PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rumours & News (https://www.pprune.org/rumours-news-13/)
-   -   AF 321 close to stall (https://www.pprune.org/rumours-news/495368-af-321-close-stall.html)

A37575 13th Sep 2012 12:17


and the PNF shouting "Airspeed" when the trend or instant value wasn't going the right way) was a given.
Why on earth would the support pilot be "shouting"? One would have thought mandated support calls required normal talking style on the flight deck. One does not "shout" V1 or rotate, or 1000 to go and so on?:ok:

llagonne66 13th Sep 2012 12:58

Dubious translation
 
Well, well, well ... already 44 posts on a thread that has started with a very dubious translation of the BEA report by The Aviation Herald.
BEA :
Incident
20/07/2012 AD Paris Charles de Gaulle(95)
Passage sous la vitesse d'évolution en approche, déclenchement de la protection grande incidence

Vol AD Bordeaux Mérignac (33) - AD Paris Charles de Gaulle (95). Lors de l'approche, pilote automatique engagé et A/THR déconnectée, l'avion passe en dessous de la vitesse
d'évolution. Le pilote automatique se déconnecte à la suite de l'activation de la protection grande incidence ''ALPHA PROT". L'équipage reprend les commandes, réajuste la
poussée et atterrit normalement.
The Aviation Herald :
Incident: Air France A321 at Paris on Jul 20th 2012, speed drops to alpha floor on approach
By Simon Hradecky, created Wednesday, Sep 12th 2012 16:34Z, last updated Wednesday, Sep 12th 2012 16:34Z

An Air France Airbus A321-200, registration F-GTAN performing flight AF-7633 from Bordeaux to Paris Charles de Gaulle (France), was on final approach to Charles de Gaulle's runway 26L with autopilot and autothrust engaged, when autothrust disconnected and the speed decayed until the alpha floor protection activated accelerating the engines to takeoff/goaround thrust and disengaging the autopilot. The crew took control, stabilized the aircraft and continued for a safe landing on runway 26L.

The BEA reported in their weekly bulletin of Sep 11th that the autothrust system had disengaged permitting the airspeed to decay to a point where the alpha floor protection activated, disengaged the autopilot and accelerated the engines. The crew took manual control and continued the landing. The BEA is investigating the serious incident.
So it appears that autothrottle was off "A/THR déconnectée" and has NOT "disengaged" on its own and that it is not considered as a "serious incident" by BEA but just as an incident.

hetfield 13th Sep 2012 13:04


So it appears that autothrottle was off "A/THR déconnectée" and has "disengaged" on its own and that it is not considered as a "serious incident" by BEA but just as an incident.
Indeed, A/THR disconnect is not a serious incident at all.

But a flight crew who allows the speed to drop almost to stall speed causes surely a "serious incident" IMHO.

BTW

AB calls it auto-thrust, not autothrottle.

fireflybob 13th Sep 2012 13:50


Why on earth would the support pilot be "shouting"? One would have thought mandated support calls required normal talking style on the flight deck. One does not "shout" V1 or rotate, or 1000 to go and so on?
A37575, ok yes wrong choice of word there but am not sure an Airspeed prompt should always be in "normal talking style". There again when humans become maxed out the first sense the brain dumps is hearing so the monitoring pilot might, on certain occasions, have to do some sort of pattern interrupt to draw attention.

CrazyStuntPilot 13th Sep 2012 15:43

That's why I prefer autothrottles to autothrust. I can see the levers moving.

Microburst2002 13th Sep 2012 16:48

Ok, so it is the pilots who disconnected the A/THR

no problem, but then you have to mind the shop...

grimmrad 13th Sep 2012 18:24

Wasn't there also a plane near stalling right over Paris some years ago, don't remember if it was AF as well...

Clandestino 13th Sep 2012 18:49

Tarom 310 in 1994, similar to Interflug at Moscow in 1991.

hetfield 13th Sep 2012 18:57

Yes, but totally different scenario.

In both cases, like some others, a goaround was misshandled. A typical A300/310 issue (have been there, got the t-shirt).

But with AF7633 a flag carrier's crew allowed a speed decay of about 30kts during approach until the automatics slammed in.

llagonne66 13th Sep 2012 19:26

Totally true, they let the speed decay and that needs to be explained.
And true, the automatisms saved the day by giving control of the A/C back to the pilotswho have then reacted correctly.

