At FL350, if the decompression was rapid the time of useful consciousness (TUC) is 'round 30-60 seconds, dependin' on various factors.:uhoh:

A slower rate would have provided more time fer the crew, provided tha cabin altitude didn't get too high too quickly an' they got their masks on.

Interestin' to note the AF talkin' heads are spinnin' a lightning strike; weather related cause this early in the game...:suspect:

thPaulsen: Your clarification duly noted.

eagle21: It's still a big ocean, but yes, the final impact site may well have been over the Sierra Leone Rise.

Would it be correct to say that if the black box pingers have a range of 2 miles, a searcher would either have to be directly over them at 2 miles range, or at the same depth and within 2 miles laterally? I.E. the slant range would have to be no more than 2 miles total (ignoring the possibility of thermoclines that might change the effective range substantially one way or the other)?

Hi based on a very innacurate position of N6 W29 , I have found the following ships nearby.

http://www.sailwx.info/shiptrack/shi...9.0&radius=300

Ship locations


LEXA MAERSK and ARNEBORG seem to be within 250NM from my assummed position.

Ship locations
is the best I can find, is it possible to get a picture of ship locations when the plane dissappeared?

Even if there is an area of 400NM of CBs - you cannot fly through. Flying through a core of a CB means certain death. Books say: fly around it at least 20 NM. You should never fly over or under them.

If they did - well, then that doesn't put a good light on them. Maybe they lost the radar (because of lightning), as someone already mentioned. It happened to me over Malaysia once and it's not a good feeling.

btw I flew 3000 hrs in the tropics and crossed the ITCZ up to 4 times a day. There is no big problem, you just have to do right thing.

Dani

pattern is full: The answer is yes; you are correct. And, as you also correctly allude to, the oceanic envronment is far more variable and unpredictable compared to the atmosphere in terms of signal propogation.

Having said the above, I reiterate my earlier comment: The recorders will almost certainly be located and retrieved.

Live Ships Map - AIS - Vessel Traffic and Positions

Check on the nautical maps for depths; vessels updated constantly.


Nearest location - the uninhabited St Peter and St Paul rocks - Saint Peter and Paul Rocks - Wikipedia, the free encyclopedia

Water temperature is around 27-28C in the area at the moment.

Surely, it's like having press problems over high terrain. Do you descend into a mountain? No. Find an escape route...

Yes, a big CB can. Amongst others, Liu and Zipser (Liu, C., and E. J. Zipser (2005), Global distribution of convection penetrating the tropical tropopause, J. Geophys. Res.,
110, D23104, doi:10.1029/2005JD006063.) indicate that this is more common over land, although with a reasonable distribution over the oceans along the equator. Furthermore, the oceanic tropopause penetration is more likely to be nocturnal.

The region of were the wreck likely is unless its nearer to the coast, so Im not speculating were it is, becuase I dont have a clue. However the water pressure at the bottom of the Atlantic is very heavy, something like several tons per inch, about 31 bar, 465 psi, 3100 kPa per 1000ft, looking at the figures thats roughtly would put that plane 2.5 miles down, so surviving it is remotely Impossible, The only things to implode on a person are the lungs and air cavities, and the inner ears. Not the bodies itself, so if you can get a sub down there its recoverable but then with a storm nearby the surface of the water will be mirky, so its likely going to be a few days, maybe weeks.

If looking at that map, its near enought if the wreck has sunk its about the depth of the titanic so were talking about only seven submersibles in the world can go to such depths.

The last AF Airbus to be destroyed because of the threat of lightning was an A 340 in YYZ
( Toronto, Canada)

Dilemma surely is that an instant breakup would have scattered debris over a wide area which would surely have been found by now. Descent required to get everything under water would have required the airframe to hold together and therefore have given time for crew communications. I assume that there are comms if the main power goes off.

Very sad and makes us transatlantic flyers think.

I see everyone talking about a 2 mile range on the CVR pinger , I went back to the Helderberg report and they say 4 mile range underwater and possible to hear via sonar pickup.

They trolled the ocean with a 3-4 mile sonar buoy for 2 months , just in case despite knowing the battery would only last 30 days. Eventually using sidescan they found the wreck.

I would think a submarine dispatched now would find this within a few weeks as their equipment is by far the most sensitive,

South Africa did not have this luxury for the Heldeberg , but still found one recorder and retrieved about 1% of the wreckage at a depth of 4500meters

Aerospace101

Re: the escape route - As an example The Andes terrain has an average height of 13,000ft (Wikipedia) - Most people can function normally at 13,000ft for a long time without oxygen. 35,000ft with nothing but storms below you is a different matter

Sea swell seem pretty calm, 3 feet (1 meter) so I guess some debris must be found floating.
Arneborg tracking map

positive lightning
 

Hajik also refers to the l999 composite K-21 glider brought down over Dunstable; and I mentioned before that the UK Air Accident investigation found that the control rods were melted by the voltage of the strike, a more powerful one than anticipated by current airliner design.

