[Simon]

I think the important thing is that such massive rudder swings do not constitute "course corrections". They were clearly the wrong reaction to wake turbulence and the FAA concluded that bad training on behalf of AA didn't make pilots aware of how dangerous such swings are. We're not talking about rudder movement. We're talking about ripping the rudder back and forth several times from one maximum setting to the other. That is neither hairpin turn nor course correction.

That said, be have reason to believe AF 447 didn't encounter the same scenario. We know now that there were ten minutes between the first distress signal (CBs encountered) and a whole array of error messages including autopilot disengage, loss of primary bus, impaired stabilizer and aileron control. Another three minutes later a loss of electrical power and cabin pressurization (possibly disintegration) is recorded. This could have already been the impact. In any case it happened below 3300 ft above MSL.

Had pilot error in the thunderstorm led to the vertical stabilizer being ripped off at FL 350 the airplane would have never lasted for three minutes. In the case of AA 587 there were seconds between separation of the fin and total loss of control.

[Spheric Harlot]

Originally Posted by Simon 

That's exactly the point. Pilots know that thunderstorms can be dangerous and thus try to avoid them.

But pilots also know that lightning doesn't lead to spontaneous explosion of the plane just as severe turbulence doesn't rip wings off an airliner. It just doesn't happen and no pilot will claim it does.

These ideas are either from the imagination of people who don't know jack about aviation or from the media frantically trying to fill newspaper pages when actually they have very little to tell.

THE LINK ABOVE IS FROM A PILOT WHO CLAIMS THAT THIS CAN *EASILY* HAPPEN.

No problem at all.

It would seem he knows a little more than jack about aviation, certainly more than the media, and most certainly more than you or I.

"Hasn't happened ever" does not mean that it couldn't easily happen.

[Simon]

Actually he didn't claim wings fall off planes because of wind.

I'll post it again just for you:

Originally Posted by Patrick Smith (ATP)

But airplanes themselves are engineered to take a remarkable amount of punishment, including stress limit criteria for both positive and negative G-loads. The level of turbulence required to seriously damage a plane is something that even the most frequent flier will not experience in a lifetime. Around the globe each day, about 5 million people take to the air aboard 35,000 commercial departures. Yet over the past half-century, the number of airliners downed by turbulence can literally be counted on one hand, and almost always there were extenuating circumstances.

That's from a pilot with thousands of hours on various large commercial airliners.

You can shout in forums all you want. You may also go ahead and believe that every time the plane jolts you're about to go down. I'll be sipping my drink up front with a grin on my face.

[Simon]

And for anybody else who's interested in actual reality, here are two nice little Youtube clips demonstrating wing stress testing on commercial airliners. The first is from Boeing's 777 Project, the latter is the brand new 787 Dreamliner wing. Note how the engineers explain that the wing fails beyond the stress level a wing would ever encounter in a thunderstorm (they both fail at >150% of their design maximum). Note also, that the reason they do these tests is not to determine if the airliner's safe in case of a storm, but to calibrate their numerical models.

777 wing load test (1995)

787 Dreamliner composite wing stress test

[Spheric Harlot]

Originally Posted by Simon 

Actually he didn't claim wings fall off planes because of wind.

That's from a pilot with thousands of hours on various large commercial airliners.

So's this:

A thunderstorm is a violent and scary entity. It has the power, and I mean real power, to easily rip the wings from an A330, or any other make or model of aircraft. No problem whatsoever.

You will notice that he does, in fact, make that very claim, and quite explicitly.


I just posted this the second time, as well, and this is from the link Phileas posted WAY up on the first page.

I appreciate the effort.

[Simon]

That statement is outright wrong as every (real) pilot will tell you. But you can go on believing it if you chose. I prefer to stick with the facts. And they say no A330 (or any other modern airliner for that matter) has ever had its wings ripped off by wind.

Here's some more from an actual pilot.

When pilots change altitudes and routings to avoid bumps, this is by and large a comfort issue. The captain isn't worried about the wings falling off, he's trying to keep his customers as content and relaxed as possible.

The frightened passenger imagines the pilots in a sweaty lather: the captain barking orders as the ship lists from one side to another, hands tight on the wheel. Nothing could be further from the truth. The crew is not wrestling with the beast so much as merely riding things out. Most of the time, pilots will sit back and allow the plane to buck and buffet rather than attempt to recover every lost foot or degree of heading. Indeed, many autopilot systems have a special "turbulence" mode. Rather than increase the number of corrective inputs, it does the opposite, desensitizing the system.

