Beta

Slashdot: News for Nerds

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Flight 447 'Black Box' Decoded

timothy posted more than 3 years ago | from the impressive-feats-come-in-waves dept.

EU 449

fermion writes "An initial report has been released by the BEA concerning the details of the last minutes of Flight 447 en route from Rio de Janeiro to Paris. According the report, the autopilot disengaged and stall warning engaged at 2 hours 10 minutes and 5 seconds into the flight. Less than 2 minutes later the recorded speeds became invalid. At 2 hours 14 minutes and 28 seconds, the recording stopped. The final vertical speed was recorded around 10,912 ft/min."

cancel ×

449 comments

Umm, no... (4, Insightful)

Maury Markowitz (452832) | more than 3 years ago | (#36268574)

“So, we think that until impact they did not realize the situation, which for the family is what they want to hear — they did not suffer.”

A three minute decent at 10,000 ft/min over the middle of the ocean?

I'm pretty sure everyone onboard knew exactly how that was going to end about half way in.

Re:Umm, no... (1)

Hatta (162192) | more than 3 years ago | (#36268628)

If it's free fall, it would be 3 minutes of weightlessness. The end would be quite abrupt.

Re:Umm, no... (2)

Kenneth Stephen (1950) | more than 3 years ago | (#36268680)

Not quite free fall. My back of the envelope calcuations (38000 feet in 3 mins 30 secs) shows that assuming constant acceleration, the descent acceleration would have been approx .5 m/s^2 . This is about what you would experience in an elevator going down before the elevator reaches constant speed.

Re:Umm, no... (1)

antifoidulus (807088) | more than 3 years ago | (#36269000)

I doubt the acceleration was constant, furthermore it looks like they rolled the plane significantly, which definitely would have been noticed by the passengers.

Re:Umm, no... (1)

Interoperable (1651953) | more than 3 years ago | (#36269082)

It sounds like the plane was flown into the ocean. It was 12.7 km high at cruising altitude, so the rate of descent was 217 km/h. The cruising speed of an A330 is 871 km/h, so the pitch of the aircraft was roughly 14 degrees below the horizon.

In heavy turbulence it might be very difficult to tell if accelerations up and down balance out over the course of a few minutes, allowing a nose attitude to go unnoticed. The downward acceleration may well have begun in the minutes leading up to the "3 and a half minute" descent, and was simply glossed over for a short press release.

Re:Umm, no... (2)

rthille (8526) | more than 3 years ago | (#36269356)

The articles I read stated that the nose was up, not down, and that was the problem, the plane was stalled, nose-up, flying too slow and falling out of the sky.

Then again, having read stuff I know something about in the media, I know not to believe anything I read in the media.

LOST (1)

android.dreamer (1948792) | more than 3 years ago | (#36268996)

If it were me, and I only had 3 minutes left, I'd grab a pen from my pocket and carve into my shoulder "4-8-15-16-23-42" to send a message to my family that 'even if the ending sucked, at least I will find happiness in purgatory.'

Re:LOST (2)

WillKemp (1338605) | more than 3 years ago | (#36269170)

If it were me, and I only had 3 minutes left, I'd grab a pen from my pocket and carve into my shoulder "4-8-15-16-23-42" to send a message to my family that 'even if the ending sucked, at least I will find happiness in purgatory.'

I'm sure the sharks that ate your body would have been impressed by your ingenuity and would have passed the message on to your family.

Re:Umm, no... (2, Funny)

jhoegl (638955) | more than 3 years ago | (#36268636)

Saying "They did not realize the situation" is in fact true. They had no idea cheap speed sensors purchased by the plane manufacturer did not protect against freezing.

Re:Umm, no... (1)

Simon80 (874052) | more than 3 years ago | (#36269262)

Citation needed.

Re:Umm, no... (4, Interesting)

Bitsy Boffin (110334) | more than 3 years ago | (#36268750)

1. Unless it's pressurization system was faulty (it wasn't) the pressure change wouldn't have been great.
2. Unless accelerating, you wouldn't know you were going down (or up, or banked or upside down...).

So the claim that the passengers probably didn't think it was anything more than turbulence is not hard to believe.

It is perhaps surprising to non-pilots that you can be in unusual attitudes and not know it, pilots however are acutely aware. VFR (Visual Flight Rules) pilots flying into IMC (Instrument Meteorological Conditions - ie, zero visability) is a big cause of crashes, not because they can't see where they are going, but because they don't know which way is up.

Re:Umm, no... (1)

Bitsy Boffin (110334) | more than 3 years ago | (#36268766)

To be clear, this was not a case of VFR into IMC, an airliner is basically IFR all the way these days.

Re:Umm, no... (1)

SINternet (1194899) | more than 3 years ago | (#36268878)

Look at you gettin all Aeronautical and shit.

Re:Umm, no... (0)

Kjella (173770) | more than 3 years ago | (#36269204)

2. Unless accelerating, you wouldn't know you were going down (or up, or banked or upside down...).

At least under normal conditions I find gravity is the overwhelming force and that banking is easily felt as leaning into the sides, not to speak of upside down - I doubt you could miss the fact that you're hanging from your seat belt. What you don't really notice is vertical gain/loss, without looking out the window I doubt I could distinguish between a climb and a stall - if you have a water bottle in your seat pocket it'll look exactly the same.

