Airbus A330-200

CNN reports reported electrical problems, depressurization, turbulence.

Aircraft are struck constantly, unless there is some other serious mitigating conditions lightning is a non-factor.

Better to focus on the storm they were in.

I agree Edignan - way too much dampening & reduction in all raceways & systems...the systems can dissapate a whopping charge.....in theory though, if this took several very quick strikes, who knows....

we may never know, but something much worse surely had to happen

Driving in to work today it hit the news...Sad & said a few words for them

as an aircraft mechanic, under certain components testing & r & r , procedures is to wear a " grounding " strap.. around the wrist then plug into a fixture in the frame holding the rack, ".. before touching the unit..the new unit being packed in a static free wrapping , even with the c/b pulled & collared.

i have seen many " static discharge wicks " crispy.

is it plausable that the lightning strike overloaded the a/c capitcity to handle a strike?.. yes...might the sensitive avionics systems then be subjected to failure, yes.

~~I'll give the possibility a qualified ...perhaps~~

We beat them up pretty hard before the get out to the fleet, including zap testing each piece of avionics as well as the entire aircraft.

But it is a fly-by-wire....

It has been many years since I was in the lightning biz, but as I recall it wasn't uncommon for 6, 7 or more strikes to "flicker" down the same hot channel. I don't know if cloud to aircraft lightning yields multiple hits like cloud to ground. My best guess (only a guess) is that the risk of multiple hits is reduced but far from non existent. Thus, I bet it is a statistics game. Given thousands of flights a day there will come a time when a "one in a million" comes up. Multiple hits per second might do something unexpected.

I recall a number of times when lightning in one cloud would seem to trigger lightning in a neighbor cloud. While we are in the "one in a million neighborhood" what about two different strikes (remember multiple "flicker strikes" for BOTH) hitting different parts of the plane at effectively the same time. I'm just making this one up, but if it can happen then it might have fields and currents outside the envelope that they designed and tested for.

If I recall correctly the 1985 Delta Flight 191 DFW crash was initially thought to be due to lightning "blowing the fire out" of the engine. (Later the cause was determined to be microburst induced wind sheer.) A "flame out" similar to the initial DFW theories would not explain this crash. But, a jet engine has lots of parts spinning at incredible speeds. Aspirating a lightning bolt during heavy turbulence, rain and possibly hail sounds like a bit of a bitter pill to swallow. I would hate to trash an engine to begin with, but to do it while the body is in an updraft and the wing is in a downdraft sounds like asking for trouble.

Just to set the record straight, I'm not "qualified" to have an opinion. People like Emmett Edigan and others work in the field and know what they are talking about. I worked with lightning many years ago and like to sound like "I stayed in a Holiday Inn Express last night". (If you don't see American TV commercials then don't bother trying to figure it out).

Or, if you prefer, the crash is only 4000 miles SE of the Bermuda triangle. Elvis has been pretty quiet lately and .........

Today is the beginning of hurricane season.

There are currently some big storms in the area where the A330 was flying between Brazil and Cape Verde Islands.

They appear to have been entering the "womb" of the Hurricanes that we hear about at this time of year.
Those babies can be strong enough to do some damage when they grab and shake a plane like a rattle.

Usually a pilot would evade such an area trading extra fuel for safety but there was a wall of storms in their path.

I don't care much for the fly by wire system either.

Jon

I am just thinking about grounding, of which when there is a lightening strike grounding would take care of that in most cases. Away from just the fuselage, how does grounding works for a plane off the ground ? Bloke

GA!!

I have also seen massive green coronal discharges from the blade tips of a hovering Chinook helicopter on a hot sticky Southeast Asia night. Literally rings of fire. They dissipate as soon as the ground wick straps on the aft landing gear touch the ground, but it's awesome sight while it lasts. Chinooks typically build up around 50k Volts of potential after a short hover.

I've also seen the results of an instant discharge by some dummy grabbing the hook while trying to hand guide the helicopter over a sling load. The term getting "knocked ass over teakettle" applies.

Anyway, most lightning strikes to aircraft result in the bolt passing "through" the aircraft on its way to an area of higher opposite potential. The vast majority of modern aircraft are well equipped to handle these. There is always that one in a million, though, as someone mentioned.

I'm betting on the side of structural failure in heavy turbulence, likely originating from a badly secured door. Pure SWAG.

