The Children of Magenta / Rage against the Machine
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Hi DownIn3Green,
The link is incorrect - it should say: (in BFU's language)
http://www.bfu-web.de/EN/Publication...ublicationFile
On seite 46 "During the next few seconds the aircraft rolled to a 23° left wing down attitude in spite of the full right deflection of both sidesticks and application of right rudder."
On seite 47 "Within this investigation the wind conditions derived by simulation and calculation were used as additional factual information. This enabled the BFU to work on the assumption that the actual crosswind component was about 30 kt gusting up to 40 kt."
On seite 35 "The following values were documented in the manufacturer's FCOM for Airbus A319/A320/A321 in the
chapter OPERATING LIMITATIONS (Appendix 6):
• Wind for takeoff and landing:
• Maximum crosswind demonstrated for takeoff: 29 knots gusting up to 38 knots
• Maximum crosswind demonstrated for landing: 33 knots gusting up to 38 knots"
The crew had no idea that they were about to run out of aileron authority when (seite 63) "The aircraft was designed so that the effect of lateral controls (along the longitudinal axis) would reduce by about one half of full deflection as soon as one main landing gear touched down."
Old Smokey sums up nicely Airbus documentation in post 6 of http://www.pprune.org/tech-log/51505...-question.html
It leads you to an article in the AvHerald, quoting the ACTUAL REPORT.....In other words, journalist license...
http://www.bfu-web.de/EN/Publication...ublicationFile
On seite 46 "During the next few seconds the aircraft rolled to a 23° left wing down attitude in spite of the full right deflection of both sidesticks and application of right rudder."
On seite 47 "Within this investigation the wind conditions derived by simulation and calculation were used as additional factual information. This enabled the BFU to work on the assumption that the actual crosswind component was about 30 kt gusting up to 40 kt."
On seite 35 "The following values were documented in the manufacturer's FCOM for Airbus A319/A320/A321 in the
chapter OPERATING LIMITATIONS (Appendix 6):
• Wind for takeoff and landing:
• Maximum crosswind demonstrated for takeoff: 29 knots gusting up to 38 knots
• Maximum crosswind demonstrated for landing: 33 knots gusting up to 38 knots"
The crew had no idea that they were about to run out of aileron authority when (seite 63) "The aircraft was designed so that the effect of lateral controls (along the longitudinal axis) would reduce by about one half of full deflection as soon as one main landing gear touched down."
Old Smokey sums up nicely Airbus documentation in post 6 of http://www.pprune.org/tech-log/51505...-question.html
Last edited by rudderrudderrat; 25th May 2013 at 08:06.
Here's the report
http://www.bfu-web.de/EN/Publication...ublicationFile
The wording of the crosswind limits in the manuals played a part as they discounted the gusts when they shouldn't have. It was interesting to note that half of the pilots surveyed for the report at the time thought that the crosswind limits were only guidance.
Our Part B has changed since this incident (same a/c type but different airline) with a single value (gusts included) and the statement that the numbers are limits except in unavoidable circumstances.
http://www.bfu-web.de/EN/Publication...ublicationFile
The wording of the crosswind limits in the manuals played a part as they discounted the gusts when they shouldn't have. It was interesting to note that half of the pilots surveyed for the report at the time thought that the crosswind limits were only guidance.
Our Part B has changed since this incident (same a/c type but different airline) with a single value (gusts included) and the statement that the numbers are limits except in unavoidable circumstances.
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And yes, I thought that discrepancy of understanding was strange...
For the record folks, Cool Guys didn't ask me to link the report - he asked me for supporting information regarding Lufthansa's crosswind minima. It was late, I was knackered, so I just Googled for the first relevant link that came to hand.
RRR - I concur totally about the somewhat quirky language of Airbus documentation, probably a result of their policy of writing first in French, then translating to English rather than writing them separately. I also agree that the systems response to the dual input during flare and touchdown was non-optimal - however the fact is that dual input during that final landing phase is a no-no, and I believe (again, correct me if I'm wrong) is trained as such.
(Incidentally, aside from the Hamburg incident, I'd be interested in your views on my post #59...)
Last edited by DozyWannabe; 25th May 2013 at 16:43.
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Originally Posted by rudderrudderrat
The crew had no idea that they were about to run out of aileron authority when (seite 63) "The aircraft was designed so that the effect of lateral controls (along the longitudinal axis) would reduce by about one half of full deflection as soon as one main landing gear touched down."
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Small point of order - the magenta-coloured line is actually used on Boeing's FMS displays. Airbus FMGS uses a line which if I recall correctly is either white or green.
