[runningdogx]

I've followed the discussion of the AF447 investigation on several flight discussion forums.

The PF (Bonin) apparently never became aware of his angle of attack (once the airplane fully stalled, AOA was absurdly high). He did not seem to be aware that his constant inputs had caused the Airbus's THS (trimmable horizontal stabilizer, horizontal flaps on the tail) to deflect to maximum in order to try to keep the nose up. Therefore when he tried to input stick up (nose down) several times briefly, and there was no obvious response (the computer takes a while to reduce THS elevation in response to opposing input), who knows what he thought -- maybe that all readings were incorrect.

Strangely, Bonin was the one pilot who had significant recent glider experience as I recall. The Airbus computer even in "alternate law" functions nothing like a glider (only "direct law" is sort of close to direct input), so maybe that further confused him.

In my opinion, at night, over an ocean, in a storm, with no visibility, in possibly significant turbulance, a modern aircraft cutting off Autopilot for any reason other than computer failure is completely unacceptable. A computer should be able to fly as well as a human under those circumstances.

People suggesting that on airliner forums get flamed. But it's true. Most pilots kept up the refrain that a computer cannot safely fly by gps and gyros unless they also have airspeed. Which is true. It's dangerous to fly if you don't have true airspeed (gyros and gps cannot accurate provide relative wind speed). However, if pitot tubes are frozen and the computer no longer has valid airspeed, the pilots no longer have valid airspeed either. Pitch and power is all they can do. The computer can do that just as well. All it needs to know is aircraft weight, which can be entered (maybe it is entered) before takeoff and automatically adjusted to account for fuel consumption.

There are a bunch of factors that contributed to the accident:

Pitots shouldn't have frozen.

Lack of Air France training for controlling an aircraft at altitude with the computer in "alternate law" (mode without full flight envelope protection; it's therefore possible to stall).

The command structure in the cockpit without the Captain (who had just gone on break) actually had Bonin in command, even though the co-pilot in the left seat outranked him... AF has since changed that. CRM (crew resource management) was poor; the co-pilot in the left seat didn't try to take control until way too late. The co-pilot was preoccupied with where the Captain was rather than offering constructive input on how to fly.

Bonin was not adequately aware of what his inputs were doing, or what the plane's Angle of Attack was, and did not react properly to the stall warning which in almost every case at high altitude means drop the nose, not raise it (though without valid airspeed there's a risk of overspeed which can cause a new set of problems).

The Airbus computers had some quirks; stall warnings stop if airspeed drops too low (due to some computer programming logic involving low airspeed, AOA sensors, and the result being silencing the stall warnings).

Nobody believed a passenger aircraft would be so stable during a full stall. This undoubtedly contributed to confusion about whether they were actually stalled. The Airbus's computer setting the trimmable horizontal stabilizer to max nose-up deflection, in response to Bonin's almost constant nose-up input, possibly contributed to the stability during stall.

Angle of Attack information may not have been adequately displayed to the PF (Bonin) -- the black box doesn't record data from the right set of instruments, so nobody knows what Bonin had on his screen.

There was poor notification on the co-pilot's side of what the PF (Bonin) was doing. Unlike traditional aircraft, it is not easy to see what the pilot in the other seat is doing with the stick.

There was poor notification on either side of the cockpit when the other pilot took control. When the co-pilot took control, Bonin almost immediately took control back, and it's not clear either of them knew what the other was trying to do. Apparently there's a light that indicates override, but who would notice such things under that amount of stress?

IOW, it was a disaster from top to bottom. Usually in aircraft accidents there's a chain of events, but in this case there were so many possible contributing causes that other than having better pitots that didn't freeze over, solving any one other problem may not have broken the chain.

[bambax]

What's missing from this article is the fact that the Captain chose to fly right into the storm, saying "on va pas se laisser emmerder par des cunimbs" (in essence: "fuck this storm")

http://www.lexpress.fr/actualites/2/actualite/des-dialogues-...

