Air crashes in computerized planes

[Kapitan]

For the generation born 80´s onward. For the worshippers of glass cockpits and big computer screens in cockpits. For the believers that a plane that deals with physics can be controlled by computer electronic devices alone. For you guys that think piloting is equal to monitoring systems in modern Airbuses, with joysticks instead of Yokes and flashing lcd´s showing all the systems planes are "cool":

Since fly-by-wire lcd systems came around in the 90´s an increasing number of airplane crashes were affected or had systems failures that contributed to the accident.

Airbus A330 that disappeared yesterday. Though causes are still unknown, and though there was a storm in place, thousands of planes cross the atlantic since the 1930´s. My father crossed it twice a week for 40 years, crossing storms earlier with a DC-6 up to later with 747-200.

Last year accident of TAM in an airbus landing in sao paulo, computerized system accelerated cause the reverser was off so it "thought" the plane wanted to take-off, powering the right engine...to make the story short. A similar thing happened in the Airbus inaugural flight. A Fokker-100 in the same airport accidentally armed itself the reverser during take-off.

Im not going to make a list here but being curious reading reports on many modern accidents concerns about the amount of interference with "systems" in each casualty. Im not saying flying has to be the "old" way but...

Hydraulics-mechanics, or instruments that read information directly from the source, like a pitot tube, should still exist, even if as back-up ways of control. Early in the 90´s all planes had this dual mechanic-computer control, but gradually planes were released completely electronic-digitallly ...even if with 3 or four redundant systems...we know how fragile electronics are, we all know that each time we turn our home computer on, ...something could fail, the HD, memory, motherboard, the OS crashes...we have to live with that.

If the storm harmed the plane in a way electronics affected its controls...I wonder if an old 707 would have resisted. Just an argument for discussion
K

[ytzpilot]

If the storm harmed the plane in a way electronics affected its controls...I wonder if an old 707 would have resisted. Just an argument for discussion
K

I was thinking the same sort of thing. The 707 wasn't lightning proof as it pre-dates the NASA experiments and was built when they had little knowledge of lightning strikes. The aircraft wasn't grounded like the next models were. but it was a tough old bird though.

As a passenger I have always felt most comfortable in a 737, 747, or 767. No Fly-By Wire, No composite construction (Back then). Good old American know how.

I swear by the 747 after heavy turbulance due to a storm system over the pacific enroute to New Zealand. Sitting in the back of that aircraft you could see the fusilage twisting ever so slightly from front to back as it flew through the system, look out and see the wings flex up and down as well as each engine rock back and forth on there mountings. Lots of praying in those moments. But the old girl comes out the other end with not even a scratch.

I don't like Fly-By-Wire as there is something comforting knowing that their is a cable attached to the control column to each control surface. I consider this the last life-line if all else fails.

Hydromechanical systems are heavy though and modern planes are built around reduced weights. This is why they are now Fly-By-Wire and use composites today.

[3rett]

Agreed...... I know way too many pilots that think setting up glass, an auto pilot, and drinking coffee makes them the best pilot on earth. I even read an article that suggested that because this route is uncontrolled for so long that pilots who fly it take naps on this leg. It went further to say that may have happened in this situation and by the time the pilots woke up it was too late. Normally in one ear out the other. But this wouldn't be the first time pilots have done this. Just google this and you'll see a bunch of these incidents.

I want to be clear. I am not suggesting what happened to AF447. I have no idea what happened. I also can't stand all of this speculation. Let the professionals figure this out. Just sayin I'm really with you guys on pilots and planes not being, oh how should I say this? They sure don't make'm like they used to.

Anyway, lets hope they get this thing figured out quick for the families and overall safety of flying..............

[Kapitan]

Agreed...... I know way too many pilots that think setting up glass, an auto pilot, and drinking coffee makes them the best pilot on earth. I even read an article that suggested that because this route is uncontrolled for so long that pilots who fly it take naps on this leg. ...

Well, yes and no.
Dont know what strict economic airline rules are today. But in the old days there were two crews for international flights, one was resting while the other flying. The 707 even had two beds for the crew, separated by a curtain (which I used too). Its also true beyond Natal there was an uncontrolled airspace.

It was international norm that pilots should pick the mic at certain fixes/waypoints and anounce in a known open frequency (dont remember the number)
"Atention to all stations, this is Lufthansa 3210 flying heading 220 at FL330 position YURAT"

...and eventually any plane hearing would reply with his positon and farewells were exchanged.
K

[scott967]

Fortunately, planes never crashed in the days of cables and pulleys. Should we also return to wood and doped fabric?

scott s.
.

[=Hollywood=]

From all accounts of the systems report the on board systems reported, there was all manner of failures, including rapid decompression, which leads to the conclusion the plane broke up in flight...

If it was just a lightning strike and the electrical system alone failed then there's no way you'd also get rapid decompression, the aircraft would have had to be at altitude for the systems to send an alert about that, from what I remember from the reports, the decompression happened near the beginning, followed by increasing electrical and other failures...