We suspected that the pilots had been flying too close to the base of the cu-nimb. They survived (by parachute after the glider broke up in midair) to testify that they were several miles away from any cloud when struck. This was corroborated by witnesses on the ground.
So you do not have to fly into a cu-nimb to be clobbered.

I hope that designers of composite airliners have studied this report.

Unlikely: Portuguese Media Reporting Text Messages from Plane
 

The answer is, they can't. 900/1900 MHz cell phone signals at 0.6 watts aren't going to make it more than 5-10 miles, or so. Only possibility is if this A330 was equipped with some new system to permit mobile phone use in flight. Such a system would pick up mobile phone signals from inside the airplane, then retransmit them on some long-distance-capable frequency (perhaps via satellite) to some land location for re-injection into the public cell phone network.

Ok as someone with very little experience, what are the chances of a successful ditch into the ocean bearing in mind the current conditions, and how long would the aircraft stay surfaced for if it was successful?

One wonders if the 02.14GMT ACARS transmission which the press has picked upon as news of "an electrical short circuit" could have been triggered by break-up of the airframe? How does ACARS react in transmitting malfunction data? Does it report instantaneously or periodically? If that signal was indeed a symptom of catastrophe then elapsed flight time along track would surely indicate a reasonable initial area to search...which presumably is what the Brazilians are conducting right now. Irrespective, this is indeed a sad and tragic businesss...

iwalkedaway

With no firm evidence yet available, it seems unusual that AF feel able to publicly state the cause at this stage.

Maybe they have information that they have not yet made available to the public?

Regarding ships
 

It's highly unlikely that the watch on a bridge will be looking out for falling aircraft; their view of the sky - from inside - is practically nil.

Having said that you can be pretty certain that all ships in the possible vicinity were alerted quickly and that at the very least their courses would be altered to cross the possible wreckage path. Ships traveling between East Coast South America and Europe are pretty much under the flight path and I would guess that at least twenty commercial vessels right now will have all the crew that's awake on a sharp lookout.

By the way Automatic Vessel Identification System or AIS only works in vhf range.

Message is normally sent via ACARS after several sensors confirm a failure (data are checked by a maintenance oriented system). So the sending of the failure message is not immediate. I would say the possibility of the message being sent during the break up is highly unlikely.

Sparelung:

The flight crew would breathe 100% Oxygen under pressure at FL350. Sure it wont last forever, but longer than the PAX 15mins oxygen supply, and one would think give enough time for crew to find a suitable exit strategy. If the path behind was clear of CB activity, turn around and fly out the way you came in!?

The reports of texts from the plane would not be the first tasteless hoax of this type. Someone was prosecuted in Greece, I believe, for pretending to have received a text from someone on board the Helios 737 that crashed near Athens.

Yeap, in Cyprus, where i come from. It was a foreigner who was at the time living and working in Cyprus, and thought of playing the cruel farce of claiming he received an sms from a friend passenger on the plane that he saw the pilot of the plane turning blue in his face and running towards the back of the plane. And that the passengers were also freezing and that the alleged friend was scared.

Later on investigation prooved that he didn't know anyone on board and he was arrested when he admited the farce.

I think he (or his lawyer) later claimed he was either a lunatic or suffered from depression.

And surely the ACARS would pick up a lot more failures if it was breaking up.

For what it's worth ACARS is a fairly primitive digital system, invented in the 1970's and works in a similar way to Telex.

Flying through thunderheads
 

Responding to messages implying that airliners studiously avoid CBs:
As a scientist and relatively frequent SLF mostly in the US, I'd say that incidental CB penetration is fairly common. I've experienced many episodes over the years, usually at high altitudes when the PF is attempting to stay at the ATC assigned altitude and thread between overshooting tops hidden in the anvil cirrus. The last one was just a week ago over Colorado. As heard on Ch 9 on UAL, a missed ATC check-in led to confusion when the pilot requested a diversion around a CB. We were denied the turn and clipped the convective tower leading to violent updrafts and downdrafts for about 30 sec. Just about every flight over terrain in the southwest or anywhere in the southeast this time of year is a roulette wheel for convective excitement given the volume of air traffic around/over storms, and the Alps in summer speak for themselves. I think the biggest problem could be dry CB tops which don't show up well (or at all) on the WX radar (especially a problem over Africa, I gather). Flying through anvil cirrus or at night, I suspect the PF won't see it until the plane is inside it. Certainly, I have experienced night-time ITCZ CB penetration on the way to Australia where I saw the clouds and lightening prior to the turbulence. Of course, most of these are non-events in terms of fatal consequences (just a little more fatigue on the airframe and PF/CC/SLF nerves), but citing the manuals on CB avoidance doesn't seem to capture the true richness of today's flight environment. As to how CB penetration guidelines or lore may have contributed to today's tragedy, I only speculate, but normalization of deviance can be a killer.
Apologies for the non-pilot post - back to lurking...

