Air France Jet Missing Off Brazil Coast

[68Wooley]

Fly by wire................ computer. Or did I miss something.......

You missed something.

[Golfer]

If by "the computer" you mean hydraulic actuation then via the pilots feet then yes.

[68Wooley]

Also, let's remember - the A330 that went missing today is a design generation newer than the A300 that came down over NY. Not sure how many comparisons we can draw.

[humble]

The 300 series not FBW but the 330 is. My initial post was not meant to infer that it was. The underlying issue is still the same. At a speed of roughly 250 knts the pilot should not have been able to break the plane. The combination of material choice and aircraft design created a problem that should have been impossible in the circumstances. Fast forwarding to the current scenario my concern is the combination of design and the significant documented problems already inherent in the 330 might have "lined up the holes". In my mind the simple words "what is it doing now" are the scariest in the history of commercial aviation. The available service history of composite materials in airframes is limited and I think its shortcomings are going to become more and more apparent over time.

[Die Hard]

At a speed of roughly 250 knts the pilot should not have been able to break the plane.

All non-computer-limited airliners are breakable by the pilot at 250 knots. It doesn't take much to over stress them.

[Boxman]

It was a shoe-bomb.

[Angus]

All non-computer-limited airliners are breakable by the pilot at 250 knots. It doesn't take much to over stress them.

You sure about that speed?
Anyway, here is an airbus linkie and the narrator is a Boeing guy. Very good
Sort of blows away any theory that the Airbus folks are not aware of abnormal cirkumstances.
http://www.youtube.com/watch?v=IKBABNL-DDM&feature=related

[Die Hard]

You sure about that speed?

If we use a B737 as an example it has a load limit of +2.5G to -1.0G, and the pilots handbook states: "Avoid rapid and large alternating control inputs, especially in combination with large changes in pitch, roll, or yaw (e.g. large side slip angles) as they may result in structural failure at any speed, including below VA."

Airliners aren't fragile, but they are fully capable of destroying themselves trough overly aggressive maneuvering.

[Angus]

2.5G and -1, that's....nothing! Thought they could do a little more than that.

[Die Hard]

They can, but not for long and not without incurring damage, and eventual failure. What you feel during take-off and landing is at most 1.5G. 2.5G is actually a lot more than most virtual "pilots" think.

[Golfer]

Those are pretty standard limitations.

A Learjet 45 is +2.9/-1.0 flaps up.  +2.0/0.0 flaps down (any amount)
Citation Excel +3.0/-1.2 flaps up.  +2.0/0.0 flaps down.

They're not fighter airplanes and are plenty rugged provided you keep them within their limitations.

You simply cannot do some things in transport airplanes that you could in a fighter or aerobatic airplane.  Part of American Airlines issue was they had fighter pilot teaching fighter pilot things to airline pilots flying airliners regarding upset/unusual attitude recovery in their "Advanced Aircraft Maneuvering Program" which was partly to blame for the accident of AA587.

587 and this Air France accident have nothing in common other than they were fown in airplanes designed by Airbus built probably two decades apart.

[Sombra]

About the a300 discussion:

MYTH: I CAN FULLY DEFLECT THE CONTROLS BELOW MANEUVERING SPEED! - x-plane.com

[humble]

Thats not completely true. All companies share a commonality of thought (with in). Airbus has pioneered development in a lot of area's in response to real or percieved needs of its potential customers. The two area's of concern for me are the use of composites and the ever more complex avionics that increasingly take over pilot work load. If we look at the AA crash the bottom line (from my perspective) is still very simple, the overall design was substandard and inappropriate for the materials used. The plane had control authority significantly higher then the norm in combination with an unproven material. Please show me any incident ever (commercial aviation) where a pilot caused catastrophic failure via control surface input at moderate speed.

Obviously any comments on the current event is speculative. One stark fact is that in the event of failure of the FBW system due to electrical failure the plane is only controllable by trim input, differential thrust....and rudder. So a failure of the FBW would leave the plane in a situation where the only major control surface available for unusual attitude recovery is the rudder. BTW the rudder in later build A330's is smaller then in the one that crashed...

[Golfer]

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

AA587 is that accident.  There was nothing gentle, subtle or smooth about the flying pilots use of rudder during the upset recovery.

If I took those same actions in many other airplanes significant damage could/would/should occur and a catastrophic failure is not out of the realm of possibility.  The tail did not depart the airplane because of one misguided input or a proper use of the rudder.  Incorrect rudder inputs to the opposite several times in sequence did.  That rests squarely on the pilot and the misguidance of the AAAAMP training for trying to teach him to be aggressive on the rudder in unusual attitude/upset recovery situations.

Vertical stabs just aren't designed to do that.

[Stoney]

the use of composites

Most of the composites in an airliner are not even structural components.  Especially during the development of composites early on, no manufacturers were willing to make a spar, for example, out of composites.  The floor panels, interior bulkheads, non-structural access hatches, etc. were the first components to be made from composites.  Its only now, after significant research, are structural components of the airframe being constructed of composites.  And, in my opinion, when properly engineered for the application, composites are and will always be better than their alluminum, historical predecessors.