Another Blow to Airbus

a writes:

A couple of days ago the NTSB found the 320 series to have too
sensitive a rudder, it can be torn off with peddle pressures. What's
especially of interest is the problem seems to persist even when crews
are given special training about the problem.

There are some details here.

http://content.usatoday.com/communit...y-2001-crash/1

Hmm. The whole purpose of having computers that fly the airplane, and ignore
the pilots' inputs if they find them contrary to what French engineers have
decided, is to prevent exactly this sort of incident. Why don't the
all-knowing, all-wise computers prevent any rudder movement that might
endanger structural integrity?

If my confidence in Airbus weren't already almost nonexistent, this news would
certainly crank it down a few notches.

On Aug 9, 1:49*am, Mxsmanic wrote:
a writes:
A couple of days ago the NTSB found the 320 series to have too
sensitive a rudder, it can be torn off with peddle pressures. What's
especially of interest is the problem seems to persist even when crews
are given special training about the problem.

There are some details here.

http://content.usatoday.com/communit.../2010/08/ntsb-...

Hmm. The whole purpose of having computers that fly the airplane, and ignore
the pilots' inputs if they find them contrary to what French engineers have
decided, is to prevent exactly this sort of incident. Why don't the
all-knowing, all-wise computers prevent any rudder movement that might
endanger structural integrity?


Because the computers don't know actually know the relationship
between yaw, airspeed and allowable rudder input/structural load and
they are not required to. Neither do most pilots when they step on the
rudder pedals. Think about it...

Cheers

Flaps_50! writes:

Because the computers don't know actually know the relationship
between yaw, airspeed and allowable rudder input/structural load and
they are not required to.

They can be programmed to know this. And much of the reputation of Airbus
rests upon its implicit and explicit claims that their heavy computerization
of their flight decks somehow makes aircraft safer. But if the computer isn't
even programmed well enough to prevent something like this, how can it be
making the airplane safer?

Neither do most pilots when they step on the rudder pedals. Think
about it...

It would be tough for a pilot, but not for a computer.

There's a fundamental contradiction between claiming on the one hand that
computer-enforced limitations on control movements can prevent structural
damage, and then claiming on the other hand that computers should not be held
responsible for that enforcement. Either they protect the airplane or they
don't. If they are only creating the illusion of protection, then they need to
go.

On Aug 15, 3:19*am, "Flaps_50!" wrote:
On Aug 9, 1:49*am, Mxsmanic wrote:



a writes:
A couple of days ago the NTSB found the 320 series to have too
sensitive a rudder, it can be torn off with peddle pressures. What's
especially of interest is the problem seems to persist even when crews
are given special training about the problem.

There are some details here.

http://content.usatoday.com/communit.../2010/08/ntsb-....

Hmm. The whole purpose of having computers that fly the airplane, and ignore
the pilots' inputs if they find them contrary to what French engineers have
decided, is to prevent exactly this sort of incident. Why don't the
all-knowing, all-wise computers prevent any rudder movement that might
endanger structural integrity?

Because the computers don't know actually know the relationship
between yaw, airspeed and allowable rudder input/structural load and
they are not required to.

You jest, surely?? If I understand what you say, most flights in
Autopilot through moderate turbulence would result in splintered
aluminum tubes raining down.

Any pilot would tell you that humans are incapable of matching
computers' sophistication in precision flying. Why else would most
airline SOPs actually bar pilots from hand-flying above 1,000 feet?


Neither do most pilots when they step on the
rudder pedals. Think about it...


Well, if the manufacturer intends to convey a limit that can be
reached where the airplane's structure is threatened, it should either
automatically limit the pilot's motion to a point before such
threshold is reached. Proper pilot training is a sine qua non, however
not a substitute for the automatic limitation.

I still can't believe the ultra-sophisticated Airbuses allow rudders
to move so much that the empennage can actually sever from the rest of
the fuselage. As omissions go, that must take the biscuit!

Cheers,

Ramapriya

D Ramapriya writes:

Any pilot would tell you that humans are incapable of matching
computers' sophistication in precision flying. Why else would most
airline SOPs actually bar pilots from hand-flying above 1,000 feet?

Above 1000 feet? Did you miss a zero there?

I know that RVSM requires autopilot and some airlines have policies that
require autopilot for normal operations under certain conditions, but
requiring that autopilot be used above 1000 feet is hard to believe.

Which airlines require this, and why?

I still can't believe the ultra-sophisticated Airbuses allow rudders
to move so much that the empennage can actually sever from the rest of
the fuselage. As omissions go, that must take the biscuit!

Having been the victim of French engineering on multiple occasions in the
past, I have no trouble believing that French engineers overlooked this. Their
objective is not to maximize safety, but to show the world how clever they are
(a rather tall order, given that they aren't actually very clever).

On Aug 15, 6:41*am, Mxsmanic wrote:
D Ramapriya writes:
Any pilot would tell you that humans are incapable of matching
computers' sophistication in precision flying. Why else would most
airline SOPs actually bar pilots from hand-flying above 1,000 feet?

Above 1000 feet? Did you miss a zero there?

Nope. 1000-2000 are the typical figures for most airlines in the
Middle East. I could get you figures from Qatar Air and Etihaad (two
of the leading lights, not just of the region) in a few days.


I know that RVSM requires autopilot and some airlines have policies that
require autopilot for normal operations under certain conditions, but
requiring that autopilot be used above 1000 feet is hard to believe.