Why the Air France plane crashed | Salon Technology

[Spheric Harlot]

I'll stand down and defer to your obvious expertise.

I find it interesting that experienced airline pilots disagree with other experienced airline pilots, and you throw around "actual pilots" and "actual reality" and infer that others are interested in neither, and that they are panicky passengers (I may well have logged more flight miles by the time I was twelve than you have in all the years since - I used to *love* those air pockets).

What I find almost more insulting than your tone, though, is your fallacious argument from authority, when various authorities have gone out of their way not to exclude ANY possibilities, and in fact state clearly that thunderstorms do pose very real dangers to commercial aircraft, regardless of size.

Your sources may be better than my sources, but neither you nor I are able to judge that.

[Simon]

Actually, the fact that I actually have a PPL, fly regularly and also sit in the back of commercial airliners more than once a week put me in a pretty good position to trust my sources over yours. And all your screaming (plus that cute attitude) won't change a thing about that. But I'll repeat what I said above, you are free to believe whoever you chose.

[Phileas]

Simon, this guy IS an actual pilot. A working pilot, with over twenty years experience. And had you read the discussion at the end of that link you would have found several other working pilots agreeing with him.

I find it difficult to understand how you can just completely dismiss the opinion of an expert, just because you have a different opinion. The real answer appears to be that the experts disagree.

[Simon]

Originally Posted by Phileas 

I find it difficult to understand how you can just completely dismiss the opinion of an expert, just because you have a different opinion. The real answer appears to be that the experts disagree.

Maybe they do. But it seems a small group with credentials I cannot verify disagrees not only with pilots I trust 100%, but also with manufacturers like Boeing. And I have no trouble admitting I'll side with the latter.

But will you agree with me, that whatever any "expert" says right now, it's too early to draw conclusions about what happened to AF 447 and that no passenger should be afraid of falling out of the sky just because his plane jolted as it passed through a CB?

[Dakar V]

A heated debate in a Lounge thread?

Welcome, Simon, you're one of us now.

[Laminar]

[driven]

Originally Posted by Simon 

Actually, the fact that I actually have a PPL, fly regularly and also sit in the back of commercial airliners more than once a week put me in a pretty good position to trust my sources over yours. And all your screaming (plus that cute attitude) won't change a thing about that. But I'll repeat what I said above, you are free to believe whoever you chose.

Wow ... I fly "in the back of a commercial airliner" 2-3 times per week also. I'm an expert on aviation too !!!!

Now where is that chick with the drink cart?

[Simon]

I take it you missed the part about me having a PPL. Reality check time. Who else here is actually a pilot?

[chabig]

Originally Posted by Simon 

Reality check time. Who else here is actually a pilot?

More than you might think. And in the argument about whether turbulence will rip a plane apart, I will go on record with a qualified "no". As has been pointed out, the plane is built with a huge margin of safety. Wings don't fall off because of thunderstorms. Airplanes don't explode because of lightning. Turbulence and lightning strikes occur every day. Heck, the Airi Force used to fly C-130s into hurricanes on purpose for research (maybe they still do)!

Now the world is not black and white. It's statistical. If airliners are designed to withstand the turbulence seen in 99% of thunderstorms, could there be that single thunderstorm with 99.5% turbulence? Sure.

I say give the investigators time to figure things out. We won't solve the mysteries of this crash on this board.

Chris (former Air Force test pilot, current airline transport pilot)

[Simon]

Originally Posted by chabig 

More than you might think.

I'm listening.

And in the argument about whether turbulence will rip a plane apart, I will go on record with a qualified "no". As has been pointed out, the plane is built with a huge margin of safety. Wings don't fall off because of thunderstorms. Airplanes don't explode because of lightning. Turbulence and lightning strikes occur every day. Heck, the Airi Force used to fly C-130s into hurricanes on purpose for research (maybe they still do)!

Now the world is not black and white. It's statistical. If airliners are designed to withstand the turbulence seen in 99% of thunderstorms, could there be that single thunderstorm with 99.5% turbulence? Sure.

I say give the investigators time to figure things out. We won't solve the mysteries of this crash on this board.

Chris (former Air Force test pilot, current airline transport pilot)

I agree with everything you say. Most importantly the conclusion that we will have to wait for a thorough investigation to shed light on what really happened.