This is incredible hubris.

Then, in the middle of the storm he leaves the two copilots alone, one of them quite inexperienced, and goes for a nap. He's obviously trying to demonstrate that he's not afraid of anything.

Well, maybe he was fearless, but now he's dead and so are all the passengers, passengers he was in charge of.

- - -

Once in the storm, and with the incredible amount of stress, it's hard to say if other pilots would have done better (other pilots that night avoided the storm!)

I've read that pilots are trained to react to a stall at the beginning of their career, but not as part of their regular training -- I don't know if it's true or not.

What's true is that stall is one of the worst things that can happen; it's like training bus drivers to hit the brakes when they're going right into a wall: of course they would do that...

[einhverfr]

IANA Pilot. I do make aerodynamically correct fixed-wing and lifting-body type paper airplanes, however, and I have had a LOT of fun playing with aerodynamics in this hobby.

One thing to keep in mind regaring stall is that it's 100% dependent on angle of attack, not speed (something Popular Mechanics gets entirely wrong). What happens basically is that at a high angle of attack the air layer doesn't track the wing surface properly and so you are deprived of standard lift. With certain aircraft designs (SR-71 for example) this is very hard to make happen (but the SR71 can stall it's engines before the wings stall due to AoA).

If you are faced with a stall, I would expect the first thing to do is to pitch down to reduce angle of attack then accellerate and pitch up to get out of it. T-tail designs are generally disfavored because the elevators can get blanked by the wings in a deep stall, but with the A330 this isn't an issue as it doesn't have this tail design.

I find it puzzling that a professional pilot would pitch up in response to a stall warning. Popular Mechanics is right to flag that is as difficult to understand.

[bambax]

A commenter below (cellularmitosis) makes a very interesting point: Bonin may not have realized he was in "alternate law" (let's call it "mode" instead of "law").

In "normal mode" the computer will not let pilots stall the plane, whatever they do; it will accept the commands up to what it considers dangerous. There's an "envelope" of acceptable plane movements; pilots can move inside this envelope but not outside of it.

In "alternate mode", the envelope is much wider and you can actually stall the plane.

If you're in normal mode, it makes sense to pull the stick all the way so that you're at the edge of the envelope: you climb as fast as you possibly can (as fast as the computer will let you).

And you can probably fool yourself when the stall alarm rings: the computer is telling me I'm near stalling -- I'm at the edge of the envelope, THIS IS WHAT I WANT!!

In fact you're not in normal mode anymore, and the computer is telling you that you're way past the envelope. But you can't register that, because for you that is simply impossible.

If that's what happened, the cause of the crash is insufficient training in alternate mode.

[brazzy]

Bonin would have had to realize that the plane is in alternate mode in the first place in order to react correctly. It probably never crossed his mind since he never trained in it, and conversely if he had trained in it, he may have been more likely to at least check.

But to me the bigger problem seems to be that such an important change in the plane's behaviour could happen without anyone noticing. I'd consider the mode to be something the pilot must be made aware of, not something he has to deduce from the fact that the airspeed isn't available.

Perhaps the mode is shown prominently and the pilots just didn't notice it in their state of panic. Making it more prominent probably leads right into an insane arms race - the stall warning was as prominent as anything can be and still got ignored.

I don't envy the person who has to design a airliner cockpit's user interface and decide which of a hundred potentially vital pieces of information should be displayed how.

[presto8]

Bonin had to have known that the plane was in alternate law.

In the flight recorder log, at 2h10m05s, there was an audible "cavalry charge" alarm that indicated to everybody in the cockpit that the autopilot was disconnecting (plus message at the same time on the ECAM).

Then, on the ECAM message console 1 second later, the message "F/CTL ALTN LAW (PROT LOST)" was displayed: alternate law, protection lost. At the same time, Bonin said "I have the controls", which to me indicates that he knew that the autopilot was off and that alternate law was engaged.