So maybe A. philosophy is not so bad after all :O

hetfield 13th Sep 2012 19:30


the automatisms saved the day by giving control of the A/C back to the pilots
No, the automatics took control with alphafloor protection and saved the day of many souls and maybe AF at all.

Alex757 13th Sep 2012 19:35

I'm not trying to start Airbus V Boeing here ... but surely ... if the throttles moved (like a boeing) the crew would hold them until 80kts (or is it V1?) and would instantly recognise a power reduction

llagonne66 13th Sep 2012 19:35

Guess it was some joint effort between the A/C and the crew !

As stated in the BEA report :
Following activation of the ALPHA PROT, autopilot disconnected. The crew took control, reajusted thrust and landed normally.

hetfield 13th Sep 2012 19:43

@illa

I'm not saying the philosophy of the aircraft is wrong with regards to this serious event.

All I want to point out is, a flag carrier's crew goofed it up almost to stall.

Needless to say, in a flight phase where speed is an important issue.

oxenos 13th Sep 2012 21:24

Boeing/Airbus, Autothrottle/Auto thrust, Alpha floor, Rad Alt etc. etc. are all completely irrelevant.
Microburst has hit the nail on the head - WHO IS WATCHING THE SHOP?
If you are so unaware of what is happening, you are in the wrong job.

DozyWannabe 13th Sep 2012 21:43


Originally Posted by EcamSurprise (Post 7410470)
Also, this similiar incident happened at a uk airbus operator sometime last year apparently...

Just to clarify, the post that arrived just prior to yours stated correctly that the Thomsonfly incident at Bournemouth was in fact a B737, not an Airbus.


Originally Posted by fireflybob (Post 7410539)
Are these incidents not caused partly by the diminution of basic handling skills due to the increased automation and an up and coming generation of pilots who have little or no experience of hand flying jet aircraft?

Possibly, but the truth is that everyone has bad days at the office and pilots are no exception.


I am not against use of automation but I believe this is where the root cause of the problem is. I don't blame the individuals - it is the system (or lack of it) that has produced this result.
Remember that it's not just a case of bean-counting - with increasingly crowded skies, more and more airspace is becoming RVSM, which *mandates* use of automation in order to traverse it.

Agreed entirely that there should be more focus on training handflight - especially at altitude, but the fact is that if the industry intends to continue expanding then it's going to become practically impossible to practice handflight on the line.


...given the dumbing down of basic skills the software/techie guys will seek all sorts of solution with extra warning systems I suppose.
I can speak with some authority in saying that the "software/techie guys" only solve the problems they are presented with by a design committee that includes pilots and aeronautical engineers - they don't get to specify their own remit and never have.

DozyWannabe 13th Sep 2012 22:15

Can't remember one - happy to be corrected though...

gerago 14th Sep 2012 00:25

Remembered a stick and rudder hero at my previous outfit who decided to fly manually with A/P, A/T off. He flew down to level off at Circuit altitude; unfortunately he forgot he had disconnected the autothrust and totally forgot to manually add thrust. The airspeed dropped to near stall speed before the sleepy eye PM noticed the f**k up, slammed the throttles up and saved the day!

iceman50 14th Sep 2012 02:49

Crazy stunt pilot


That's why I prefer autothrottles to autothrust. I can see the levers moving.
The moving thrust levers did not save the Turkish crew flying into AMS so your argument is flawed, we pilots need to monitor the "SHIP".


It must have been an interesting recovery, although there was no mention of TOGA LOCK.

noclue 14th Sep 2012 06:18

Having no idea of "airbus laws" can someone briefly explain this "alpha floor" logic that they have??

Out of interest re auto thrust/throttle if a speed significantly lower (initial approach limit down to Vref) than the aircrafts current speed is selected on an approach, will the auto thrust/throttle system automatically reduce power to idle to slow the aircraft?? Or will it be a 'powered deceleration', or am I way off the mark re how this system works??

Cheers.

hetfield 14th Sep 2012 06:20

Can someone enlighten me, it's long ago that I flew that thing.

When on final approach with alpha floor active, speed should have been somewhere between VaProt & VaMax, right?

I know, alpha floor is an A/THR feature, but to get a picture...