[driven]

Originally Posted by Simon 

I take it you missed the part about me having a PPL. Reality check time. Who else here is actually a pilot?

Yeah ... I've got one of those too (Got it when I went to Embry Riddle in the mid-80s). I don't wear it on my shirt-sleeve, and it does nothing to enhance my expertise "from the back" of a commercial aircraft.

[Simon]

And what is it about statements like Boeing's that wings don't snap in thunderstorms that you disagree with?

[driven]

Who are you replying to? (Use quotes)

If it is me .... I was commenting on your qualifications as an expert by "flying in the back" of a commercial aircraft. I never said that a planes wings snap off in a thunderstorm. I did earlier say that a vertical stabilizer has been shown to "snap off" on an Airbus A300 during extreme rudder maneuvers. (Which hopefully pilots no longer do).

[Simon]

Huh?

[chabig]

Originally Posted by driven 

I don't know .. I'd like to think that a pilot doing rudder swings shouldn't rip the vertical stabilizer off of the aircraft. That's about the same as me taking 3 or 4 hairpin turns over the course of 45 seconds and having the front wheels rip off the car. That crash has always bugged me for that reason.

You don't think that massive course corrections could be required in horrible weather?

I'm a bit late to this party. But Simon is right. Rudder has nothing to do with course corrections, nor is rudder the appropriate control to be using in any kind of turbulence. The rudder is sized for and designed for two purposes--crosswind landings and engine out. That's all. It's not built to withstand repeated, full deflection, rudder reversals. Doing that was unthinkably inappropriate. And it's not a design flaw. If not flown correctly, there are a lot of things I can do to break an airliner.

[driven]

Originally Posted by chabig 

I'm a bit late to this party. But Simon is right. Rudder has nothing to do with course corrections, nor is rudder the appropriate control to be using in any kind of turbulence. The rudder is sized for and designed for two purposes--crosswind landings and engine out. That's all. It's not built to withstand repeated, full deflection, rudder reversals. Doing that was unthinkably inappropriate. And it's not a design flaw. If not flown correctly, there are a lot of things I can do to break an airliner.

No argument. It was inappropriate .. but that *IS* how American had trained their pilots for turbulence and no pilots corrected them at the time. Airbus had "suggested" that it might be inappropriate, but apparently didn't stress the danger to it.

[chabig]

Originally Posted by driven 

No argument. It was inappropriate .. but that *IS* how American had trained their pilots for turbulence and no pilots corrected them at the time. Airbus had "suggested" that it might be inappropriate, but apparently didn't stress the danger to it.

I believe American's training was shown to be wrong, yes. As for the manufacturer's stance, I don't think they had any idea that anyone was flying their airplanes that way. The conditions for which airplane structures are designed, built, and tested certainly isn't a mystery to the manufacturers or the test pilots.

[OreoCookie]

AFAIK the point where the vertical stabilizer is connected to is the part of the plane that has to deal with the greatest amount of force -- at least that's what a friend who has worked for Airbus has told me. I always thought it was the wings -- shows you what I know.

[chabig]

The wings carry more load than the vertical stabilizer. But the magnitude alone isn't important. It's how much structure is there to support the load and over what area it's spread.

[Spheric Harlot]

...

[glideslope]

I would suggest everyone read this link.
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data

IMO, AF already knows what happened from the final 4 min uplink transmission, especially the directive issued today on revised A330 guidelines for entering a CB (cumulonimbus). IMO, a huge updraft induced a High Speed Stall due to entering the CB too slow. That for unknown reasons was unrecoverable.

Pay special attention to part 3 and note the severity of the WX. I can only imagine the ride for the 15 min preceding the final event.

Godspeed AF447.

[Simon]

Thanks for that link. A very thorough analysis of the meteorological situation AF 447 encountered. There is a lot of WX details to read, but also a interesting conclusion.

Overall what we know for sure is weather was a factor and the flight definitely crossed through a thunderstorm complex. There is a definite correlation of weather with the crash. However the analysis indicates that the weather is not anything particularly exceptional in terms of instability or storm structure. It's my opinion that tropical storm complexes identical to this one have probably been crossed hundreds of times over the years by other flights without serious incident.

Still, in the main MCS alone, the A330 would have been flying through significant turbulence and thunderstorm activity for about 75 miles (125 km), lasting about 12 minutes of flight time. Of course anything so far is speculation until more evidence comes in, and for all we know the cause of the downing could have been anything from turbulence to coincidental problems like a cargo fire.