Hooker

Has anyone considered this? Is it possible that a lightning strike entered the cockpit through the windscreen and either incapacitated the the crew or fried some controls on the flight-deck?

There was no communication because they were outside the communication zone. There is about a 3hr gap between the route where there is no radio contact (so I've been informed)...hence the desperation to get to the flight data loggers.

However, the plane did send automatic electronic signals to indicate electrical failure for about 4 minutes.

daffy

One solution to the 3 hr gap would be to fit HF radio as well as VHF radio.

I do not quite understand why satellite communications is not utilised to bridge the gap - after all many airlines are starting to fit GSM radios for passengers!!

Apparently, todays news, the plane sent 24 signals just before it vanished.

Sleepy

What is really astonishing in this tragedy is the fact that now days,in 2009, with worldwide GPS satellites ,spy satellites, hi performance radars and many other devices ,is possible that a 30 meters plane so easy to disappear without any trace !

About the accident cause ,only a blow-up could explain such instant disappearing,I can guess a bomb or a horizontal lighting hit thru the wings ,via winglets,exploding the fuel tanks .

All composite wings should be tested to such an electric discharge ,at least for the future.

The wire system should be replaced by optical glass fiber remote control, not sensitive to electric discharges.

All composite wings should be tested to such an electric discharge ,at least for the future.

The wire system should be replaced by optical glass fiber remote control, not sensitive to electric discharges.

They are, extensively.

And the measures worked out over 50 years of commercial flying are working quite well - thanks for the advice. As a matter of fact we ramped up the levels of testing - again - just about a decade ago.

I will be very, very surprised if this turns out to be lightning.

(Oops! Wrong posting. I am referring to the same guy, but with posting #38)

Good answer, kiddo! Cum ii vremea p-acolo?

Am avut aseara o furtuna pe cinste, mii de tunete,vijelie,s-au rupt vreo doua sute de copaci,vreo douazeci au cazut pe masini,a plouat cu galeata,eu am iesit pe balcon,ca-mi place furtuna, ma uitam cum imi spala masina si ziceam "da-i Doamne cu galeata,sa se ia gainatii de vrabii,dar nu da cu piatra ca-i faci bube "!Acum e soare si bine,25C,ca-n Tenerife ! Unde locuiesti ?Cred ca ne-njura astia daca nu scriem pre limba lor,ce zici ?!

Oricum i-am facut destul trafic tipului care administreaza situl,nu-i asa ?!

Nemesis,

Storms are nice if you are in a safe place like your balcony.

We get storms AFTER washing the car or watering the grass. They just sit back and wait. And then, POW!

Jon

Forget an electrical cause, except for the chance that lightning may have knocked out their radar. The most likely cause for the crash is an F4 - F5 tornado embedded in the 50,000 ft tropical thunderstorm, which they would not have seen if the radar was not working. Back in my USAF days, we flew through one of those 50,000 ft frontal storms in Texas, and we were all over the sky. We used the radar to avoid the worst of the turbulence.

A better possibility

We have only in the last few decades begun adding knowledge to the library on unusual atmospherics.

Just about a decade ago we acquired data on high altitude shears in clear air that no one had anticipated. Some "elevators" running at better than 30,000 fpm!

It has been reported that the automatic distress signals indicated loss of electrical power and depressurization. Sounds like the plane came apart.

What makes this more of a mystery is that there were about 100 other planes that night that flew that same path and were not affected...lightning yes...turbulence yes...dropped out of the sky no...why?

I believe that if the wreckage is ever found and a determination can be made that it will be found that the wiring used on Airbus aircraft up to 2005 was defective and should never have been used on an aircraft. Especially on a fly-by-wire aircraft that cannot be controlled without a functioning avionics suite. Lightning or turbulence might have been the trigger, but cracked/chafed wiring insulation and low level arcing (ticking) was most likely the primary cause of the failure in my opinion. It is my understanding that in 2005 when this aircraft was built, Airbus was still using "KTT" wire in non-essential systems (such as in-flight entertainment systems, etc.). KTT wire is Kapton with two thin layers of teflon. Boeing switched to TKT wire (Teflon, covered with Kapton, covered with another layer of Teflon) for all wiring in 1996 due to problems that had been observed on 737, 747, DC-9, MD-11, MD-80 and L-1011 aircraft which used kapton and kynar insulation systems. This is what is believed to have brought down Swisair 111.electrical fires on aircraft are far more common than most people realize, typically there are around three incidents of small electrical fires a day in the US, typically on older aircraft with a large number of take off/landing cycles. Airbus did not switch to a similar TKT wire insulation system until 2006, a full ten years after Boieng did.