To bring some corrections:

The passengers came from numerous countries:

Paris, 01 juin 2009 - 19h41 heure locale
Communiqué N° 5
Air France est en mesure de confirmer les nationalités des passagers qui se trouvaient à bord du vol AF 447 du 31 mai 2009, disparu entre Rio de Janeiro et Paris-Charles de Gaulle. Cette liste a été constituée sur la base des informations fournies par les autorités brésiliennes.

1 Africain du Sud
26 Allemands-Germans
2 Américains- US
1 Argentin
1 Autrichien- Austrians
1 Belge
58 Brésiliens
5 Britanniques
1 Canadien
9 Chinois
1 Croate
1 Danois
2 Espagnols
1 Estonien
61 Français
1 Gambien
4 Hongrois
3 Irlandais-Irish
1 Islandais
9 Italiens
5 Libanais
2 Marocains
1 Néerlandais-Netherlands
3 Norvégiens-Norwegians
1 Philippin
2 Polonais
1 Roumain
1 Russe
3 Slovaques
1 Suédois-Swedes
6 Suisses
1 Turc

Unlike the hudson ditching, the air france ditching into the atlantic would be faced with;
-sea swell
-unstable atmospheric conditions
-night - no visual references
-no immediate rescue

Not the best conditions :(

1 Africain du Sud-South African
26 Allemands-Germans
2 Américains- US
1 Argentin-Argentinan
1 Autrichien- Austrians
1 Belge-Belgian
58 Brésiliens-Brazilian
5 Britanniques-Great Britain
1 Canadien-Canadian
9 Chinois-Chinese
1 Croate-Croatian
1 Danois-Danish
2 Espagnols-Spanish
1 Estonien-Estonian
61 Français-French
1 Gambien-Gambian
4 Hongrois-Hungarian
3 Irlandais-Irish
1 Islandais-Icelandic
9 Italiens-Italian
5 Libanais-Lebanese
2 Marocains-Maroccans
1 Néerlandais-Netherlands (Holland)
3 Norvégiens-Norwegians
1 Philippin-Philippino
2 Polonais-Polish
1 Roumain-Romanian
1 Russe-Russian
3 Slovaques-Slovakian
1 Suédois-Swedes
6 Suisses-Swiss
1 Turc-1 Turkish

Composites and Lightning Strikes
 

In the early to mid 90s I was doing air to air videos for kitplane manufacturers. Glassair in Arlington, WA was one of our clients.

There was great concern over the effects of lightning strikes on composite airframes. When hit by lightning, they often exploded.

The solution was to incorporate a wire mesh into the composite layers.

Glassair was also doing contract research for Boeing at the time.

sottens, re buoyancy and DFDR/CVR.

It's not a stupid question; many safety experts and engineers have suggested and even worked on possible designs.

In essence there are some serious problems associated with a design that would work as intended, and with the requisite VERY high reliability. One simple example of a problem with the concept is that, in order for the recorder to not remain trapped under whatever sturcture or parts or debris it might be underneath, it would have to be "jettisoned" somehow, rather than simply "deployed". That in itself leads to a myriad of additional design, engineering, certification, and other issues. As always, any resultant action is a function of cost versus relative benefit. In this example, there are very few instances where recorders have not been retrieved -- regardless of ocean depth or location -- so there is really no incentive to spend the enormous amounts of time and money to change the current specs.

> how many bars of pressure can the black box take, because were that's situated on
> the aircraft surely has taken it down to the bottom of the atlantic withit, IF being the
> case. That blackbox will crush.

The US specifications, which I think are similar to those in other countries, require that they withstand depths of up to 20,000 feet.

http://www.ntsb.gov/aviation/CVR_FDR.htm

Note also that the NTSB site suggests that the pinger can be received at up to 14,000 feet (2.65 statute miles), though the way the description is written, one could infer that it won't work below 14,000 feet. In any event, a surface ship wouldn't pick up the signal if the box was at a depth of more than 14,000 feet without some sort of towed antenna.

Fly by wire
 

i am a non professional. I would like to know what the role of "fly by wire" could be in lightning storms. Presumably such aircraft have very high protection against electrical surges ? Are FBW aircraft more prone to control problems during electrical storms ?

and in any case this technology might be overtaken by improvements in data comms that allow key data to be copied to a server in a safe location during flight.

Sky says the presidents deliverd the news to the familys.
Its now very much a serch and recover mission.

In answer to the post about a flight not being cleared to avoid and hitting the cb I'd like to add my two cents.

Don't ask for avoidance. Tell them you're avoiding. That's how I do it, and I've never had a problem yet. What they do to reshuffle what they have to reshuffle is their problem - but I'm not flying into a ****storm.:E

location found (sorta)
 

Air France annonce avoir localisé la zone où l'avion a disparu lundi matin, Amériques - Information NouvelObs.com

Rough translation from Google reads:

"Air France announced it has located the area where the plane disappeared Monday morning. The CEO of Air France says that the area was located "a few tens of miles around. Des passagers de 33 nationalités dont 61 Français, 58 Brésiliens et 26 Allemands se trouvaient à bord de l'appareil. Passengers of 33 nationalities including 61 French, 58 Brazilians and 26 Germans were on board the aircraft."