Re:Umm, no... (1)

n1ywb (555767) | more than 3 years ago | (#36269224)

Have you eve played flight simulator? There's this thing called an "artificial horizon" that tells you exactly how you are oriented. It is not affected by freezing of the pitot tube.

Re:Umm, no... (1)

MrQuacker (1938262) | more than 3 years ago | (#36269292)

but because they don't know which way is up.

This is why all the pilots I know tie a washer to a string and tape it to the cabin ceiling. No matter what an instrument says, that washer will point down.

If you are buried in an avalanche you can use a similar trick to figure out what way the surface is, so you can dig yourself out.

Re:Umm, no... (0)

Anonymous Coward | more than 3 years ago | (#36269302)

2. Unless accelerating, you wouldn't know you were going down (or up, or banked or upside down...).

I don't know about you, but I can tell with a high degree of accuracy when I'm upside down, and when I'm in free fall. In an airplane I can also often tell when we're ascending or descending by looking out the window or noticing my ears pop.

With centrifical force, yes but strait down? No. (2)

Sipper (462582) | more than 3 years ago | (#36269310)

1. Unless it's pressurization system was faulty (it wasn't) the pressure change wouldn't have been great.
2. Unless accelerating, you wouldn't know you were going down (or up, or banked or upside down...).

So the claim that the passengers probably didn't think it was anything more than turbulence is not hard to believe.

This pre-supposes that the passengers felt approximately 1G of gravity downward from their point of view, which pilots normally carefully maintain for passenger comfort. A banked turn that maintains 1G of gravity downward by carefully controlling the turn rate feels "normal" as if the plane were flying straight. Pilots can't do this in an emergency when there are systems failures.

Remove that 1G of gravity like in a free-fall, or flying straight down, and the passengers are going to become acutely alarmed very quickly. Normal turbulence of sufficient magnitude can do this -- and the conditions they were in were worse.

So put your thinking cap on for a second, and consider how it might be possible for a plane flying directly downward to somehow create 1G of gravity sideways such that from the point of view of the passengers, they feel 1G "downward". How is that possible? The only way that could be done is through centrifical force, such as if plane were pulling up, and if it's flying strait down, it's not pulling up. At best, the passengers felt gravity at their backs from the acceleration downwards. As soon as they reached terminal velocity downward, the gravity they felt would be 1G to their front. I'm quite sure that as a passenger I'd notice all of that.

I think this was three minutes of terror for everybody on that plane.

Re:Umm, no... (0)

Anonymous Coward | more than 3 years ago | (#36269326)

Color me ignorant (I don't know much about 'planes... just enough to avoid them), but wouldn't an independently powered GPS tell which way is up? Like, uh, constantly?

Also, did a French plane hit the water at 10,912 ft/min? Seriously? I heard it was 200km/h, which is way simpler. And Fermion, if you really must use stupid units, at least be wise enough to consider errors and say 11,000 ft/min. Better yet, say 11000 ft/min, because at first sight -- for half the world -- it reads as 11 ft/min (unless you decided this post is US-only, then ok, go on and use commas).

- http://en.wikipedia.org/wiki/Decimal_mark

Re:Umm, no... (0)

Anonymous Coward | more than 3 years ago | (#36269338)

I think the passengers had to know something was going on... From the report, and I quote (cut and paste)...

"The altitude was then about 35,000 ft, the angle of attack exceeded 40 degrees and the vertical
speed was about -10,000 ft/min. The airplane’s pitch attitude did not exceed 15 degrees
and the engines’ N1’s were close to 100%. 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."

Angle of attack of 40 degrees is not flat. You would be pressed quite hard to the back of your seat.
Roll oscillations up to 40 degrees is not flat. Your inner ear would tell you you are turning.
Your tray/table would be empty as it would have spilled into your lap or dumped your laptop onto the floor.

They had to know...

Re:Umm, no... (1)

jambarama (784670) | more than 3 years ago | (#36269272)

Just FYI, 10,000 ft/min is only about 113 miles per hour. [google.com] Typical cruising speed for a long-distance large jet aircraft is about 550 mph, so the pilots had slowed the plane quite a bit. The plane didn't go screaming into the ocean.

10,912 ft/min (0)

Anonymous Coward | more than 3 years ago | (#36268586)

I need to see this in km/h to understand how quick that is... soooo my math skills tell me that it's about 200km/h.

Re:10,912 ft/min (1)

Jarik C-Bol (894741) | more than 3 years ago | (#36268622)

Or, about 120mph. (about). Yeah, seeing as that is the vertical speed, i think the passengers would notice that.

Re:10,912 ft/min (1)

CapOblivious2010 (1731402) | more than 3 years ago | (#36268674)

Wait, how does that compare to the speed of a falling library of congress? They need to give us units we can understand!

Re:10,912 ft/min (1)

tchdab1 (164848) | more than 3 years ago | (#36268946)

Irrelevant. A Library of Congress and an Archie comic both fall at the same rate.

Re:10,912 ft/min (1)

MichaelSmith (789609) | more than 3 years ago | (#36269074)

200 km/h is terminal velocity, for a human anyway. I did some indoor skydiving and the airflow is between 190 and 200 km/h depending on how heavy you are. It puts those 300 km/h tornado winds into perspective. Thats more than one G, horizontally.