I have been on a flight (767-300) once in extreme mechanical turbulence and the interior lining was slamming against the fuselage ribbing and lateral movement of the interior cabin walls was about 1m (3ft) and we were getting tossed around the sky severely. Now understand my father was a 767-200 Flight Engineer and that being the case I've also spent many many hours on the 767's. I'm also a pilot IRL. We had so much movement that the wings were flexing way above the main fuselage of the aircraft, the woman next to me was dry reaching, I was white knuckled and knew the aircraft was close to it's structural limits... We did make it through but sometimes knowing too much about an aircraft can be a bad thing as you can recognize when things are going wrong...

Anyway all that is to say that I would hazard a guess that the aircraft in the Air France incident was struck by lightning and some part of the airframe was damaged by the strike, possibly punching a hole in the airframe or even igniting fuel in the wings... At over 500mph and air racing by the fuselage coupled with extreme mechanical turbulence could quickly lead to the airframe breaking up in flight...

Remember that the flight crew did not make any radio contact so this had to be a catastrophic failure that kept the crew busy and had to be a rapid failure, interesting that the onboard systems were able to get a message out but the pilots were not...

My money is on a catastrophic airframe failure due to a possible lightnining strike which punctured a hole in the airframe or ignited fuel... I'm not sure of the construction of the A330 but I do know that carbon fiber is very bad news in lightning storms and has brought down aircraft before because the composite components basically exploded when struck... Although advances have been made to make composites safer they are only now beginning to understand how it behaves within the flight environment...

[Kapitan]

My money is on a catastrophic airframe failure due to a possible lightnining strike which punctured a hole in the airframe or ignited fuel... I'm not sure of the construction of the A330 but I do know that carbon fiber is very bad news in lightning storms and has brought down aircraft before because the composite components basically exploded when struck... Although advances have been made to make composites safer they are only now beginning to understand how it behaves within the flight environment...

I guess you may be right, it makes sense. Islanders from Fernando de Noronha, about 350 miles from the possible crash location, claim they saw a light spash in the sky.

To Scott:
No, I dont think we must go back to wood,
but somethings should be kept, for security reasons, and controls is one of them.
Another typical downside of modern planes is instrument display.
Human eye-mind is used to round things.
Our planet is round.
I look at a VSI and immediately feel comfortable if climbing or descending by looking at the needle in a round gauge, if its above zero, its climbing. Below zero, descending.

But the modern HSI with incorporated VSI and that "half-needle" in a stretched vertical tape is totally unpleasant to my eyes and comprehension. It takes me a few seconds more to interpret the information in my mind. Modern pilots dont get afected cause they dont fly the plane, they just sit there watching! But if you need to fly the plane, like most do with small planes, you need to grab your hands in controls and scan your instruments properly. In this case its better if they are round instruments.

Look at your watch. Is it round with needles? Or is it digital electronic?
Cause digital watches have been around since the 70´s you know?
Why dont you use them?

Humans are used to information round the clock literally. Same comparison between a classic airspeed indicator and those stupid digital indicators in modern planes with just numbers on a tape! A round classic gauge/instrument, be it a horizon, IAS, altimeter or VSI is much more user friendly and clear. Modern manufacturers say: "Pilots should be trained and get used to it"

OK. Take a small Cesna, piper or single engine. They all have standard classic gauges. Give them a modern lcd to fly. Any pilot will feel completely disturbed and would want his classic cockpit back, even if he has the money for expensive lcd instruments. Since he´s not an employee...the market makes its choices.

And yes, I do believe and support Airbus should have proper hydraullic controls, proper control device (Yoke) and proper instrument indicators...at least as back-up.
K

[loki]

I would argue that most of your post is basically about what you prefer yourself. If a pilot was trained in a Cessna with a glass cockpit, they would find it equally difficult to switch to the old style gauges as one going the other way. Personally I don't find round gauges or objects any easier to read or more attractive just because they are round. With more and more kids growing up using computers and playing video games, glass cockpits are probably a better way to go. Never mind that they tend to be far more reliable than the old style gauges. And with glass cockpits you can do other interesting things like overlaying a simulated view of the outside world for IFR or night flying.

[ytzpilot]

My money is on a catastrophic airframe failure due to a possible lightnining strike which punctured a hole in the airframe or ignited fuel... I'm not sure of the construction of the A330 but I do know that carbon fiber is very bad news in lightning storms and has brought down aircraft before because the composite components basically exploded when struck... Although advances have been made to make composites safer they are only now beginning to understand how it behaves within the flight environment...

Well said....We are moving back to New Zealand this January so......I am booking on the Air New Zealand 747 again......Love this plane :D

It's not about wood and doped fabric. Statistically the 737 is the safest and most successful aircraft ever built. As a customer and passenger I take these things to mind when booking flights.

