Commercials pilots: stall warning, and they pull up!

[Madfish]

You didn't answer my question. The information was alright - they got a stall warning and pulled up. Considering their altitude this was the most unlogical thing to do I believe. They could've just nosed down a bit and see if that levels the plane out, clears the stall warning or makes it accelerate. Pulling up is not a gamble - it's just stupid.


And why it makes a difference? Because those huge airliners behave like cargo ships compared to racing boats. They are not just a simple chessna with the weight of a fly. Also they carry hundres of passengers, not just 2 or a dozen. There is a HUGE difference of responsability and you'd expect only the elite of the elite to fly a REAL passenger plane.

These guys clearly made a mistake and were unable to cope with the situation. From what I've read they just acted on some panic feeling instead of going through real emergency procedures also. Not a very good sign.

As for replacing pilots completely, times change. People get replaced by better tools and computers all the time. Feelings have nothing to do with this. How do you think the families of the people who died on that flight feel?
Let me tell you straight: everyone would've felt better if there was 50 backup computers instead of 2 untrained pilots. The people who died. The families of the dead. The ocean that wouldn've have to get polluted once again. Air France if they didn't lose a multi million dollar plane. And also the pilots who wouldn't be ashamed if they lived through it.

I can't see a single reason why you'd try a nose up with a stall warning. It's like when my car's automatic brake system tells me on a highway I'm about to crash into a car ahead but I override it and I accelerate because I gamble that it might be wrong.

[IvanK]

"You didn't answer my question. The information was alright - they got a stall warning and pulled up. Considering their altitude this was the most unlogical thing to do I believe. They could've just nosed down a bit and see if that levels the plane out, clears the stall warning or makes it accelerate. Pulling up is not a gamble - it's just stupid."

Err they got a darn sight more than just a Stall warning ... they got a whole series of conflicting warnings including many transient and erroneous airspeed readings/fluctuations and changes in flight control laws as well. That aside on the surface there apperrs to be some Human factors issues in that incident based on the interim report made after FDR and CVR evaluation.

http://www.bea.aero/fr/enquetes/vol....mai2011.en.pdf

Like all accidents though its better to wait until the full investigation is complete before making sweeping statements.

For the record here are the memory recall items for a stall in the biggest bus:



As you can see AOA reduction is the first action.

[Madfish]

http://en.wikipedia.org/wiki/Air_Fra...interim_report

Not sure which part of that I am unable to comprehend but by my logic they did wrong all they could. The only thing that would've been the right thing to do was to nose down. And that was even before the whole thing happened?

[IvanK]

A simple stall warning is pretty straight forward event to handle. In an Airbus aeroplane its also quite an exceptional event.

What they got was a bucket load of trouble, Multiple warnings, erratic airspeeds, and a change in Flight control laws to boot. It was not a simple event.... they had their hands full.

All will be revealed when the final report comes out.

[Anvilfolk]

I'm not so sure - I've not seen anything in these reports to indicate that any other sensors but speed were malfunctioning. I mean, the speed changed from 300kt to 60kt suddenly? Even if you don't notice such an absurd change, wouldn't you realize that you don't want to climb at 60kt?

According to the report, they were rolling around like crazy, 40 degrees and more. It doesn't seem it was because of their inputs, so it should've been obvious they were in a stall. They barely did nose-down inputs, mainly nose-up.

That's the thing that frightens me... you identify you are in a stall (or don't, despite what seems like relatively obvious signs), and your gut tells you to pull up?

[Blackdog_kt]

In case of pitot related malfunction you can get all sorts of weird and conflicting instrument readouts. There was a case, i think in Chile, where the instruments were displaying warnings for overspeed while the stick shaker was activated. What is this you might ask?

Well, since these aircraft are usually fitted with fly by wire or otherwise assisted controls, the pilots don't have the same kind of tactile control feedback that simpler rod and linkage controls allow. In a cessna you can feel the stall because the stall buffet transfers through the control linkages to the yoke, in a fly by wire system you can't. So, these airliners have a feature that simulates this by shaking the control column when they near a stall, it's like force feedback.