Remember this is an initial report (1)

UnknowingFool (672806) | more than 3 years ago | (#36268602)

So far, there is no speculation as to why the airspeed sensors failed or assignment of blame. It is noted that the co-pilots tried to take control and may have stalled the plane. Nothing in the readings contradicts the leading theory of icing on the pitot tubes. It may take a year for a full report.

Re:Remember this is an initial report (1)

Maury Markowitz (452832) | more than 3 years ago | (#36268626)

Yeah, can't fault the NTSC's way of doing this... refuse comment until you're sure you have something to report.

Re:Remember this is an initial report (1)

OverlordQ (264228) | more than 3 years ago | (#36268732)

NTSC?

That's a video system. Do you mean the NTSB? They're not really involved either, it's the BEA [wikipedia.org] .

Re:Remember this is an initial report (1)

barlevg (2111272) | more than 3 years ago | (#36269096)

Typo aside, I very much agree with this sentiment: don't say anything until you know for sure, don't cause a premature outrage or get people's hopes up (not sure that last part really applies here, but still).

Re:Remember this is an initial report (1)

spongman (182339) | more than 3 years ago | (#36268710)

i believe the speculation is that the heaters in the sensors were faulty/insufficient and they became clogged with ice. the flight envelope at high altitudes is very narrow and apparently very difficult to fly without reliably knowing the airspeed.

Re:Remember this is an initial report (1)

marcosdumay (620877) | more than 3 years ago | (#36269012)

"...apparently very difficult to fly without reliably knowing the airspeed."

That is true on any situation, any altitude.

Re:Remember this is an initial report (1)

Mindcontrolled (1388007) | more than 3 years ago | (#36269070)

True, losing airspeed indication makes the situation very difficult, but not impossible to handle. As long as you know altitude, attitude and throttle setting, as well as the resulting climb/sink rate for a certain trim, you can still work it out. In the middle of a thunderstorm out of hell, at night, with hell breaking loose all around you, well... yeah, then all bets are off. But generally speaking, you can handle a plane without airspeed indication, and that is trained for.

Re:Remember this is an initial report (2)

countertrolling (1585477) | more than 3 years ago | (#36269320)

The training has proven to be entirely inadequate. This type of accident is far too common, since the earliest days. One guy should always be flying the plane, but all too often everybody's trying to troubleshoot the problem. and even in a storm it is possible to maintain control with a working artificial horizon and a fixed power setting as you point out.. Key word is 'situational awareness'. Lose that, then indeed, all bets are off. A lot more hours in the simulator are needed to burn this into the guy's head.

Re:Remember this is an initial report (1)

obarthelemy (160321) | more than 3 years ago | (#36269090)

i would guess not. air closer to the ground is denser, supplying more lift ? hence "the flight envelope at high altitude is narrow" ?

Re:Remember this is an initial report (1)

MichaelSmith (789609) | more than 3 years ago | (#36269164)

"...apparently very difficult to fly without reliably knowing the airspeed."

That is true on any situation, any altitude.

Flying by the seat of their pants, most instrument qualified pilots should be able to guess airspeed well enough to stay flying below about 20K feet. Stall buffet indicates you are too slow. Screaming airflow: too fast. In the middle, just right.

Re:Remember this is an initial report (2)

bob8766 (1075053) | more than 3 years ago | (#36269086)

The pilots have to keep the plane within a pretty strict speed range to both keep the plane together and avoid a stall. Even when the speed sensors fail and the pilots have no airspeed indicator, there is a standard procedure that allows them to keep the plane within that narrow range by setting the throttle and controls at specific settings until it unfreezes. Frontline even aired a special where two flight instructors demonstrated this after being presented with this exact scenario in a simulator. The problem happens because the pilots don't have a lot of time to react, and if they panic or misinterpret the situation it's all over.

Re:Remember this is an initial report (1)

Mindcontrolled (1388007) | more than 3 years ago | (#36268722)

Yeah, can't see any causality there so far. The speeds given in the press releases I read only show that there was a stall. If this happened due to faulty speed readings, pilot error - maybe due to loss of orientation in a very confused environment -, or the pilot fighting an actually correct behavior of the plane is completely open so far.

Re:Remember this is an initial report (0)

larry bagina (561269) | more than 3 years ago | (#36268818)

I think the first step is to check if the co-pilot was named Osama Muhammed al Hussein bin Mohammed Alluhu Ackbar.

Re:Remember this is an initial report (1)

fluffy99 (870997) | more than 3 years ago | (#36268862)

The answer is pretty much in the report. The co-pilot put full thottle on and kept pulling up, probably not understanding that that they were losing altitude because they were in a stall situation.

Re:Remember this is an initial report (1)

UnknowingFool (672806) | more than 3 years ago | (#36269050)

The assignment of blame is not in the report yet as this is initial. While it is curious that the pilot pulled up, one expert noted that after the stall, the plane should have lowered the nose which would have aided in stall recovery. The nose however stayed up which might mean that the rudder was frozen by ice or immobile by other factors. That would turn the stall from a simple stall to a "flat stall" which is unrecoverable. If there was ice then the pilot may have initially pulled up but could not push down after a certain amount of time. Again this is all speculation until the final report.