There is a lot of magenta about though, in about five seconds somebody will state which flashy bits are magenta, there is also a yellow temporary line - which is there when you are making slight adjustments to the flight plan invariably in PLAN but also / or in the SEC FLT PLN and they turn - grren? Normal when you insert it, (othewise known as tmpy)
(actually, am gonna take a look to see what is magenta on the A320)
Well, I have just returned from my trip on the internet - looking for Magenta, there is a whole world out there of Magenta colouring (and we are stuck on avionics):
Its a sort of Orange pink to shocking pink, to flourescent day-glo in yer face pink.
found on the PFD, ILS
the Donut is magenta
Spd select ind is magenta unless you - - - ? and then its - - - ?
Am trying to think what is on the ND that is magenta. . . .?
Next speed is magenta
Glideslope is magenta
LOC is magenta
ILS ident and freq is magenta
wpts not in the flt pln display magenta
Alt constraint arrows magenta - if not selected not the FCU
decell point (a dot on the ND) is magenta
Alt constraint if predicted to be met is magenta
DME/TACAN on the ND in magenta - if not part of the flt pln.
VORs, Airports, asterisk magenta
NDB.........................magenta
selected heading (not the one you are on) magenta
I wonder what Orville and Wilbur would have thought about magenta.
Last edited by Natstrackalpha; 27th May 2013 at 22:35. Reason: got bored
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And yet in every one of the countless landings executed in an Airbus FBW model bar that one, the setup seems to work just fine. As far as I know, training does state that dual input - at that stage especially - is to be avoided. The ins and outs of flare mode are documented should one choose to look into it more closely.
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Originally Posted by dozy
As far as I know, training does state that dual input - at that stage especially - is to be avoided.
The ins and outs of flare mode are documented should one choose to look into it more closely.
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Originally Posted by dozy
In a trainer, such a setup is vital - however in an airliner which is only ever supposed to be controlled by one pilot at a time it becomes more optional.
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Originally Posted by dozy
Both AF447 and EgyptAir 990 provide examples of how those design decisions can cause problems when that assumption is violated, whether accidentally or deliberately.
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Originally Posted by dozy
One thing that came out of the EgyptAir 990 investigation is that when the yokes are pushed and pulled in opposite directions on the 767 - with sufficient force you get a split elevator condition (i.e. one elevator deflects up, the other down). Boeing had to spend a lot of money correcting that.
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*I apologize for the thread drift but I'm really curious..*
Why don't you have a PPL Dozy? It's very easy to get. Shirley with your vast knowledge of aviation and flying big jets you should be able to safely takeoff and land three times on a Cessna.
Why don't you have a PPL Dozy? It's very easy to get. Shirley with your vast knowledge of aviation and flying big jets you should be able to safely takeoff and land three times on a Cessna.
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Back to the plot then . . .
Some of you seasoned hallowed Captains (young and less young alike)
refer to stick and rudder manual - real flying (I know what you mean of course) but, is not dancing the skies on laughter silvered wings - just that? - Flying.
You are in it. Off the Earth. In the air. Flying.
So, as long as you are in that dimension, what difference does it make if you pb a push button or apply fwd pressure and trim?
I mean, look at the Primary Flight Display (PFD) you`ve got speed, altitude, RoD, heading(track) artificial horizon plus general state of what modes are in force FMA - all in one place all the engines and fuel and electrics and hydraulics and every thing are contained on quite large electronic screens - all in one place. Heck, its like flying a book, or should I say a Kimble. It is sssoooo laid back. It does half of your flying for you (because of you - you set it all up at the start of the flight, don`t forget) and yet you are still flying, you are still thousands of feet above the ground in some . . 65 tons of aeroplane - doing about 7.5 miles a minute - kewel!
Some of you seasoned hallowed Captains (young and less young alike)
refer to stick and rudder manual - real flying (I know what you mean of course) but, is not dancing the skies on laughter silvered wings - just that? - Flying.
You are in it. Off the Earth. In the air. Flying.
So, as long as you are in that dimension, what difference does it make if you pb a push button or apply fwd pressure and trim?
I mean, look at the Primary Flight Display (PFD) you`ve got speed, altitude, RoD, heading(track) artificial horizon plus general state of what modes are in force FMA - all in one place all the engines and fuel and electrics and hydraulics and every thing are contained on quite large electronic screens - all in one place. Heck, its like flying a book, or should I say a Kimble. It is sssoooo laid back. It does half of your flying for you (because of you - you set it all up at the start of the flight, don`t forget) and yet you are still flying, you are still thousands of feet above the ground in some . . 65 tons of aeroplane - doing about 7.5 miles a minute - kewel!
