Airbus Story (FWIW)

I just got this email from a retired airline pilot:

From a retired NWA buddy of mine


This from Brent Stratton, a friend and NWA pilot I flew the B-757 with
out of our Tokyo base.........Now obviously on the A-330**



Well, I'm sure you have all heard of the Air France accident. I fly the
same plane, the A330.

******Yesterday while coming up from Hong Kong to Tokyo, a 1700nm 4hr.
flight, we experienced the same problems Air France had while flying
thru bad weather.
I have a link to the failures that occurred on AF 447. My list is almost
the same.
http://www.eurocockpit.com/images/acars447.php
************
******The problem I suspect is the pitot tubes ice over and you loose
your airspeed indication along with the auto pilot, auto throttles and
rudder limit protection. The rudder limit protection keeps you from over
stressing the rudder at high speed.
******
******Synopsis;
Tuesday 23, 2009 10am enroute HKG to NRT. Entering Nara Japan airspace.

******FL390 mostly clear with occasional isolated areas of rain, clouds
tops about FL410.
Outside air temperature was -50C TAT -21C (your not supposed to get
liquid water at these temps). We did.

******As we were following other aircraft along our route. We approached
a large area of rain below us. Tilting the weather radar down we could
see the heavy rain below, displayed in red. At our altitude the radar
indicated green or light precipitation, most likely ice crystals we
thought.

******Entering the cloud tops we experienced just light to moderate
turbulence. (The winds were around 30kts at altitude.) After about 15
sec. we encountered moderate rain. We thought it odd to have rain
streaming up the windshield at this altitude and the sound of the plane
getting pelted like an aluminum garage door. It got very warm and humid
in the cockpit all of a sudden.
Five seconds later the Captains, First Officers, and standby airspeed
indicators rolled back to 60kts. The auto pilot and auto throttles
disengaged. The Master Warning and Master Caution flashed, and the
sounds of chirps and clicks letting us know these things were happening.
******Jerry Staab, the Capt. hand flew the plane on the shortest vector
out of the rain. The airspeed indicators briefly came back but failed
again. The failure lasted for THREE minutes. We flew the recommended
83%N1 power setting. When the airspeed indicators came back. we were
within 5 knots of our desired speed. Everything returned to normal
except for the computer logic controlling the plane. (We were in
alternate law for the rest of the flight.) *

******We had good conditions for the failure; daylight, we were rested,
relatively small area, and light turbulence. I think it could have been
much worse. Jerry did a great job fly and staying cool. We did our
procedures called dispatch and maintenance on the SAT COM and landed in
Narita. That's it.

--
Remove _'s from email address to talk to me.

Orval Fairbairn wrote:
I just got this email from a retired airline pilot:

From a retired NWA buddy of mine


This from Brent Stratton, a friend and NWA pilot I flew the B-757 with
out of our Tokyo base.........Now obviously on the A-330



Well, I'm sure you have all heard of the Air France accident. I fly the
same plane, the A330.

Yesterday while coming up from Hong Kong to Tokyo, a 1700nm 4hr.
flight, we experienced the same problems Air France had while flying
thru bad weather.
I have a link to the failures that occurred on AF 447. My list is almost
the same.
http://www.eurocockpit.com/images/acars447.php

The problem I suspect is the pitot tubes ice over and you loose
your airspeed indication along with the auto pilot, auto throttles and
rudder limit protection. The rudder limit protection keeps you from over
stressing the rudder at high speed.

Synopsis;
Tuesday 23, 2009 10am enroute HKG to NRT. Entering Nara Japan airspace.

FL390 mostly clear with occasional isolated areas of rain, clouds
tops about FL410.
Outside air temperature was -50C TAT -21C (your not supposed to get
liquid water at these temps). We did.

As we were following other aircraft along our route. We approached
a large area of rain below us. Tilting the weather radar down we could
see the heavy rain below, displayed in red. At our altitude the radar
indicated green or light precipitation, most likely ice crystals we
thought.

Entering the cloud tops we experienced just light to moderate
turbulence. (The winds were around 30kts at altitude.) After about 15
sec. we encountered moderate rain. We thought it odd to have rain
streaming up the windshield at this altitude and the sound of the plane
getting pelted like an aluminum garage door. It got very warm and humid
in the cockpit all of a sudden.
Five seconds later the Captains, First Officers, and standby airspeed
indicators rolled back to 60kts. The auto pilot and auto throttles
disengaged. The Master Warning and Master Caution flashed, and the
sounds of chirps and clicks letting us know these things were happening.
Jerry Staab, the Capt. hand flew the plane on the shortest vector
out of the rain. The airspeed indicators briefly came back but failed
again. The failure lasted for THREE minutes. We flew the recommended
83%N1 power setting. When the airspeed indicators came back. we were
within 5 knots of our desired speed. Everything returned to normal
except for the computer logic controlling the plane. (We were in
alternate law for the rest of the flight.)