My own opinion of the crash cause, as of Monday night, based on the complete lack of a HF radio call and consideration of all of the above, suggests severe turbulence (see the BOAC 911 and BNF 250 tragedies) combining in some unlikely way with CRM/design/maintenance/procedural/other deficiencies to trigger a failure cascade. We can almost certainly count on some unexpected surprises once the CVR is recovered. Until then, all we can do is await the investigation and hope that the world's flight operations stay safe until AFR447's lessons are revealed.

If this indeed turns out to be CRM-related we can expect a very interesting accident report.

[Simon]

For some reason this crash reminds me a bit of SR 111. I know that fire has so far been dismissed because of the amount of kerosene and oil found in the ocean. But what if (like in SR 111) a localized fire impaired the crew/instruments which then together with the severe weather led to stall conditions and eventually disintegration of the structure thus causing the large debris field and the vast amounts of unburned fuel. Just pure speculation, but somehow this suden crash of a state-of-the-art airliner over the ocean at night with hardly any communication reminds me of SR 111. SR 111 did radio in their problems and they were being given vectors for a fuel dump and emergency landing, but once the fire had reached their instruments and radios there was six minutes of pure silence and then all of a sudden the plane just fell out of the air.

[Simon]

The Aviation Herald also has an extensive article on AF 447 for those of you who are interested.

Crash: Air France A332 over Atlantic on June 1st 2009, aircraft impacted ocean

Originally Posted by Aviation Herald

New information provided by sources within Air France suggests, that the ACARS messages of system failures started to arrive at 02:10Z indicating, that the autopilot had disengaged and the fly by wire system had changed to alternate law. Between 02:11Z and 02:13Z a flurry of messages regarding ADIRU and ISIS faults arrived, at 02:13Z PRIM 1 and SEC 1 faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed. That sequence of messages could not be independently verified.

[Spheric Harlot]

Originally Posted by Simon 

For some reason this crash reminds me a bit of SR 111. I know that fire has so far been dismissed because of the amount of kerosene and oil found in the ocean. But what if (like in SR 111) a localized fire impaired the crew/instruments which then together with the severe weather led to stall conditions and eventually disintegration of the structure thus causing the large debris field and the vast amounts of unburned fuel.

Er um. It turns out the debris and the fuel found is not actually from AF447.

BBC NEWS | Americas | Debris 'not from Air France jet'

This means still haven't located the crash site!

[Eriamjh]

What are the chances the plane crashed into a ship?

[Phileas]

A Portuguese airliner in the vicinity reported a flash of white light that then fell rapidly towards the ocean. So far the amount of fuel found on the sea has been used as an indication that there was no explosion, however if the finds are unrelated a mid air explosion might have indeed happened.

[Simon]

Originally Posted by Spheric Harlot 

Er um. It turns out the debris and the fuel found is not actually from AF447.

BBC NEWS | Americas | Debris 'not from Air France jet'

I just saw that too now that I came back from lunch. Indeed quite amazing!



So the 10 km long fuel spill they found did not come from an airplane? 10 km sounds like quite a lot to me for a ship's crew to go unnoticed, but then again I don't know jack about ships. How did they confirm the fuel was from that ship rather than A-1 from an airplane?

If this indeed has nothing to do with AF 447 then as you say, there is no crash site. As if it weren't already hard enough for relatives and friends of the passengers.

[Simon]

Originally Posted by Eriamjh 

What are the chances the plane crashed into a ship?

...and nobody missing said ship? Pretty slim I guess.

On the other hand what are the chances that a well maintained modern airliner disappears without the pilots ever radioing in any problems? Also close to zero, yet it appears that just happened.

[badidea]

Originally Posted by Eriamjh 

What are the chances the plane crashed into a ship?

Ships don't fly that high!

[Phileas]

Originally Posted by Simon 

How did they confirm the fuel was from that ship rather than A-1 from an airplane?

I suspect that it would be pretty easy to tell marine diesel from aviation fuel. I mean, not by looking at it, obviously, but surely there's tests for these kinds of things.

If there was indeed an explosion then the fragments might have been shattered over a huge area. As Simon says, even more heartbreak for the relatives.

[Simon]

Originally Posted by badidea 

Ships don't fly that high!

