Air France A330-200 missing

[HeathrowAirport]

Well if we put this into context, AirFrance the AIRLINE itself has a message reported of a Short circuit via ACARS from the plane Itself, In Systems (Electronics) Its an abnormal low-resistance connection between two nodes of an electrical circuit that are meant to be at different voltages. This results in an excessive overcurrent limited only by the Thevenin equivalent resistance of the rest of the network and potentially causes circuit damage, overheating, fire or explosion. Now if I read further on in my book, It says Common usage of the term implies a condition arising from failure of electrical insulation, from natural causes (lightning, wind, and so forth)


So the likelyhood could be a Lightning strike, in a storm (Possible, not defineable) and lightning strikes at, this is what can happen; YouTube - An electric pole on fire

[Lamyna Flo]

They told me that the plane suffered a strange turbulence in the region where missing.

What passengers describe as "strange" is often just normal, moderate turbulence or aircraft movement. I would pay attention if the flight crew were making the above statement. Not pax.

There was also a breakdown in the electric system of those screens that show a map of Orta flight for each passenger - and for watching movies where too. They surprise because the sky was clear, without clouds, even with sunlight.

AVOD/IFE systems often have problems. It usually doesn't indicate anything sinister.

Someone can explain what would have happened with the Airbus A330?

If you read back over the last 26 or thereabouts pages of postings, you will see a number of intelligent speculative posts (and a large number of truly idiotic ones) about what might have happened. Nobody, however, can explain what actually did happen until all the facts are in, and even then maybe not with 100% certainty. We just have to wait.

[abc987]

Can I see you know much about airplanes. Someone can explain what would have happened with the Airbus A330?

At the moment, I personally, and hopefully everyone else here, can tell you that, with the current information that has been provided to the public, no member of the public can truly explain to you what has would have happened with the a/c. All that members of the public are able to do is speculate on what has happened, and a large amount of this speculation could very easily, and I dare say with the current information we have likely will, be proven wrong once the official investigations are finished and far more information is revealed. I would also strongly caution you as a member of media, against publishing anything that has not been supported by very credible sources. This is because once something comes from the media, most people will believe it is fact, and that could include people personally affected by this. The effects of informing people based on information that is not independently verified and checked against many sources unless coming from a highly credible one (the government being an example in some but certainly not all countries) can be far further reaching and worse than expected.

[Evanelpus]

I used online translator and not correct! Sorry ...

What does trepidou'e mean?

Can I see you know much about airplanes. Someone can explain what would have happened with the Airbus A330?

If we could do this, anxious relatives wouldn't have to wait months, if not years to find out how their loved ones died.

I'm sure that as a eager journalist you want to have all the answers yesterday. Sadly, no-one knows yet what happened to flight 447, there have been some educated guesses already here, some downright stupid ones too. I'm not going to add to the speculation on this tragic accident, I have attended the aftermath of aircraft accidents and I can tell you that the images will be with me until the day I die. Let's hope the authorities find out quickly what happened.

[Mephistopheles]

On another note, surely in this day & age we should not be relying on seriously out dated HF in some of the most remote parts of the world.
Or at the very least get better equipment-perhaps like the HF in Austrailia since that always has been very clear & easily contactable.
Again, the penny pinchers may be indirectly one of the links in a crash but they as usual will never be held to account.
So how much is safety really worth?

[hellsbrink]

Its an abnormal low-resistance connection between two nodes of an electrical circuit that are meant to be at different voltages.

Not necessarily. A "short" is when, for some reason, you have an abnormally low resistance in a circuit which results in an extremely high current flow almost instantly. Now, a common cause of that is the failure of electrical insulation in a circuit and the increase in current is so much it will cause excess heat which could cause the insulation on adjacent cabling to fail, leading to an overvoltage in a lower voltage circuit as you describe as bare cables decide to touch each other.

The cause of the original degradation could be many, of which an overvoltage from a lightning strike is one, but not the only, cause.

Let's just wait on the reports, shall we.

[jimpy1979uk]

With regards to ELTs on Airbus aircraft. There would have been likely three ELTs on the aircraft. One is fixed, its located in the rear ceiling area of the cabin with an external antenna, its the small antenna in front of the fin. Its controls are located in the overhead panel in the flightdeck. As the aircraft is likely to of broke up the chances are the ELT and antenna still being in serviceable state are very small.