Re:Remember this is an initial report (1)

Mindcontrolled (1388007) | more than 3 years ago | (#36269284)

Actually, this makes the most sense of all I heard so far. Since - as I had to learn by painful correction to my mistaken initial assumptions - the stall warning went off, but the system still recorded the PF maintaining and even forcing a nose up attitude, loss of control surface movement seems somewhat probable. The throttle went to TO/GA, so they definitely tried stall recovery - which makes it quite improbable that they would have willingly forced nose up. Unless they were seriously mistaken about altitude and thought they could not sacrifice a single foot for speed. Nose-down attitude for stall recovery should be pretty much standard procedure, after all.

Re:Remember this is an initial report (1)

marcosdumay (620877) | more than 3 years ago | (#36269068)

I'm not a pilot, but shouldn't increasing the throttle help recovering from a stall?

Re:Remember this is an initial report (1)

Mindcontrolled (1388007) | more than 3 years ago | (#36269296)

Increasing throttle is half of it - and they did that. To quickly regain speed, you push the nose down, too. That did not happen. And that is actually interesting. Either they could not do it because they lost attitude control at this point, or they thought they could not do it, because they thought they had no altitude to sacrifice for speed.

Re:Remember this is an initial report (1)

MichaelSmith (789609) | more than 3 years ago | (#36269188)

The answer is pretty much in the report. The co-pilot put full thottle on and kept pulling up, probably not understanding that that they were losing altitude because they were in a stall situation.

Anybody who has spun a sailplane would know to put the nose down in that situation. Maybe these guys had never done that.

Re:Remember this is an initial report (0)

Anonymous Coward | more than 3 years ago | (#36269350)

Trained pilots know to do this. They have to do it in training, even after qualification.

Even the bloody aircraft knows to do this.

The whole thing is starting to either stink of a failure on the aircraft itself or a pilot who panicked and did not follow his or her training.

Re:Remember this is an initial report (1)

MichaelSmith (789609) | more than 3 years ago | (#36269138)

If it was the initial stall they must have really stuffed up. If you can get the aircraft flying at 20000 feet, you won't have to be anywhere near stall speed and you can fly manually as long as you want. Airliners are not jet fighters. Stall recovery should be straightforward, at least once you have lost some altitude. My uncle, when he was a flying instructor, said he would take a VFR qualified pilot into cloud and they would inevitably exit the cloud in a spiral dive, but airline pilots should be able to fly on instruments, even with pitot tubes frozen up. Your ears will tell you airspeed, roughly anyway. Two or three minutes are a long enough time to get things under control.

10,912 ft/min (2)

spongman (182339) | more than 3 years ago | (#36268614)

= 124 miles/hour

Re:10,912 ft/min (0)

Anonymous Coward | more than 3 years ago | (#36268668)

And now some decent SI Units:
55.55 m/s (200 km/hour)

Re:10,912 ft/min (1)

spongman (182339) | more than 3 years ago | (#36269300)

bah: 333,312 furlongs per fortnight

So much new and yet nothing new (2)

Kenneth Stephen (1950) | more than 3 years ago | (#36268630)

What seems to be remarkable is that the trigger to the catastrophe has indeed been revealed to be the pitot tubes - something that was suspected very soon after the flight went down. To a layman like me, it is amazing that without the benefit of all the data that has been recovered from the flight data recorders, experts were able to get so close to the mark.

Now, one could flip this around and also say that given that so many observers were able to so accurately get to the initial trigger for the failure in the absence of hard data, it must mean that this was a really common failure mechanism that should occurred in the field only as a result of the problem being repeatedly ignored.

It is a triumph of technology that the flight data recorder survived under such extreme conditions for so long. It was a triumph of technology, that it was located and retrieved from such an extreme location. Surely, a species with such (magical?) technical expertise could have expended the effort into preventing such a failure?

Re:So much new and yet nothing new (1)

chaboud (231590) | more than 3 years ago | (#36268676)

Never underestimate the triumphs of bean-counting ingenuity.

As professional programmer for over 10 years, the idea that we fly in planes engineered and built by politically-selected contractors should scare the pants off of me. That said, I'm on a plane right now. Probably best to assume that these things drop like feathers.

Re:So much new and yet nothing new (1)

hawguy (1600213) | more than 3 years ago | (#36268832)

What seems to be remarkable is that the trigger to the catastrophe has indeed been revealed to be the pitot tubes - something that was suspected very soon after the flight went down. To a layman like me, it is amazing that without the benefit of all the data that has been recovered from the flight data recorders, experts were able to get so close to the mark.

Now, one could flip this around and also say that given that so many observers were able to so accurately get to the initial trigger for the failure in the absence of hard data, it must mean that this was a really common failure mechanism that should occurred in the field only as a result of the problem being repeatedly ignored.

Since the pitot tubes were known to have problems before the crash and Airbus had recommended (but not required) their replacement prior to the crash, perhaps it's not so remarkable.

Re:So much new and yet nothing new (1)

marcosdumay (620877) | more than 3 years ago | (#36269122)

Airbus couldn't require anything from anyone, but several countries did require their replacement before the accident. Unfortunately, France wasn't one of them.

Re:So much new and yet nothing new (4, Interesting)

Anonymous Coward | more than 3 years ago | (#36268868)

To a layman like me, it is amazing that without the benefit of all the data that has been recovered from the flight data recorders, experts were able to get so close to the mark.

Airbus records remotely some telemetry data, this is how experts where able to make a sensible guess.

Surely, a species with such (magical?) technical expertise could have expended the effort into preventing such a failure?