Bigmouth 14th Sep 2012 06:24


Remembered a stick and rudder hero at my previous outfit who decided to fly manually with A/P, A/T off. He flew down to level off at Circuit altitude; unfortunately he forgot he had disconnected the autothrust and totally forgot to manually add thrust. The airspeed dropped to near stall speed before the sleepy eye PM noticed the f**k up, slammed the throttles up and saved the day!
With your hand on the throttle there is no way you will forget to add (or reduce) thrust. Taking your hand off the throttle while hand flying is a mistake made only by pre-solo student pilots and rank amateurs.

fingal flyer 14th Sep 2012 06:44

Close to stall
 
Bigmouth,
Havent read it all and not going to bash any airline but when I trained I was taught to fly airplanes and you are dead right about the trust levers.I had an instructor who used to hit me with the control lock(C152)below 500ft if my hand was not on the throttle because I had a bad habit.To this day I would buy her a drink for all that pain because she taught me a real good habit.THe basics cant be beat even in the new stuff.

Gretchenfrage 14th Sep 2012 07:20

It's almost like groundhog day!

I wrote last year in the AF447 debate to wait for the next incident.

The worst part of these debates is that the ever same protagonists come up with the same lame an cynical statements:
"no, it has nothing to do with the AB dead stick/lever philosophy, because even the Turkish managed to dump their 737 ..... etc. blah, blah ..."

How can you try to defend a design flop by pointing to morons producing an accident with another design??? With the same argument we can abolish ABS and ESP in modern cars by showing that there are some other morons who were able to crash even highly equipped cars!
Such argumentation is not only puerile, but even cynical.


Try for once to look at the whole issue with the following view:

To my belief controls with feedback represent an additional protection in modern cockpits. Had the SFO in the left seat of AF447 had any feedback on his sidestick, he might have better realised his collegues blackout. Had the pilot of the AF321 in question had a moving throttle (that in this instance would not have moved) he might have realised the off situation earlier.

To conclude my argument:

I know there are two mights in my above statement. But if you look at feedback-controls through the above optic, namely as an additional protection, it makes absolutely no sense to abolish them.

NOLAND3 14th Sep 2012 07:53

None of you have the full fact's here.. You keep your hand on the thrust levers during approach, A/THR on or off so I would be surprised if this wasn't the case with AF231.

No doubt there was a big screw up here, however I'll say it again.. This machine will damn well tell you if A/THR disconnects without any pilot input, and it will keep telling you until you do something about it.

All this talk about moving throttles, sidestick etc etc is pointless..

I would be interested in knowing what Vapp they we're flying and the GW. Defintely not going to get that info here..

MPH 14th Sep 2012 08:29

Maybe SOP's, CRM situational awarness and good monitoring might help:oh:

Craggenmore 14th Sep 2012 11:15

Anyone know what the winds were doing..? Possible energy loss..?

charliemouse 14th Sep 2012 11:23

Usual caveats about SLF posting comments apply
 
I guess it's a good job this situation didn't happen below 500 feet?

Most dangerous phase of flight - T/O and landing. Most critical thing to staying in the air - airspeed. Professional crews with hundreds of lives in their hands keep killing themselves and others (or trying to) because... *insert personal logic here* - im not getting into it I'm "not qualified". You can go round in circles forever - humans make mistakes. If it was 11:45am or 6:45pm AF pilots will maybe have been thinking about something else. I don't think a fix will come from this thread or any other i'm afraid.

Now - how can we blame this issue on MOL? :}

Clandestino 14th Sep 2012 11:55


Originally Posted by Hetfield
Yes, but totally different scenario.

In both cases, like some others, a goaround was misshandled. A typical A300/310 issue (have been there, got the t-shirt).

Correct... it was the issue of not realizing the autopilot is on and it doesn't disconnect if force on yoke is applied when on automatic ILS app below certain radalt (this was DGAC required modification in order to certify 300/310 for autoland ops) so folks got aeroplane severely mistrimmed by fighting the autopilot. Chalk one up for autotrim.

It is interesting how folks in the heat of the battle forget to trim manually. IIRC, Karair pitch excursion somewhere around 1989 was stopped at 40° ANU as PF tried to relief the forces and trimmed, thereby kicking the AP out.

So much for this digression.


Originally Posted by Alex757
but surely ... if the throttles moved (like a boeing) the crew would hold them until 80kts (or is it V1?) and would instantly recognise a power reduction

No. Old red herring that keeps returning. You can even find YouTube videos of old pilots spouting this, only proving how lucky they were never to have engine control failure during their careers, for surely, smart they weren't.


Originally Posted by ECAM Surprise
There was also an airbus case I believe.

Very probably there was, however I wouldn't believe anything without proper reference. Maybe it is just me.