References: [1] Page 45, http://www.bea.aero/docspa/2009/f-cp090601e3.en/pdf/f-cp0906... [2] Page 88, Ibid.

[waqf]

Of course Bonin knew that the autopilot was off. I don't think that's the same as being in alternate law.

[gldalmaso]

What boggles my mind is that pilots are being trained in anything less than every mode an aircraft operates on.

[kristaps]

A mode switch as important as this should be very visible. An idea: put a two-color led under every indicator light and switch to the other color when the plane falls into alternate law. This should make it sufficiently clear that something very notable has just happened.

[Maakuth]

Something like that was my initial thought. However, you have to remember that there is massive amount of very notable things going on and data shown. As brazzy pointed out, the stall warning was as prominent as possible and still was pretty much completely ignored. I don't think they would've noticed any amount of leds in that point.

[earnubs]

There's a school of thought that says that user interfaces should be modeless, I wonder if the concept of a mode here is a fault in the design of the HCI as well as insufficient training?

[mtts]

Oh no ... we are NOT turning this into another Vi vs Emacs flamefest

;-)

[einhverfr]

Actually the normal vs alternate law thing might be a mode to build into the displays. I am usually a modeless fan and a VIM user, but this is an exception ;-)

[kelnos]

When in normal law, if you pull the nose up all the way, and are at the edge of the envelope, will the computer even give you a stall warning? I would guess (hope!) not, since the plane is never actually in danger of stalling. Assuming that's the case, a stall warning from the computer should always be heeded.

If that's not the case, and the stall warning sounds even when there's no real danger of stalling (because the controls are operating in normal law), I feel like that's a terrible user interface.

[ansible]

I really don't like the idea in general that 'normal law' mode lets the pilots yank the controls any which way and the computer (supposedly) prevents the plane from leaving the safe flight envelope. I believe that sets up the wrong attitude in the pilot's mind about having to carefully and thoughtfully control the aircraft.

If the flight computer is having to intervene and change the flight controls, then at the very least there should be a force-feedback mechanism in the stick which tells the pilot he's doing something wrong, and that he really shouldn't be yanking back the stick that hard.

The other bad part of the user interface is that the two sets of flight controls are not linked, like they were in the old days. With side sticks, it is not easy to see what the other pilot is doing. And averaging the control inputs of the two pilots is INSANE, in my opinion. Only one pilot should be flying the plane, and it needs to be quite obvious who that is at all times.

The CRM mechanism to take over flight controls should not be saying the words "I have control", it should be flipping a big switch on the center console that visibly indicates who has control.

[acqq]

I like the idea of linked control, like on the small planes. That's "the principle of least surprise" and also gives the copilot the right information of what another guy is doing -- that was obviously missing here!

However if you add force feedback of the plane computer "correcting you" you'd never know if it's plane or an another guy. Therefore, force feedback from the computer doesn't sound to me as a good idea. Some kind of feedback would be a good thing, but in panic, it wouldn't be noticed. I guess I'd put something like something "protruding up" on the stick when in another mode -- you'd feel and see it.

Finally, switch flipping is unnecessary if you have a force feedback. It think that's really the major feature missing!

[einhverfr]

yeah, I agree with that. Also there's another factor in that stall warnings may have been seen as an ADIRU malfunction rather than an actual stall. In those cases, I suppose pulling back might make some sense if you think you have bad ADIRU input and the plane is in normal law.

[tankenmate]

I think the whole point is that in almost all circumstances an ADIRU failure will lead directly or indirectly to alternate law. Hence the correct procedure should be to assume alternate law and cross check.

Once your instruments start failing left, right, and centre you should go into what I call "advanced free fall" mode, check horizon (true, false or otherwise), check altitude, check parachute, repeat... If you hit gimbal lock (or similar INS failure) in the dark, well just bend over and kiss it goodbye.

[einhverfr]

I was thinking of the Qantas and Malaysian Airlines mishaps where faulty ADIRU's lead to sudden uncommanded changes in altitude and eventual stall warnings.