Apply that knowledge to the above example and you'll see that a malfunctioning pitot system caused an overspeed warning on the caution lights panel at the same time that the stick was telling pilots they were stalling.

My point being, things are not that cut and dry. Especially at the speeds and altitudes these things fly where it's not that easy to judge airspeed by eyeballing it and simply looking at the ground, not to mention that the accident i'm talking about also happened at night.

Pilots are trained to reduce AoA when approaching a stall. Some might have botched this at times, but for the most part if a pilot is pulling up with a stall warning in place he's probably got a reason for it: conflicting information that forces him to make a choice between two completely opposite scenarios.

If you get simultaneous overspeed and stall warnings with no other reliable means to confirm which one is wrong what do you do? Well, if you're high enough and know you can recover the particular plane from a stall, i'd say go ahead and stall it mildly. If you're wrong you'll just loose a few thousand feet of altitude and then you know the overspeed is a false alarm that you can disregard from that point on, if you're right and you don't take any action however you'll overspeed it and have it disintegrate in mid-air.

In other words, it's all highly situational. In low altitude flight and provided some form of speed perception is available by looking out the window, i'd say avoid the stall first.

The problem (at least according to what an airliner pilot told me) is not so much why they did what they did, but the fact that too many young pilots in airliners are conditioned to go through the motions mechanically and rely a lot on automation, instead of flying the plane first and foremost.

[TomcatViP]

With all my respect Sir stalling an airplane does not makes you feel like over speeding an airplane if you are listening to what your old trusty calibrated stomach can tell you

For what I eared and read so far (thx for all the good links provided) those guys where falling down at 60kt 25+deg nose up. Next time you are on a roler-coaster, shut your eyes and see what kind of sensations you get (huuuu we are going dooooooooooooowwn, are we ?!!)

PS : this is a good thread

The backgrd of the question as all have said is that we have system monitoring technicians behind the yokes that are applying lessons learnt at school stamped by sophisticated diploma were we shld hve passionated (or at least commited) individuals.

A simple GA flight logged hours rules per month shld hve been enough to prevent such drama (speculation and hypothesis) since it is now generally admitted that the thousands of hours logged in airliner does account only for a fraction of actual yokes handling time what you need in such critical situations.

But perhaps the downfall in pilot salary is the key here.

[Ploughman]

I think a factor in the pilot's response to a stall warning is that below a certain speed their's no stall warning as any speed reading is invalid, then if you accelerate you get the stall warning from something like 60 knots through to the aircraft leaving the stall. In this instance the pilot in control seems to have lowered the nose, accelerated the aircraft to the point where the stall warning actuates, then perhaps thought he was entering a stall by putting the nose down, and pulled back up again, dropping the speed into the invalid range, and causing the stall warning to stop. The pilot was flying the plane to avoid the stall warning, rather than flying the plane to avoid the stall.

[Iku_es]

The investigators have not yet determined the cause of the accident, so please don't be so fast calling the pilots incompetents (they weren't). And you should read what are the requirements to be hired by this company.
And the wikipedia is very usefull, but unreliable.

(Before being asked: I'm not an ATPL. Only a PPL that loves airplanes)

The Airbus aircrafts have a lot of safety mechanisms. One of them overrides the pilot inputs and stabilizes the plane if the pilot pushes the flying envelope outside safe limits.
For instance: Overspeeding, Dangerous AoA - Stall, Dangerous bank angle (more than 60º) ...
But these safety mechanism are disconnected if the pitot or the static ports are blocked. (By the way, airbuses don't have stick shakers as they don't have yokes. Only sidesticks )

As BlackDog said, they probably had conflicting instrument readouts and if the altimeter was also malfunctioning ... the have very little chances,
IFR flying conditions, at night, without realiable instrument readouts...