Yes, of course. This will be taken in account in future projects and into airplane maintenance routines. But ya know, those damn birds are already very reliable. It's a disaster, my heart will be always with the families. But some times, you know, shit happens. We should always be aware of how fragile the human condition is and understand that despise all of our hard work into making things safe, some times the unexpected happens and a disaster awaits our destiny.

Yours sincerely,
Someone who deals with safety systems (not at Airbus ) and it's tired to see people blaming designers: we did our best.

Re:So much new and yet nothing new (1)

martin-boundary (547041) | more than 3 years ago | (#36269042)

To a layman like me, it is amazing that without the benefit of all the data that has been recovered from the flight data recorders, experts were able to get so close to the mark.

That's a logical fallacy. If enough experts (and not-so-experts) predict enough different reasons for the flight failure, then when the real reason is discovered, some expert will be very close to the mark. You're filtering out the prior speculation and choosing the segment that happened to agree with posterior conclusions. It's no wonder you're amazed how close the chosen segment is to the mark.

Now, one could flip this around and also say that given that so many observers were able to so accurately get to the initial trigger for the failure in the absence of hard data, it must mean that this was a really common failure mechanism that should occurred in the field only as a result of the problem being repeatedly ignored.

And if one did flip this around, one would be wrong. The characteristic of a common failure mechanism is that it is common. As such, it gets addressed by virtue of its repeated occurrence during repeated tests. If it does not occur frequently, then it simply isn't common.

Surely, a species with such (magical?) technical expertise could have expended the effort into preventing such a failure?

Of the millions of potential failures that never get realized, which ones should our species prevent first? Prediction problems are hard and risk is a fact of life. Before humanity starts stopping failures in alternate futures, it should try to master ways of dealing with past failures that did actually occur from repeating in exactly the same way. Fact before fiction, please.

Re:So much new and yet nothing new (2)

Kenneth Stephen (1950) | more than 3 years ago | (#36269126)

With respect to your comment that this is a logical fallacy - its not so. The pitot tubes have been for the past two years the #1 reason put forward as the cause - by a wide margin. There have been no alternative theories so widely championed. Go back through the news articles and see for yourself. If you find that too difficult, you can use the wikipedia page on this disaster (look at the page history).

And if one did flip this around, one would be wrong. The characteristic of a common failure mechanism is that it is common. As such, it gets addressed by virtue of its repeated occurrence during repeated tests. If it does not occur frequently, then it simply isn't common.

I don't understand what you are trying to say here. You seem to be conceding that this was a commonly occurring failure, and don't dispute that this wasn't fixed (i.e it was ignored), so why am I wrong?

Re:So much new and yet nothing new (4, Insightful)

OverlordQ (264228) | more than 3 years ago | (#36269058)

Surely, a species with such (magical?) technical expertise could have expended the effort into preventing such a failure?

There is, it's called heated pitot tubes, and the FAA requires them for US carriers.

Re:So much new and yet nothing new (1)

bragr (1612015) | more than 3 years ago | (#36269108)

To a layman like me, it is amazing that without the benefit of all the data that has been recovered from the flight data recorders, experts were able to get so close to the mark.

If you recall, we did have the diagnostic messages that they airplane was sending back home, which, if I recall correctly, helped identify the cause the problem. The idea of the tubes freezing up was not a shot in the dark.

Well, this should be interesting... (1)

chaboud (231590) | more than 3 years ago | (#36268632)

A fast, uncontrolled dive? Did they overspeed and get stuck with mach tuck? Other system failures? Regular ScareBus electronic wonkiness?

The only reason I can think of for them not hitting power/attack procedures for faulty pitot systems would be that they were overspeed before they had a chance to fix anything. Perhaps the AutoPilot corrected for an indicated stall and boned everyone on board? I doubt we'll ever know for sure, but automatic systems that can go straight to crap in a half a minute mean persistently alert pilots on long-haul flights. That, frankly, may just be too much to ask.

Re:Well, this should be interesting... (1)

amicusNYCL (1538833) | more than 3 years ago | (#36268778)

Regular ScareBus electronic wonkiness?

Wow, the airline manufacturing industry has fanboys, too? Might I recommend "AirBu$"? That way you can also signify it's a for-profit corporation, which seems to play well around here. Regardless, I'm going to try and work the term "mach tuck" into daily speech, so thanks for that.

Perhaps the AutoPilot corrected for an indicated stall and boned everyone on board?

It sounds like the automated systems disengaged at the beginning of the descent and the 32-year-old co-pilot put the plane into a 35 degree up angle, and the plane stayed at that angle even until impact. Apparently by the time it hit it had also rolled to the right, but was still 35 degrees up. The investigators indicated that based on the audio the pilots did not realize they had stalled. They never said the word "stall". They did recognize they had no valid speed indicators.

Re:Well, this should be interesting... (1)

Mindcontrolled (1388007) | more than 3 years ago | (#36268826)

The interesting part is the fact that they don't report any stall warning being heard on the CVR. I am not sure how it is implemented in Airbus planes, but the stall warning horn and stick shaker should make quite some ruckus that should be detectable on the CVR. This opens up more questions than it answers for now.

Re:Well, this should be interesting... (1)

hawguy (1600213) | more than 3 years ago | (#36268894)

The interesting part is the fact that they don't report any stall warning being heard on the CVR. I am not sure how it is implemented in Airbus planes, but the stall warning horn and stick shaker should make quite some ruckus that should be detectable on the CVR. This opens up more questions than it answers for now.