There are also two portable ELTs located in the cabin but these would have to be activated by anyone that could have got to them.

Some information about the ELTs that may have been to this MSN are found here: ELTA : Elt, power supply, satellite transmission, physico-chemical analysis

As for the ELBs on the DFDR and CVR these activate on contact with water. If you want some specs here's a website for the manufacurer of one type of ELB its: Dukane Seacom Aviation Products

[wes_wall]

New information provided by sources within Air France suggests, that the ACARS messages of system failures started to arrive at 02:10Z indicating, that the autopilot had disengaged and the fly by wire system had changed to alternate law. Between 02:11Z and 02:13Z a flurry of messages regarding ADIRU and ISIS faults arrived, at 02:13Z PRIM 1 and SEC 1 faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed. That sequence of messages could not be independently verified."

I have seen this posted several times, but have not seen a reply to it. Would someone explain / comment on ADIRU, ISIS, PRIM 1 and SEC 1 faults.

[clearedtocross]

Elt/elba

There are different variants of ELT's, broadcasting on at least three different frequencies (121.5, 243 and 406 Mhz), the 406 MHz now being fashionable since it is traceable by satellites and can modulate a registered ID and an optional GPS calculated position onto the carrier frequency.

However, there is a big difference regarding crash sustainability to blackboxes like CVR and FDR. The latter do not have to work after a crash, it's good enough if they keep recorded information.

An ELT however must work after a crash only. This means that it must be powered and wired to an antenna which in itself must not be obstructed by large metallic structures (faraday cage) or what's even worse - water.

Even the technically less burdened will understand that it is not so easy to construct and place an ELT that will be working after its holding structure crashed into the water (or into a rock) at a few hundred knots. An ELT is therefore totally useless for the purpose of tracking an aircraft that slammed into the sea. Black Box beacons that will work submerged are transmitting their pings in a way not detectable by satellites or flying aircraft.

However, it is possible and systems are commercially available to track an object (persons, cars, ships, containers, etc.) via satellite (and GPS position) as long as it it travelling. Then, in an emergency, the end of a track would indicate the position of the stricken object.

[MU3001A]

Mephisopheles:

Again, the penny pinchers may be indirectly one of the links in a crash but they as usual will never be held to account.
So how much is safety really worth?

Are you of the opinion that better communications equipment could have prevented this accident?

[aa73]

ITCZ without an operable radar? It has happened...

IIRC, back around the 1996 time frame, an Air France 744 was scheduled to fly the Jo'burg-CDG route. Upon accepting the aircraft, the flight crew noted that the wx radar was inop. After much discussion, the decision was reached to launch, but with a massive wx deviation around the ITCZ. Approaching the line of wx over central Africa, intense lightning was observed. Crew even called up a local control tower which was reporting heavy rain and lightning. Despite large wx deviations, crew ended up flying through a CB. After extreme turbulence and in flight upset, aircraft was diverted to Nice. Structural damage as well as one fatality were the results.

As detailed in book "Catastrophes Aeriens".

[Mark in CA]

Two earlier posts provide some data that I haven't yet seen put together. The timining is interesting.

First, this from The Aviation Herald:

New information provided by sources within Air France suggests, that the ACARS messages of system failures started to arrive at 02:10Z indicating, that the autopilot had disengaged and the fly by wire system had changed to alternate law. Between 02:11Z and 02:13Z a flurry of messages regarding ADIRU and ISIS faults arrived, at 02:13Z PRIM 1 and SEC 1 faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed. That sequence of messages could not be independently verified.

And then this from a weather analysis:

It appears AF447 crossed through three key thunderstorm clusters: a small one around 0151Z, a new rapidly growing one at about 0159Z, and finally a large multicell convective system (MCS) around 0205-0216Z. Temperature trends suggested that the entire system was at peak intensity, developing rapidly around 2300-0100Z and finally dissipating around dawn. From a turbulence perspective, these cold spots would be the areas of highest concern as they signal the location of an active updraft producing new cloud material in the upper troposphere.

If these are correct, it puts the ACARS messages occurring during the most severe convective system.