I got me some wood and cables in the back yard though. I think I'm gonna build me an aeroplane.

[Avechelice]

Hello,


Since fly-by-wire lcd systems came around in the 90´s an increasing number of airplane crashes were affected or had systems failures that contributed to the accident.


Flybywire system is actually the safest way to control a plane ..
In all flybywire aircrafts accidents it was always the human error incriminated or other exterior event .. but never the aircraft control system ...
And if you check the relevant statistics .. numbers will show you what best is ...


Last year accident of TAM in an airbus landing in sao paulo, computerized system accelerated cause the reverser was off so it "thought" the plane wanted to take-off, powering the right engine...to make the story short.

For make the story less short .. read the preliminary report .. and you will see it's a human error ... the control system acted as it was designed for... but cause the pilots don't followed the procedures to apply when a reverser is off .. the accident occured.
It's no way of worshipping here .. it's question of technic ...


I guess you may be right, it makes sense. Islanders from Fernando de Noronha, about 350 miles from the possible crash location, claim they saw a light spash in the sky.


Gees .. those islanders have very good eyes .. for seen at 350 miles distance in a stormy sky .. the light of a plane exploding or taking fire ... seem's they are human radars :)
Cause the curvature of the Earth ( yes .. she is not flat !) and the altitude of the plane(+ - 12.000 meters) .. this light is approximately at the line of horizon but at 350 miles !!! ... and the expected visibility distance is ?? :)
Conclusion .. it's make no sense ...

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

[ytzpilot]

Flybywire system is actually the safest way to control a plane ..
In all flybywire aircrafts accidents it was always the human error incriminated or other exterior event .. but never the aircraft control system ...
And if you check the relevant statistics .. numbers will show you what best is ...

I'm still sticken with the 737 as the safest and most successful aircraft ever built. I trust the older systems over the newer ones. But I don't lose sleep over it. I've been on most airbuses and the 777 by now. I still trust 737, 747 and 767 the most.

I could book the Qantas A380 from Los Angelas to Sydney this January to try that one out.....But I probably will book the 747 instead as I am a Boeing fan.

[dredgy]

could book the Qantas A380 from Los Angelas to Sydney

Don't. Even in Premium Economy it is rather uncomfortable (and you have to be in premium economy if you want to be gauranteed a seat on the top deck. Who decided to put first class on the bottom? The whole point of first is to look down at other people). Though Emirates does a nice A380.

As for crashes, I really don't care. Some of the older planes have more character in them, whereas planes such as the A330 or 777 areclinical and boring. However some of the more modern aircraft (A340, MD-11) are full of soul and character and are great to fly in. And so long as I'm in a comfortable, charismatic aircraft I won't mind if it suddenly decides to explode.

[Kapitan]

I would argue that most of your post is basically about what you prefer With more and more kids growing up using computers and playing video games, glass cockpits are probably a better way to go. Never mind that they tend to be far more reliable than the old style gauges. And with glass cockpits you can do other interesting things like overlaying a simulated view of the outside world for IFR or night flying.

Yes, its just a persoanl preference. And you are right, kids today used to games and bars and glass cockpits are indeed much better than gauges and offer a whole lot more possibilities, up to a totally computerized flight!...which was my initial point. I like flying it myself, both real and simming, thats why I prefer classic gauges.
K

[Kapitan]

Hello,

Gees .. those islanders have very good eyes .. for seen at 350 miles distance in a stormy sky .. the light of a plane exploding or taking fire ... seem's they are human radars :)
Cause the curvature of the Earth ( yes .. she is not flat !) and the altitude of the plane(+ - 12.000 meters) .. this light is approximately at the line of horizon but at 350 miles !!! ... and the expected visibility distance is ?? :)
Conclusion .. it's make no sense ...

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

Possibly. The islanders wrere not "in" the storm, they saw the storm in the distance. Their sky was clear. Also, in the distance the strom is not overcast 8/8. Visibility in the distance in a dark sky in the middle of the atlantic is far better. Dont know if they saw something, but surely a big explosion at 12km high can be seen (the clarity of it...not the explosion itself) from probably more than hundred miles away. Question is where was the plane? 350 miles of the island as they predict per flight path, or was it closer, say at 100 miles...its all speculation..
K
K

[Kapitan]

Hello,

Flybywire system is actually the safest way to control a plane ..
In all flybywire aircrafts accidents it was always the human error incriminated or other exterior event .. but never the aircraft control system ...
And if you check the relevant statistics .. numbers will show you what best is ...

For make the story less short .. read the preliminary report .. and you will see it's a human error ... the control system acted as it was designed for... but cause the pilots don't followed the procedures to apply when a reverser is off .. the accident occured.
It's no way of worshipping here .. it's question of technic ...
Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

They are indeed safer and the way to go, never denied that. My opinion is that they should leave the dual system, they should let the pilot control the plane if all electronics failed. Just that.

