The BOAC 707 which crashed in 1966, following an encounter with the turbulence from a rotor off Mount Fujiyama, broke up quite severely. It was the vertical stabiliser which failed first on that 707 - which may have been due to excessive rudder inputs placing too much lateral force on it to correct a sudden upset from turbulence, but this is considered unlikely. The more credible theory is that the excessive gusts and turbulence it enountered were sufficient to overload the fin assembly and cause it to break from sideways force. This theory is credible because the 707's stabiliser had been shown to be able to stand up to 110 percent of the load which the rudder control surface can put on it. However, that is not like the A330 with its powered surfaces; one of the the 707's nicknames is 'the lead sled' because it has little power assistance for the rudder and it is hard work to overload the rudder, whereas at least one Airbus crash has been attributed to excessive rudder inputs overloading the vertical stabiliser and causing it to fail. Another Airbus crash happened when it lost its vertical stabiliser, because a thrust reverser deployed in flight and caused enough yaw to overload the fin.When the tailfin failed on the 707, it smashed into the port side horizontal stabiliser and broke that off, which put the aircraft in a flat spin, the lateral force of the spin caused all four engine pylons to fail and all the engines broke away from the wing. When the aerodynamic loads increased as it spun down, the entire tail section broke away near the rear pressure bulkhead and the nose section of the main fuselage also broke away, with the starboard wing failing upwards but remaining partially attached. The main cabin, with what was left of the wings still attached, came down flat, trailing a cloud of escaping fuel vapour, but this section then pitched down and impacted vertically. Needless to say, there were no survivors.It is hard to really compare the two incidents with anything other than broad speculation - the 707 is largely aluminium, the A330 incorporates many composite materials, so it is difficult to say just how much of a break up would occur, and one aircraft is not going to behave the same as another. Much of that may be able to be determined from impact damage other than that caused by the final impact with terrain, as well as markings on parts and the way things are bent. For example, it is known that the tailfin smashed the left horizontal stabiliser off that BOAC 707, because of paint markings from the tail found on the stabiliser.Incidentally, it is believed the BOAC 707 encountered loads of at least +9G and -4G, in that turbulence, as Navy aircraft dispatched to the crash site to search for wreckage recorded similar exposure to those loads. Having said that, some airliners can take a hell of a beating. One Boeing 727 is thought to have exceeded Mach 1 in an emergency descent some years ago, and although it popped a lot of rivets and bent the wings, the thing survived the incident and landed safely.Al

"Last I checked an A330 or any modern jet flies way above weather. Major storms whose tops reach altitudes of +34,000FT (which would have been where this aircraft was 3hrs into the flight) would have been accounted for long before the aircraft left the ground. There's no way this flight would have been cleared to fly so close to such massive storms with the technology we have today. Now lighting on the other hand has been known to do strange things so I wouldn't rule that out but a bomb is very plausible."Thunderstorms grow rapidly and unpredictably. Having a forecast , or even recent reports is no guarantee for avoidance. Anything accounted for on the ground would be pretty useless 3 hours into flight.I just attended a Faa seminar where the limits and merits of radar, stormscopes, and nexrad composite weather feed (xm weather feed) were briefed.It was interesting watching an atc movie of the traffic flow into kord where airliners were relying on controller info and onboard radar. They showed us what the controller was seeing on his scope. The radar showed a nice hole-however, however a nexrad composite (what an xm feed shows) showed a huge red area (the composite takes a cat scan like slices of the cell and then displays the worst activity in that system-which may not be manifesting yet but could be above you about ready to come down). In the time lapse it was obvious that finally a flight experienced that developing wrath-and then one saw all aircraft turn in mass 180 from the hole and high tailing it in the opposite direction and way around it.The radar continued to show the nice hole.The seminar presenter maintained that many of the commercial crashes of the past 20 years due to microburst, convective activity could have been avoided if the planes in addition to radar had had composite nexrad feed in the cockpit to give the big picture. Scott Crossfields flight was similarly shown (he only had a stormscope). The base radar (and probably his stormscope) showed he was good-the composite nexrad which he did not have showed bad news...By the way-the nexrad you see on wsi, fbo's who use wsi, and the weather channel show the base nexrad-not the composite. (I and all the other pilots at the presentation were surprised to learn this).The presenter of this seminar is trying to get the Faa to put pressure on to switch to composite-but due to their market with boaters wsi prefers to go that route.I had a case flying to Santa Fe 2 years ago-there were pretty severe storms just south of my route. My 496 showed a very small couple pixel cell developing right in my line of flight. I asked for a deviation around it-the controller seemed surprised but gave the deviation to me. After passing it he called me up and said "how did you do that?-when you asked for your deviation I had nothing on my scope-it wasn't till you passed it that I started to paint something". I even took a picture of it-you can see me diverting to the south. Doesn't look like much-but it was right after I passed it. It was developing right then-and I saw it before the controller did.A second case was flying back from New Hamshire last summer. I was dealing with Boston Approach and asked to divert to the south of my course line in this shot which appears to go thru a "hole". Boston didn't want me to go south as it put me in New York's airspace. However, I just didn't feel very good about the proximity of the red stuff on the bottom right, and it looked visually real black with some lightening. I asked again to divert south-they said unable. A few radar equipped planes smugly behind me said their radars also showed clear and go for it. At that point my flying partner grabbed the mike and said "we just saw lightening-we are deviating south-at that point the controller had no choice and let us go. It wasn't ten minutes later that the radar equiped aircraft who had decided to go thru the hole were ######ing that they were in bad turbulence , all hell was breaking loose, and they advised not going that way. The controller suddenly treated me very respectively to the next handoff.I give these examples to show that there is a lot of decision making that goes on dodging storms, and the convection can develop very quickly and unpredictably. Even with atc , radar, and xm feed it is not an exact science getting around storms. Since I fly for fun I always take a very conservative approach, but I imagine an airliner with schedules to maintain and angry passengers when delays occur might play it a little closer.I think like many bad things that happen in life-due to a lot of bad coincidences the Airbus just ended up being in the wrong place at the wrong time.

