Missing plane probably crashed in the Atlantic

[d@rk51d3]

Originally Posted by TarJak

No the SMS capability is satellite linked so no need to be near a shore transceiver.

So, your text messages from your mobile are relayed by the plane to satellite? Because your mobile won't do it directly.

[TarJak]

Originally Posted by d@rk51d3

So, your text messages from your mobile are relayed by the plane to satellite? Because your mobile won't do it directly.

That's right. The air to ground comms systems used on airliners are used to forward your SMS.

One system in use here in Australia on Qantas domestic flights is AeroMobile: http://www.aeromobile.net/aeromobile.asp

[Skybird]

No verified information yet, so just some guesses.

1. lightning strike usually is not dagerous for an airplace, since it is pretty much a Faraday-cage and the energy harmlessly dances on the skin and disappears if there is no contact to the ground, you get some scratches in the painting eventually, and that'S it. However, what happens if the plane is struck by two lightnings simultaneously, or a lightening so strong that it travels on and contacts the plane to the ground? Probability says this is a very small chance only. However, it is not impossible.

2. An airliner at FL300 and higher, can soar for around 150-220 km, if all engines fail. That leaves one of the pilots the time to contact ground control.

3. All vital electric systems have 3 and 4 backups. Additional to the engine generators (each engine it's own egnerator), there is the RAM air turbine, and battery. All vital ciorcuits can take over duties from damaged curcuits, the system is designed to be redundant.

I take it as a given that there must have been more happening than just a lightening strike. Whatever happened, it must have happened incredibly fast, leaving the pilots no time to react or to communicate.

So, as often in air desasters, the likely cause of the catastrophe is not a single event, but an unfortunate unfortunate combination of several singluar events, of which each single one probably would have caused no dramatic consequences if happening all alone.

While in theory it is possible, I do not assume that there was a total and complete loss of electricity caused by a normal lightning strike. If it was a lightning strike, than it probably was no "normal" one, but some phenomenon that is extremely rare.

"Software error" I have very high on my list. Or mid-air-destruction by exploding fuel or engine, or explosive cabin depressurization, which still leaves the question of what caused it. My focus is not so much on lightning, but turbulences. Maybe the plane simply lost an airwing that broke away, or the tail, for example. On the other hand the plane was young, and had undergone a routine major maintenance pitstop just weeks ago.

While currently there is being seen a link between the heavy weather zone they were passing, and the accident, this does not rule out that the weather had nothing to do with it - it could have been a bomb, too, so it is too early to rule out terrorism or organised crime.

Doing research at location is difficult, and maybe we will never learn what happened. If the wreck lies too deep in the water, the blackbox maybe will never be found.

[Oberon]

http://avherald.com/h?article=41a81ef1&opt=0

This has a good overview of information. Things seem to lean towards a catastrophic loss of electrical systems such as ISIS and ADIRU coupled with a depressurisation. In the dark, heavy turbulence, no guidance and depressurisation. It doesn't paint a pretty picture. God rest their souls.

[Oberon]

FLASH

Brazillian airforce has reportedly discovered traces of metal. Unconfirmed if this is anything to do with the lost flight.

[GoldenRivet]

Originally Posted by Skybird

1. lightning strike usually is not dagerous for an airplace, since it is pretty much a Faraday-cage and the energy harmlessly dances on the skin and disappears if there is no contact to the ground, you get some scratches in the painting eventually, and that'S it.

yup.. like this image sent to me by a Captain i used to fly with quite a lot looks harmless enough... put it right on a fuel tank or one of the electrical motors responsible for Aileron or Elevator deflection - say that it jams in a full travel position... then what? you just roll or pitch uncontrollably.

Originally Posted by Skybird

2. An airliner at FL300 and higher, can soar for around 150-220 km, if all engines fail. That leaves one of the pilots the time to contact ground control.

unless you use the struck fuel tank scenario... a lightning strike severe enough as the one above makes contact with fuel vapor in a half empty wing and... KABOOM... you have about enough time to think "WTF" before your finished.

Originally Posted by Skybird

3. All vital electric systems have 3 and 4 backups. Additional to the engine generators (each engine it's own egnerator), there is the RAM air turbine, and battery. All vital ciorcuits can take over duties from damaged curcuits, the system is designed to be redundant.

correct, the ram air turbines will manage electrical signal to emergency systems (standby instrumentation, and comms and flight controls generally) but lets say that the primary motor that drives the ailerons or elevators is struck - jammed into a specific position - then what? what if the fuel tank scenario plays out... electrical power means nothing at that point. the fuel tank scenario is rare, it has only happened a couple of times in history... but why couldnt it happen in this case?