Yes, the TAM pilot didnt follow the correct procedure for leaving the reverse off and the power right engine lever in the idle position. There was human error of course. I omitted this information when I said "to make a story short"...My point was that its not "natural" that a computer system will "think" and accelerate at max power when you are trying to brake or stop the plane, just cause the pilot let the reverser off...its a too big interference of the system in a critical situation that wouldnt happen in a non-airbus plane.
If the pilot made a mistake, by not "following a procedure"...well its human, it happened in the past and it happens everyday in many flights around the world. So that kind of error could eventually happen again in similar critical condition.

If that palne was a 737, even with that human "procedure" error the passengers and crew would be alive today. Thats enough for me to deplore the Airbus and its all 100% flybywire.
K

[Avechelice]

Hello,

Some simple explaination about "Elevation distance and horizon" ......

Point of view (http://en.wikipedia.org/wiki/Horizon)

Check the table "how far away is the horizon"

Simple math....

Now .. you can have a distance view of 350 miles over sea with a line who go from your eyes to the line of horizon (result of the diagonal to the object (or light) at 350 miles and altitude of 40.000 feets) .. but not a visibility of 350 miles.(speculated distance of course)
Think simply at the sea mist ... and all the clouds between the phenomena and the observer...

you can see the stars
Sure .. I see the stars .. when it's no clouds ...
Believe me .. I'm a old sailor .... :)
Think a two horizons from a fixed point of view:
It's a true horizon (fixed math distance)
And it's visible horizon (with fluctuations distance depending of meteo phenomenas)
But I believe the report of the TAM pilot about lights on the sea .. as the distance between his plane and ocean surface was small ... provided it was no clouds or mist obscuring his view.


If that palne was a 737, even with that human "procedure" error the passengers and crew would be alive today.

A B737 must be fly like a B737 (procedures) and a A320 must be fly like a A320 (procedures)
Fly B737 or A320 and don't follow their particulars procedures cause accidents
You don't drive a bycicle like a motorbike .. that's two different beasts...
It's not the control system at fault .. but the human who use it...
Technics changes and progress .. but the human stay the same .. unfortunately... :)

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

[mgh]

They are indeed safer and the way to go, never denied that. My opinion is that they should leave the dual system, they should let the pilot control the plane if all electronics failed. Just that.

Yes, the TAM pilot didnt follow the correct procedure for leaving the reverse off and the power right engine lever in the idle position. There was human error of course. I omitted this information when I said "to make a story short"...My point was that its not "natural" that a computer system will "think" and accelerate at max power when you are trying to brake or stop the plane, just cause the pilot let the reverser off...its a too big interference of the system in a critical situation that wouldnt happen in a non-airbus plane.
If the pilot made a mistake, by not "following a procedure"...well its human, it happened in the past and it happens everyday in many flights around the world. So that kind of error could eventually happen again in similar critical condition.

If that palne was a 737, even with that human "procedure" error the passengers and crew would be alive today. Thats enough for me to deplore the Airbus and its all 100% flybywire.
K



The aircraft made its approach with the thrust levers in the climb position. First crew error. Just before touchdown the aircraft's flight computer system warned the announced "Retard Retard" to warn the crew of this. The crew responded by retarding the left thrust lever to the rear-most position which activated the thrust reverser on the left engine, They left the the right thrust lever in the climb position resulting in that engine initiating climb power. Second crew error.

What do you think would have happened with a manually-controlled aircraft if on touch down the crew retarded one thrust lever to activate the thrust reverser and advanced the other to give climb power?



The left engine

[Kapitan]

The aircraft made its approach with the thrust levers in the climb position. First crew error. Just before touchdown the aircraft's flight computer system warned the announced "Retard Retard" to warn the crew of this. The crew responded by retarding the left thrust lever to the rear-most position which activated the thrust reverser on the left engine, They left the the right thrust lever in the climb position resulting in that engine initiating climb power. Second crew error.

What do you think would have happened with a manually-controlled aircraft if on touch down the crew retarded one thrust lever to activate the thrust reverser and advanced the other to give climb power?



The left engine

According to the accident reports, the right reversor was "locked" by maintenance team, meaning "inoperative", out of order. Knowing this the crew operated the computer-plane feeding it with normal instructions for landing, and left the right lever in a climb position (pilot error) because they regarded that lever wouldnt function manually, cause the plane was in auto-computerized mode. This was correct.

So the pilots mistake was to over-trust a computer-plane thinking the lever position was irrelevant for that landing, since the plane was on autoand the reversor was not functioning.

As in autothrottle, you can swing the throttles back and forth that they will have no effect on power. And since the reversor was inoperative they disregarded (by mistake) its position.

