just sayin'
 

When the AP disconnected the PF pitched up, which eventually caused the plane to stall. Not sure why he did that, he should have just essentially left the controls alone and flown the pitch attitude at auto pilot disconnect.

But, I have no idea why the programming of the aircraft flight control systems silenced the stall warning system when in fact the aircraft was stalled. Whatever stall warning system is installed in that aircraft should have been active while the aircraft was stalled period, no excuses.

Doze

Whilst in Autopilot, notice the oscillation of the THS, it varies 1-2 degrees very consistently, and smoothes when PF inputs NU. It also flies at three degrees NOSE DOWN during the same time frame. Stick obviously caged in spring tension.

Am I seeing some "Weather" reactions? Or an anomalous "Buzz"? Of course it is not flutter, but flutter does present that way.......

Hi,

DW
Thank's for post here the graphic.
In the timeline transcript the BEA write:
Between 2H10min07 and 2H10min18 the vertical speed increase to 5200 ft/min
That's indeed true .. and when you put it in correlation with the graphic you see immediately it's a vertical speed to down (loss of altitude)
Vertical speed used by BEA in transcript is misleading less the down qualification (as in the timeline the BEA don't give the difference of altitude during the time gap)
So I can at least understand a little more why the PF give a up command (stick back) as a vario of 5200 ft/min down is not a negligible vertical speed ...

http://i.imgur.com/uYwUs.jpg

@jcjeant

Sorry, but not so - look at the altitude trace. From 2:10:07 to 2:10:18 the aircraft is climbing. It reaches the apogee of the climb at about 2:11:15 and then begins to fall.

DozyWannabe

ColganAir: I do recall that incident. They said that he had been recently trained to stick up because under certain circumanstances. So he had both the reflex and some training indicating it was the right thing. Like you say it was lower so they had no second chance after the initial nose up stall response. Clearly the problem with a stall is that you must do the opposite of normal flight i.e. a/c drops so I nose up to get back up whereas a stall - i have stalled, nose down to get my wings flying and generate lift.

It makes me think that stall recovery is ripe for automation, so long as above a certain height, AoA sensors valid, etc. We want the pilot to do something counter intuitive, quickly. Stall recovery is not practiced often enough to become familiar let alone a reflex except for special pilot categories.

Thanks for the graphic and scaling. Has anyone figured out why the speeds spike up and down between 400kts and 50kts. Looks really odd. If the PFD showed radical jumping then it confused them even more.

Hi,

Look better at the altitude line (blue first up table) .. it's a step down ... sorry but it's very evident .. with my spectacles or not :8

http://i.imgur.com/aOtC5.jpg

It's an initial step down, for sure (at 2:10:07 or thereabouts), possibly due to turbulence - but from that point onwards the aircraft is climbing, and at 2:10:18 the climb is well established.

@bearfoil - I reckon that's the autotrim trying to ride the weather.

jcjeant....... (vertical Speed)

And it can be understood at a gut level to be consistent with an overspeed dive. (As well as STALL). More so than a STALL, actually. Nose first, she slips quickly down. Butt first, less logical for the reads they saw.

I have never been in a Stall long enough for it to get loud. Were they all thinking "Dive", at one point?


A-6 guy. See up here. I think no bumps on the ss? That would accede way too much control to the Pilots. The control is like the one on the 402, a big bakelite frisbee that gives elbow cramps on short final. A WHEEL!

Does the Airbus have a stab trim button on the sidestick? If it does, there is absolutely NO sane reason why, in almost 3 minutes, at least one of the pilots would not take control and push both the stick and the trim button forward to try to break the stall. There is also NO sane reason to explain why those pilots would expect the plane to NOT be stalled with the excess pitch attitude they had.

Regardless of any control laws or design flaws, there was PLENTY of time to get the airplane out of the stall, and they failed to even make a reasonable attempt to do that. THAT is sad!

