seven years ago, Minovalov bought his first aircraft, a Dassault Falcon 10, and he has since logged 2,500 hours as a pilot in that airplane and the Citation X. He also owns an AgustaWestland A109 Grand, in which he has 350 hours.

On July 27, Minovalov was at the controls of the German-registered Citation X. Built in 2003, the airframe had logged nearly 2,400 hours and 1,660 landings.

Due to thunderstorms in the Moscow area, air traffic controllers placed the airplane at a rather high altitude, 39,700 feet, over the villages of Sukhotino and Skurygino (22 miles south of central Moscow). At around 1 a.m. the crew was cleared for descent.

The initial descent was rapid, at 5,500 feet per minute, and in between two thundercloud fronts, 25 nm to the right and 40 nm to the left. At around 34,500 feet the Citation X entered heavy turbulence.

A minute later Minovalov and his German copilot saw light shining on the other side of the windshield. “For the first time in my flight experience I saw an electric charge; it was shining brightly like welding [torches]. A golf ball in size, it was sitting on the shroud of the windshield airflow system,” Minovalov recalled. Apparently, a huge amount of static electricity had amassed on the airframe. Its protruding parts, such as the shroud and, quite possibly, pitot probes, were carrying high charges of electrical current, Minovalov surmised.

Thirty seconds later the pitot heater fail left warning light came on. The crew was not too concerned about this since the speed indication remained accurate. But after another 30 seconds the speed-measurement system suffered a complete failure. All three pitot static probes were apparently producing incorrect readings.

The captain’s and copilot’s indicators gave an airspeed reading of some 40 knots, while the standby instrument was on zero. Pitot heater fail right and pitot heater fail sb warning lights came on. The pilots also got an audio low-speed warning at this point.

The incorrect speed reading caused the yaw damper to disengage and issue the warning yd fail–lower. Other aircraft systems responded to the false readings. For example, mechanical limitations for rudder and aileron deflection adjusted to the wrong speed reading.

The Rolls-Royce AE3007C1 engines produced enough thrust, but their full authority digital engine controls (Fadec) reacted to the erroneous speed reading by activating reverse [reversion] mode and generating a fadec rev adc l-r message.

The cabin pressurization system appeared to be fooled by the wrong speed reading. Both pilots sensed bad pressure settings with their ears; it was rather uncomfortable, but bearable. Later Minovalov discovered that control of cabin pressure and pitot heat in the Citation X is linked.

“Having accepted the controls, I felt the yoke and pedals had wrong gearing for the actual speed, requesting very careful handling,” explained Minovalov. A sharp deflection of hydraulically boosted control surfaces might have led to entering dangerous flight regimes or airframe structural damage.

To their credit, the captain and copilot acted in unison, sharing a common view about how to cope with the situation. The crew preferred “vertical speed” mode to “flight level change” in following the flight directors and ATC commands. They focused on keeping airspeed within the safety corridor while descending at some 2,500 feet per minute, once heading, gyroscopic horizon, barometric altitude and descent rate readings seemed correct, and the radio and flight directors remained intact.

“We flew through darkness sparked by lightning flashes all around, no visual reference to the ground,” Minovalov recalled. “There was a strong feeling the airplane had been flying too slowly, and it was tempting to add thrust. But doing so may have resulted in [exceeding] Vne [never exceed speed].”

The crew asked air traffic controllers to keep them informed of their groundspeed. “I did not know what the wind was, but, having information on speed from the ground, I could figure out that, despite the feeling of too low a speed, the airplane in fact flew rather [more] fast than slow.” When the airplane was at 27,900 feet, the air traffic controller reported ground- speed of 397 knots.

The shining ball of light outside remained visible for a minute or two. “I cannot recall exactly when it vanished since I was preoccupied with smooth handling and keeping safe speed, while the siren screamed alarm. But the ball was certainly on for quite a while,” Minovalov said.

The Citation flew in turbulence for some four minutes, getting out of it at about 19,500 feet. Back in stable air, the crew checked the circuit breakers. Then Minovalov tested the system by pressing the yaw damper button. Everything went back to normal and the yd fail-lower light went off. In a split second the system displayed the correct speed reading.

Then Minovalov turned on the autopilot, which also worked. Some warning messages remained on the screens for another couple of minutes and others disappeared one by one. Pitot heater fail lights went off midair, and fadec rev adc l-r at landing. As the airplane taxied to its parking position, no warning lights were illuminated.

The next day essential information about the case–including files from flight recorders–was passed to FlightSafety International and Cessna.

Not an Icing Incident

At the request of the manufacturer, the pilots discussed the incident with Cessna over the phone. It was hard for them to convince Cessna that the incident had not involved icing. “I frequently fly from Moscow, sometimes to Innsbruck [in Austria], and so I know very well what icing is like,” insisted Minovalov.

In his view, the symptoms were different from what would have happened if the pitots had been iced up. The speed readings on all three indicators dropped simultaneously, while icing normally causes smooth changes depending on the altitude. All three pitots failed within a split second and started operating again in tandem. What’s more, there was no rain and the ambient temperature outside the aircraft was -15 degree C.