Last edited by Natstrackalpha; 28th May 2013 at 00:22.
Boeing had to spend a lot of money correcting that.
The B767 flight control system has not been re-designed. The mechanical link between the control columns are designed with a breakout link, it is part of the design to ensure control with a part jam.
Tootle pip!!
Mmmmm PPruuune!
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Having tried both, my gripe with AB is its quirkyness, and the fact as a pilot you only get what AB deems important, until something happens that is! (LH incident)
Magenta generally is what is commanded - why does the speed bug move to Vapp when flaps are deployed? Surely it should overlay F indications?
I hate the static thrust levers with AT engaged especially in gusty conditions with GS mini. Actually wound up doing a GA from an approach when AT was slow to react and PF moved thrust levers forward past CLB giving GA mode. Never mind GS mini was still commanding 30kts above Vapp!
Hate being PM on a gusty approach as you can't see / help / follow through on the controls plus you do certainly get pitch coupling as the system changes from NL to Landing mode.
But every aircraft has its foibles and you have to accept understand and live with them, however, if its all gone to rats**t I do prefer to have direct control of the beast, not through some interface which can modify my input. Why do AB treat Direct Law as there dragons be? It's the law under which all other aircraft I've ever flown have operated!
As mentioned before 90% of the time it's great but you need to have your wits about you in abnormal situations as sometimes things be less than logical!
Magenta generally is what is commanded - why does the speed bug move to Vapp when flaps are deployed? Surely it should overlay F indications?
I hate the static thrust levers with AT engaged especially in gusty conditions with GS mini. Actually wound up doing a GA from an approach when AT was slow to react and PF moved thrust levers forward past CLB giving GA mode. Never mind GS mini was still commanding 30kts above Vapp!
Hate being PM on a gusty approach as you can't see / help / follow through on the controls plus you do certainly get pitch coupling as the system changes from NL to Landing mode.
But every aircraft has its foibles and you have to accept understand and live with them, however, if its all gone to rats**t I do prefer to have direct control of the beast, not through some interface which can modify my input. Why do AB treat Direct Law as there dragons be? It's the law under which all other aircraft I've ever flown have operated!
As mentioned before 90% of the time it's great but you need to have your wits about you in abnormal situations as sometimes things be less than logical!
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I didn't say re-designed, but I'm sure I read somewhere the breakout settings were tweaked so a situation whereby the elevator could be fully split to the point where the outcome was a potentially unrecoverable loss of control was no longer possible.
Last edited by DozyWannabe; 29th May 2013 at 15:55.
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I'm not actually seeing an A. vs. B. situation developing in the conversation here.
I'm seeing a lot of misunderstandings (including my own re: 767) about the Airbus FBW vs. traditional control layout, but given that the Airbus FBW technology is probably the most misunderstood application of technology to aviation in history, I guess that's not surprising. I'm also seeing a worrying lack of understanding as to the fact that FBW and FMS (including automation) are completely separate concepts - especially in the original poster.
RRR's concerns that he still finds the flight control system on the Airbus FBW series to be something of a "black box" are perfectly reasonable, but then even with the old electro-mechanical and electro-hydraulic control systems, it was a rare FE, let alone pilot, who understood the principles of cam setup and gearing used within them. Maybe it's a question of there being a generational mistrust of digital computing technology over and above the old mechanical setup?
Of course, saying that, reading HTBJ it becomes apparent that pilots of the era were muttering darkly about the old stick-push mechanisms for much the same reasons...
I'm seeing a lot of misunderstandings (including my own re: 767) about the Airbus FBW vs. traditional control layout, but given that the Airbus FBW technology is probably the most misunderstood application of technology to aviation in history, I guess that's not surprising. I'm also seeing a worrying lack of understanding as to the fact that FBW and FMS (including automation) are completely separate concepts - especially in the original poster.
RRR's concerns that he still finds the flight control system on the Airbus FBW series to be something of a "black box" are perfectly reasonable, but then even with the old electro-mechanical and electro-hydraulic control systems, it was a rare FE, let alone pilot, who understood the principles of cam setup and gearing used within them. Maybe it's a question of there being a generational mistrust of digital computing technology over and above the old mechanical setup?
Of course, saying that, reading HTBJ it becomes apparent that pilots of the era were muttering darkly about the old stick-push mechanisms for much the same reasons...