The chain of events probably went something like this:

The wiring that had begun to form radial cracks due to age and vibration in the inner kapton layer, over time the teflon outer layers cold flowed/chafed to the point that there was now an arc path between the wire and the metallic structure and low level arcing to ground began to form a carbon track in the kynar. moisture ingress, either from condensation or a leak would have exacerbated the problem because kynar burns explosively if it has absorbed much moisture from the environment. This "ticking" arcing might have been of a low enough level that the conventional circuit breaker systems might not have tripped. Or if they did, the crew may have reset them. That used to be the standard troubleshooting step, but now the NTSB recommends that if a breaker trips it should be left tripped until a maintenence crew can ascertain the reason for the trip. This recommendation is a direct result of the large number of aging wire caused electrical fires that are becoming more and more common as the aircraft fleet ages. A lightning strike near the electrical fault could have caused an instantaneous flashover that triggered a fire, or the turbulence may have chafed the wire enough for it to arc over catastrophically. If the fire was in close proximity to (or was in part of) the flight control systems, then the pilot might have lost control of the aircraft and it might have broken up from aerodynamic forces caused by sudden extreme control surface movements caused by a malfunctioning flight control system.

Airbus knew of this problem for over ten years but continued to use defective wiring systems because it was cheaper and lighter than the TKT wiring system that should have (and eventually did) replace it.

Any airline still flying Boeing aircraft built prior to 1996 or Airbus aircraft built prior to 2006 is just asking for a catastrophic crash cause by an in-flight electrical fire. Further, I believe Airbus was criminally negligent in continuing to use unsafe wiring systems for a decade or more after they should have known that there was a problem. but they will likely never be prosecuted because the Europeans will circle the wagons and protect their vaunted (government owned!) aerospace industrial complex as they have always done. Boeing at least had the decency to change to a better system as soon as they realized there was a problem and they found a solution. Airbus apparently didn't give a crap, after all, who is going to make them take responsibility for it? Certainly not the European governments that own them.

UPDATE: just as I was about to hit "publish" I saw that there are now reports of a floating debris field being spotted from the air along the likely track of the flight. I expect that they will begin recovering wreckage soon.

http://news.yahoo.com/s/ap/20090602/ap_on_re_la_am_ca/brazil_plane

From the Yahoo article:

"We are in a race against the clock in extremely difficult weather conditions and in a zone where depths reach up to 7,000 meters,"

7,000 meters down, spread over many hundred square miles. The retrieval of the black boxes seems unlikely.

http://news.yahoo.com/s/ap/20090602/ap_on_re_la_am_ca/brazil_plane

Sonsub has a line of Innovator ROV's that can go to to 7000 meters. I know, when I worked there we modified one to do just that. all we had to do was replace the lights and cameras with ones that would go deeper. The rest of the system was fine for that depth. In fact if memory serves (and it may not, it has been a couple years) it was for Petrobras so that ROV may already be in the area.

this is a direct result of an air crew resetting the c/b on a 737 aux hyd pump.. they reset the breaker , the aux pump caught on fire , on the ground, burning the keel and wheel well, before extinghised...

fly by wire isnt the problem in itself.. see f 16..

in today's modern cockpit, with tcas ,wind shear indication, weather radar.. flight plans submitted and approved before takeoff..notams, wea advisories..

catostrphic decompression, coupled with numerious repeated strikes...

coupled with an inferior wiring harness..

well, somebody's gonna want a lawyer.

