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-   -   Air France A330-200 missing (https://www.pprune.org/rumours-news/375937-air-france-a330-200-missing.html)

kingoftheslipstream 1st Jun 2009 17:21

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:

pattern_is_full 1st Jun 2009 17:22

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)?

eagle21 1st Jun 2009 17:25

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.

alexmcfire 1st Jun 2009 17:28

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

Dani 1st Jun 2009 17:29

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

grizzled 1st Jun 2009 17:31

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.

Re-Heat 1st Jun 2009 17:31

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

eagle21 1st Jun 2009 17:32

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

Aerospace101 1st Jun 2009 17:34


Trainee (non-commercial) pilot question. So, you get hit by lightning during the cruise, have some electical issues (maybe loss of HF coms) and pressureisation problems. Do you descend into CB's?
Surely, it's like having press problems over high terrain. Do you descend into a mountain? No. Find an escape route...

Evening Star 1st Jun 2009 17:37


Originally Posted by wilyflier (Post 4966464)
thpaulsen,
Doesnt a really big CB punch up through the tropopause? Tops above cruising height anyway

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.

HeathrowAirport 1st Jun 2009 17:38

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.

tsgas 1st Jun 2009 17:39

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

funfly 1st Jun 2009 17:41

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.

Zulu01 1st Jun 2009 17:41

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

Sparelung 1st Jun 2009 17:42

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

alexmcfire 1st Jun 2009 17:43

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

mary meagher 1st Jun 2009 17:44

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.

SeenItAll 1st Jun 2009 17:59

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.

ImPlaneCrazy 1st Jun 2009 18:05

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?

iwalkedaway 1st Jun 2009 18:10

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


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