Air France Jet Missing Off Brazil Coast

[FTJR]

Not mine , but ok...

[Angus]

And sattelite based link once elevated from the ground is not iffy.
Not too sure about ATC standards, but a sattellite linked aircraft (GPS) could absolutely (in theory) forwards it's gps points to anywhere. Baffles me a bit, that there still is the "old" flying over vast areas of water.

[FTJR]

The "iffy" bit I was refering to was the HF, and It is still is the primary communications for Flights in that part of the world, not from the aeroplanes point of view, but the ground stations.

[rabbidrabbit]

How much would the use of ceramics affect the acceleration on a treadmill?  Personally, I don't think they can handle it.

[Die Hard]

Please show me any incident ever (commercial aviation) where a pilot caused catastrophic failure via control surface input at moderate speed.

Please show me any incident ever (commercial aviation) where a pilot commanded alternating full deflections of the rudder multiple times.

[humble]

My opinion is just that, an opinion. No question that composite materials offer tremendous potential benifits. However lets look at a few fundemental realities that are true to the best of my knowledge (feel free to correct)....

1) Composites flex then break, metals flex, then bend and then break
2) We have thousands of documented cases of "warped" airframes and "popped rivets" with metal
3) Composite planes have a minimal operational history so wear issues do to fatique are less well known
4) Regardless of pilot error in 587 I am unaware of a single incident ever of pilot induced strutural failure similiar to that prior...EVER

Looking at how this applies to the current situation based on the limited facts we have...

The 1st warning AF recieved was that the AP had disengaged and switched to alternate law. This preceeds any electrical fault issues and indicates some type of signifcant upset and/or mechanical/structural failure. The alternative would apparently be a massive electrical failure that took the plane to "recovery" alternate law (no indication of what mode that I saw).


 

[Tordon22]

Didn't see this already posted, but some wreakage found.

http://www.bloomberg.com/apps/news?pid=20601085&sid=aGqVhPoRLAtM&refer=europe

[Hajo]

Steel comes in various densities and composition.  Steel making is a chemical process believe it or not.

There are literaly thousands of types of steel.  All have differing physical and chemical properties based on the customers needs and use.

Carbon Fiber I don't know enough about to comment on.   How many differing types of carbon fiber are there?

[Masherbrum]

Isn't there a single discussion with americans anywhere on the matter of the missing plane without airbus vs. boeing hoopla!? Come on, you all have been discussing this like hundred times over in the past years and it only ceased for a while when the 787 experienced a delay, after there had been so much whining about the tiniest problem with the A380. There's no such thing as a perfect plane nor a perfect company and you can debate about that all day but it's not going to change. Neither company would be in the business if their record would be piss poor.

Now, about the missing plane... I've read from the news that supposedly some passengers were able to send short text messages with their cellphones to their relatives. Nothing was heard from the pilots, but there was still time to send text messages?

Fishu, those with ACTUAL Aviation experience (Golfer, WW, etc) are the victims of noodle envy.   MrRipley makes sense too, the rest are just trying to be "an expert".   

I've notice a couple of people posting for "shock value" and someone bit on the Airbus thing.   

It's a shame a plane goes down and people have to find the time to act like love muffines "because they're cool". 

[humble]

Please show me any incident ever (commercial aviation) where a pilot commanded alternating full deflections of the rudder multiple times.

This is the problem here, your attempting to argue that this is a singular event. In 50+ years of commercial jet aviation it hasn't happened ever  before (that I'm aware of). Have you actually read the NTSB report or are you just mouthing off what "everyone" says...the guy didnt "stomp on the rudder". The problem is a relatively complex combination of questionable training, simulator programing and the airplane design itself.

Lets look at the simple truth here. This is the 1st accident ever on this flight route which has been active since 1947 even though its easily the toughest weather in the world (for weather issues like this). Obviously a lot of stuff had to have gone wrong...my question and comments here are simple. A plane designed to be cutting edge in all ways might not be "safer". This is no different then the Titanic, no ship is unsinkable and no plane is completely "safe"....

So when we have materials whose real purpose is cost savings not safety and avionics that attempt to protect the plane from the pilot and engineering done to a standard of "just enough" all marketed under the banner of "safest and best ever" the end result is inevitably bad. Pilots need skill, training and experience. Airplanes need to be over engineered and as simple as practically possible. Flying is inherently dangerous and always will be....

The surprise for me is that the alternate law/AP disconnect came 1st. That indicates a massive upset or failure preceding the electrical faults.
In effect leaving the pilots chasing the avionics and then having a situation where it appears that the avionics may have gone totally offline....leaving the pilots with minimal control availability at unusual attitude in IMC in major turbulence...end of story. I'd almost 100% bet a 767 would have had no similar issues here....

[humble]

Fishu, those with ACTUAL Aviation experience (Golfer, WW, etc) are the victims of noodle envy.   MrRipley makes sense too, the rest are just trying to be "an expert".   