[StavrosK]

Is it possible that the warning speaker was broken? It's odd that none of the pilots would even acknowledge it. Or does the recorder record the stall warning noise too?

[gnaffle]

From what I read from the preliminary report, it's established that the stall warning sounded. If it had not been audible on the CVR, they would probably have noted it.

One problem was that the stall warning stopped due to high angle of attack even though the plane was stalled, and it started again when the nose was lowered and the AOA was in the "valid" region again. This might have confused the pilots in a situation when they already had inconsistent airspeeds etc. to deal with.

[StavrosK]

Ah, yes, I read that too. It was so frustrating that the pilot kept pulling up all the time, it makes no sense. You'd think that at some point he'd stop and reassess, but I guess he was too confused and shocked to do it...

[gnaffle]

Yes, maybe a combination of shock, confusion or distrust in the instruments was a factor. It will be interesting to see what the human factors group of the investigation comes up with.

I'm sure that the flight training will also be investigated, there has been concerns that improper stall recovery technique is being taught by some instructors: http://www.caa.co.uk/docs/33/012010.pdf

(And of course, in planes that are not certified for stalls, you can't really practice full stalls and have to train on approach to stalls instead.)

[onli]

It's especially frustrating for me because i remember all the times i crashed in a simulator due to stall until i understood what was happening. I don't even remember the name of the simulator, i'm not even an amateur-pilot - but that makes that report almost unbelievable, that something like this happened in a real flight to a real pilot.

[Florin_Andrei]

> One thing to keep in mind regaring stall is that it's 100% dependent on angle of attack, not speed (something Popular Mechanics gets entirely wrong). What happens basically is that at a high angle of attack the air layer doesn't track the wing surface properly and so you are deprived of standard lift.

So the air layer on the back "peels off", and you have turbulent flow on the back, instead of laminar, is that right? So the negative pressure is greatly diminished.

[mike_ivanov]

Exactly.

http://en.wikipedia.org/wiki/Stall_(flight)

[vannevar]

One thing to keep in mind regaring stall is that it's 100% dependent on angle of attack, not speed...

While the degree of stall with respect to the wing is independent of airspeed, the effects of stalling on the aircraft are very much dependent on speed. Even with the wing in the process of stalling, it can still generate enough lift to keep flying if you're going fast enough.

[krschultz]

I find the fact that the control sticks do not move together the most troubling design flaw. Bonin's actions were not obvious to the other two pilots, if the other pilot saw his stick pulled all the way back when he knows they need to get the nose down and pick up airspeed, he'd instantly know what was wrong. Instead he is looking at instruments and talking to the other pilot and is completely unaware of how self-inflicted the crisis is.

[abstractbill]

That, and the fact that the computer chooses to average inputs from the two sets of controls even when they're very different. One pilot pulling back, and the other pushing forward and the system just quietly averages them out rather than sounding another alarm?

[crististm]

This clearly looks like an anomaly that the plane should detect and correct. Or at least announce somehow. The computer should average only when controls are consistent with each other.

You never know what's the time when you have two clocks.

[afterburner]

You suggest that one problem might be that Bonin didn't know his angle of attack. Alternately, I remember a similarity here with an Egypt Air flight that went down when some instruments went dead: when one of the instruments experienced malfunction, the pilots suddenly found it hard to believe anything the computer was saying. So maybe, on some level, Bonin dismissed the stall warning because the speed sensor had failed. One sensor is faulty, he might have reasoned, how can I know the computer isn't just over-reacting to that?

[bhickey]

The NTSB concluded that 990 was a homicide. A relief pilot assumed control after take-off and then deliberately crashed the aircraft. From what I hear, it wasn't a fun week at the RI Medical Examiner's office.