True, but a fly-by wire system that has erroneous inputs or shorted outputs can cause flight control surfaces and flight instruments to do strange things. This was a problem with early F-16's that used teflon wiring and no alligator grommeting to save weight. the teflon cold-flowed until the wire was in contact with the frame members causing a number of "controlled flight into terrain" accidents because the instruments indicated that the plane was upright but losing altitude when in fact the plane was inverted and diving. the pilot, being disoriented from high G maneuvering tried to pull up based on his instruments but instead did a nose dive into the ground.

my buddy:

has worked on the Airbus for 15 years..same carrier different city...

so i asked some questions:

turns out that the reputation of this airplane not doing well in turbulence & numerous reported cases of injured flight attendants during flight will lead this legacy carrier to mothball the Airbus portion of its fleet . real soon...

turns out the avionics is a good system on the Airbus...fuel and hyd systems are a different story.

this is the same type of aircraft that had the vertical stabilizer shear off in flight..out of JFK shortly after 9/11 . ( wtf !!! ) even if the tail did that. that doesn't explain the elect and decompression failure..but the fwd wall of the fwd cargo pit and the aft wall of the avionics bay are the same bulkhead...

i wonder if something in the cargo bay .... didn't like being jostled around .. or worse

once upon a time...

the Phantom F-4 was used in nam , well some of those airplanes after returning home.. would explode in flight for no reason.. just booommbbb...

turns out that all the high G combat manouvering caused the skin in the fuel cells to crack, rupture the fuel bladder on some models, and dump fuel on to the engine.

the 1st crack i found was 14 inches long... and a gap of , oh .25 inches..

the Airbus, or any commerical aircraft doesn't pull that sort of g's.

: to the f 16 early problems.. is that when the Thunderbirds augured in..?. in the mid 70's ? didn't they change aircraft after that , go back to F-4 for awhile ? but i do get the time line confused.. Blue Angles in F-4's Thunderbirds in F-4's then F-16's.

:someone asked if the lightning could ignite the fuel...

it's fuel vapors that would be the issue...and it's possible that the center fuel tank had some of those vapors..not supposed to.. but the fuel system suckz.

well, that'z about all of the questions i asked about...

hope this sheds some light...

Appreciated!

Anything for those of us not intimate with the aircraft is better than the talking (speculating) heads on the TV.

I personally will be very surprised if it turns out to be lightning......aircraft get hit almost daily......

I agree with you Andy.

I am not expert on the matter by any measure.

But I remember an incidence, few years back. I wanted to fly from Delhi to Mumbai that evening. I had not prebooked any ticket, thus arrived at airport directly and was trying for the seat. All flights were full. Suddenly clouds started covering the sky and the storm started with big ligtenings.

As this continued for long, many passengers cancelled thier tickets, and I was fortunate to get the seat in one of 737.

Air lines also decided to fly. Finally the plane took off with only 9 passengers.

We travelled for about half an hour through all those clouds and lighening. We could feel the trembling of plane and could see many lightenings through windows. I am not sure, if any lightening struck the plane or not, but I why it should not, if something unusual was happening there.

We obviously travelled safely.

Lots of great comments, with being in the lightning protection field for nearly 20 years this post piqued my interest.

As a start, you might want to view the FAA report from 2004 at http://www.tc.faa.gov/its/worldpac/techrpt/ar04-13.pdf

The skin of the aircraft acts as a conductor and faraday cage around the aircraft, that is when the skin is made of a good conductor material. The conductor and faraday cage typically protects the aircraft from catastrophic electrical failure. New composite materials are not as good as the metallic skins. I am not familiar with the A330 design, but others should be able to inform on that.

Nevertheless, aircraft are subjected to frequent lightning test events during development, yet these laboratory setups even when based on data, cannot predict all possilble strengths, numbers and types of strikes. Therefore, statistically speaking, it is still possible for the A330 to have been subjected to an atypical lightning event.

As previously mentioned, communications systems (radios) can experience damage and/or interruption from lightning. This should not cause a catastrophic electrical system failure.

Some reports have leaked out that indicate the aircraft had some major electrical malfunction just prior to its disappearance. With the known local storm, one can easily speculate that lightning can be the cause. However, also realize that just as statistically plausible is the possibiliy of electrical connections becoming dislodged due to "beyond" tested values of physical stressors due to atypical turbulence.

Unfortunately, we may never know the real cause. However, realize that engineers & technicians spend countless hours of evaluation and testing of aircraft against lightning damage and that air travel remains incredibly safe - statistically speaking that is.

By the way, has anyone questioned why the pilot and crew were even in such a storm. I suspect human error will be the ultimate cause in this case.

It could have been hit by a meteor. It has happened to automobiles, and an airplane at 30,ooo feet has an even better chance of being hit by a rock the size of a bowling ball, since the atomosphere has not yet burned it all up.