You mean something like this:

From 2 h 10 min 05 , the autopilot then auto-thrust disengaged and the PF said "I have the
controls". The airplane began to roll to the right and the PF made a left nose-up input. The stall
warning sounded
twice in a row. The recorded parameters show a sharp fall from about 275kt
to 60 kt in the speed displayed on the left primary flight display (PFD), then a few moments
later in the speed displayed on the integrated standby instrument system (ISIS).

Or this:

At 2 h 10 min 51 , the stall warning was triggered again. The thrust levers were positioned
in the TO/GA detent and the PF maintained nose-up inputs. The recorded angle of attack, of
around 6 degrees at the triggering of the stall warning, continued to increase. The trimmable
horizontal stabilizer (THS) passed from 3 to 13 degrees nose-up in about 1 minute and
remained in the latter position until the end of the flight.

Re:Well, this should be interesting... (1)

Mindcontrolled (1388007) | more than 3 years ago | (#36268930)

I stand corrected. Didn't read the linked article and only went by what a local news source reported, which, quite obviously, was utter crap. Interesting though. Why would the PF maintain nose-up after a stall warning? Especially when he went TO/GA to get out of it? Did he believe that he had no altitude to work with?

Re:Well, this should be interesting... (1)

MichaelSmith (789609) | more than 3 years ago | (#36269242)

A bit like that pilot recently in the US. Aircraft stalled during approach due to ice on the wings. PIlot pulled up (the plane was going down right? When you want your elevator to go Up you press Up) and basically stalled the plane into the ground. I think airline pilots should be required to stay current in general aviation. Fly some ultralights, hang gliders, sailplanes, aerobatic planes or normal light aircraft. Hours flying a computerised airliner don't give you stick and rudder skills.

Re:Well, this should be interesting... (1)

Mindcontrolled (1388007) | more than 3 years ago | (#36269328)

Guess so - put em into a Piper Cub every couple of months. However, I am reluctant to place blame at this point. You gotta remember that they were inside the mother of all thunderstorms - turbulence would have all your indications fluctuate all over the place. They should not have been there in the first place. Why they were there is another quite interesting question.

Re:Well, this should be interesting... (0)

Anonymous Coward | more than 3 years ago | (#36269332)

Rudder could've been frozen, preventing the nose-up situation from correction.

Airbus (0, Flamebait)

religious freak (1005821) | more than 3 years ago | (#36268648)

Airbus is run by software. Boeing by pilots. I don't trust either, but I trust the software less

Same here (1)

publiclurker (952615) | more than 3 years ago | (#36268716)

Pilots have more skin in the game. Software doesn't really care if it crashes or not.

Re:Same here (1)

MikeBabcock (65886) | more than 3 years ago | (#36268792)

Software can be programmed to care :)

Re:Airbus (1)

bhcompy (1877290) | more than 3 years ago | (#36268726)

Truer words won't be said in this thread.

Re:Airbus (0)

Anonymous Coward | more than 3 years ago | (#36268728)

Since Airbus has a better safety record, you should trust the software more.

That software isn't your common run of the mill PC stuff made by hacks. It's a whole different kind of thing.

Re:Airbus (-1)

Anonymous Coward | more than 3 years ago | (#36268784)

Since Airbus has a better safety record, you should trust the software more.

Citation Needed

Re:Airbus (2)

Derekloffin (741455) | more than 3 years ago | (#36268754)

Now the question is, how many air crashes have been due to pilot error versus those due to software error. I suspect software has the better record.

Re:Airbus (0)

Anonymous Coward | more than 3 years ago | (#36268880)

I wonder how much that might be due to the fact meat packs have flown more hours hand software...

Re:Airbus (0)

Anonymous Coward | more than 3 years ago | (#36268776)

This was clearly pilot error.

There are standard operating procedures for this situation, if the pilots had done NOTHING AT ALL, then the flight would have been normal.

What you apparently aren't aware of is that ALL commercial airplanes are flown by computers at a very low level. All in service Boeing aircraft prior to 777 have a cable from the pilot control to a COMPUTER in the aft quadrant. That computer is part of the ARTIFICIAL FEEL SYSTEM and takes the pilot input and converts that to a zero airload surface command which is then converted to a final surface command to be executed by hydraulic actuators.

Newer boeing aircraft (i.e. same age as Airbus's) use fly by wire, too.

Re:Airbus (1)

hawguy (1600213) | more than 3 years ago | (#36268956)

This was clearly pilot error.

There are standard operating procedures for this situation, if the pilots had done NOTHING AT ALL, then the flight would have been normal.

Really? I'm not a pilot, but what happens when the auto pilot disengages (as it did in this case), but no pilot takes control? Does the plane keep flying straight and level?

How good is a computer at flying when it loses a key sensor input that tells it the plane's airspeed? Will the computer make the right decision when it thinks the airspeed is 50 knots and the plane is stalling, but in reality is 400 knots?

Re:Airbus (1)

tnk1 (899206) | more than 3 years ago | (#36269240)

Will the computer make the right decision when it thinks the airspeed is 50 knots and the plane is stalling, but in reality is 400 knots?

Yes, it will detect that the speed measurements it is getting make no sense. It will disengage and let something whose sensors are still working take over, that being the pilot. That is what the right decision is.