Hi,

Well it's a nice turbulence .. 5000 and more ft/min at vario and the plane stay at a down altitude for 7-10 seconds and in the same time the PF made nose up stick command
So .. and despite stick up commands (nose up) .. the aircraft still not climbing all this gap of time ..
Speak of little turbulence .. lol .. it's a downdraft for sure .. and a good ..
And I repeat .. the BEA transcript is misleading .. until you put the graphic in correlation ...

http://i.imgur.com/YECUr.jpg

The contrary (increase or no change of altitude) would be much more curious as there is a (false) loss of about 300 ft (recorded) at the start of each UAS event. (due to loss of mach correction for static pressure). -> See BEA reports #1 & 2 for explanations, including projected table of loss of airspeed effects on the other flight parameters.

Second, the change of pitch (reduction) that was recorded after 0209:58 is due to the crew reduction to Mach 0.80, followed by a change of N1 of -16% in 8 seconds. Pitch decreased from +1.8° to 0° in three seconds (0210:00-0210:03).

2 h 09 min 58
La gestion de la vitesse passe de
managée à sélectée. Le Mach
sélecté est 0,8.

2 h 10
L’assiette longitudinale diminue de
1,8° vers 0° en 3 secondes.
En 8 secondes, les N1 commandés
et les N1 passent de 100 % à
84 %.

Funny, that "staccato" buzz on the trace. Weather is that short term, and Consistent?

Another opinion, before I go all VS?

http://i1088.photobucket.com/albums/...r-vs-munge.png

That's the Vertical speed trace. The slight drop at 2:10:07 is nowhere *near* -5000ft/min.

Hi,

Indeed this is best understand with this graphic !

Is Vs calculated on anomalous readings? Or raw data?

The drop looks like less than 700fpm. The vertical speed trace is beyond my meager comprehension, are those fluctuations due UAS, or are those, they're not actual, are they?

That THS graphic is (they all are) full of bit rash, but the zipper trace is not bit rash, what is that dang deal, dozy?

Turbine D? Stop me. What is that? Because if it is real, the THS was oscillating 1+ degrees once per second. Right up til it quit. It looks at least noisy, if not mechanical.

A one second wave generated by the one second sampling/trigger that repeated? How long? The aft cabin must have shook like a wet dog.

@bearfoil - The graphic is too far zoomed-out and too low-resolution to draw any conclusions from anything other than large and significant trends. I don't think you're seeing quick fluctuations in THS angle so much as you are seeing the graphics renderer trying to cope with displaying the data at that granularity.

I'd say the extreme AoA was probably fouling the static data from 02:11:47 onwards.

I think that is reasonable, and thanks for your patience. What makes it suspicious to me is its connection with a mechanism that exhibits that precise artifact in rare though actual circumstances. We'll see.

Statics? Quite agree. especially with the ROLL coupling the AoA. For that matter, the airframe was in very untrod territory, all bets off.

Just to be clear, I am noting the zipper trace at prior to ap loss. I do not take that to be AoA fluctuations, there isn't time enough between 'cycles'.

No, no, no... V/S increased to +5,200 ft/min between 0210:07 and 0210:18 !!!

But sure, right before this point, two seconds before precisely, it decreased, say at -18,000 ft/min in one second... (or you can even make a 10 times much bigger number if you use 1/10th of second), because it was the false loss of about 300 ft due to UAS at 0210:05.

. ADR 1 (altitude, ft)
0210:00 -> 35,044
0210:05 -> 35,024 (UAS after this point, barely no mach correction of static pressure)
0210:09 -> 34,664 (ISIS: 34,900)
0210:11 -> 34,636 (lowest altitude recorded)
0210:17 -> 34,976
0210:25 -> 35,856

Explanations, BEA report #2 p.48: (they should have anticipated that far the cover up of those tracks "issues")

http://takata1940.free.fr/static.jpg

Hi,

I wonder if the PF had knowledge of this phenomena ..

To everyone here
 

When a french pilot said GAUCHISSEMENT he speak 's about ROLL

That common sense