[nikcub]

the other similar incidents are Birgenair Flight 301, where the pitot tubes were blocked because of insect nests, resulting in pilot confusion:

http://en.wikipedia.org/wiki/Birgenair_Flight_301

and Aeroperu Flight 603, where the pitot tubes had been covered by maintenance workers and not removed prior to takeoff, also resulting in pilot confusion and lack of confidence in instrument readings:

http://en.wikipedia.org/wiki/Aeroper%C3%BA_Flight_603

With these similar incidents you would think that air crews would have learnt from these disasters. If you read the reports on those two accidents, the similarities to the AF disaster are remarkable.

[Simon_M]

Considering how many incidents there seems to be due to the loss of these airspeed sensors it seems crazy not to have an additional, different method of calculating airspeed.

Is there a reason GPS is not suitable here?

[aperiodic]

GPS gives you speed relative to the ground, not speed relative to the air, which is what's important for aerodynamics.

[eftpotrm]

Yes, but when groundspeed with a slight lag is all that's available is it really that much worse than nothing, which seems to be the failure mode at present?

I stress I'm not a pilot and I'm sure you'd want to have a Big Flashing Warning Light telling you that ground speed <> air speed, but there'd seem to be some benefit over nothing at all.

[andrewmccall]

GPS can only tell you how fast you're moving over the ground. It can't tell you how fast you're moving through an airmass that might be moving with or against you, this is far more important to keeping a plane in the air than how fast you're moving between point a and point b.

[al_james]

I wonder if GPS could be used to estimate the air speed by means of a permanently refining mathematical model? E.g. If I know I have heading X, ground speed Y, weight Z, thrust A, you should be able to work out your predicted ground speed. Any variation in real ground speed and estimated ground speed is got to me made up of wind direction and velocity right??? Just a thought.

(Disclaimer: I know nothing about aerodynamics so this may be nonsense)

[rwmj]

GPS gives you ground speed. Airspeed is a different thing -- imagine if you're flying into a strong headwind.

[alpyne]

It can't give you the relative speed of the air around the aircraft.

[mtts]

Given the speed at which the readings in my android phone update while driving a car, I'd say yes.

[Shivetya]

let alone we forget losing a B2 bomber during take off for similar reasons.

http://en.wikipedia.org/wiki/Andersen_Air_Force_Base_B-2_acc...

[afterburner]

Yes, I keep hearing about pitot tube problems... I thought the Egypt Air flight I was thinking of had the same problem but I can't find information about it. It might be harder to find because I'm not sure the plane actually crashed.

[bulte-rs]

That last thing is the most important thing to notice since this is what most people think is the main result of air crash investigations: making a change to break the event chain leading to the incident.

In this case there were probably a number of human errors, a.o: not noticing speed restrictions on the speedtape (even in alternate and abnormal alternate law/mode these are present, although Valpha max and Valpha prot are removed a barberpole is present up to Vstall warning) and 'ignoring' the nose-down moment the airbus tries to induce in a low speed situation.

Possibly some design errors in the form of the alpha-floor protection removed in alternate law/mode.

Seems like there is a lot to learn from this investigation for both pilots and manufacturers and although it might seem harsh and insensitive (believe me, it's not; I've lost friends due to an aircraft crash) I am actually looking forward to the 'final incident reports'.

[sliverstorm]

Making a computer that can fly without airspeed makes less sense to me than making an airspeed sensor that either doesn't ice, or can de-ice itself. Is that so impossible?

[jarcoal]

Supposedly they do de-ice themselves, but that obv didn't work properly here.

[bdonlan]

According to the article, the pitots did, in fact, de-ice and return to normal functioning. However, apparently the alternate law needs to be manually reset, since the plane remained in direct input mode, and thus the pilots managed to stall the plane even though its instruments had all recovered.

[omegant]

Pitot tubes are always under strong heating during flight( so strong that the steel may blue). The problem with the 330 pitots brand in particular( there are several ) is that they cant evacuate water fast enought and sometimes they could become unserviceable ( as it happened to the af ) as they don't sense air preasure anymore.

[sliverstorm]

Ah, I was not aware they already could. My next question is why not make themselves de-ice better?