What is not clear is why the pilots nosed up in a stall, even when getting stall warnings. It may be possible they did not know their altitude and thought they were low, or for some reason they distrusted the stall warnings they were getting. Given that the autopilot shut down, they may have assumed the worst about their instruments.

Re:Airbus (1)

obarthelemy (160321) | more than 3 years ago | (#36269280)

i think what parent is saying is that the pilot put the plane's nose UP, actually creating the fatal stall. If left to fly level, the plane may have recovered.

Re:Airbus (2)

sinan (10073) | more than 3 years ago | (#36269104)

I trust software more and more in the long run. And I m not a geek!!

Re:Airbus (1)

tnk1 (899206) | more than 3 years ago | (#36269308)

Software can be made to be very safe and takes care of a lot of things in airliners these days. In theory, it is more than good enough to take off and land the planes on its own already.

However, when the software has not been programmed to deal with an unusual case, it will simply not work. For software, there really is no try, there is either do or do not.

Its failsafe is to complain about it very loudly and have something which can adapt better take over for it: a pilot. Someday we may have AIs in planes, or at the very least, very, very advanced expert systems, and pilots really will be obsolete and maybe even unsafe to have relative to the abilities of the system. That day is not quite here yet, since the difference between pilots and software is not enough so that the general public stops believing the humans are far superior in the cockpit.

seems obvious to me (0)

Anonymous Coward | more than 3 years ago | (#36268650)

the plane crashed because the passengers weren't molested before boarding the flight. Had they been molested, some would have chosen not to fly and would therefore still be alive.

120 mph vertically, probably out of control (0)

Anonymous Coward | more than 3 years ago | (#36268794)

60 mph is a mile per minute. 10,000 feet is a bit less than two miles. 10,000 feet in one minute is two miles per minute. So, 120 mph vertically. That's a lot. It isn't totally out of reason for a gliding jet though. Big jets have a really crummy glide path. They go down almost as fast as they go forward.

On the other hand.

Some jets have been known to run out of fuel and then glide to a safe landing. Consider the jet that landed in the Hudson; a safe landing on water.

The plane was probably out of control when it hit the ocean.

Re:120 mph vertically, probably out of control (1)

hawguy (1600213) | more than 3 years ago | (#36269034)

60 mph is a mile per minute. 10,000 feet is a bit less than two miles. 10,000 feet in one minute is two miles per minute. So, 120 mph vertically. That's a lot. It isn't totally out of reason for a gliding jet though. Big jets have a really crummy glide path. They go down almost as fast as they go forward.

Untrue - a 747 has a glide ratio of about 15:1, so at 30,000 feet, you've got around 80 miles to find an airport if all of your engines fail. Granted, it's a far cry from a 50:1 or better glide ratio you can find in a good sailplane, but it's also far from the space shutle's 1:1 hypersonic glide ratio.

Re:120 mph vertically, probably out of control (1)

Cowclops (630818) | more than 3 years ago | (#36269088)

Of course, achieving a 15:1 glide ratio requires you to be at the appropriate airspeed to do that... and since the main problem was loss of airspeed indicator, they were falling, not gliding.

Re:120 mph vertically, probably out of control (1)

hawguy (1600213) | more than 3 years ago | (#36269318)

Of course, of course, they didn't lose engine power, so glide ratio has nothing to do with this particular incident...glide ratio is not what dropped this plane into the ocean.

The parent poster claimed that a 10,000 ft/minute drop is within reason for a gliding jet, which is not the case unless there are other mitigating factors, like loss of hydraulics.

I believe the last recorded sentence was (0)

youn (1516637) | more than 3 years ago | (#36268808)

"oh a double rainbow, what does this meannnnn?" :)

People who know nothing about airplanes are wrong (0)

Anonymous Coward | more than 3 years ago | (#36268848)

Are all up in arms that the computer crashed this airplane. That is 100% incorrect. The computer dropped offline and the pilots had to take teh controls. That is what crashed this airplane and most modern airplane crashes. Pilots simply do not know how to fly anymore.

I think the computers should be programmed to manage the situation and only alert the pilot that they are dealing with it instead of disengaging. In that case the computer would automatically do what the pilot is taught to do.

Re:People who know nothing about airplanes are wro (1)

MichaelSmith (789609) | more than 3 years ago | (#36269290)

Pilots simply do not know how to fly anymore

Yep. Send them all out to do spins in a sailplane. Twice a year.

If God had meant for man to fly... (1)

Alien Being (18488) | more than 3 years ago | (#36268922)

Then he wouldn't have put corrupt manufacturers and regulatory agencies in charge of the airplanes.

I've logged plenty of airmiles, but I'm never climbing aboard one of those hand grenades again in my life.

Re:If God had meant for man to fly... (0)

Anonymous Coward | more than 3 years ago | (#36268972)

Must be nice to not have a desire or need to travel anywhere outside of driving distance, or the flexible enough hours, spare time, and money to drive thousands of miles at once to, for instance, cross the US (Boston to San Francisco) or Europe (Madrid to Moscow). I guess I can't blame you for having such a superiority complex, living in what must be Shangri-la, such that you never have to leave and cast your eyes on the rest of the inferiors outside your city.

Frankly, though, seeing the accident and death rates of ground vehicles and foot traffic, I'm never setting foot outside an airplane again in my life.