If in a manual or semi-manual plane, like a 737 for example, this would never happen. Why? cause the pilots KNOW they are in a manual 737 and they will look at the lever and KNOW that its position IS impórtant, cause its manual, so it must be retarded to idle otherwise the plane will power up.
K

[Kapitan]

The left engine

Another thing.
On nice, safe non-Airbus planes, pilots disconnect autopilot before touchdown and have his right arm and hands on the throttles, (in the 707 even Flight engeneer put his hands on the reversers), so with the pilot in command and his own hands in the throttles...this would have never happened. Whilst on the Aiurbus pilots are shamingly watching arms-crossed...:)
K

[ytzpilot]

Don't. Even in Premium Economy it is rather uncomfortable (and you have to be in premium economy if you want to be gauranteed a seat on the top deck. Who decided to put first class on the bottom? The whole point of first is to look down at other people). Though Emirates does a nice A380.

As for crashes, I really don't care. Some of the older planes have more character in them, whereas planes such as the A330 or 777 areclinical and boring. However some of the more modern aircraft (A340, MD-11) are full of soul and character and are great to fly in. And so long as I'm in a comfortable, charismatic aircraft I won't mind if it suddenly decides to explode.


Thanks Dredgy, I will avoid the A380. I must admit last year when I went to New Zealand I flew down in a 747 and Air New Zealand's pacific service makes you feel like the 1970's when air travel was something special. The flight crew was great, the service was exceptional, Air New Zealands uniforms are a bit retro which add's to the feel as well. They call this route NZ1 and they put a lot of pride into it.

Returning I was on an Air New Zealand 777. Not the same feel. It's very modern and clinical like you said. The old 747's days are numbered and eventually I won't have a choice other then 777 or A380 so I will stick to a good thing while it lasts. I bet the next generation 747 will feel just like the 777 as well.

[mgh]

According to the accident reports, the right reversor was "locked" by maintenance team, meaning "inoperative", out of order. Knowing this the crew operated the computer-plane feeding it with normal instructions for landing, and left the right lever in a climb position (pilot error) because they regarded that lever wouldnt function manually, cause the plane was in auto-computerized mode. This was correct.

So the pilots mistake was to over-trust a computer-plane thinking the lever position was irrelevant for that landing, since the plane was on autoand the reversor was not functioning.

As in autothrottle, you can swing the throttles back and forth that they will have no effect on power. And since the reversor was inoperative they disregarded (by mistake) its position.

If in a manual or semi-manual plane, like a 737 for example, this would never happen. Why? cause the pilots KNOW they are in a manual 737 and they will look at the lever and KNOW that its position IS impórtant, cause its manual, so it must be retarded to idle otherwise the plane will power up.
K

The fact that they got a "Retard retard" warning shows the aircraft was not properly configured. Yet despite being warned they still failed to respond properly. Had they done so the result may have been very different.

You argue that in a 737 aircrew would always check. Unfortunately there are many reports on accidents where the aircraft was not properly configured. Relevant examples involving 737s include, the 737 that attempted to take-off from Pekanbaru in Indonesia on 14 January 2005 with the flaps up fortunately with no fatalities; and the 737 that attempted to take-off from Medan-Polonia Airport (Indonesia) on 5 September 2005 with the flaps and slats retracted 5 killing 249 people - I believe this is still the worst accident to a 737.

In these cases, aircrew failed to make obvious checks.

[Avechelice]

Hello,

As always ...
Piloting-Navigating-communicating
When those three requirements are executed perfectly ... and a accident occur .. you call it a act of God.
When those three requirements are not executed perfectly and a accident occur .. you call it human or pilot error.

Regards.http://smilies.sofrayt.com/%5E/a/bye.gif

[scott967]

If in a manual or semi-manual plane, like a 737 for example, this would never happen. Why? cause the pilots KNOW they are in a manual 737 and they will look at the lever and KNOW that its position IS impórtant, cause its manual, so it must be retarded to idle otherwise the plane will power up.
K

that must be why the TK 737 didn't crash at EHAM last Feb.

scott s.
.

[scott967]

According to the accident reports, the right reversor was "locked" by maintenance team, meaning "inoperative", out of order. Knowing this the crew operated the computer-plane feeding it with normal instructions for landing, and left the right lever in a climb position (pilot error) because they regarded that lever wouldnt function manually, cause the plane was in auto-computerized mode. This was correct.
There is no "auto-computerized mode". The flight controls were in normal law, and the throttles were in auto-throttle. The final approach was hand-flown.

So the pilots mistake was to over-trust a computer-plane thinking the lever position was irrelevant for that landing, since the plane was on autoand the reversor was not functioning.

As in autothrottle, you can swing the throttles back and forth that they will have no effect on power. And since the reversor was inoperative they disregarded (by mistake) its position.

that is not correct. With throttles in auto-throttle, the normal 2-engine procedure is to place both levers in climb detent. That allows auto-throttle to control engine thrust from idle to climb power. Same as everyone's fave Boeing, except the levers don't move on their own. The pilot can move the levers out of the climb detent, and that will limit max autothrottle to lever position, and cause alerts. At about 20 ft RA, the bus will call out "Retard, Retard, Retard", reminding the pilot to close the throttles if he wants to land which one would expect to do in any aircraft, right? Now this pilot apparently wanted to select reverse idle on the engine with operative reverser, and left the other throttle advanced out of idle, and the computer did not read his mind that he actually wanted idle power.