This maybe seems trollish or silly, but in all seriousness, if your sensors aren't good enough, first rule out improving the sensors before you try to compensate with the system.

[bdonlan]

According to the article's timeline, dual pitot failure occurred at about 02:10:06. Recovery of one pitot occurred at 02:10:36, and the other at around 02:11:03. That's about 30 seconds to recover one pitot, and 57 seconds to the recovery of the second. When you consider that this all boils down to melting off ice, that's not so bad, really. And if they hadn't royally screwed up their manual handling, it wouldn't have downed the plane - there is, in fact, a procedure for maintaining safe lift when airspeed indications are lost; somehow the copilots in command managed to screw it up, and continued to screw up even after the pitots recovered. The BBC tried replicating a pitot failure in a simulator, and when the sim pilots went by the proper procedure, there was no problem: http://www.youtube.com/watch?feature=player_detailpage&v...

So basically, this is human error, but exacerbated by a lack of training in cruise problems and poor feedback from the controls when the copilots gave conflicting commands.

[crististm]

The simulated test is always in a more relaxed environment. But anyway, if your instincts are good they you are OK. The problem is when your instincts tell you to do the opposite of what needs to be done. Probably the pilots need more training to break their instincts?

[jrockway]

There is other debris that can clog pitot tubes. Birgenair Flight 301 crashed because some wasps built a nest in a pitot tube during an extended layover:

http://en.wikipedia.org/wiki/Birgenair_Flight_301

189 people died.

(Also note the failure to react properly to the stall warnings. This comes up again and again.)

[jarek]

I wonder if in a couple of decades we'll look back at pitot tubes and wonder what the hell we were thinking using such a fragile solution.

(Of course, in a couple of decades we'll probably have a much more accurate external method of finding out speed/airspeed.)

[gnaffle]

Maybe, but keep in mind that they are in operation on thousands of planes operating night and day, and they very seldom fail. So it's not what you would call a fragile solution. After all, the pitots involved in this flight were already due to be replaced because of icing problems.

[jrockway]

It's hard to measure how fast you're going through the air without being able to sample the air. Pitot tubes are just the tubes that bring the air to the inside of the plane to be sampled; nothing more.

[Florin_Andrei]

The real WTF is that planes are kept aloft by aerodynamics. One day we'll look upon that the way nowadays we think of zeppelins.

[nufta]

Being restricted to rich people with "fuck the planet" attitude, hopefully the jet airliner market will be small enough to stall technologically.

[antoinehersen]

The fact that the heating element was not effective enough was a known fact. Since similar incident of lost of air speed had already happened. Pitot were being replaced with beefier heating elements. It was just not considered a high priority.

[reledi]

I agree. I know little about aviation, but wouldn't it be better if the sensors would automatically de-ice themselves rather than only being de-iced at the pilots' command?

[jonah]

I believe they're continually heated.

At least every one I've seen is labeled "heated probe" or the like which probably wouldn't be necessary if they had to be manually de-iced.

http://www.flightglobal.com/blogs/flightblogger/pitot-tubes_...

[presto8]

Thanks for the great summary. I also read the full BEA report which was very informative.

Is there ever a situation in a commercial plane where a stall would be a good thing? My non-pilot brain is trying to figure out why the plane would allow a stall even in alternate law mode.

I'm sure the Airbus user interface designers know what they are doing, but wouldn't it be possible to make stall protection always enabled, and then add a failsafe requiring both pilots to press a button to override stall protection? Then they would both have to consciously do a physical act to enter this dangerous state.

[munin]

as far as I understand, "stall protection" is a feature of the autopilot knowing its current airspeed.

you can drive down the road without hitting things, right? what if you're blind?

[presto8]

The plane did have the air speed information, at least at the time it made the stall warnings. Starting at time 2h10m17s, the pitot tubes started working again, the air speed was available, and the Flight Director came back online [page 89 of BEA report]. That is why the plane was able to make the stall warning in the first place.

