Air France Black Box ResultsPilot Error

"Robert Barker" wrote:
And to protect Airbus, they'll call it "pilot error".

Based on what I've read, that is most likely the case. As I understand it,
this isn't the first time the pitot tubes have iced up on an Airbus and the
pilot has had to fly manually. This is just the first time a pilot has
failed to resort to book procedure all the way to impact.

From what I've read, if the speed readings don't make sense, the book
procedure calls for the pilot to set a specific thrust and elevator
setting. It sounds like the junior pilot did not follow the book procedure.

Impartial
analysis will probably show the pilots had their hands full trying to
turn off all the automation so they could actually fly the stupid
thing.

As I understand it, the autopilot released control to the pilot once the
speed readings on the pitot dropped below a threshold point, so there was
no automation to turn off - it was already off.

"Robert Barker" wrote:

"Edward A. Falk" wrote:

Robert Barker wrote:

Airbus thinking seems to be that the computer is always right so
don't argue with it. There's a LOT more that makes Airbus less than
a treat to fly.

There's a saying that on an Airbus, the autopilot outranks the
captain.

And to protect Airbus, they'll call it "pilot error". Impartial
analysis will probably show the pilots had their hands full trying to
turn off all the automation so they could actually fly the stupid
thing.

No, the system switched to alternate law all by itself when the speed
signals went screwy, and there was no need to shut off the automation. In
this mode, it is like flying any direct fly aircraft, but without stall
protection. It still maintains some protecton against overstressing the
airframe. Automation didn't initiate the climb, which is what doomed the
flight, it was the pilot input that did that, resulting in the upset.

On the surface, the pilot lost control of a perfectly flyable airplane,
which was in stable flight before he took control. However, part of the
investigation certainly has to be why the pilot flying didn't put the
nose down as a reaction to repeated stall warnings. This is something
any pilot learns when first starting to fly, and should be a natural
reaction when hearing the alarm. Was he overwhelmed by all the alarms and
missed the stall warning? Did he think he was correcting for wind shear
or some other problem?

The pilot of the Colgan Air flight approaching Buffalo did the same
thing, and some studies suggest that when surprised, the majority of
pilots will try to pull the nose up when they hear a stall warning, which
is exactly the wrong thing to do. Is it just human nature to pull back
on the controls, thinking you want to stay away from the ground, rather
than point the aircraft at the ground to recover?

Further, why did he never figure out that he was in a stall and take
appropriate action? Beyond the alarms, the lack of wind noise past the
cockpit should have been an obvious clue, yet only once did he try
putting the nose down, and only then for a short time.

That said, there have been a number of other times on both Boeing and
Airbus aircraft where the pitots froze up in similar conditions, and the
pilots were easily able to maintain control without the need for
aggressive control inputs. Why was it different this time?

James Robinson writes:

The pilot of the Colgan Air flight approaching Buffalo did the same
thing, and some studies suggest that when surprised, the majority of
pilots will try to pull the nose up when they hear a stall warning, which
is exactly the wrong thing to do. Is it just human nature to pull back
on the controls, thinking you want to stay away from the ground, rather
than point the aircraft at the ground to recover?

Yes, I think so. The number of pilots who do this, even with long experience
and extensive training that is supposed to prevent them from doing it, implies
that it has some sort of instinctive component. Perhaps in much the same way
that a person will reach out to catch a falling coffee pot, even though he
knows very well that the coffee pot is extremely hot and will burn his hands
badly if he just grabs it.

Further, why did he never figure out that he was in a stall and take
appropriate action? Beyond the alarms, the lack of wind noise past the
cockpit should have been an obvious clue, yet only once did he try
putting the nose down, and only then for a short time.

Perhaps all the other alarms distracted him. Apparently a lot of things were
going wrong.

That said, there have been a number of other times on both Boeing and
Airbus aircraft where the pitots froze up in similar conditions, and the
pilots were easily able to maintain control without the need for
aggressive control inputs. Why was it different this time?

Sensory overload and no prior experience in the same type of situation,
perhaps.

Jim Logajan wrote:

The PBS NOVA TV series aired an episode in February that attempted to
apply accident forensics on the facts then known. This being nearly
two years after the crash, with the not unreasonable assumption that
the recorders would never be recovered, they could not be accused of
leaping to conclusions.

If the preliminary indications from the recorders are as claimed, then
it appears the NOVA experts did a remarkable job in determining the
most probable accident sequence sans recorder data.

The NOVA show can be viewed online here (I thought it well done for
its target audience):

http://www.pbs.org/wgbh/nova/space/c...light-447.html

A professional airline pilot writing on another blog doesn't agree with
its quality:

"Nova tried to explain the events leading up to the crash. I'll address
only the Wx radar here.

Their expert, from NCAR part of NOAA, said the Wx radar on AF447 had only
50 mile range. Strike one. It's 320 miles, if the storm is dense enough
to matter.

Nova showed a small/medium sized cell in the plane's track toward the
major line of storm. Nova said the small cell would obscure the radar
view of the major storm, causing them to stumble into it.

Poppycock/BS/Hogwash! The Wx radar on 447 returns were calibrated for
rainfall intensity. When the intensity of return is high, an algorithm
called "Path Attenuation Compensation" kicks in to assure calibrated
display. When the storm is too intense for penetration without reserve to
see the full picture of the "storm behind the storm," the Wx radar puts
up a yellow band, called PAC Alert, at the outer range ring of the
display.