Originally Posted by gerago
Remembered a stick and rudder hero at my previous outfit who decided to fly manually with A/P, A/T off.

Manual flight with autothrottle/autothrust active is strictly prohibited at my outfit so no confusion about it being on/off. I think it's a good thing.


Originally Posted by noclue
Having no idea of "airbus laws" can someone briefly explain this "alpha floor logic that they have??

Alpha floor is generic term for automatic high power command when AoA gets way too high. Even 737 NG have it and on them it's called...."Alpha floor".


Originally Posted by Bigmouth
Taking your hand off the throttle while hand flying is a mistake made only by pre-solo student pilots and rank amateurs.

Blasé aerosexual jetpilots too.


Originally Posted by Gretchenfrage
It's almost like groundhog day!

Sure it is, since some folks building their theories of advanced flight control architecture, found them on spectacular misunderstanding of basic flying principles and are unable to take subtle hints their notions are so at odds with reality, they only have some limited entertainment use. As explicitly pointing them they are somewhat clueless would go against RoE, I guess we have to live with it.


Originally Posted by Gretchenfrage
no, it has nothing to do with the AB dead stick/lever philosophy, because even the Turkish managed to dump their 737 ..... etc. blah, blah ..

It wasn't just Turkish. There are thousands of Airbi landed uneventfully every day, as there are hundreds of pilots throughout the history neglecting to monitor their airspeed. Nothing to do with flight instruments or flight controls architecture.


Originally Posted by Gretchenfrage
How can you try to defend a design flop by pointing to morons producing an accident with another design???

What flop? What morons? In real world, airliners are stil flown by human beings and, unlike machines, they tend not to perform equally every time. Just because a pilot makes "stupid" mistake it doesn't qualify anyone, especially not some participant in anonymous internet discussion, to label him as "moron". Overall performance is a pointer of how one might act when thinks go pear shaped, not guarantee. Clueless pilot might get lucky and fly throughout career without scratching his aeroplane and knowledgeable and competent pilot can be faced with task far beyond his capabilities early in his career. Of course, all Joe Public sees is smoking hole and wants to blame anyone for that. Easy if pilots are foreign. Even easier if Airbus is involved as all the false stereotypes about computers surface.


Originally Posted by Gretchenfrage
With the same argument we can abolish ABS and ESP in modern cars by showing that there are some other morons who were able to crash even highly equipped cars!

Nope. If pitch feedback is comparable to ABS/ESP, then Airbus is waaaay beyond it, nothing like we have in the cars yet.


Originally Posted by Gretchenfrage
Such argumentation is not only puerile, but even cynical.

Argumentation you have presented is straw man. Argumentation Airbus needs not control feedback to be safe might be even sarcastically delivered, yet it's true.


Originally Posted by Gretchenfrage
To my belief controls with feedback represent an additional protection in modern cockpits.

Yes they do, but they have synthetic feedback to prevent pilots from ripping their wings off or killing their passengers Synthetic pitch feel is not designed to be speed cue, its use as such is incidental and unapproved and anyway, there were numerous incidents and accidents where unusual feel or displacement of controls provided no cue for hapless crews. Airbus has G protection to deal with overstress risk. Loss of it puts it in config similar to loss of pitch feel on "conventional" aeroplane. A bit more difficult but definitively manageable even for the subpar pilot.


Originally Posted by Gretchenfrage
But if you look at feedback-controls through the above optic, namely as an additional protection, it makes absolutely no sense to abolish them.

Of course. Problem is that this proposed optic is largely based on total misunderstanding how manual instrument flying works in real life. Pilots sets pitch and power, trims out, checks for performance. If it isn't what is expected, pitch and power are adjusted, forces trimmed out, performance checked. So on and so forth until rollout. Control position is just demand, not delivery and every clue about aeroplane behaviour is taken through visual channel. That's why those officially tasked with recognizing whether the design is airworthy have certified A318-A380 even if it has no synthetic feedback or moving thrust levers.

jcjeant 14th Sep 2012 12:12


unlike machines, they tend not to perform equally every time
Just a reminder ....
Machines can have also malfunction .. and so no to perform equally every time
Put all his trust in a machine is a mistake .. as has been often shown

mike-wsm 14th Sep 2012 12:26

Speaking as a retired software/techie guy I would recommend that the PF should always be in the loop, receiving inputs and producing outputs. Mere monitoring does not keep him fully aware and he will not be in a sufficient state to take over.