I've notice a couple of people posting for "shock value" and someone bit on the Airbus thing.   

It's a shame a plane goes down and people have to find the time to act like love muffines "because they're cool". 

I'm not looking for shock value and my comments are relatively simple and straight forward. Every aspect of aviation has gone from safety and engineering to profit and "ease of use". The reality is that in order to gain market share Airbus had to create an alternative positioning. This is business not engineering per se...

[Stoney]

So when we have materials whose real purpose is cost savings not safety

Composite materials often times are much more expensive than conventional materials.  Composites offer designers a couple of different advantages.  First, composites can be engineered to perform exactly the way an engineer needs them to perform.  Be it in compression, tension, torsion, you name it, you can engineer a component to exhibit the qualities you want.  The higher the percentage of reinforcement, the more the composite behaves like the reinforcement.  The higher the percentage of matrix, the more the composite behaves like the matrix.  Second, composites are typically much lighter but possess the same or higher structural qualities of the metal components they replace.  Third, composites offer the ability to make very complex aerodynamic shapes that metals cannot be easily formed into.

There is a tremendous amount of historical data on composites, and it comes from the most demanding aeronautical applications in the world--the military.  Planes as old as the F-4 and F-111 used composites to achieve weight savings.  Almost every military aircraft since then has made more and more extensive use of composites since.  I remember looking at an F-18 crash, and there was carbon fiber everywhere--I had no idea it contained so much of the material--the structural part of the wing is almost entirely carbon.  These aircraft are designed to the highest tolerances, the highest structural characteristics, and are subjected to more punishment than any other aircraft in the world.  So, to say that the materials themselves are a poor substitute for metal is not true.

Engineering can be flawed, no doubt.  But, that does not ultimately mean anything with respect to the materials themselves.  If an engineer uses an aluminum structural component the wrong way, it will fail.

In my opinion, composites are the future, and will enable designers to wring every drop of performance out of aircraft in the future.  It doesn't have anything to do with cheaper--it has to do with better.

[Skuzzy]

Steel comes in various densities and composition.  Steel making is a chemical process believe it or not.

There are literaly thousands of types of steel.  All have differing physical and chemical properties based on the customers needs and use.

Carbon Fiber I don't know enough about to comment on.   How many differing types of carbon fiber are there?

It is not the fiber, per se.  It is the resin used to bind the fiber that is important.  The other factor being the density of the fiber per square foot versus resin content.  Resins are like metals.  They come in many configurations.  Virtually all airplane resins are based off the epoxy family.

Resins, in all families, continue to cure as they age.  Epoxies form more polymer molecule chains to the fiber than any other family.  They crosslink to other fibers in a high content fiber blends.  In other words, they get stronger as they age.  Now, here is the rub.  Depending on the resin mix, they could get brittle as they age.  However, that would take a major mistake in production for that to happen.

Resins can flex.  Resins can bend.  How the fiber is laid and the configuration of the resin determine how much flex and the orientation of the flex, will be tolerated before structural failure occurs.

Composites are far more difficult to work with in a manufacturing environment and thus add substantially more cost to the airplane.

Composites have been used for a long time in non-load bearing structures in order to test how well they perform as they age.  I do not know if the results have ever been made public.  It would be interesting reading though.

[Nilsen]

You see the same thing in formula 1 and all kinds of racing and fast sailing yatch too. Has nothing to do with cost during the design atleast. The saved weight will save money over time but not at the cost of strength. Only time i would want steel in my boat is if i went to places with lots of ice or to far away places were a welding machine is easyer to find for repairs than a boatyard that can do epoxy fixes.

[humble]

I recognize that both composite technology and fly by wire are "cutting edge" and have been pioneered in military applications for a significant period of time. I also know that even simple epoxy can be stronger then steel (JB weld for example) and offer tremendous design flexibility. My simple questions remain....

1) Is there anywhere ever in the 50+ years of jet age aviation a prior case of pilot induced structural failure at moderate speed? I'm not blaming it on the composite entirely since the underlying design was at fault. However we have here a tortional effect and my understanding is that a composite by its nature is more susceptable to "snapping" if torqued against the grain so to speak then a metal component that might be nore prone to "twist" (again feel free to correct me)...

2) In a sudden upset at cruise speeds are the components engineered for the stress of recovery or are the systems designed to eliminate the possibility before an incident?

It seems that more and more the design criteria is to eliminate the possibility of an issue then survivability in the issue. To me accepting the argument that a pilot can snap the tail in an attempt to recover from unusual attitude in a wake vortex is absurd. Using Golfers Lears, has one ever suffered a similar fate?

Since the event started with an AP disconnect/alternative law and not an electrical fault that would appear to indicate unusual attitude do to turbulence (unless the avionics went nuts like on the Quantus bird). If that is the case then the either the airframe failed or the avionics precluded or contributed to the pilots inability to correct the upset. My comment is based on the rarity of turbulence induced crashes at cruise ? {I cant recall any but again correct me}....