Air France Jet Missing Off Brazil Coast

[Angus]

Most crashes are pilot error. Most lead-ups for a crash are pilot error too.
And the naughtiest, high-G fighters and even aerobatics aircraft are not necessarily more made of riveted alloys.
Saying that, where one aircraft would pop rivets due to stress, the "carbon" one wouldn't.
Problems with our synthetic materials would rather be UV and such IMHO.
As for this accident occuring on that flight leg, I have my doubts. First airliner with a 3 digit number though....

[Skuzzy]

Not quite right there humble.

There are resin/fiber combinations which have better memory than currently used aircraft metals.  Pound for pound, there are resin/fiber combinations which are stronger than metal as well.

Now, where you may not want to use composites are in areas which have a constant high load force applied, such as a wing spar.  Due to the nature of resins continually curing, a structure under constant high stress loads could form a new memory over time.  That is theory.

This is an area still under going testing.  "Scaled Composites" is really pushing the limits of composite structure and design.  So far, the results have been rather impressive.

Without knowing the exact breakdown in the resin used, it is difficult to make any types of assumption as to the strength or flexibility of the component.

[jdbecks]

forgive me for my lack of knowledge with aeroplanes and flights,

But if an airliner suffered engine failure would it be able to glide gentley down like other planes?

[humble]

Thats really where my questions are, composites have been used with much success in extreme enviornments where those properties are in effect "over engineered" to provide exceptional performance...often at high cost. We're now seeing the use of this technology in a more consumer driven market place where cost/performance drives purchasing. No question that "smart cockpits" are designed for the lowest common denominator of pilot skill. Engineering is driven by "maximum" performance for each dollar spent. Airlines are under tremendous pressure to cut cost per passenger mile and all decisions are driven by that. No question that Airbus is pioneering the road ahead...

The thought that scares me is that the combination of factors might have reached the point where the plane in question was the victim of these trends. Given the sheer # of operational hours 1 in a million is an operational certainty not an unlucky event. We have a very experienced crew in a state of the art plane that has suffered a catostophic failure of an unexpected type. We expect planes to crash due to pilot error, or weather (normally landing/taking off) or wind shear or terrorist events or even design flaws (DC-10/L1011) in combination with mechanical errors. I have a sense we might now have "concept" caused crashes...why does a commercial airliner need to be FBW? Why use composites to enhance "just enough" engineering? Why create programs that limit/over ride a pilots ability to control his plane in difficult circumstances?

[humble]

forgive me for my lack of knowledge with aeroplanes and flights,

But if an airliner suffered engine failure would it be able to glide gentley down like other planes?

An airbus 330 suffered double engine failure and glided (18 minutes) to a successful landing in the Azores so the answer is yes.

[Die Hard]

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).

That would make it a singular event. The fact of the matter is, and as stated in the B737 pilot's handbook, had the AA pilot done the same in a B737 the result would have been similar. The rudder was not designed for alternating full deflections, but the pilot did so anyway (and not accidentally, he was trained to do so) and cost 265 people their lives.

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....

Since we know absolutely nothing of what actually happened your bet is as baseless as your arguments so far. Only five A330's have been lost in accidents since its debut in 1991 and only two of those had fatalities (including this latest one). In the same time period eleven B767's have been lost in accidents, six of them with fatalities. About 300 more B767 have been built over the 600 A330's delivered so far, so you'd expect a slightly larger number of accidents, but not more than double. So from a safety record point of view I'd rather fly the A330 than the B767.

[Die Hard]

I'm not blaming it on the composite entirely since the underlying design was at fault.

Which design fault would that be?

[OOZ662]

I find it rather entertaining how humble's posts are apparently always the "simple truth." Anyways...

1) Is there anywhere ever in the 50+ years of jet age aviation a prior case of pilot induced structural failure at moderate speed?

And what if there isn't? That simply means that no one has thrashed the rudders around so improperly until this guy. You're also disproving your own point; yes, we can only show you one account of this. Does this not mean that the REST of the identical A300s out there have been doing their job and not falling out of the air due to a leadfoot?

It "frightens" you to think that a plane can snap apart by "moderate use" of the rudder. Anything but a fighter jet (and even those at some point) will fall apart with that much shearing force put upon their structure, no matter the material it's made of.

[OOZ662]

Which design fault would that be?

Quoting the terrible English at Wiki due to laziness, but it's already been stated.

However, contributing to these rudder pedal inputs were characteristics of the Airbus A300-600 sensitive rudder system design and elements of the American Airlines Advanced Aircraft Maneuvering Training Program. The A300 family has the distinction of having the lightest breakout force and the highest number of degrees of rudder travel per pound of force of any other transport category aircraft. Once a pilot initiates rudder movement, he or she will be challenged with the most sensitive rudder handling qualities of any transport category airplane. This sensitivity is a precursor to a characteristic known as Aircraft Pilot Coupling (APC), a condition typically “…not feasible for a pilot to realize and react to in real time,” and considered unacceptable in U.S. certified designs (National Research Council 15). Simply, a very light application of force coupled with a very small movement of the rudder pedal will yield full deflection of the rudder.

[Die Hard]

The Air France A330 apparently flew through the inter-tropical convergence zone; a phenomenon feared by seafarers and aviators alike. This is where two air masses meet, sending huge storm clouds more than 40,000 feet into the sky creating lighting storms with hailstones the size of softballs and sudden mini cyclones.

[Die Hard]

Quoting the terrible English at Wiki due to laziness, but it's already been stated.

That is not a design flaw. The aircraft was certified as safe to fly; in other words the sensitivity of the rudder controls were not deemed unsafe, and thus the plane was designed within the safety regulations governing commercial flight. If the pilot had just stomped on one pedal the rudder and vertstab was designed to take it. What it wasn't designed to take was the alternating stomping on both pedals; something few, if any, airliners are designed to tolerate. While the A300-600 had lighter and more sensitive rudder controls than other similar airliners they still required a 35 lbs force for maximum deflection; that's not a hair trigger by anyones standard.

[Denholm]

Anyone know what the airliner's Flight Level was when it failed to make the regular check-in?

[Die Hard]

Anyone know what the airliner's Flight Level was when it failed to make the regular check-in?

35,000 feet.

[Skuzzy]

humble, there is no such thing as "consumer" grade composites.

There are resins and fibers designed to meet specific requirements.  Just like specifying any metal alloys to be used.  Resins/fibers can also be used to augment metals, and vice-versa.

Most of the expense in resin/fiber construction are in the layup process.  It is a very difficult and exacting process.  When a mistake is made, you normally have to throw away the entire section and start over.

With metal, not so much.

[Denholm]

35,000 feet.

Seems rather low for an inter-continental flight. Well, then I guess they could have run into some clouds.