That made me literally LOL.

Thanks for the laugh.

[Simon]

Originally Posted by Phileas 

I suspect that it would be pretty easy to tell marine diesel from aviation fuel. I mean, not by looking at it, obviously, but surely there's tests for these kinds of things.

I would think so as well. What I was wondering about is if they had actually gone down and taken samples to confirm it's not jet fuel.

[glideslope]

Originally Posted by Simon 

I would think so as well. What I was wondering about is if they had actually gone down and taken samples to confirm it's not jet fuel.

Yes, the oil content was deemed too high for K-1. In other words it was Marine Diesel.

[glideslope]

Originally Posted by Phileas 

A Portuguese airliner in the vicinity reported a flash of white light that then fell rapidly towards the ocean. So far the amount of fuel found on the sea has been used as an indication that there was no explosion, however if the finds are unrelated a mid air explosion might have indeed happened.

More likely if it was 447, the plane had already begun it's uncontrolled decent, and an explosion occurred during the breakup. My assumption is based on the fact that cabin decompression was the last code transmitted during the 4 min period. It is plausible that the airframe was being so violently hit during the 12 min CB time (the last supercell (BIG ONE) for the 4 min transmission, then exploded.

Unfortunately, IMO I do not think anyone will ever find a trace. Very sad, very rare situation. Sometimes stuff just happens despite all the training in the world. Mother Nature is always Supreme.

[driven]

Originally Posted by badidea 

Ships don't fly that high!

Ok ... I rarely literally laugh out loud. I did at that.

[driven]

Ok ... those of you who are familiar with fly-by-wire systems more than I do ... if this turns out to be a cascading systems failure of the electronics that prevented the pilots from controlling the aircraft, would you re-think the utility of fly-by-wire systems?

(Just curious)

I hope they find the flight recorders. (Even if that's ALL they recover). How sad. How tragic.

[chabig]

I don't think that will turn out to be the case, but to answer your question--not at all. There is nothing inherently dangerous about fly-by-wire, nor is there anything inherently safe about cables and pulleys. Fly-by-wire offers tremendous advantages (including safety advantages) over the older systems. That's why fly-by-wire is here to stay. The only old-fashioned cable airplanes still being built are those that were designed that way in the '80s and earlier.

[Simon]

Every once a while I run into people who are somewhat worried abut flying in an Airbus because of FBW. I usually try to point out that FBW has been so successful that it has also been adopted by Boeing for their latest model (777) and also for their 787 that is about to be put into service.

[driven]

Originally Posted by Simon 

Every once a while I run into people who are somewhat worried abut flying in an Airbus because of FBW. I usually try to point out that FBW has been so successful that it has also been adopted by Boeing for their latest model (777) and also for their 787 that is about to be put into service.

I think those same people would have the same concern about a 777 or 787, or are they simply manufacturer loyal? (In that case it's not an FBW issue, but rather a brand issue.)

[Eriamjh]

They found two bodies and a suitcase with a boarding pass for the Air France flight. Crash is confirmed. Cause is not.

[Simon]

Originally Posted by driven 

I think those same people would have the same concern about a 777 or 787, or are they simply manufacturer loyal?

It's probably a bit of both. I think they're often relieved that it's not just Airbus being "reckless" but that maybe FBW isn't such a bad thing at all if even Boeing is using it.

[Simon]

Originally Posted by Eriamjh 

They found two bodies and a suitcase with a boarding pass for the Air France flight. Crash is confirmed. Cause is not.

debris sighted June 6

Originally Posted by Aviation Herald

Crash: Air France A332 over Atlantic on June 1st 2009, aircraft impacted ocean

Forca Aerea Brasileira (FAB) have announced today (Jun 6th), that they have found two male bodies today as well as a blue chair (serial number 23701103B331-0 not yet confirmed to be part of F-GZCP), a bag with a vaccination card and a leather briefcase, which contained a ticket for flight AF-447 and a laptop. The bodies and debris were found about 1200km off the coast of mainland Brazil and about 69.5km northwest of the airplane's last ACARS position report.

Air France confirmed the ticket number to be a valid ticket for flight AF-447.

[SVass]

Originally Posted by Simon 

It's probably a bit of both. I think they're often relieved that it's not just Airbus being "reckless" but that maybe FBW isn't such a bad thing at all if even Boeing is using it.

Boeing engineers trust pilots more than they trust computers or their software.
sam