Originally Posted by Skybird

I take it as a given that there must have been more happening than just a lightening strike. Whatever happened, it must have happened incredibly fast, leaving the pilots no time to react or to communicate.

Pilots live by a three step process that determines their course of action in a tense situation 1. Aviate First 2. Navigate Second 3. Communicate third.

Im sure your 100% right about the situation happening so fast they couldnt communicate, but the primary focus of any experienced pilot is going to be to fly the airplane first - communicate his plight second... the worse the situation - the more true this becomes. so even if they had a couple of minutes it would not surprise me if they made no transmissions.

Originally Posted by Skybird

"Software error" I have very high on my list. Or mid-air-destruction by exploding fuel or engine, or explosive cabin depressurization, which still leaves the question of what caused it. My focus is not so much on lightning, but turbulences. Maybe the plane simply lost an airwing that broke away, or the tail, for example. On the other hand the plane was young, and had undergone a routine major maintenance pitstop just weeks ago.

While currently there is being seen a link between the heavy weather zone they were passing, and the accident, this does not rule out that the weather had nothing to do with it - it could have been a bomb, too, so it is too early to rule out terrorism or organised crime.

Doing research at location is difficult, and maybe we will never learn what happened. If the wreck lies too deep in the water, the blackbox maybe will never be found.

Im in complete agreement here

[Jimbuna]

This is an hour old:

http://www.telegraph.co.uk/news/worl...bus-crash.html

[Skybird]

Golden Rivet,

as a rule of thumb, pilots and engineers calculate one lightning strike per 1000 flight hours. Another rule of thumb says that each airliner is hit at least 1-2 times per year.

That means each day, wordwide, probably dozens of planes get hit by lightning. Even parked planes get hit, with their tyres on the ground and being in close proximity to it. But when was the last time you heared that a parked plane went up due to lightning? And how many planes do fall out of the air because of it? A lightning strike usually does leave only cosmetical traces on an airplane. Many flights near the equator have to deal with thunderstorms that usually are several times as strong than what can be seen in europe, becasue they are a quite common thing in that region, especially over the ocean. If things like what you picture say were the rules inc ase of lightning stikres, then there must be several times as many air desasters as there actually are. therefore it would be interesting to see the exact circumstance of that lighting causing the damage in that picture. that polanes get struck by lightning is no unusual thing. And mostly, passangers do not even notice it.

The heavy winds and turbulences inside a heavy weather zone like the one the AF flight fas trying to sneak thourhg, can be easily underestimated, and they can shake an airframe so violently, that I find it much easier to imagine that structural damage occured due to such violent pushing and shaking. It can cause material (structure, surface) to break, and it can make hydraulic as well as electric wires breaking, too.

This does not mean that the plane was not hit by a lightning. But it means seen from a statistical perspective probably much more was happening to the airplane. I still see turbulences as the most likely cause for catastrophic damage appearing onboard the plane. tjhat storm front was more than a 1000 km wide and 18 km high, and the passage the weather satellites showed between two centres, had disappeared and united to one giant front at the time the AF flight was passing the area where before that passage was.

But all this is pub talking only. We simply do not know fopr sure what happened. The Brazilians say the Atlantic is 4-6 thousand meters deep where the Blackbox likely was buried, and there are strong currents as well. At 6 thousand meters it is even quersitonable that the radio signal of the box will reach the surface. And when it stops sending in a month or so, and has not been found until then, then it'S over. And even if it is being located, it is no certainty that diving robots will get it up.

Researchers will need plenty of luck to solve this puzzle. It is possible that they succeed, but I don't hold my breath.

[GoldenRivet]

Skybird,

Im not saying your wrong, and i do know that there are thousands of lightning hits per year. but would you argue that it only takes ONE critical lighting strike -out of all those thousands or millions - to make things go ca-ca?

I mean i have seen thousands of lightning strikes in my life time... but i have never been hit by one. does this mean i will never be killed by lightning? no. even though the statistics are in my favor - it could happen tomorrow.

you are absolutely right about the thunderstorm turbulence... the typical figure we go with when teaching it - is at least 6,000 foot per minute up drafts and down drafts - obviously a force that could tear an aircraft apart.