Starbear 14th Sep 2012 14:36

AF 321 close to stall
 
For those who asked: With A/T engaged actual IAS will not reduce below Vls (Vref) regardless of speed selected but if A/T off/disengaged (still serviceable) and levers at idle IAS will reduce below Vls but upon reaching the speed equivalent to alpha prot range, TOGA thrust will be applied regardless of thrust lever position or A/T status (except if u/s) A/P will disengage Alpha Floor annunciated and if on G/S, aircraft will climb away in Alpha Prot speed range. Pilot action will be to lower nose accelerate and recover. A/T will annunciate TOGA LOCK until further action on levers by pilot.

woodja51 14th Sep 2012 15:33

Oeb
 
OEB Already mentioned affects Airbus and Boeing , possibly the issue with rad alt 1 going to zero and causing speed decay ( flaremode) when coupled to an ILS will lead to a rapid drop in speed until alfa floor kicks in.

If they were in manual thrust or disenaged a/Thrust then toga lock would appear until throttles moved , or the throttles would have to be manually moved to cause the speed decay...

If the automatics ie rad alt was the problem , then the automatics caused the problem ....which then fixed the problem...? Sort of ironic really.

As far a pilots flying 'hotas ' totally agree, BUT maybe , just maybe the manufacturers ( both) should FIX THE FRIKKIN PROBLEM not just write nice bulletins OEBs etc for crew to remember in this less paper AKA more paper cockpit they inflict on us.

AIrbus lost a jet and test pilots due to engine thrust reduction on one side after takeoff some years ago as the aircraft transitioned via ALT* at lowish level where it is not speed protected. T

his is a nice little note or caution in the FCOM... Prob should be a WARNING but the lawyers got hold of it - dont want to alarm the punters!! .

Alternatively they could have FIXED it before someone gets the chance to test it for real with a eng prob. after takeoff with hi ROC and low ALT level offs.

. IMHO Airbus and Boeing both run by lawyers and accountants ... Bring back decent engineering not paper mache coverups and then blame pilots when they dont pick it up.

eightmileshigh 14th Sep 2012 16:30

Soon, very soon we will rid ourselves of these pesky pilots with their ridiculous salary and benefit demands and refusal to work 20 hour shifts. All flights will be controlled from ground stations located in various third world countries staffed by low cost x-box players.


Signed …

The accounting department.

:cool:

hetfield 14th Sep 2012 17:45

@woodja51

wtf are you talking about?

Two pros of a flag carrier ignored a speed decay of about 30kts during approach.

That's it.

fullforward 14th Sep 2012 18:00

Point made, mate!
 
Hetfield,

I am too fed up with this empty bull****ting, endless bla bla bla trying to explain the unexplanable.
Unfortunately, as I wrote here regarding the idiot that slammed a perfectly flyable aircraft into a montain in Indonesia (Sukoi), for each Capt Sully 1,000 morons are born.
No more political correctness! Just facts and actions. One thing is an unnavoidable disaster, other is to screw up with people's lives by irresponsible training, poor evaluation system combined with criminal negligence and lack of basic airmanship.

ATC Watcher 14th Sep 2012 20:26

fullforward :

the idiot that slammed a perfectly flyable aircraft into a montain in Indonesia (Sukoi), for each Capt Sully 1,000 morons are born.
I wonder how the (Suhkoi) Russian Capt in question would have done with 2 engines out above the Hudson, and what Sully would have done in a badly planned demo flight in Indonesia ? 2 totally different situations where "luck" also played a role.
So I would be careful before giving idiots/morons adjectives.

exeng 14th Sep 2012 22:15

ATC Watcher
 

and what Sully would have done in a badly planned demo flight in Indonesia
I suspect Capt. Sully would hae been very unlikely to have accepted a very badly planned demo flight in the first place.

In flying planning is everything - that is what we do. I also doubt that Capt. Sully would have started a planned flight and then decided on a whim to to change the plan at the last minute - although I am not suggesting for one minute that this happened on the Sukhoi disaster.

White Knight 14th Sep 2012 22:23


I suspect Capt. Sully would hae been very unlikely to have accepted a very badly planned demo flight in the first place.
What the heck has sully got to do with AF? Stop kissing his arse!

They're a dangerous airline. THREE hull losses since 2001!

hetfield 14th Sep 2012 22:23

PLEASE...

come back to that particular AF issue.


All times are GMT. The time now is 17:24.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.