On Jun 28, 7:36*pm, James Robinson wrote:
spanky wrote:


My understanding from the pros in other groups, is that message simply
says that the autolimiter disconnected, and as mentioned, the limits are
clamped at what they were prior to the disconnect. *It is supposedly
part of the change from normal to alternate law.


....and if the pitot tubes were providing low airspeed data (which the
OP mentioned in his post, saying "the Captains, First Officers, and
standby airspeed indicators rolled back to 60kts...") prior to the
rudder travel limiter disengage, those travel limits would be far less
stringent than if the ADC "knew" the aircraft was travelling at cruise
speed.

This was followed in fairly short order by a TCAS fault, an
autothrottle disconnect, a/p disconnect and institution of alternate
flight law algorithms. *
Look at the failure point of the 447 vertical
stab and compare that with the failure point of the AA 300 that went
down in 2001 on departure from JFK. *

They are different. *Not at all the same type of attachment or type of
failure.

Wrong. Both failure modes are nearly identical in apparent result
(side loads beyond design limits) and the attach fittings (composites
with steel/titanium attach points) are nearly identical as well. look
at the photographs of both verticals. there is no crushing on the
lower leading or lower trailing edges of the AF447 component that
would indicate the failure took place fore and/or aft; on the other
hand, the AF447 vertical shows skin tears along its lower edge that
would indicate that the failure mode was due to sideloads exceeding
design limits.


Despite having a rudder travel limiter in place and working,

The A300 was not a FBW aircraft.

So what. The A300-600 has a rudder travel limiter, and its
effectiveness has been the subject of numerous NTSB Safety
Recommendations, to whit:

"A review of the flight data for rudder position showed that, even
after accounting for the slow response rate of the RTL, the rudder
still appeared to exceed the estimated position at which it should
have been limited by the RTL. This exceedance was as high as 4° near
the end of the upset. The A300-600 RTL is designed and constructed so
that it limits the rudder by reducing the allowable displacement of
the rudder pedals. Testing of the RTL determined that if a pilot
applies a sufficiently large pedal force when the pedal is at its
travel limit, this will further slow or stop the movement and,
consequently, the effectiveness of the RTL. As demonstrated by this
event, such slowing or stopping of the RTL by application of large
pedal forces could result in the rudder position substantially
exceeding the designed travel limit. The Safety Board is concerned
that such an increase in available rudder beyond the designed RTL
restrictions could permit excessive rudder movements and possibly
result in high loads on the vertical stabilizer."


the 2001 incident proved rather markedly that it is entirely possible,
even at climb speeds, to overstress the vertical attach points of the
structure. *...at cruise, in what may have been beyond extreme
turbulence, that possibility may indeed be a probability in this case.

Why would an experienced pilot be using the rudder at all at cruising
speed and at that altitude?

Because the first word governing an experienced crew's reaction to an
emergency is "Aviate."

That means (especially in light of a highly experienced crew reacting
to an A/P disconnect as well as multiple warnings) put your feet on
the pedals and your hands on the yoke and fly the thing until you, and
the rest of the crew, can sort it all out. CRM 101.


We'll never know until the FDRs and CVRs are found and the data
downloaded, but on that subject I have no faith that they will be
found and, given Airbus's shenanigans with black boxes from earlier
incidents, I have no faith that the company wants them to be found.

So they will just hope no other aircraft decide to disappear while in
cruise flight? Or do you think they already know what went wrong, and are
correcting it behind the curtain?

i have no opinion one way or another. all i know is that there was a
fly-by accident at a press event years ago involving (if i recall
correctly) an A320 where, despite a TOGA command, the aircraft did not
respond and sank into the trees at the end of the runway. when the
"black boxes" were made available to the NTSB and public the serial
numbers (as well as the paint) on what were purported to be the boxes
from the accident aircraft were not the same as those that had been
installed on the accident aircraft.