Great post Geof!The radar at our facility is an older one and it cannot show intensities of weather, only what the primary radar returns. What we do is tell the pilots what we see on our end then ask the piots of they concur (if they have a stormscope/weather radar onboard)It would be interesting to see what other facilities have, I know a lof can display intensities of weather and their radar will do a lot of neat things.Either way I've been following this story on the news (finally got online after a week of ATC training) and I think turbulence played a factor in this plus mechanical issues.

Great post Geofa the only problem I have is the pilots were unable to call in a 'mayday' or any kind of transmission of building problems/circumstances. Turbulence doesn't just hit all at once to this degree. You usually fly into it and it builds as you go along. Something hit this plane like lightning all of a sudden. They were flying along and 'BAM' they were gone. No "We're experiencing heavy weather", "Were Going Down Mayday" nothing. The last time I heard of something like this was TWA Flight 800. I will concede a point a flying buddy of mine mentioned that is no group has taken responsibility for this tragedy. I really hope they find those data recorders because this is one heck of a mystery...

Great post Geofa the only problem I have is the pilots were unable to call in a 'mayday' or any kind of transmission of building problems/circumstances. Turbulence doesn't just hit all at once to this degree. You usually fly into it and it builds as you go along. Something hit this plane like lightning all of a sudden. They were flying along and 'BAM' they were gone. No "We're experiencing heavy weather", "Were Going Down Mayday" nothing. The last time I heard of something like this was TWA Flight 800.

You guys may want to check this out:http://www.weathergraphics.com/tim/af447/

Great post Geofa the only problem I have is the pilots were unable to call in a 'mayday' or any kind of transmission of building problems/circumstances. Turbulence doesn't just hit all at once to this degree. You usually fly into it and it builds as you go along. Something hit this plane like lightning all of a sudden. They were flying along and 'BAM' they were gone. No "We're experiencing heavy weather", "Were Going Down Mayday" nothing. The last time I heard of something like this was TWA Flight 800.

You guys may want to check this out:http://www.weathergraphics.com/tim/af447/As far as sudden-I have never entered a cell. I had lunch with someone the other day who had back in the '60's before anyone had much avoidance equipment. He said he was flying along nice and happy-entered the cell and the next thing he knew he was in the most violent experience he had ever had. He said the turbulence was so bad he could not read any of his instruments-could hardly tell if he was upright or upside down. Exited it in what seemed to be an relative eternity into relative calm. So yes-my understanding is it can happen at once to that degree. Perhaps you are talking of normal clear air turbulence vs. entering a 35-50,000 high cell or so?The same goes with normal build up cumulus clouds-you almost always hit fairly sudden turbulence upon entering them-and it can be calm as silk both before and after. One of my videos here on avsim "clouds over Wisconsin" shows this-when due to a vector around a hot moa I just touched a fair weather cumulus cloud.

