AF447

[Captain-Crunch]

Kulwin Park,

It's possible the airplane didn't hit the water intact. But so far, from the scraps of clues we have (lack of a red cab alt warn, tight debris dispersal pattern if that is the case), tends to discount the likelihood that it came apart at hight altitude.

Because of the ACARS transmission requirements and characteristics and need for normal ships power, I feel it's safe to say that the airframe was intact at the time of the last transmission 0214z. Whether that Amber ECAM Advisory was a Cab decent advisory, or, an amber "Excessive Cabin V/S" has not been answered yet completely to my satisfaction by the techs here and other places in an affirmative fashion. They suspect that that's what it is; but the jury is still out even when they are referencing the 330 TSM and AMM's. It's not a red warning however imho.

Again, I don't see any acars evidence that a complete loss of cabin pressure occured prior to 0214z. (Maybe later in the dive at breakup.) But there is evidence of a severe loss of full flight control protections at 0213z caused most likely by loss of Air Data Computer function caused by loss of pitot air sensor data a few minutes earlier. (caused by, if previous airbus accidents reports are any guide: probe icing.)

Disclaimer: I have not flown the A330 and am unfamiliar with FBW.
But considering their wx and weight, a loss of control (jet upset) seems likely. Once you dive tens of thousands of feet in the dark like Adam Air did, high G's in the pull up are going to guarantee that things start coming off the airplane, (Cowlings and Fairing are the first to leave: we had two crews do this) likely followed by major structural damage of the forward and aft main spars in the wings and horizontal stabilizer. If you lose the rudder, then you're in bad trouble. But if you lose the vertical stabilizer (as was floating in the water), the game is completely over. I have examined airliners (as just a line pilot) after evasive flight control deflections, and the counter weights come off the control horns of elevators and large sections at the tips break off (if the stab is designed properly).

Some flyers brought the subject back up of Dutch roll at altitude. Unfortunately, airbus training that I've been in, doesn't demonstrate how to counter the effects of dutch roll if all yaw damper function is lost (the: that's never going to happen mentality). If line pilots try to use the rudder to right the aircraft, they will loose control even if all the flight controls are working properly. The correct way to keep flying at altitude is so tricky with the roll spoilers only (opposing every roll motion AFTER the roll is at it's zenith), that you are strongly advised to slow down and descend to a lower altitude immediately, like say FL290. This is sadly, going to put you is the bad weather were you don't want to be. But if you don't do it, I'm afraid not even old Mr. Neil Armstrong could save this one. Maybe at Edwards on a nice day, but not in the dark, in a storm with failing flight controls and failing instruments at the same time.

If all yaw damp function was lost, this would have quickly become a compound emergency that 90% of line pilots could not control even if they were "sticks".

My experience with rudder limiters is that it is expected that it will fail in its present mode. For example, if it fails at FL350, in high speed/low travel mode, you will loose rudder travel capability at low/slow altitude. If it fails in low speed mode, and now you're indicating fast, you could break the tail off with even normal rudder inputs. The problem is, with AF447, nobody knows at 350 in cruise what mode it failed in with the airspeed all over the place.

Right?

CC

The above, as all my posts are, are just my opinions only.