Any updates on the Airbus lost in the Atlantic?

Watching OGlobo tonight (Brasilian news) and the quasi-official reports they have from France are all being "framed" to point in the direction of pilot error. No surprise there..........the equipment and the industry that produces it is much more important than a couple of hundred tourists and an aircrew. They have already been replaced, but the industry cannot readily be, as it would potentially bring down a government and utterly destroy an already shattered eurozone economy if the truth was to come out much earlier.

Reading Pprune for about 3 hours today as well, and the current type rated Airbus pilots posting there seem to be of the conclusion that the equipment (specifically the overwhelming level of Airbus automation) is directly to blame.

AF is a third world airline with 3 hull losses since 2000..............

 

Can you share a few links on that? I've been reading off and on and I did not see one post that said that.

 

Um... I have a question that might strike a few of you as odd... but ummm can you other males tell when you are descending rapidly without the use of any instruments?

Let's just say there are a few parts of me that always know. If I were falling at the speed they were... I'd know! (just me?)

 

Keep reading Pprune..........

 

If you were falling at that speed you would absolutely know. You feel the weightlessness and you can see things in the cockpit floating or on the ceiling.

 

Did you mean to say "doesn't" or "does"? Are you agreeing with me?

I'm not reading the information the same way you are. It seems to me they were able to recover from the initial stall warning without an actual stall indicated be the rate of climb after the warning.

Then they physically positioned the THS to 13 degrees nose up. Which seems puzzling to me and something that would be difficult to control. I wonder if the Captain picked up on the setting as he came back into the cockpit and took PIC.

I'm not certain what instruments were lost. But, I'm very puzzled by the pilots actions. Though we don't have any data on the storm and the fluid (air) they were flying through.

 

Nope. Put-up or shut-up.

 

Anybody here whose first inclination after getting a stall warning horn at altitude is not to push the nose down? In the olden days when we had bold face items we had to memorize, stick forward and centered was one of them.

So two primary causes:

1) AF did not change out the pitots rapidly enough when warned to do so by Airbus.

2) Aircrew failed to fly the frigging airplane and allowed the aircraft to depart controlled flight.

Secondary causes:

1) Pitot system iced up.

2) Bad weather and turbulence causing the aircraft to be flown at high altitude to avoid as much weather as possible and keeping the crew confused after the aircraft departed controlled flight.

3) Aircraft commander not at his station.

4) Aircrew unable to determine what was happening from the warnings they received. Should have had an air data system failure indication initially, but failed to recognize the significance of the failure warning.

With the other incidents with the pitots, you would think Airbus aircrews would have received some simulator training showing what happens when the pitot freezes and you lose airspeed and VVI information.

Do they have any standby instruments using an alternative air source system, or are the displays all Kalman filtered inputs from the air data system and the INS/GPS? The INS and GPS certainly knew what was happening, even if the data lags an air data system and you use a baro/inertial mixer. Unless of course, Kalman was weighted so heavily on air data, it just threw out the INS/GPS inputs and they were not presented in a back-up form.

Taz
Terry Phillips

 

You would feel and see those things only during the initial acceleration of the fall, not while descending at a relatively constant rate which the plane seemed it did for quite some time.

 

Weren't they in moderate turbulence as well? That could certainly confuse things also.

 

Loss of airspeed indication is a memory item and it calls for 5° pitch and CLB thrust setting until you sort things out. That of course did not happen.

yeah um... I'd feel it... trust me. (the key word in my initial post is 'male') maybe I'm just special.

 

All this stuff is well over my head and I have to just listen but if I had a stall warning either from a horn or stick shaker believe I would push forward instinctively and stay there until I could sense that the airplane was flying but these guys were obviously terribly confused.

 

So, what you're saying is you don't think you knew they were descending at a rate of 10000'/ minute.

Have you ever done "zero G" maneuvers?

 

decending at 10,000'/minute is a constant speed decent, thus still 1G.

0 G requires constant acceleration towards the ground.

 

still confused by the rudder travel fault so early in the telemetry.

Did the lack of valid air data cause the rudder to report a fault because it had no or bad data?

or was there in fact a problem with the tail already, triggering the rest of the failures and loss of control?


i can see they are not looking at the tail " breaking off " but it seems odd the aircraft had such a strange stall profile, all the way down.

why the hell did they not fly out of the stall?

why was the vertical tail section found so early, and so intact?

 

Why do you guys feel the need for a physics lesson?

You don't think they knew they were descending and falling out of the sky?

"The airplane was subject to roll oscillations that sometimes reached 40 degrees. The PF made an input on the sidestick to the left and nose-up stops, which lasted about 30 seconds."
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Michael, where are you getting the info regarding the rudder. This is the official report from BEA and I don't see rudder travel mentioned.
http://www.jettimes.com/air-france-447-crash-prelim-report-pilot-missunderstanding-of-wrong-air-speed-indications/

I still don't understand why "they positioned the THS to 13 degrees nose up". I don't think it would be easy to counter act that pressure.

 

Yes I'm agreeing with you.