Minovalov is convinced that static electricity was the root cause of the pitot failure. He believes that a static electricity charge can create a plasma that affects the air flow. Rather than being stuck, the pitot static probes were not getting a rush of air flow, which resulted in all of them having the same incorrect speed reading from the pressure measured on both ends of the tube. Incoming airflow was unable to create a difference in pressure since the plasma prevented it from entering the pitot probe.

Minovalov and his crew were back flying in the Citation X the next day. He said that he had complete faith in the aircraft.

“What happened the previous night was merely a natural phenomenon,” he said. “Static electricity charge and plasma build up in certain weather conditions and naturally disappear when ambient conditions change, leaving aircraft systems intact. In a way, it is like icing: the substance builds up and disappears, and the airplane is fully operable again.”

Soon after the incident the Citation X underwent scheduled maintenance, and all systems were found to be working. Neither the manufacturer nor aviation authorities required any additional work on the airplane.

“After that flight, I began my own research into what happened, this natural phenomenon. I also read much about Air France Flight 447 [the June 1 crash of an A330-200 into the Atlantic Ocean],” he told AIN. “In my view, we experienced the same phenomenon. We both flew in heavy turbulence. The French crew also radioed about static electricity charge. It could be nothing else but them actually seeing a shining ball. There is some evidence that the A330-200’s engines changed mode; in my case the Rolls-Royces went into reversion. Reportedly, the other airplane had also had the yaw damper and autopilot disengaged. It seems to me that the chain of events and the flow of failures were much the same in their case and mine.”

However, there are differences between the two incidents. Unlike the Airbus over the middle of the Atlantic Ocean, the Citation flew over land in the vicinity of airports, with sufficient ATC support. “Seemingly, in my case it was a lot more comfortable, morally and psychologically,” Minovalov admitted. “Besides, it was easier to maintain safe speed on descent than in level flight at high altitude.”

Importantly, the Cessna has a yoke, not a sidestick like the A330. If the speed reading is incorrect, the flight-control system’s gearing in pitch, yaw and bank channels may become inadequate and cause greater difficulties for handling.

It is important to note that speeds, descent rates and altitudes of the Citation X’s troubled flight were typical, much the same in everyday use by many fast jets. This makes Minovalov believe that the same incident could happen again.

The hypothesis that a static electricity charge can create plasma that blocks airflow is something that has previously been considered by pilots, but evidently no one else has yet reported simultaneous failure of all pitots.

Cessna responds: This appears to be an isolated event. We have had no other reports of this type in any of the 305 Citation Xs, which have accumulated some 1.3 million flight hours to date. Extensive maintenance was done on the airplane in an effort to determine the cause of the incident; however, to date we have been unable to determine the probable cause. We have obtained several system components from the aircraft, have subjected them to extensive testing and have not been able to duplicate the event. We are keeping the FAA fully informed concerning the scope of our investigation and our progress.

AF 447 : significant events
 

« The crews can inherit latent conditions created by people far removed in time and space from the event. »

Slideshow: http://henrimarnetcornus.20minutes-b...1981295835.pps

...I would strongly suspect icing of the pitot probes that exceeded the heating capacity of the probe heating anti-ice system...

...but then again, what the heck would I know..?

Just a quick one.

A "transponder" does not have to be located within the "black boxes". Just located in the same vicinity with the same robustness as them to give any potential searcher an idea where to start looking 4000ft under the ocean.

I was told yesterday by people that support the operation of the Rov Homer that if Airbus/Air France/Whoever really wanted to have found the FDR they would have had ships mobilised and in the search area far quicker, and they would have done a deep (c 2000m subsea) trawl with a listening device as first activity

Vague memories of my father doing this a few times. IIRC snag is to have something with a unique signature which is both detectable and which can give a concentration (for tracing currents) a fairly short half life is required. The stuff (mostly a gold isotope) was dissolved and in the sea within 24hrs after it came out of the reactor.

Pilot suspects static electricity in Citation X pitot failures
 

Can someone enlighten me where in the official BEA reporting the AF447 crew radioed about this issue of static electricity? The only reference about this issue I could find in the reporting is flight LH507, a Lufthansa B744 preceding AF447 by about 20 minutes at FL 350. This crew reported that `They saw St. Elmo´s fire on the windshield on the left-hand side.´

I have checked Appendix 3 of the BEA Interim report which contains the AF447 radiocommunications transcript but it does not mention anything about static electricity.


Regards,
Green-dot

Re: Pilot suspects static electricity in Citation X pitot failures


Interesting. I wonder what paint formulation/type/manufacturer was on that Citation compared with the AF A330.

Also, if the theory is correct, than it wouldn't really matter which make of pitot-tube were fitted.

Guys get it through your heads - They will Never find AF447 A330

Its not in Air France or Airbus "BIG PICTURE" best interests to do this

Quite a sweeping statement to make Flyboy.

I suspect though, it will be in the best interests of all pilots & air passangers world wide to discover what happened to AF447.

Makes sense MATELO!

BEA communicate
 

Hi,

Information, 07/12/2009

Pprune ref:
http://www.pprune.org/rumours-news/3...yday-call.html

"Quite a sweeping statement to make Flyboy.

I suspect though, it will be in the best interests of all pilots & air passangers world wide to discover what happened to AF447."


Indeed it is.