We had good conditions for the failure; daylight, we were rested,
relatively small area, and light turbulence. I think it could have been
much worse. Jerry did a great job fly and staying cool. We did our
procedures called dispatch and maintenance on the SAT COM and landed in
Narita. That's it.



Sounds plausible to me. A direct path from unexpected rain at high
altitude (warm massive updraft in cu-nim?) to ice to frozen pitots to
loss of rudder limiting.
Then all it takes is injudicious heavy rudder in heavy turbulence
and you are in deep do-do....

Brian W

Brian Whatcott wrote:

Sounds plausible to me. A direct path from unexpected rain at high
altitude (warm massive updraft in cu-nim?) to ice to frozen pitots to
loss of rudder limiting.

This meteorologist suggests that it would be highly unlikely for the Air
France flight to have encountered rain or even supercooled water. He also
suggests that the cause, if any, would be from descending air warming
rather than an updraft:

http://www.weathergraphics.com/tim/af447/

Then all it takes is injudicious heavy rudder in heavy turbulence
and you are in deep do-do....

Why would they be using rudder at cruising speed? Further, according to
the discussion in some of the other groups, the rudder limiter is still
effective in alternate law. It supposedly clamps the limit at where it was
when the shift was made from normal to alternate law.

James Robinson wrote:
Brian Whatcott wrote:
Sounds plausible to me. A direct path from unexpected rain at high
altitude (warm massive updraft in cu-nim?) to ice to frozen pitots to
loss of rudder limiting.

This meteorologist suggests that it would be highly unlikely for the Air
France flight to have encountered rain or even supercooled water. He also
suggests that the cause, if any, would be from descending air warming
rather than an updraft:

http://www.weathergraphics.com/tim/af447/

I read this over carefully, a few days ago. It seems like a respectable
evaluation. And yes, it is highly unlikely situations which we are
addressing. Both the eye-witness testimony of a person observing
considerable precipitation at altitude, and the obvious meteorological
observation that the higher the air, the colder, and the dryer (in
absolute terms). If you accept this, then you have to accept that the
water can only have come from below, via meso scale uplift (as the
report puts it). That's not to say the uplift was not pulling water up
higher than the fatal flight, then dropping it. These buildups are
invariably turbulent.

Brian W

Why would they be using rudder at cruising speed? *Further, according to
the discussion in some of the other groups, the rudder limiter is still
effective in alternate law. It supposedly clamps the limit at where it was
when the shift was made from normal to alternate law.

....look at the first line in the ACARS messages: RUD TRV LIM FAULT...
in other words, the rudder travel limiter not doing what it was
supposed to do, i.e., limit the rudder travel. 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. Despite having a rudder travel limiter in place and
working, 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. 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.

spanky wrote:



Why would they be using rudder at cruising speed? *Further, according
to the discussion in some of the other groups, the rudder limiter is
still effective in alternate law. It supposedly clamps the limit at
where it was when the shift was made from normal to alternate law.

...look at the first line in the ACARS messages: RUD TRV LIM FAULT...
in other words, the rudder travel limiter not doing what it was
supposed to do, i.e., limit the rudder travel.

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.

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.

Despite having a rudder travel limiter in place and working,

The A300 was not a FBW aircraft.

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?

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?

On Jun 28, 9:36*pm, James Robinson wrote:
spanky wrote:

Why would they be using rudder at cruising speed? *Further, according
to the discussion in some of the other groups, the rudder limiter is
still effective in alternate law. It supposedly clamps the limit at
where it was when the shift was made from normal to alternate law.

...look at the first line in the ACARS messages: RUD TRV LIM FAULT...
in other words, the rudder travel limiter not doing what it was
supposed to do, i.e., limit the rudder travel. *

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.

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.

Despite having a rudder travel limiter in place and working,

The A300 was not a FBW aircraft.

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?

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?

Look at the behaviour of US Scare and Boeing with the 737 rudder
reversal problem.

"Problem? There is no problem" Meanwhile, back at Area 51, er,
Seattle, all manner of work towards a solution is being performed.

Richard wrote:

Look at the behaviour of US Scare and Boeing with the 737 rudder
reversal problem.

"Problem? There is no problem" Meanwhile, back at Area 51, er,
Seattle, all manner of work towards a solution is being performed.

They had access to the FDR information, and I don't think US Airways was
complicit in blaming pilot error. That was only Boeing, and yes, they
were ass covering.

In the case of AF447, the last thing the would want is for another aircraft
to self-destruct, given the design is the basis for the potential US tanker
program, and the 350. Without the FDRs, can they be sure they have
actually solved the problem? Do they know enough to identify the cause
with certainty, and know what needs to be done to correct things?

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.

Loss of airspeed renders the rudder limiter inoperative, which can
lead to vertical stabilizer overstress and possible failure. This may
have happened on Flight_447. One possible solution would be to add
strain gauges that directly measure the stress in the vertical
stabilizer and feed this data to the rudder limiter along with the
airspeed and altitude information. This would allow the rudder
limiter to continue functioning even when the air-data system fails.