Ditto here, but that's the way it is. "Passenger comfort and safety"
is what's apparently at the root of this requirement.


Which airlines require this, and why?

I still can't believe the ultra-sophisticated Airbuses allow rudders
to move so much that the empennage can actually sever from the rest of
the fuselage. As omissions go, that must take the biscuit!

Having been the victim of French engineering on multiple occasions in the
past, I have no trouble believing that French engineers overlooked this. Their
objective is not to maximize safety, but to show the world how clever they are
(a rather tall order, given that they aren't actually very clever).


I beg to differ, mate. Apart from one A320 crash - a runway overrun in
Warsaw? - where the computers misread aquaplaning and didn't allow
braking, I struggle to think of an incident where computers and/or
automation caused a crash. On the other hand, I know a few instances
where the automation forfended accidents by thwarting ill-judged
premature takeoff attempts, which were an upshot of wrong loading
figures having been input, etc. There have been at least two incidents
involving Emirates A340 aircraft and one Virgin A330.

Not being a pilot, I'm utterly unqualified to enter Boeing-Airbus
debates but it does strike me that Boeing does have more friends in
the press, with its glitches getting downplayed. The dicky RA that
contributed to the Turkish crash at Schipol and the near-disaster with
the BA 747 @ Jo'burg caused by a faulty slat sensor are good examples.
If you analyze Airbus crashes, nearly every one of them has been
because of pilot error, including the Aeroflot A310 where they risibly
ended up blaming the kid on the Cap'n's seat when what really happened
was that the 3 other qualified pilots looking on within the cabin
failed for a very long time to detect that the AP had disconnected.
Most Airbus crash reports would tell you that they could've been
prevented had pilots acted correctly.

I admire the 747s and 777s and think the A340 a clunker, yet would
wager my life on Airbus's sophistication any day. It could be just me
but that's the way it is

Ramapriya

On Aug 15, 1:31*pm, D Ramapriya wrote:
On Aug 15, 3:19*am, "Flaps_50!" wrote:





On Aug 9, 1:49*am, Mxsmanic wrote:

a writes:
A couple of days ago the NTSB found the 320 series to have too
sensitive a rudder, it can be torn off with peddle pressures. What's
especially of interest is the problem seems to persist even when crews
are given special training about the problem.

There are some details here.

http://content.usatoday.com/communit.../2010/08/ntsb-...

Hmm. The whole purpose of having computers that fly the airplane, and ignore
the pilots' inputs if they find them contrary to what French engineers have
decided, is to prevent exactly this sort of incident. Why don't the
all-knowing, all-wise computers prevent any rudder movement that might
endanger structural integrity?

Because the computers don't know actually know the relationship
between yaw, airspeed and allowable rudder input/structural load and
they are not required to.

You jest, surely?? If I understand what you say, most flights in
Autopilot through moderate turbulence would result in splintered
aluminum tubes raining down.


I don't know if autopilots ever put in full rudder deflection during
yaw -do they?

Cheers

On Aug 15, 1:45*pm, "Flaps_50!" wrote:
On Aug 15, 1:31*pm, D Ramapriya wrote:



On Aug 15, 3:19*am, "Flaps_50!" wrote:

On Aug 9, 1:49*am, Mxsmanic wrote:

a writes:
A couple of days ago the NTSB found the 320 series to have too
sensitive a rudder, it can be torn off with peddle pressures. What's
especially of interest is the problem seems to persist even when crews
are given special training about the problem.

There are some details here.

http://content.usatoday.com/communit.../2010/08/ntsb-...

Hmm. The whole purpose of having computers that fly the airplane, and ignore
the pilots' inputs if they find them contrary to what French engineers have
decided, is to prevent exactly this sort of incident. Why don't the
all-knowing, all-wise computers prevent any rudder movement that might
endanger structural integrity?

Because the computers don't know actually know the relationship
between yaw, airspeed and allowable rudder input/structural load and
they are not required to.

You jest, surely?? If I understand what you say, most flights in
Autopilot through moderate turbulence would result in splintered
aluminum tubes raining down.

I don't know if autopilots ever put in full rudder deflection during
yaw -do they?


My point is that flight automation would forestall a situation where
the airframe is imperiled, including not deflecting the rudder beyond
safe limits.

Ramapriya

On 8/8/2010 7:05 AM, a wrote:
A couple of days ago the NTSB found the 320 series to have too
sensitive a rudder, it can be torn off with peddle pressures. What's
especially of interest is the problem seems to persist even when crews
are given special training about the problem.

There are some details here.

http://content.usatoday.com/communit...y-2001-crash/1

The more I fly and the older I get the more I want to be gentle with
the flight controls. Remember, fellow aviators, there are demons
lurking near the edges of the envelope.

I am not going to act all shocked that pilots can pull pieces off of an
airframe: these pieces include
1) Wings
2) horizontal elevator/stabilator
3) vertical stabilizer, and pieces hinged or connected to the above.

That includes EVERY plane that has a certificate of airworthiness.

It is more troubling if pilots can get into the danger area (maneuver
speed plus as you know) and still inadvertently pull bits off if
correctly trained. A very troubling thought: how many incidents had
ex military fighter pilots at the yoke?

Brian W

brian whatcott wrote:
It is more troubling if pilots can get into the danger area (maneuver
speed plus as you know) and still inadvertently pull bits off if
correctly trained.

The most troubling part is that many pilots think the cannot pull bits
off below maneuver speed.