My suspicion is that the aircraft was flying at 35 thousand feet. The storm clouds ran up to 50 thousand feet.

I suspect that the Captain had flown through successfully similar "fronts", and tried again to do so. I suspect there was a strike of lightening between a Cloud, and the plane, along with severe up and down drafts.

I suspect that the decompression of the airframe happened as the plane was flipped, and at the weakest part of the plane a crack was opened in the fuselage, and the plane simply came apart. First it came apart in the air. Then it came apart when it hit the water. I did see a report of seats afloat, that imply that the fuselage broke apart either in the air, or at impact. We all who are interested in this sort of event are interested in preventing such events and give great sympathy to any who are suffering grief, which may never end.

Could the lightning have ignited the fuel in the wing or is that not possible these days.

i am sure that they will retrieve the black box even if they have to use an old bathyscaphe's to do it

Epke

The French govt have just announced that retrieval of the black box is unlikely, presumably due to the depth and the enormous area that would need to be searched. <The area that we see wreckage in is a very small guide to the area of the sea floor that would need to be searched>

Perhaps a new requirement, Black Box (A) to be ejected before crash! With Flotation collars etc. Balck Box (B) to remain with the aircraft as long as practicable.

We should all be glad the we had no memeber of the family in that aircraft.

Sleepy

The airfoil that I mentioned in my earlier posts was capable of being jettisoned by the flight crew and would float. It had an airfoil design that would allow it to gently fall to terra firma et oceanus.

tropical speed

hi, thanks for that - it sounds like good system.

In the Uk we used to have a Uk wide system which was, theoretically able to pinpoint a downed aircraft within our area. This took in inputs like the one you reported on as well as the floating devices which were water activated.

We used to have a two maps in the UK showing locations of downed aircraft. I had rsponsibilities for the software and hardware for that system many years ago - I suspect that it has ben overtaken my a newer system but have no details.

Sleepy

I'm sure they will want to retrieve the black box.The air line will want to blame the manufacturere of the plane and airbus will want to blame the human error.

It won't matter, Air France is owned by the French government and Airbus is part owned by the French government, I don't see much finger pointing happening because any way you slice it, the French government is the one with blood on their hands.

wherezmabeer

I just hope that you re right.

i have been flying as a passenger for almost 50 years and I do not want to stop now!

Sleepy

Nemesis,

If the the recorders are jected or float away the plane may never be found.

These?

Nice color!

And the silver cylinders on them provide an ultrasonic signal for a minimum of a month.

Data can be transmittted during flight if it is required.

Streamed via satellites.

Mostly military and other government agencies have had the capability since 1979.

Jon

Why should the floating boxes never be found ? They are emitting the radio signals for more than a month if they are supplied with solar cells ,e.g.!

But why not broadcasting online all technical data of the plane with cockpit sounds and images ,even the passengers cabin (why not ?)so that the aeronauthical authorities or the flight operator can monitorize and record all informations ?

This should be the ultimate solution to enhance the flight security for ever.

Solar cells would not survive and the batteries used are more than adequate.

The recorders do not emit radio signals. They emit an ultrasonic ping every second when in the dirt or water so they can be found.

The gold plating, bells and whistles are not practical but are possible. The price to fly would be very high with all the extras.

People know that flight safety is a lot better than any other form of transportation and would fly on the airlines that are less technical and less pricey.

Some planes have telephones at every seat so you know what you suggest is possible.

You can see and hear about a disaster after it happens but some ghoulish people like to see it happen blow by blow. Either way you wont stop it from happening.

Jon

Back in my military days, the C-141 Starlifter contained an airfoil device mounted in the rear crew door that could be either jettisoned by the aircrew upon ditching or automatically deployed upon impact. This airfoil contained a radio beacon that transmitted a distress call on the 243.00Mhz emergency frequency.

I do not understand why this technology couldn't be employed in commercial aircraft and also contain a flight data recorder?

Can, there is a company trying to commercialize it right now. I used the same system on the P-3.

Of course it will require mandates since that is the only way to keep the playing field level.

I worked in the private sector as a ramp rat, and there were times of great beauty, sometimes even comaradare. Much about life is fleeting. My brother once said, "We're all only temporarily, able bodied."

