Hot: Air France Jet Missing (AF 447)

Snoopy2 said:
Has anyone seen evidence where this jet was flying straight through the heart of a towering thunderhead? It's not enough to have storms in the area. The updrafts are found in the core of the storm. The only way a severe updraft is in play here is if the plane flew straight into the center of a bad thunderstorm.
Midair break-up seems quite likely here given what we know about the debris field and numerous system failures on the plane.
Question is how does a young jet with an experienced crew become so aerodynamically compromised that it breaks up in midair??
Can't think of a crash where answers from the FDR and CVR were more desperately needed than with this one.
Hope somehow they can be recovered.
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We know very little about the crew. I read the CA had about 11,000tt with 1,700 in type, but don't know anything about the FO and SO. Who knows if the CA was even on the flight deck when it hit the fan?
 
For trivia: many of the pingers are make by Dukane. I know them as the company that made those combination filmstrip/audio cassette players on which we used to watch instructional slideshows back in elementary school. They are are a little bigger than a roll of quarters.

Maybe it is not a good analogy, but it seems like their task of finding the recorders is akin to finding a car alarm somewhere within a remote mountainous county-sized area of Idaho.
 
seagull said:
No, look up what a microburst is (not trying to talk down, but you need to know anyway!). They don't happen at altitude and the only thing dangerous about them at low altitude is not having enough altitude and energy to get through them.
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Yea that is what i was thinking once i posted it. :banghead:
 
lesson1.jpg

A tail of a AF C-141 that inadvertantly penetrated a TS. Good discussion here about TS penetrations.
http://www.nwas.org/committees/avnwxcourse/teachl2.htm
 
Minuteman said:
Maybe it is not a good analogy, but it seems like their task of finding the recorders is akin to finding a car alarm somewhere within a remote mountainous county-sized area of Idaho.
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Someone with a better background in acoustics should chime in here, but if it's a known frequency band to listen on, they can likely hear it from a looooong way away. Sound travels much much further in water than in air.

I don't know what it's like for the USN these days and tasking subs, but I would imagine that a Seawolf or a 688 or even an Ohio could probably hear the thing if they got deep enough and under the thermocline, if there is one.
 
Snoopy2 said:
Has anyone seen evidence where this jet was flying straight through the heart of a towering thunderhead? It's not enough to have storms in the area. The updrafts are found in the core of the storm. The only way a severe updraft is in play here is if the plane flew straight into the center of a bad thunderstorm.
Midair break-up seems quite likely here given what we know about the debris field and numerous system failures on the plane.
Question is how does a young jet with an experienced crew become so aerodynamically compromised that it breaks up in midair??
Can't think of a crash where answers from the FDR and CVR were more desperately needed than with this one.
Hope somehow they can be recovered.
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Very improbable, particularly at altitude.
 
FlyChicaga said:
The pilots of American flight 587 did not think the tail would depart the aircraft through their control movements. I'm not saying overcontrolling is a cause here (never know), but sometimes things occur that nobody would have expected.

I'm actually not to upset about the speculation in this thread, because it's prompting so many quality learning discussions. That's awesome!
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Not likely on a FBW Airbus with envelope protection.
 
tlewis95 said:
Yes
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Possible? Sure, anything is possible. Likely? Not even close!

Have you ever seen the structural stress/strain tests performed on transport category aircraft/ wings? It's amazing the amount of force required to break a wing or wing-box. Keep in mind here, we're talking about a nearly new aircraft.....don't remember exactly, but I seem to think this particular airframe had only several thousand hours on it.....practically fresh off the assembly line.
 
Cruise said:
Possible? Sure, anything is possible. Likely? Not even close!

Have you ever seen the structural stress/strain tests performed on transport category aircraft/ wings? It's amazing the amount of force required to break a wing or wing-box.
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Saw a show on Discovery and the flex on the wings before they broke/snapped was truly amazing and scarry at the same time.

about 2 minutes in....
[yt]pe9PVaFGl3o[/yt]
 
JEP said:
Saw a show on Discovery and the flex on the wings before they broke/snapped was truly amazing and scarry at the same time.
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That's an amazing video! But I wonder what would happen if they applied that force more dynamically, a sudden huge burst. Would it still stand 154%?
 
What did other aircraft in the area report? Surely AF wasnt the only airplane on that track.
 
CaptainCrickettMan said:
That's an amazing video! But I wonder what would happen if they applied that force more dynamically, a sudden huge burst. Would it still stand 154%?
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Probably. Most of them are stronger than 154%. The certification requirement is at LEAST 150%.

Additionally, it is highly improbable to get that much force at altitude due to the low q-factor.
 
Cptnchia said:
Wasn't AA 587 an Airbus? Are you saying that it was an Airbus with no FBW? Do they even make them like that? (Serious question.)
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CamYZ125 said:
It was an A300/A310, right? Were those FBW?
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Nope, the A300/A310 are Airbii that do not have envelope protection via a fly-by-wire control system (they are not FBW).

Their primary control surfaces are moved by hydraulic actuators or hydraulically-powered motors, commanded by cables from the controls to servo valves. Any envelope protection is done by a control feel system and mechanically limiting the control movement. It is essentially an open-loop setup that does not adapt in response to the actual loads encountered.
 
killbilly said:
Someone with a better background in acoustics should chime in here, but if it's a known frequency band to listen on, they can likely hear it from a looooong way away. Sound travels much much further in water than in air.

I don't know what it's like for the USN these days and tasking subs, but I would imagine that a Seawolf or a 688 or even an Ohio could probably hear the thing if they got deep enough and under the thermocline, if there is one.
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It really depends on the sound propagation path - yes sound does travel long distances in water - no sound does not travel in a straight line. The saying is "sound is lazy" in other words the path sound will take is the path where the speed of sound is the slowest or "path of least resistance."

It's not just enough to get under the thermocline (if one even exists.) You might hear something from 100 miles away, but get five miles closer - you won't be able to hear the sound. It all depends on the sound propagation path.

Having a known frequency of the pinger doesn't help directly in locating it - you can't dial in a "frequency" to listen for like you can a radio... however a known frequency or a harmonic will help you with determining if that other ship or submarine is a friendly or not. Most importantly (more relevant in this case) what it will help you with is determining the doppler shift (up-doppler or down-doppler) - it helps you to determine the speed you are closing or opening the sound source along the "line of sound" especially with moving objects like other submarines or ships. Because the data recorder isn't moving - shouldn't be anyway, any doppler shift will be caused strictly by the motion of the receiving sonar array. If there's no doppler, it means you're not getting any closer or further away from the sound source (which means you're sailing a perfect circle around the sound source - which is very unlikely, but the info is helpful (the object is at the center of the circle you're sailing - very simplified) - or you are not moving which is not very helpful - you still don't know how far away the source is - other than you can hear it)

Having the ability to sonar map the bottom helps but unless you can localize the source within a few miles, you'll be looking for a needle in a haystack.
 
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