Oh no. Here we go again. This is definitely not cool.

http://www.nbcnews.com/news/world/ai...e-says-n275696

On 12/27/14 11:29 PM, Tim wrote:
Oh no. Here we go again. This is definitely not cool.

http://www.nbcnews.com/news/world/ai...e-says-n275696

Another air travel tragedy.

They're not sure but the searchers are finding oily stuff floating. The news is saying it's probably on the bottom of the ocean...

Late last evening and just this morning, I've begun hearing discussions about the flight control systems in Airbus and pilot's misinterpretations being a possible factor. Another topic touched upon briefly was "jet upset", an event that can happen because of the fact that jets operating at such high altitudes where the air is very thin can be very close to the stalling speed even at the proper cruising speed. Any sudden movement of the controls or rapid change in relative wind because of weather (especially in a thunderstorm) can cause a high speed stall from which it is very difficult if at all possible to recover.

On Mon, 29 Dec 2014 11:31:38 -0500, wrote:

On Mon, 29 Dec 2014 06:30:56 -0800 (PST), Tim
wrote:

They're not sure but the searchers are finding oily stuff floating. The news is saying it's probably on the bottom of the ocean...

AvWeb had this interesting tidbit from the FAA about the AirBus 320
(the plane that floats better than it flies)

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/210629d32e131bc986257daa007ccddb/$FILE/2014-25-51_Emergency.pdf

http://tinyurl.com/qjmagsd

===

Automation run amok, scary stuff when there are lives at stake.

Tim wrote:
They're not sure but the searchers are finding oily stuff floating. The
news is saying it's probably on the bottom of the ocean...

The air bus is mostly plastic, so should be a lot of floating debris.

On 12/29/2014 3:20 PM, wrote:
On Mon, 29 Dec 2014 13:40:19 -0600, Califbill
wrote:

Tim wrote:
They're not sure but the searchers are finding oily stuff floating. The
news is saying it's probably on the bottom of the ocean...

The air bus is mostly plastic, so should be a lot of floating debris.

I am sure they will turn up a debris field pretty soon and this is
relatively shallow water so getting the boxes will be easier to do as
soon as we get decent assets in the area.

The more we hear, the more this sounds like a departure stall and an
unrecoverable dive into the sea.
If these 3d world bozos maintained their boxes, they should have the
real answer pretty soon. Politics and the legal issues may determine
when it is actually announced to the public.


Not technically a "departure" stall, but similar if the pilot
was trying to climb at too steep of an angle of attack for speed.

Departure stalls are practiced all the time in flight school and
simulate a take-off with too steep of an angle of attack. Basically
you are trying to stand the airplane on it's tail at full throttle
while balancing it with the rudder. Eventually it stops flying and
drops, usually to one side which, if not corrected, can result in a spin.

Another thing to consider is the plane was already at 38000 ft and the craft is rooted for a safety cowling of 39. And the pilot requested to climb? Maybe it was like the USS Thrasher only reverse

On 12/29/2014 4:30 PM, Tim wrote:
Another thing to consider is the plane was already at 38000 ft and the craft is rooted for a safety cowling of 39. And the pilot requested to climb? Maybe it was like the USS Thrasher only reverse


Thresher.

What I am hearing is it was flying at 32,000 ft and the pilot requested
38,000. That request was denied due to other aircraft in the area.

It raises the question of why the pilot tried to climb anyway (assuming
he did).

What actually happened will eventually come out if they recover the
black boxes. My pure guess right now is faulty input data in the flight
management system causing the pilot to react in a manner that was
inappropriate, further complicated by the thunderstorms and attempts to
avoid them.

I think the altitude rating is conservative and is for normal flight
conditions. It can actually go higher but it's not normal procedure.

On Mon, 29 Dec 2014 15:58:50 -0500, "Mr. Luddite"
wrote:

On 12/29/2014 3:20 PM, wrote:
On Mon, 29 Dec 2014 13:40:19 -0600, Califbill
wrote:

Tim wrote:
They're not sure but the searchers are finding oily stuff floating. The
news is saying it's probably on the bottom of the ocean...

The air bus is mostly plastic, so should be a lot of floating debris.

I am sure they will turn up a debris field pretty soon and this is
relatively shallow water so getting the boxes will be easier to do as
soon as we get decent assets in the area.

The more we hear, the more this sounds like a departure stall and an
unrecoverable dive into the sea.
If these 3d world bozos maintained their boxes, they should have the
real answer pretty soon. Politics and the legal issues may determine
when it is actually announced to the public.


Not technically a "departure" stall, but similar if the pilot
was trying to climb at too steep of an angle of attack for speed.

Departure stalls are practiced all the time in flight school and
simulate a take-off with too steep of an angle of attack. Basically
you are trying to stand the airplane on it's tail at full throttle
while balancing it with the rudder. Eventually it stops flying and
drops, usually to one side which, if not corrected, can result in a spin.

===

If you closely read the Airworthiness Directive that Greg found, you
will notice that it is not an actual stall condition they are warning
about. Instead it is an instrumentation error that triggers the
flight automation system into an erroneous stall recovery mode. The
stall recovery automation does the text book solution by putting the
plane into a nose down dive to build airspeed and get the plane flying
again. The problem is that the plane was never in a stall to begin
with, and there is a special sequence that the pilots have to follow
to disable the automation and get the plane out of the dive. Scary
stuff if it takes the pilots by surprise and they are not carefully
trained.

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/210629d32e131bc986257daa007ccddb/$FILE/2014-25-51_Emergency.pdf

I quote:

-----------------------------------------

An occurrence was reported where an Airbus A321 aeroplane encountered
a blockage of two Angle of Attack (A of A) probes during climb,
leading to activation of the Alpha Protection (Alpha Prot) while the
Mach number increased. The flightcrew managed to regain full control
and the flight landed uneventfully. When Alpha Prot is activated due
to blocked A of A probes, the flight
control laws order a continuous nose down pitch rate that, in a worst
case scenario, cannot be stopped with backward sidestick inputs, even
in the full backward position. If the Mach number increases during a
nose down order, the A of A value of the Alpha Prot will continue to
decrease. As a result, the flight control laws will continue to order
a nose down pitch rate, even if the speed is above minimum selectable
speed, known as VLS.

This condition, if not corrected, could result in loss of control of
the aeroplane.

---------------------------------------------------------