I have great respect for Public Broadcasting in the US, but this program
failed miserably. I wonder if major sponsor, billionaire David H. Koch,
didn't have too much editorial input?
--------

PS: Why did they choose to interview a radar guy unfamiliar with that
specific airborne Wx radar? The least the guy could have done would be to
study the Pilot's Guide in NCAR's own C-130, which is operationally just
like the WX radar that was in AF447."

On 2011-05-29, James Robinson wrote:
No, the system switched to alternate law all by itself when the speed
signals went screwy, and there was no need to shut off the automation.

Indeed.

On the surface, the pilot lost control of a perfectly flyable airplane,
which was in stable flight before he took control. However, part of the
investigation certainly has to be why the pilot flying didn't put the
nose down as a reaction to repeated stall warnings. This is something
any pilot learns when first starting to fly, and should be a natural
reaction when hearing the alarm. Was he overwhelmed by all the alarms and
missed the stall warning? Did he think he was correcting for wind shear
or some other problem?

Like any crash, there is a chain of events. There could be user interface
issues (a famous example of this was the Three Mile Island incident,
a famous aviation related incident of bad user interface being a
contributory cause of a crash was the Boeing 737 that crashed near
Kegworth in England after the crew shut down the wrong engine).
There could be training issues. I'm certainly not going to condemn
a crew even though on the obvious face of it, it may look like pilot
error. There is likely to be plenty of contributory factors.

The pilot of the Colgan Air flight approaching Buffalo did the same
thing, and some studies suggest that when surprised, the majority of
pilots will try to pull the nose up when they hear a stall warning, which
is exactly the wrong thing to do.

I think in the case of Colgan Air, the recent emphasis on icing related
tailplane stalls (recovery procedure the opposite of main wing stall)
may have been a contributory cause. Similarly, perhaps the high emphasis
on windshear recovery (which when all the automation in a modern airliner
be it Boeing or Airbus is to do a maximum performance climb, which may
not work as expected if the automation is turned off and the crew are
too busy to remember that stall protection has gone away). These
aren't the first times either, long before automation was a factor
a crew crashed a Hawker Siddeley Trident 3 (an airliner superficially
similar to a Boeing 727, 3 engines and T-tail) near London by getting it into
a deep stall. After inadvertently retracting the leading edge devices,
the crew deliberately deactivated the stick shaker and pusher while
pulling up, getting the aircraft into a deep stall from which it was
impossible to recover. Why? There had been recent incidents of false
stick shaker activations, the weather was not great, the captain had
an undiagnosed heart condition which may have started to cause him some
pain thus fogging his judgement, there were industrial relations problems
(with the captain on one side of the argument and the rest of the crew
on the other), and the first officer was timid about challenging the
captain's decision to keep pulling back on the stick because he had
recently been reprimanded for challenging a captain. So the captain
assumed it was a false activation of the stick shaker and turned off
the stick shaker and stick pusher, and stalled it.

Is it just human nature to pull back
on the controls, thinking you want to stay away from the ground, rather
than point the aircraft at the ground to recover?

And how often is stall avoidance/recovery trained for in an airline
setting?

On 2011-05-26, James Robinson wrote:
Mxsmanic wrote:
At Airbus, pilots are always at fault by definition, no matter who or
what was actually at fault. Remember Habsheim.

Ignoring much of the controvery over the investigaion, the pilot at
Habsheim should get a major chunk of the blame.

The aircraft also actually performed slightly better than book figures.
The aircraft was put in a situation from which it would be impossible
to get away without hitting those trees, whether it was fly by wire
or fly by steel cable.

On Jun 2, 10:46*am, Dylan Smith wrote:

And how often is stall avoidance/recovery trained for in an airline
setting?

Not nearly enough.
Dudley Henriques

Have you catch the episode of aviation destroyed and cause of bee. A bee has build a small net on the rear side of wings. Just because of that simulator showing a wrong reading and pilot increased the speed though he know that something wrong is happening.

On Jun 2, 12:38*pm, Dudley Henriques
wrote:
On Jun 2, 10:46*am, Dylan Smith wrote:

And how often is stall avoidance/recovery trained for in an airline
setting?

Not nearly enough.
Dudley Henriques

Unless the controls were jammed and the attitude indicator was busted,
it is tough to blame any other instrument failure for this. Most
likely pilot error due to complacency developed from thousands of
hours of cruising at flight levels in a highly automated airplane.

(Edward A. Falk) wrote:

A heavy aircraft at high altitude is approaching what is known as
the "coffin corner" in which slowing down *or* speeding up is a Very
Bad Thing. Being up there and not knowing your airspeed would be very
unhappy-making. But again, the proper thing to do in those
circumstances is to lose altitude, so pulling up would still be the
wrong response.

Found a fascinating blog when searching for the term "coffin corner"
on the intertubes:
http://www.fromtheflightdeckbook.com...in-corner.html

It was written over a year ago, and speculates that Air France 447
encountered the coffin corner.

The report from the French accident investigation agency is a bit too thin
on details to come to any firm conclusions, but it does imply that the
initial zoom climb was initiated by the PF, and not because of weather or
because of a low or high speed stall. There is no doubt that once the
climb was initiated, the aircraft became a victim of a low speed stall,
which the crew were not able to recover from.

The vexing question is why the PF initiated the climb. We will have to
wait for the final report for more enlightenment, otherwise it's just
speculation.