In addition, with autothrottle there is alpha floor protection until descending below 100 ft RA, which is why typical SOP is to use autothrottle on the approach.

I would never claim AB system is perfect or ideal, but I don't dismiss it out of hand either. there seems to be no shortage of pilots on either side.

scott s.
.

[scott967]

Remember that the flight crew did not make any radio contact so this had to be a catastrophic failure that kept the crew busy and had to be a rapid failure, interesting that the onboard systems were able to get a message out but the pilots were not...


In fairness, all we can say is apparently no communications were received. Can't really say if they transmitted, or attempted to transmit.

scott s.
.

[Gavin]

\I wonder if an old 707 would have resisted. K

Maybe yes, maybe no:


http://en.wikipedia.org/wiki/BOAC_Flight_911

Or for a more detailed explanation:
Job, Macarthur (1995). "When the sky is blue, Fuji is angry". Air Disaster. Weston Creek: Aerospace Publications. pp. 44–52. ISBN 1875671110.

[mgh]

that must be why the TK 737 didn't crash at EHAM last Feb.

scott s.
.

Thanks, I'd forgotten that accident. During the approach, the flight crew left the thrust levers in the idle postion in the retard mode. They attempted to maintain speed by setting the autothrottle which by design doesn't respond with the thrust levers in the idle position. Realising something was wrong at about 460 ft they advanced the thrust levers which did engage the autothrottle but then moved them back to idle which disengaged it.

[ytzpilot]

Thanks, I'd forgotten that accident. During the approach, the flight crew left the thrust levers in the idle postion in the retard mode. They attempted to maintain speed by setting the autothrottle which by design doesn't respond with the thrust levers in the idle position. Realising something was wrong at about 460 ft they advanced the thrust levers which did engage the autothrottle but then moved them back to idle which disengaged it.

Just curious - Wasn't there an issue with flight instuments which led to the confusion on the pilots part. I though an altimeter was reading a lower altitude and the other one was not.

[mgh]

Just curious - Wasn't there an issue with flight instuments which led to the confusion on the pilots part. I though an altimeter was reading a lower altitude and the other one was not.

That is true, but it occured athigh altitude at an earlier stage. The aircraft had intercepted the glide path and was following it. At about 770ft the speed was 144 kts and the flight crew selected that speed for the autothrottle. As previously explained, because the thrust levers were set to idle the autothrottle didn't respond. The and commandedthe aircraft to pitch up. At about 460 feet the stick-shakers actived to warn the flight crew. That was when the thrust levers were advanced then immediately moved back to idle.

[azur]

For the generation born 80´s onward. For the worshippers of glass cockpits and big computer screens in cockpits. For the believers that a plane that deals with physics can be controlled by computer electronic devices alone. For you guys that think piloting is equal to monitoring systems in modern Airbuses, with joysticks instead of Yokes and flashing lcd´s showing all the systems planes are "cool":

Since fly-by-wire lcd systems came around in the 90´s an increasing number of airplane crashes were affected or had systems failures that contributed to the accident.

That's expected.

If you go from 0 -> N numbers of aircraft with advanced electrical systems, then the number of accidents contributed to by those systems logically increases. Note the use of the word contributing - usually they're a contributing factor only when combined with a human factor.

But those systems also help prevent accidents, and the argument in their defence is that they directly help prevent significantly more accidents than they 'contribute' to.



Airbus A330 that disappeared yesterday. Though causes are still unknown, and though there was a storm in place, thousands of planes cross the atlantic since the 1930´s. My father crossed it twice a week for 40 years, crossing storms earlier with a DC-6 up to later with 747-200.

And the number of accidents and airframe losses then was significantly higher. Have a look at these numbers.

http://www.b737.org.uk/accident_reports.htm
Since the 737NG series was introduced in 1997, 12 years ago there has been 4 hull losses out of >2500 aircraft.

Similarly the A320 has lost 20 hulls in more than 20 years of service with a total of 3859 delivered. A320 is FBW, with hydraulic backup AFAIK.

Compare that with the 737-200 which had 9 hull losses in 12 years, yet there were significantly fewer aircraft (<700) flying during that period.




Hydraulics-mechanics, or instruments that read information directly from the source, like a pitot tube, should still exist, even if as back-up ways of control. Early in the 90´s all planes had this dual mechanic-computer control, but gradually planes were released completely electronic-digitallly ...even if with 3 or four redundant systems...we know how fragile electronics are, we all know that each time we turn our home computer on, ...something could fail, the HD, memory, motherboard, the OS crashes...we have to live with that.