I do agree with you on the statistics of catastrophic structural failure induced by severe to extreme turbulence vs. lightning. but lets think of it this way...

...what if it was both?

in my experience - hard lighting strikes usually affects the aircraft's weather radar pretty badly, probably worse than any other system.

if the flight was operating at night, and their weather radar got fried, seeing and avoiding thunderstorms in the night gets to be an interesting game when that radar stops radaring.

at that point it wouldnt have taken much to stray right into a thunder head.

EDIT: i find it interesting in the article that it mentions the airline had received automated messages of errors and malfunctions in the flight control computers.
hmmm

[sharkbit]

Originally Posted by GoldenRivet

yup.. like this image sent to me by a Captain i used to fly with quite a lot looks harmless enough... put it right on a fuel tank or one of the electrical motors responsible for Aileron or Elevator deflection - say that it jams in a full travel position... then what? you just roll or pitch uncontrollably.





unless you use the struck fuel tank scenario... a lightning strike severe enough as the one above makes contact with fuel vapor in a half empty wing and... KABOOM... you have about enough time to think "WTF" before your finished.

This photo has been erroneously reported as a lightning strike. It was in fact a electrical fire on the ground after ground power was hooked up.

Lightning does cause damage though. Normally airplanes are designed to dissipate the energy. Most of time, there is usually a entry hole somewhere and a exit hole somewhere. These are usually small. You'll usually see the entry on the radome on the nose and the exit up on the tail at the rudder or elevator. Sometimes it wil blow off a static wick or a end cap on a flight control. If an engine or prop gets struck, it will sometimes magnetize the bearings which causes problems and you usually have to replace the engine and/or prop.
None of this is catastrophic though.

We had a Lear 35 get hit a few years ago. It hit the nose, bounced along the top of the fuselage, leaving burn holes in 3 places, and exited the elevator, blowing a static wick apart. No catastrophic damage though.

I think the biggest threat after a strike is the effect it has on the electronics. I'm not familiar with the Airbus, but I bet it is a pretty electronic intensive aircraft. Who knows how bad lightning could have affected it.

My bet is severe turbulence but I would think they can avoid that with the aircraft radar showing returns of severe thunderstorms ahead.
Probably a combination of things, like any other aviation accident.

Hopefully they can recover the flight recorders and figure out exactly what happened.

[sharkbit]

Here's a link about the hole in that ASA aircraft with some good pictures:
http://blog.flightstory.net/1158/pho...rdier-crj-200/

[TDK1044]

I think this is the most likely scenario.

http://news.uk.msn.com/world/article...ntid=147760267

[GoldenRivet]

Originally Posted by sharkbit

Here's a link about the hole in that ASA aircraft with some good pictures:
http://blog.flightstory.net/1158/pho...rdier-crj-200/

neat find!

i was told lightning strike... ah well.

I have seen one as small as a penny or dime, and another about the size of a basketball, both at my home GA airport.

it can be pretty impressive being hit by lightning though!

[heartc]

Originally Posted by Skybird

Or mid-air-destruction by exploding fuel or engine, or explosive cabin depressurization, which still leaves the question of what caused it.

I don't know of course, but that's what I'm thinking. And it might have been from a lightning strike, however unprobable that might be. At some point this happened to another airliner once - lightning struck the fuel tanks and caused an explosion. I've now also heard from the news that the parts of the wreckage are dispersed over a pretty wide area, which would favor a disintegration mid-air at high altitude.

Anything else makes it difficult to see how they were not able to send a mayday call. I know the "aviate, navigate, communicate" rule, but when you are outside radar coverage, over the middle of the ocean in the middle of the night, it must occur to you that reporting your position and status is like EXTREMELY important if you want to provide your passengers with any chance of survival. So if they didn't, either all electrical systems failed, which is somewhat improbable with the high redundancy in modern airplanes, or what happened must have been so disastrous to disable them at once. And that could only be an explosion or catastrophic depressurization.

Even a catastrophic loss of control due to a software or whatever failure with the airplane departing and entering a spin or whatever and the crew trying to recover, doesn't explain why they wouldn't send a radio call while the plane goes down from 11 km. Or they must have gone down like a comet to not make a call while their radio was still working.

[d@rk51d3]

Originally Posted by TarJak

That's right. The air to ground comms systems used on airliners are used to forward your SMS.

One system in use here in Australia on Qantas domestic flights is AeroMobile: http://www.aeromobile.net/aeromobile.asp

Thanks for the info and the link.