There is the possibility that they were not in a position to send a radio message, for example if the lightning had taken out their comms radio equipment, or they were perhaps busy with handling the aircraft, or even something as mundane as not having their radio tuned correctly, or a blown fuse, or popped circuit breaker going unnoticed, owing to a distraction of some sort.It's true that aircraft radios have protection against lightning, and so supposedly should not be affected, but only in the same sense that the Titanic was supposedly unsinkable. So maybe they could not send a radio message, or perhaps they were sending radio messages that were being blocked by electrical storm activity? Who knows? Not receiving a radio message does not necessarily mean one was not being sent, or that the attempt was perhaps being made.But radio message or not, imagine if your aircraft suddenly rolls ninety degrees when it hits mad turbulence, perhaps even injuring someone on the flight deck in the process and slumping them over the stick or jamming their foot in the rudder, then it stalls and starts being flung all over the sky, do you first get on the radio, or do you grab the stick and try to solve the immediate problem? First responsibility is to fly the airplane, and in a critical situation, telling people about it can often wait.Not saying that is what happened, but since it could have, the lack of a radio message doesn't necessarily mean that it was a split-second disintegration, or some other instantaneous calamity.Al

After looking at the website provided above I must say weather is diffidently a factor. The problem I have is the length the aircraft was flying through this weather and mentioned nothing on the radio about it. Usually pilots warn other pilots in the area and ATC to stay clear if they've entered problem areas in the sky. The final cell wasn't small by any means, they flew over multiple ones before that and the last would have taken 12 minutes to get across if they would have made it. Nothing to ATC or warnings to other pilots in the area was ever transmitted. There was absolutely nothing from this aircraft and the data sent to France from this flight only showed a problem the last few seconds before something fatal happened... I don't know guys... :(

Someone mentioned modern airliners operating above the weather ...Not out on the Great Plains of the USA. By August it is quite common in eastern Colorado to have individual thunderheads top out at 70,000-80,000 feet, with CBs in squall lines frequently getting up to 60,000 feet ...But I'm still thinking "bomb".

Someone mentioned modern airliners operating above the weather ...Not out on the Great Plains of the USA. By August it is quite common in eastern Colorado to have individual thunderheads top out at 70,000-80,000 feet, with CBs in squall lines frequently getting up to 60,000 feet ...But I'm still thinking "bomb".

In cases like that airliners surely fly around those cells... Getting back to recent news it appears the debris found in the ocean are not that of the Air France jet.Hopefully an X-File doesn't have to get opened on this one... No broken pieces in the water and no oil spill from the plane found. In a case like this the plane would have had to come down in a more controlled manner and slowly sank after it hit the water. There's allot of ocean out there and allot of possibilities... Either way something that's not instant would spark calls home from the passengers saying 'goodbye' and/or pilots contacting ATC to report serious weather in their flight path enlisting other traffic to beware. It's amazing no sign of the jet has been spotted. Something should have floated above the water but like I said it's a big ocean out there...

Analysis of the recovered wreckage may (repeat may) reveal the cause of the crash. In advance of that I'll offer a couple of thoughts ...1 - I'm aware of only one airliner that was brought down by a lighting strike, a 707 in 1963 or thereabouts. However, I'm aware of a DC-9 that suffered total engine failure due to ingestion of hail.2 - Structural failure due to turbulence is possible but not likely, in my opinion. The 707 that crashed near Fuji got caught in a mountain rotor, which is a whole 'nother animal.3 - My guess is a bomb on board. I certainly could be wrong, but they'll be exploring this possibility, and if the right parts of the wreckage can be recovered they will show the effects of a high explosive detonation, assuming that this is in fact what happened.4 - Another possibility is a fuel tank explosion such as brought down TWA 800.But I'm guessing. Hopefully we'll learn the facts at some point.

I agree a bomb. There are only two explanations and a suspicious common thread:* Sudden total catastrophic break-up due to unknown causes. How many times does this happen with an airliner of the Airbus category* Sudden total catastrophic break-up due to a detonation of a bomb-on board. How many times has this happened in the past? I suspect multiple, even on an airliner of the Airbus category* Sudden total catastrophic break-up due to a detonation of a bomb-on board DAYS after a bomb threat was called in for the same run or one suspiciously close to it?Bomb is the most plausible explanation until disproved. The lack of coverage on the connection between the two indicators (sudden catastrophic break-up and bomb threat) astounds me.My two cents added to yours.bt