The aircraft went to "alternate law" at 2:10:16 and the trim was moved at 2:10:51 to the 13 degree nose up position. In alternate law the trim is controlled by the pilot and the pilot trimmed the aircraft to a nose up condition which either caused or exacerbated the stall. Doesn't make sense that they would do that. The aircraft didn't stall until the second stall warning, and then there was a third stall warning when they almost recovered. I was talking about between the second stall warning (when they stalled and apparently didn't realize it) and third stall warning where they came close to recovering.

I find the BEA report very minimal. With NTSB reports we get a very detailed listing of the control inputs and what time they were initiated. The BEA report sure doesn't tell you much.

 

Remember the BEA report is very preliminary and I think it was released because of pressure and nonfactual leaks. I think the BEA wants to make sure everyone knows they are in control. Personally, I think they've been doing a good job of keeping the public informed and I look forward to their final report est. in July. I bet it will be very detailed. Though, I hope nothing is lost in translation.

I do think there is a little bit lost in translation in this prelim report.

I'm really leaning on thinking that the THS to 13 degrees nose up is a huge, huge issue that is being brushed over here.

I too agree with you that the pilots seemed to recover from stall warnings and had the plane flying almost straight and level. I don't think the Captain realized the trim setting as I would think he would have readjusted it back to a more neutral position. I think there was a great deal of confusion as to why the plane was not responding correctly. I also think the loss of the stall warning contributed to their not reacting instinctively to lower the nose.

It baffles me that they seemed to forget to just "fly the plane". But, maybe I'll understand more once more data is released.

 

I agree with this statement too. It is probably what actually killed them. In the ANZ incident, when they lost ASI readings at near stall, the auto trim disconneted and left the trim at a nose high setting. Because the trim was set to a nose high condition, as the airspeed came back during the recovery, the aircraft pitched up and stalled for good.

In this case, for whatever reason, the trim was set to a nose up condition. Not sure, and hope it comes out in more detailed reports, but, based on the ANZ incident, I'm not convinced that simply pushing forward on the stick would have recovered the aircraft with the trim set where it was. The nose high trim setting might have prevented recovery (and allowed them to get to the near recovery that was noted), but not break the stall, or it might have allowed them to recover and as with the ANZ crash, simply stalled the airplane again as the airspeed came back up.

Some in the PPRue forms have noted that the Airbus aircraft aren't equipped with a stick pusher. I guess that they believed that, because the pilots can't (when the computers are functioning) stall the aircraft, then a stick pusher isn't necessary. But when your computers aren't working maybe you need a simple AOA backup stick pusher to keep you from stalling the aircraft. When it is working the FBW systems are fine, but as we saw in this case it's easy for everything to go to crap when they aren't.

 

I've read nothing so far in the data that would lead me to believe this plane was not flyable. Further, under VFR conditions there might have been a different outcome. Just think if the Captain reset that trim we may not be discussing this flight at all.

 

Because it was floating on the surface of the ocean.

Because it separated from rest of the aircraft upon the 125mph vertical impact with the sea and was thrown off at a distance.

 

FWIW An Airbus driver on another forum stated emphatically that given the input was giving with authority it would correct the trim. Reading his other posts, he clearly knew of what he spoke and he worded that post so clearly there was no doubt his meaning. From reading the alternative law stuff it seems correct. (If I wander into it, I'll post a link but I've read so much I have no clue where I read it)

Yup. Which also explains how the 'black' boxes were in the condition they were in. They were at the point of greatest impact.

 

430man- That 5 degrees might be fine if all you had was airspeed indicator failure, but there was a whole lot more going on right then. Trading altitude for airspeed and lift solves a lot of problems when things really start to come apart. Has saved many an airplane. The weather below did not help the aircrew make a good decision. The missing VVI was more of a handicap than the airspeed indicator.

Is there a separate AOA probe on the A330 or does the pitot probe pivot for AOA? Possibly another factor.

I think the 10,000 ft/min descent rate is probably underestimating the sink rate. That is only 133 ft/sec or 80 KTAS downward vector. The dash one in my old airplane, admittedly a fighter and much smaller, says descent rates of up to 50,000 fpm can be observed in an out of control descent. That is more like 500 KTAS descent rate. The Airbus has a lot more surface area, but I would be willing to bet descent rates were way above 10,000 fpm until they reached denser air.

Taz
Terry Phillips

 

Yes, I saw that post and I, like the person on the other forum had confused alternate law and direct law. In direct law the trim is manual, in alternate law it is still in the auto trim mode.

The question remains, as posted there too, did the flight control system trim the nose up? Or, were the pilot control inputs such that the system commanded nose up trim even after the aircraft had stalled? And finally, was the aircraft recoverable from that condition, and how long would it take for the aircraft to respond to a nose down command?

 

Probably correct, but I think with their apparent loss of situational awareness the feel of the stick would have just added to the confusion. What they would have felt as a neutral position would have been nose high.

Though the prelim. report provides some good info, there are still many holes to fill.

It just seems to me that had they pushed the nose down like the PF did at the first stall warning they could have recovered. The difference between the two is the trim setting.

It seems as though they were fighting the stall as the plane oscillated left and right with roll corrections.