People are funny sometimes. I remember when I was briefly an indoor station agent, as opposed to outside throwing bags, or towing the things around, or fueling.

ROC and snow so heavy you couldn't see anything 6 inches out the terminal windows.

People were actually irate and yelling at me, "Why is my flight delayed!" I didn't really fit in on the inside. "Hey, buddy, take a train.." You can put all the ELTs in the world, black boxes that float, or whatever, and there will be times when the forces of nature will tear a plane or a boat to bits, or sink it no matter what.

Rogue waves, clear air turbulence, crack in some bonding cement, a wire comes undone... NYTimes Reported there was part of the control program that prevented manual override of automatic stall recovery information that could well have been in error, that in a downdraft situation could well have been the cause of the crash.

It is the "inertia sensor" that Hans Weber suspects.

-best report I've read so far was in Tuesdays NYTimes of June 2nd.

I always though it was a good system. And by the way, I believe the airfoil was actually mounted just above the rear crew door flush with the skin of the aircraft on the C-141. It was a long time ago. Other aircraft also employed a similar device. An FAA mandate would be necessary although it would present a significant cost in the construction.

Single word - Cost. Besides, we already have ELT's and other transmitting devices on the commercial and general aviation fleets. How much else must/should be mandated in these days of the highest aviation safety records ever?

Besides that, none of this stuff is foolproof. Case in point:

My company was flying a uranium prospecting mission for a Canadian company in Guyana. The aircraft went missing over triple canopy very remote jungle. Everybody was super-confident we'd find the plane, our two pilots and the Canadian sensor operator in a day or two. Search aircraft were even picking up sporadic ELT signals in a broad area.

Long story short - It's almost a year later and no sign of the plane has been found. Every possible technical and non-technical search procedure has been implemented, including the latest technology military sensors and direct military support, with zero results. The jungle is too thick for a general ground search, though the locals have been asked to keep their eyes open.

Most people do not have a clue how difficult it can be to find downed aircraft, even when equipped with all the latest gadgets. Triple canopy jungle, in this case, that swallow up airplanes without a scratch to the jungle, smoke that will not penetrate up through the canopy, ELT signals that either cannot escape the canopy or propagate out in weird places that just confuse the search effort.

Holy cow, we're still finding aircraft that I helped search for 40 years ago in the Southeast Asia jungles. They're mostly found by people stumbling across the remains and kindheartedly reporting back to the authorities.

Hooker

The recorders or black box is not expected to help in locating the plane (wrackage). It is to trace back what happened before accident and causes of accident.

Correct.

GA from me.

let's use the Boeing 767 as an example:

both fdr & cvr are in the over head in the aft galley...

and the data used is to reconstruct the events.. the location is to facilitate recovery...ie: hopefully the tail is that last to have impact.( hopefully the plane " breaks " at the aft production break.).. along with real time data sent via acars , fadac,systems...typically on the a/c's vhf # 3 comm channel....

So, both of you are correct

Airbus has ACARS and, according to news sources, and that one was sending the codes that represent what was happening.

I have seen and used flight recorder data to diagnose problems related to takeoff and climbout anomalies related to a system that I had equipment on.

Sorry if this is a dumb question.

After all that's been said on here about lightning I still don't understand why an aircraft would be a target for lightning in the first place since it isn't attached to the earth and therefore cannot be considered a route for the lightning to take to ground, can it?

If an aircraft gets hit by lightning, is it that the aircraft just happened to get in the way of a bolt that was heading somewhere else anyway, and so gets zapped because of just being in the wrong place at the wrong time, or are aircraft actually a target for lightning bolts?

The reason lightning jumps from point to point is due to unequal charges being redistributed. The ground is not always involved in the process.

Any object in the sky can be part of the path of discharge especially large metal tubes full of people or cargo. They are a target as they are a path of least resistance for a discharge.

It is when the turbulence of a storm slaps an airplane around good and hard that the problem comes. Strong turbulence is associated with lightning but not always.

Jon

Also all that air moving past the airframe generates a significant charge on it's own, so in theory the plane could be a source of the charge differential as well as the conductor.

I would guess that an aircraft is a better "way down" than going through air alone.....its probably similar to the problem of being killed when sheltering under a tree, the lightning goes down through the tree, till it sees the human being nearby and "hops" out of the tree to strike that person and flow to ground......its simply a lower resistance path....