They may also suffered of "Tunel vision", I'm not saying that it wasn't also pilots fault. But they didn't pull the nose up because they were retarded, as is suggested in the original article.

I can only guess the fear and confusion they felt in that cockpit...

Ding Ding Ding Ding Ding (Master Alarm)
ECAM RED MESSAGE: OVERSPEED
Ding Ding Ding Ding Ding (Master Alarm Again)
ECAM RED MESSAGE: STALL
Repeat several times
GPWS Warning: WUUUP WUUUP TERRAIN .... PULL UP
Ding Ding Ding Ding
- Crash - and no refly button ...

Example of Master Alarm, and ECAM Messages: 0:12 onwards

http://www.youtube.com/watch?v=7QcOgLdwg9w

Originally Posted by TomcatViP

With all my respect Sir stalling an airplane does not makes you feel like over speeding an airplane if you are listening to what your old trusty calibrated stomach can tell you

For what I eared and read so far (thx for all the good links provided) those guys where falling down at 60kt 25+deg nose up. Next time you are on a roler-coaster, shut your eyes and see what kind of sensations you get (huuuu we are going dooooooooooooowwn, are we ?!!)

PS : this is a good thread

The backgrd of the question as all have said is that we have system monitoring technicians behind the yokes that are applying lessons learnt at school stamped by sophisticated diploma were we shld hve passionated (or at least commited) individuals.

A simple GA flight logged hours rules per month shld hve been enough to prevent such drama (speculation and hypothesis) since it is now generally admitted that the thousands of hours logged in airliner does account only for a fraction of actual yokes handling time what you need in such critical situations.

But perhaps the downfall in pilot salary is the key here.

I'm sorry Sir, with all my respect I strongly dissagree with you:

1. The fact is that in IFR conditions, you cant rely on your senses.
http://en.wikipedia.org/wiki/Spatial_disorientation

I have experienced this in a PA28 as a passenger, and is very, very disturbing. Without watching the instruments, you can't tell after a couple of manouvers if you are climbing, falling, upside down.
I encourage you to try it, if you have the oportunity. I was amazed the first time.

2. Those technicians have allowed for instance aircraft landings every 2 minutes in the same runway, decreased the chances of accident, etc

3. GA flight logged hours rules are great for VFR, and lightweight aircrafts (Single or twin engined).
Airliners are flown following procedures, not following your guts (sorry I don't know the english expresion for that)

Originally Posted by Blackdog_kt

The problem (at least according to what an airliner pilot told me) is not so much why they did what they did, but the fact that too many young pilots in airliners are conditioned to go through the motions mechanically and rely a lot on automation, instead of flying the plane first and foremost.

Todays comercial flying is all about following procedures.
Most of the accidents happen because procedures are not followed.
I have a romantic idea of flying by the feel of the aircraft too, but I have to say, that following aircraft procedures has been proven as the safest way. Old hands hate this idea of course

Watch this video as example. They seem Robots.

http://www.youtube.com/watch?v=TSfVPRS9b9Y

Life is easy for us armchair combat pilots

[ruggbutt]

I have several airline pilots in my squadron, as well as a couple current fighter pilots (Hornets). The airline pilots are ex-fighter pilots as well. Anyhow, there has been a discussion on our squadron forums for quite a while about this. Especially about the Air France Airbus crash. Seems that all of the airlines are skimping on training to save money and hiring less experienced and lower pay grade guys while at the same time forcing higher paid/high hour guys to "retire". One of ours who flies for Northwest (now Delta) is retiring. We hear all about the charlie foxtrot that the airlines are now and commercial air travel is in worse shape than it was at the turn of the last century. You're going to see more crashes, more dead people and it will still be cheaper to pay off a lawsuit rather than pay for proper pilot training. Be it initial or ongoing refresher training.

It's not just the U.S. that is seeing this, one of ours is a 747 driver for Qantas. Same s**t, different airline and country.