They do exist. Most aircraft out there still have mechanical/hydraulic systems. And just about every aircraft flying still gets various air data from the pitot system though in different forms. The pure FBW aircraft are few, but even they have *significant* fault tolerance and redundant systems, down to an almost ridiculous level. The probability of a total FBW failure is incredibly small and actually less than that of a mechanical based system failure. It's safer.

Even if the fine details of computers are a black box to you, that does not mean that they cannot be designed to an extremely high standard of reliability matching or exceeding pure mechanical systems. They are not 'fragile' as you describe and can be hardened like any other component. The aerospace industry in particular has a long history of working with such critical computing systems. You can find their use right back to the 60's and the Apollo missions.

The Space Shuttle is _dependent_ on the continuing functionality of it's GPCs and it was designed in the 70's. Surely we've learnt even more about designing redundant and high reliability computer systems since then. In 11 versions of it's 420,000 line code, there were 17 errors total. That's phenomenal. Then consider their definition of an error would also extend to what most would consider insignificant.
http://www.fastcompany.com/magazine/06/writestuff.html

Further, the 'computers' on aircraft have nothing in common with that on your desktop. They are computers designed for a specific purpose, with software designed for a specific purpose and for that specific hardware. They're generally solid state, and don't resemble the 'general purpose' mess that exists on your desktop in any way shape or form.

Maybe your general purpose try-to-do-it-all windows isn't particularly reliable, but that has no reflection on the type of technology used in aircraft. Most desktop software developers don't bother with trivial proper error handling, let alone fault tolerance, fault trees, thorough checks, qualification!



If the storm harmed the plane in a way electronics affected its controls...I wonder if an old 707 would have resisted. Just an argument for discussion
K
With the levels of redundancy and fault-tolerant design in FBW aircraft, effectively physical damage is required to fail the FBW system. Once aircraft are in a storm that's causing physical damage, any aircraft is vulnerable.

Given the statistics for the A320, 20 hull losses in 20 years for a FBW aircraft, then clearly FBW technology does not introduce any relevant level of danger or risk.

I don't consider FBW faultless, but the numbers prove that it can be at least as safe as a mechanical system, if not safer.

[ytzpilot]

That is true, but it occured athigh altitude at an earlier stage. The aircraft had intercepted the glide path and was following it. At about 770ft the speed was 144 kts and the flight crew selected that speed for the autothrottle. As previously explained, because the thrust levers were set to idle the autothrottle didn't respond. The and commandedthe aircraft to pitch up. At about 460 feet the stick-shakers actived to warn the flight crew. That was when the thrust levers were advanced then immediately moved back to idle.


Thanks - That would mean the instrument should not have been a contributing issue from what I can tell. It should not have led to the confusion with the autothrottle system anyways.

[ytzpilot]

A testiment to modern aircraft would be Air France Flight 358 in Toronto - Complete loss of aircraft, No Casualties and of course US Airways 1549 in the hudson, No casualties as well.

Too bad Americans blamed Canadians for causing Flight 1549....How did they know those geese were born in Canada :D

[Bridget]

They were "Canadian" Geese :) not Bald Eagles

[skylab]

They were "Canadian" Geese :) not Bald Eagles

Actually, they're Canda Geese, not Canadian. I know.....picky, picky.:)

[ytzpilot]

Actually, they're Canda Geese, not Canadian. I know.....picky, picky.:)

Yeah - The Canada Goose. I was just poking fun at the US - Canadian Rivalries.....Bridget knows that one too. Kiwi's and Aussies don't like each other....They just pretend to like each other :D

[skylab]

Hey.....I've got some good Canadian friends. Spent some good times in Canada as well. Only thing I dislike is your healthcare plan. Let's not get started on THAT though !!:D

[Kapitan]

That's expected.

I don't consider FBW faultless, but the numbers prove that it can be at least as safe as a mechanical system, if not safer.

Appreciate your valuable info.
As the timeline advances into the "future", everything improves giving more safety to air transport. Composites, structure, bolts, procedures, controllers radars, navigatin aids, etc.
vortex, icing, weather, windshear...all the database knowledge gets safer.

Safety numbers cant be measured by FBW alone. Obviously we cant stop progress, and I believe too its much safer than mechanic-hydraulic. But not immune to failure. Was pointing if it would be possible to kee p some sort of dual system, like they had in the 90´s , during the transcision from analog gauges to lcd´s.
L

[ytzpilot]

I wonder if as a result of this last Air France Flight 447 accident. They will update the black box technology so that that information is uploaded to a satalite link in realtime and recorded at a central location as well as on an inflight recorder. So if the black boxes are never found they have the information anyways.

The technology is there to do this now so it would be up to regulators.

[scott967]

I think there are some systems along those lines currently in test -- ADS-B and CPDLC come to mind.