I also wonder if, once the FD was back online, could the pilots have just re-engaged the auto pilot and the plane would have fixed itself? This is just such a tragic accident when there was nothing at all wrong with the plane for most of the incident!

[Terretta]

Almost all of this is in the article, and what isn't, takes some parsing to sort out. I would have found those bits of color more helpful if the additional info was related alone.

[Florin_Andrei]

> without valid airspeed there's a risk of overspeed which can cause a new set of problems

What problems specifically?

> Nobody believed a passenger aircraft would be so stable during a full stall.

What was the plane "supposed" to do during the stall? If you're inside the plane, how does it feel when the plane has stalled?

[crikli]

> What problems specifically?

All aircraft have a VNE speed, the NE standing for "never exceed." Going beyond this threshold invites structural failure and loss of control.

> If you're inside the plane, how does it feel when the plane has stalled?

I've mentioned this in another comment, but the body is a horrible judge of spatial reference. How the body is going to feel during a stall is tough to predict, particularly given that as a passenger a) you will have no visual reference and b) you will be at a unique distance from the aircraft's center of gravity.

That said, you might feel a little buffeting as the wing reaches a critical angle of attack, but once the plane is in a full stall you probably wouldn't feel a whole lot. It's impossible to overstate just how much the body relies on the Mark One Eyeball to properly interpret the sensation motion, gravity, centrifugal force, etc.

[lutorm]

Not all planes are stable in a full stall, some lose longitudinal stability and will be almost impossible to keep level.

[crikli]

Oh sure but most passenger planes are pretty docile a stall.

[sandee]

>at night, over an ocean, in a storm, with no visibility, in possibly significant turbulance

Instead of finding out strategies on how to fly under these circumstances, why can't the plane change its course, if they anticipate the flying route to have these conditions. How about running some reconnaissance drones in the popular routes if they suspect a bad weather and want to check out. Or try out better weather monitoring methods and tools on these routes.

Edit : Ok my mistake.On reading again, the article states "Unlike other planes' crews flying through the region, AF447's flight crew has not changed the route to avoid the worst of the storms. ".

[antoinehersen]

Not changing course like almost all other flight that night was their first mistake.

[einhverfr]

I noticed that the article suggested their weather radar was incorrectly set up, so that might be their first mistake.

[antoinehersen]

They should have pay extra attention to the weather since this region of the globe is prone to the worst storm. They even aknowledge it in the recording.

[yardie]

1. This is a region that is quite regular with thunderstorms. The captain probably assumed this was like any other storm in this area any other day of the week.

2. This route is at the upperlimit this plane configuration can fly. If they had to reroute they would need to stop and refuel in another country, possibly Spain, Senegal or Morocco. I assume the captain didn't want to do this and soldiered ahead.

[omegant]

You simply don't fly through a thunderstorm, as you simply don't drive through A concrete wall at 100mph. No matter how short you are on fuel.

[jonah]

That was the first thing I noted in reading this.

Is there any discussion as to why they didn't seek an alternate plan and if not, is this something that needs to or has been remedied?

[bambax]

> Is there any discussion as to why they didn't seek an alternate plan

The Captain chose not to, because he "wasn't afraid of clouds" (see my comment above). This was a huge mistake.

But Captains are in charge of their route and it makes sense; it would be incredibly bureaucratic and dangerous if routes were decided from a central command somewhere at the airline headquarters...

What we need are humble pilots; there should be psychological evaluation to weed out those who think they are John Wayne hunting down Indians.

Part of the difficulty is that the job attracts daredevils -- among others: that night, all other Captains went around the storm...

[ncw]

Would the weather radar not being set up correctly have played a part in the reasoning of the captain?

[brohee]

I can't find any reference of Bonin having glider ("vol à voile" in French) experience, do you have a source? I see many blog entries asserting that if he did it would never have happened...

[crististm]

indeed, a computer can continue to estimate for a certain amount of time the readings of the lost sensor. You can think of solutions. But its strange to see so many cases of lost planes because of pitot problems.