[starliner]

Failure Mode Analysis

During design and certification it is incumbent upon the manufacturers and agencies to consider an "infinite" number of failure modes and satisfy themselves that systems and software will react to failure modes in a manner that does not compromise the safety or integrity of the aircraft.

Human fallibility will surely miss something along the way, as any software designer will attest. The design response to this is to provide redundancy.

The few data that seems to be emerging here does suggest that here could be a situation where the system responses may not have been appropriate. It is a moot point as to whether human control responses may have been more suitable.

For this reason it is critically important to recover as much evidence as possible.

[peter we]

At the million volt level of lightning, insulators can become conductors.

Air, for instance, is an superb insulator, but put a few tens of million volts across it and it will conduct.

The heating effect is caused by multiplying Volts by Amps to get Watts.

The behaviour of lightning when it strikes is sometimes bizarre.

Which is why all sorts of equipment ( e.g aircraft) are tested in a lightning test chamber.

[jimpy1979uk]

The ADIRUs(Air Data Inertial Reference Unit) provide information such as Altitude, Airspeed and other air data information as well as inertial position which is an independant navigation position for the aircraft, search for inertial navigation on the net and you'll get an idea about what its all about. There are three ADIRUs on this type of aircraft.

The ISIS(Integrated Standby Instrument System) is electronic version of the back up instruments. It contains all the required sensing elements in a single unit to provide similar information to the ADIRUs

Prim 1 is one of the primary flight control computers of which there are three.
Sec 1 is one of the secondary flight control computers of which there are two. These are brains behind the flight control system. There are three laws for the FBW system and these are Normal Law, Alternate Law and Direct Law.

[Geotrash]

Besides that, inside an airplane is a perfect Faraday Cage which is also immune to external interferences.

Not quite correct. A Faraday cage depends on being effectively grounded, which an aircraft in flight is not.

Cheers,
Dave

[Akhenaton]

Facts !

[Quote Aviation Herald]
New information provided by sources within Air France suggests, that the ACARS messages of system failures started to arrive at 02:10Z indicating, that the autopilot had disengaged and the fly by wire system had changed to alternate law. Between 02:11Z and 02:13Z a flurry of messages regarding ADIRU and ISIS faults arrived, at 02:13Z PRIM 1 and SEC 1 faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed.
.../...
The sequence of messages reportedly received via ACARS raises memories of the Accident: Qantas A333 near Learmonth on Oct 7th 2008, sudden inflight upset injures 74 people on board and Incident: Qantas A333 near Perth on Dec 27th 2008, navigation system problem, and turns attention towards the emergency airworthiness directive released by both FAA and EASA, see also EASA issues updated emergency directive regarding Airbus A330 and A340 ADIRU issues.
[End of quote]

Seems to me the most accurate and troubling facts... (But i'm not a pro)

[Loose rivets]

BBC News

"In this area, they saw an orange buoy, an airplane seat, small white pieces, an airplane turbine as well as oil and kerosene.

Shallow water, or light turbine?



Folk should get some idea of the scale of potential power when talking about lightning. The worst scenario could see an aircraft vaporized. The total energy in a mature cell is up there with an atomic bomb. It's just that the the discharge is seldom focused in line with an airborn hull.

Faraday cages, and fiber-optic's immunity, is nothing but wishful thinking.

I know from personal experience, that a 'bolt' can enter an aircraft. The light intensity, once the sheath has been irradiated away, would saturate then destroy the fiber data-lines.

A discharge goes much where it wants. My biggest went in what became a 4" hole in the top of the wing, round the rubber fuel bags, and out a similar hole - in line with the top hole. I'm under no illusion that if the 'bolt' had been more vigorous, we'd have lost the wing in moments.

[H_Pipeline]

I found this very interesting and factual analysis of the weather condition prevailing near the INTOL and TASIL location at the time AF447 would have been flying in the area, I though some would find it interesting. I assume that the author of this analysis is okay to share it on a forum since he made it available on the internet.

Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data

If the link isn't working, try a bit later, it is because the server is too busy, or down...

[Tail Chase]

Shallow water or light turbine

The Brazilian AF press release makes a few points quite clear...
1,) They are not identifying the objects as belonging to AF447...
2.) It wasn't a turbine that was seen floating, but rather a drum-like object....

Cheers
Tail Chase