Though I think there are some bandwidth limitations on the satcom systems that are commercially available -- what I am aware of are INMARSAT and Iridium.

scott s.
.

[=Hollywood=]

From all accounts of the systems report the on board systems reported, there was all manner of failures, including rapid decompression, which leads to the conclusion the plane broke up in flight...

If it was just a lightning strike and the electrical system alone failed then there's no way you'd also get rapid decompression, the aircraft would have had to be at altitude for the systems to send an alert about that, from what I remember from the reports, the decompression happened near the beginning, followed by increasing electrical and other failures...

(snip)

Anyway all that is to say that I would hazard a guess that the aircraft in the Air France incident was struck by lightning and some part of the airframe was damaged by the strike, possibly punching a hole in the airframe or even igniting fuel in the wings... At over 500mph and air racing by the fuselage coupled with extreme mechanical turbulence could quickly lead to the airframe breaking up in flight...

Remember that the flight crew did not make any radio contact so this had to be a catastrophic failure that kept the crew busy and had to be a rapid failure, interesting that the onboard systems were able to get a message out but the pilots were not...

My money is on a catastrophic airframe failure due to a possible lightnining strike which punctured a hole in the airframe or ignited fuel... I'm not sure of the construction of the A330 but I do know that carbon fiber is very bad news in lightning storms and has brought down aircraft before because the composite components basically exploded when struck... Although advances have been made to make composites safer they are only now beginning to understand how it behaves within the flight environment...

Ha!

http://news.yahoo.com/s/ap/20090617/ap_on_re_la_am_ca/brazil_plane

Autopsies suggest Air France jet broke up in sky

By STAN LEHMAN and EMMA VANDORE, Associated Press Writers – 1 hr 47 mins ago
SAO PAULO – Autopsies have revealed fractures in the legs, hips and arms of Air France disaster victims, injuries that — along with the large pieces of wreckage pulled from the Atlantic — strongly suggest the plane broke up in the air, experts said Wednesday.

That's what I said right at the start...

[ytzpilot]

Ha!

http://news.yahoo.com/s/ap/20090617/ap_on_re_la_am_ca/brazil_plane


That's what I said right at the start...

Not Quite...The cause is not determined to be by lightning. It is most likely a malfunctioning pitot tube made worse due to the massive storm system. If it was Lightning or a Pitot Tube that is yet to be determined.

Break-up in the air has been obvious since the discovery of the aircrafts rudder. What caused the break-up is still unknown...I'm thinking a malfunctioning pitot tube made worse by a storm led to loss of control of the aircraft leading to an airframe failure.

Scorch marks caused by lightning would be the smoking gun for lightning however that has not been found so far....What is certain is a pitot tube recall by Airbus due to this event as an issue with the pitot tubes has been known for some time now.

[=Hollywood=]

I wasn't saying definitely that it was lightning what I was pointing to was a break up in flight, with lightning being one possibility due to reports of the thunderstorm and previous problems with composites and lightning strikes.

I made two separate statements, although maybe not clearly written enough, one was a possible lightning strike being a possible contributing factor, the other statement was that the aircraft definitely broke up in flight due as was evidenced by the automated reports the computer sent out.

Statements about aircraft breaking up in flight (This is not a guess rather it is based upon being a pilot and my father having been a 727 and 767 flight engineer):


From all accounts of the systems report the on board systems reported, there was all manner of failures, including rapid decompression, which leads to the conclusion the plane broke up in flight...

...the aircraft would have had to be at altitude for the systems to send an alert about that, from what I remember from the reports, the decompression happened near the beginning, followed by increasing electrical and other failures...

Remember that the flight crew did not make any radio contact so this had to be a catastrophic failure that kept the crew busy and had to be a rapid failure, interesting that the onboard systems were able to get a message out but the pilots were not...

Statements about one possible theory due to previous crashes that have occurred in composite construction aircraft, which was within 24 hours and in response to reports of a possible lightning strike bringing down the aircraft and knocking out the electrical system (This is a guess and speculation):


If it was just a lightning strike and the electrical system alone failed then there's no way you'd also get rapid decompression, the aircraft would have had to be at altitude for the systems to send an alert about that, from what I remember from the reports, the decompression happened near the beginning, followed by increasing electrical and other failures...

Anyway all that is to say that I would hazard a guess that the aircraft in the Air France incident was struck by lightning and some part of the airframe was damaged by the strike, possibly punching a hole in the airframe or even igniting fuel in the wings... At over 500mph and air racing by the fuselage coupled with extreme mechanical turbulence could quickly lead to the airframe breaking up in flight...

My money is on a catastrophic airframe failure due to a possible lightnining strike which punctured a hole in the airframe or ignited fuel... I'm not sure of the construction of the A330 but I do know that carbon fiber is very bad news in lightning storms and has brought down aircraft before because the composite components basically exploded when struck... Although advances have been made to make composites safer they are only now beginning to understand how it behaves within the flight environment...