Stalls (0)

Anonymous Coward | more than 3 years ago | (#36268938)

According to some media-released transcrips I have read, the plane was stalled for over three minutes and yet the pilots consistently kept the nose of the plane at an upwards angle. Piloting 101 states that if your plane is stalled, the proper maneuvar is to point the nose downwards and dive sharply to pick up enough airspeed so that you can swoop and obtain lift so that you are no longer stalled. Apparently the pilot's actions deviated from this almost universal practice and further doomed the situation.

I am not nor have I ever been the pilot of an aircraft, however I fly remote control planes and I've had to deal with stalls a time or two using such a tactic. If the pilots of 447 had executed such a practice, odds are the stall would have broken. Perhaps that accounts for the 'human error' portion of the blame, but it was significant. I realize that airspeed and altimeter tools are invaluable to flight, but with the loss of those a firm knowledge of aviatic physics can mean the difference between life and death. As it was here.

Re:Stalls (2)

hawguy (1600213) | more than 3 years ago | (#36269152)

According to some media-released transcrips I have read, the plane was stalled for over three minutes and yet the pilots consistently kept the nose of the plane at an upwards angle. Piloting 101 states that if your plane is stalled, the proper maneuvar is to point the nose downwards and dive sharply to pick up enough airspeed so that you can swoop and obtain lift so that you are no longer stalled. Apparently the pilot's actions deviated from this almost universal practice and further doomed the situation.

I am not nor have I ever been the pilot of an aircraft, however I fly remote control planes and I've had to deal with stalls a time or two using such a tactic. If the pilots of 447 had executed such a practice, odds are the stall would have broken. Perhaps that accounts for the 'human error' portion of the blame, but it was significant. I realize that airspeed and altimeter tools are invaluable to flight, but with the loss of those a firm knowledge of aviatic physics can mean the difference between life and death. As it was here.

Of course, in this case, even the computer didn't have the data it would have needed to fly the plane - if the pitot tubes were blocked and not giving a speed reading, the pilots may have attempted to outguess the situation. They may have looked at thrust settings and maybe even GPS speed reports and concluded that there was no stall despite the warnings since they knew the airspeed was far above what was reported.

I trust that an airline pilot has enough training to know how to handle a stall, but if he knows his instruments are lying to him, then he may choose to ignore them.

Do stall warnings use anything other than airspeed and angle of attack to warn about a stall, or are there some type of sensors on the wings to detect airflow and lift?

Re:Stalls (1)

MichaelSmith (789609) | more than 3 years ago | (#36269306)

In the plane, stall buffet is impossible to ignore. Anybody who has flown a light aircraft will know to push the nose down. Unfortunately flying is more about filling in the forms and programming the onboard computer these days. Maybe the plane is at fault, by not making the pilots fly all the time.

sad (0)

Anonymous Coward | more than 3 years ago | (#36268974)

Merely losing air speed really shouldn't result in a crash.
Unless some other system failed, this might be a case of pilot error due to vertigo.

The Garmin GPS I use while driving tells me how fast I'm going.

And no, you wouldn't feel weightless for three minutes. You need increasing (not constant) vertical descent speed.

Re:sad (1)

hawguy (1600213) | more than 3 years ago | (#36269264)

Merely losing air speed really shouldn't result in a crash.
Unless some other system failed, this might be a case of pilot error due to vertigo.

The Garmin GPS I use while driving tells me how fast I'm going.

Your GPS tells your speed relative to the road, which, being firmly attached to the ground, is the speed you care about.

However, in a plane, your GPS tells you your speed relative to the ground, which could be plus or minus 300mph from your airspeed (depending on the speed of the jetstream) and I imagine that in the stormy conditions they were in, wind gusts could have made their airspeed even more variable and unpredictable with respect to ground speed.

Blaming the pilots, protect the corporation (0)

Anonymous Coward | more than 3 years ago | (#36269084)

Imagine that.

Airspeed indication fails because of poorly-designed sensors that were known to be prone to icing, the pilots react incorrectly for the actual flight conditions because they couldn't know what the actual flight conditions were, and it's their fault.

Gee, I wonder who that conclusion shields from millions of dollars of liability?

Its not a crash... (1)

Roachie (2180772) | more than 3 years ago | (#36269094)

its was falling... "with style".

A failure in training (1)

countertrolling (1585477) | more than 3 years ago | (#36269120)

If all this is true, it appears the pilots 'froze up; and failed to monitor the instruments that were working properly, namely their HSI or artificial horizon.. 'Partial panel' training, or learning how to fly with what you have left is part of every pilot's training, but under high stress situations like this, it a llgoes out the window, and the result is a form of tunnel vision, focusing on the malfunctioning instruments. This is what happened in the BergenAir crash when its pitot tube was obstructed, and AeroPeru with the taped over static port.. A similar incident happened to Eastern's flight 401 in 1972 when the nose gear down light didn't light up. All three crew members were trying to troubleshoot that and nobody was flying the plane. A very common cause of these things when situational awareness is lost.

Seems to be pointing to pilot error (1)

bhmit1 (2270) | more than 3 years ago | (#36269194)

So far, the NOVA summary [pbs.org] is on target. In addition to the pitot tubes freezing, which is an obvious design flaw, it sounds like the pilots reacted improperly to the loss of speed data.

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Create a Slashdot Account

Loading...