Last edited by DozyWannabe; 29th May 2013 at 17:43.
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Hi John,
It's been discussed a lot on other threads (a few examples here):
http://www.pprune.org/tech-log/37979...-airlines.html
http://www.pprune.org/tech-log/35175...ing-tests.html
http://www.pprune.org/rumours-news/5...raining-4.html
http://www.pprune.org/middle-east/22...fly-plane.html
It's been discussed a lot on other threads (a few examples here):
http://www.pprune.org/tech-log/37979...-airlines.html
http://www.pprune.org/tech-log/35175...ing-tests.html
http://www.pprune.org/rumours-news/5...raining-4.html
http://www.pprune.org/middle-east/22...fly-plane.html
The current view of “Children …” is not necessarily aiding the industry’s quest for safety improvement.
AFAIR the original ‘Children of the magenta line’ quote is attributed to Don Bateman, the Father and Mentor of GPWS/EGPWS. The context was that of pilots blindly following computed navigation solutions - the magenta flight plan route, without further thought.
The famed video clip is one particular airline’s view of the need to revert to manual flight control, often overlooked as complex situations evolve. This is similar to many manufacturers’ recommendations to reassess the level of automation, use a lower level, or disengage the autos.
The underlying issue, which the video and much of the discussion overlooks, is how does the pilot become aware of the need to change, how does a crew achieve an understanding of the situation and then decide to change. What are the key factors, the processes, and thus what training and guidance is provided to aid this judgement.
This discussion and previous threads have toyed with A vs B, or the symptoms encountered in modern day operations, and as much of this involves automation, allocates a causal effect, but fails to identify the deep seated reasons for incidents and accidents.
Recommending more manual flight practice etc, may only be throwing a wet blanket over the problem. The underlying cause could erupt elsewhere and with greater effect. Most of the problem situations require the use of automation, areas where the human cannot, or is not allowed to operate. More manual flight practice might aid recovery from the very rare abnormal situations, but not the normal situations involving automation and human aspects which deteriorate to incident scenarios.
The operators (we the pilots) probably have the greater value information as to the real ‘cause’, but in the majority have failed to think about this, or if known, been unable to communicate the issue. We tend to confuse factors of events or outcome with cause.
One particular aspect could relate to how automation is perceived; it’s not human and thus will not fly or behave like a human. Yet much of the ‘quick-fix’ training focuses on comparing the human and computer.
A rage against the machine might only represent our frustration of not understanding.
We have a very powerful and useful set of tools; we have to understand their purpose, capabilities (particularly the limitations), and the optimum methods of use. Following the magenta line is generally very safe and helpful, but we need to know when this might not be so, and then change what we think and do.
AFAIR the original ‘Children of the magenta line’ quote is attributed to Don Bateman, the Father and Mentor of GPWS/EGPWS. The context was that of pilots blindly following computed navigation solutions - the magenta flight plan route, without further thought.
The famed video clip is one particular airline’s view of the need to revert to manual flight control, often overlooked as complex situations evolve. This is similar to many manufacturers’ recommendations to reassess the level of automation, use a lower level, or disengage the autos.
The underlying issue, which the video and much of the discussion overlooks, is how does the pilot become aware of the need to change, how does a crew achieve an understanding of the situation and then decide to change. What are the key factors, the processes, and thus what training and guidance is provided to aid this judgement.
This discussion and previous threads have toyed with A vs B, or the symptoms encountered in modern day operations, and as much of this involves automation, allocates a causal effect, but fails to identify the deep seated reasons for incidents and accidents.
Recommending more manual flight practice etc, may only be throwing a wet blanket over the problem. The underlying cause could erupt elsewhere and with greater effect. Most of the problem situations require the use of automation, areas where the human cannot, or is not allowed to operate. More manual flight practice might aid recovery from the very rare abnormal situations, but not the normal situations involving automation and human aspects which deteriorate to incident scenarios.
The operators (we the pilots) probably have the greater value information as to the real ‘cause’, but in the majority have failed to think about this, or if known, been unable to communicate the issue. We tend to confuse factors of events or outcome with cause.
One particular aspect could relate to how automation is perceived; it’s not human and thus will not fly or behave like a human. Yet much of the ‘quick-fix’ training focuses on comparing the human and computer.
A rage against the machine might only represent our frustration of not understanding.
We have a very powerful and useful set of tools; we have to understand their purpose, capabilities (particularly the limitations), and the optimum methods of use. Following the magenta line is generally very safe and helpful, but we need to know when this might not be so, and then change what we think and do.