I agree a bomb. There are only two explanations and a suspicious common thread:* Sudden total catastrophic break-up due to unknown causes. How many times does this happen with an airliner of the Airbus category* Sudden total catastrophic break-up due to a detonation of a bomb-on board. How many times has this happened in the past? I suspect multiple, even on an airliner of the Airbus category* Sudden total catastrophic break-up due to a detonation of a bomb-on board DAYS after a bomb threat was called in for the same run or one suspiciously close to it?Bomb is the most plausible explanation until disproved. The lack of coverage on the connection between the two indicators (sudden catastrophic break-up and bomb threat) astounds me.My two cents added to yours.bt

* Sudden total catastrophic break-up due to unknown causes. How many times does this happen with an airliner of the Airbus categoryKnown cause--the AA flight in 2001. Do you think that aircraft would have survived intact had it lost the rudder in the flight levels?What about the Aloha Airlines "Pop top"?I am not surprised you'd be partial to the bomb theory Braun, given your history of posts regarding TWA-800. Bomb threats are called in almost daily on aircraft that never crash, including flights I have been on after the first Gulf war. Maybe the press is getting wise regarding not giving every would be terrorist and nut case lip service when a catasrophe like this happens by lending weight to their bomb threats. I do have to wonder how many people are out here with vested interest in the industry (investments, etc) either conciously or unconciously try to divert attention from the fact that aircraft can and do sometimes have catostrophic failure without intervention such as a bomb?One other theory I believe possible, given the weather and exposure to electical storms, is that of cargo being onboard that was highly volatile in such circumstances. Even if such cargo shouldn't be onboard, a lot of merchandise travels back and forth on the globe that is not what's stated on the manifest, people look for a cheap or quick way to ship their goods.It is too early to cite or dismiss anything as the cause, IMHO. Bomb? Maybe. Structural failure? Maybe. Flight crew gone mad? That's a possibility too. But some will declare "bomb" no matter what just as some still believe TWA-800 was part of some evil conspiracy.

In cases like that airliners surely fly around those cells...

As I noted in an earlier post, cells can develop in mere minutes if the air is unstable enough. Had the pilots flown into a fairly safe looking area only to suddenly get hemmed in by bad weather on all sides, they would have no choice but to punch through regardless of the risk. Storms can come out of nowhere in tropical or unstable environments.Another personal experience, I was flying a Luscombe with a friend several years ago. We took off in overcast skies but otherwise nothing was forecast to move in, and the base of the cloud deck was well above our planned crusing altitude. I was busy flying the Luscombe when my friend thought he saw a flash of lightning in the distance. I turned over control of the Luscombe to him, and we returned to the airport ASAP. On touchdown, we were in the midst of a full bore super cell. It rained for several hours afterwards and Tornado warnings started popping up all over the place. None of it was on radar or forecast when we left. The entire experience, from take off, to the observed lightning, to touchdown--it lasted less than thirty minutes. I have a flight video of the landing, I should put it up on Youtube.....I still think there is something wrong when we can lose track of any aircraft in this era of aviation. I'd be willing to pay a few bucks more for a ticket if I knew someone knew where my flight was every step of the way. Just because these things happen rarely, it does not mean we should take it for granted that it won't happen again.-John

I don't see any facts so far that can lead to a "bomb" theory. It appears that the lack of reported receipt of voice comms from AF447 is taken as proof of lack of transmissions, or attempted transmissions. Since there is credible data from AF447 ACARS system (which I understand is transmitted via INMARSAT SATCOM) that would seem to be the place to start.From what I've read, that data suggests that the ADIRUs were not in agreement, resulting in several warning and system mode changes (AP off, AT off, alternate law). Various interpretations of the ACARS data are looking at one message which apparently is on the static pitot system.ACARS doesn't seem to show any electrical system warnings. I don't know what that means, but I would think lightning or bomb would have different warning messages than those received.scott s..

I think a far more likely explanation than a bomb is something like the following: the pitot tubes and static ports ice up in some CB, that causes erroneous speed indications to various systems, the autothrottles push up to add speed because the icing on those systems is causing them to report that the aircraft is going slow, with that occurring, the combination of turbulence and overspeeding causes some sort of aerodynamic load-induced structural damage, perhaps exacerbated by heavy control inputs when trying to battle with the turbulence.It's a guess, but it would explain the thing sending a series of ACARS failure messages one at a time, of which, among the last ones were the rudder limiter being overridden and the pressure control being effected, perhaps indicating that the tailfin was damaged, which may have then caused damage to the rear pressure bulkhead.Al