A safety reminder: If standing on a high-voltage potential vacate the area in very small steps. This will minimize the potential difference between your two feet. I've also been told that hopping out of the area will work but is risky if you should happen to stumble.

I heard on Oz radio this morning that the black box would be in only 2-3000M of water, that would surely increase the chances of retrieving it?

Eh, yes and no. Anything deeper than say 100 meters or so is going to require an ROV or submersible. The current world record for tri-gas sat diving is 1000 ft. More work class and observer/survey class ROV's are capable of 3000 meters than 5000, or even 7000, but such ROV's exist, it is just a question of how much money you want to throw at the problem. Such ROV's cost more to build and since there are fewer of them they can demand higher day rates than less capable ROV's.

Manned submersibles are orders of magnitude more expensive to operate at that depth and there is little (if any) that a manned submersible can do that an unmanned one can't so there is very little reason to risk lives and equipment for such a job.

increased depth is not going to seriously expand the area that needs to be covered (some drifting will occur with currents on the way to the bottom, but you are not going to find anything between the surface and the bottom to speak of. it is either going to be on the surface ot the bottom, so the area to be covered is going to be roughly the same.).

How about this one?

Nereus

Hi Guys,

The important thing, surely, is to establish the cause of the event.

When a tragedy like this occurs it is our joint responsibility to understand WHY it occurred so that we attempt to mitigate that cause and make flying, or whatever means of transport, safer for all.

If it takes a new ROV or the hire of one at considerable expense, so be it. Who foots the bill, we do, all of us. Primary focus being Air France and Brazilian and French governments with possible assistance from the UN and other interested parties, including the major air frame manufacturers, they all have a stake in this.

Remember it is future pasengers that stand to gain from any investigation.

Lets just do it.

Sleepy

Absolutely!

Hmmmm, Pitot problems?

Link here

The memo sent Friday said Air France has been replacing instruments known as Pitot tubes and will finish in "coming weeks." It does not say when the replacement process started.

The plane's "black boxes" may be miles below the surface and investigators are looking for clues in the messages sent from the plane's computers just before it disappeared. One theory: the outside probes that feed speed sensors may have iced over, giving incorrect information to the plane's computers. The autopilot may have then directed the plane to fly too fast or too slow when it met turbulence from towering thunderstorms.

Airbus sent an advisory to airlines late Thursday reminding them how to handle the A330 in similar conditions.

Hmmm, handling icing, and recognizing or being warned of icing conditions are two mightily separate things.

A sophisticated airplane like the Airbus 330 doesn't have any icing condition warning facilities?

Hooker <-- who knows nothing about Airbus airplanes

Yeah, a possible reason they'd be replacing the probes would be some problem with "handling" icing - which *might* mean difficulties with the heaters that prevent freezing up?

*Shear speculation warning.

I finally read the article you linked and, frankly, find it very disturbing.

I can understand problems with icing on pitot tubes and resultant inaccuracies in instrument readings.

What I can't understand is that a functioning Flight Director System should be constantly monitoring and comparing GPS data (flight speed, actual altitude, etc) versus analog data (pitot/static system) and warn the flight crew of any divergence well in advance of any critical failures.

Anything less in today's level of technology is bordering on criminal, IMO.

Hooker

Airlines need to charge customers enough to stay out of the red so they could afford to pay for the recommended non-mandatory upgrades to their fleets.

THIS IS ABOUT AIRBUS AVIONICS:

THEY HAVE BEEN KEEPING UP WITH THE CHANGES.

http://www.davi.ws/avionics/TheAvionicsHandbook_Cap_30.pdf

"Optional" GPS...

I wonder if the downed 330 had one. For trans-Atlantic I would imagine so.

Good read. Thanks.

Hooker

If the airspeed equipment indicated that they were close to stallspeed and they throttled up manually to correct their speed they may have broken the sound barrier and broke the aircraft.

GPS does not provide airspeed. Groundspeed would not be very useful to a plane in a storm, a fast headwind or tailwind.

Airbus is GPS capable. It is included in the Flight Management System Firmware and Hardware.

Jon

Bob Crandall , the ceo of AA " if we raise the ticket price by one dollar..people wont fly. "

paraphrased to the best of my ability to recall correctly