Man-machine interface and anomalies
Join Date: Aug 2011
Location: Grassy Valley
Posts: 2,074
Likes: 0
Received 0 Likes
on
0 Posts
"Not only is it clear that they did pay attention to exactly what you say they didn't, but they also rejected the first sidestick design after flight test (not sim, flight) and sent it back to the engineers not for a bit of tweaking but for radical design changes."
IF789.... If you read my opening, I specifically say they did addresss the pilot to pilot interface, and rejected it, as an engineering decision...
"I am reasonably convinced that the lack of Pilot/Pilot interface engineered into the Airbus cockpit was not arrogance , nor ignorance."
I also believe they rejected interconnectivity due to overconfidence in the flight test crew's ability to intuit commands from the other seat. Perhaps due to the implementation of test pilots with highly developed intuitive skillset in assessment of the p/p interface....should they have used more mediocre and perhaps more independent pilots?
You say....
"... Interconnection. Yes. Really. They had interconnection and they scrapped it after test flying it. Apparently it was great in theory but didn't work when you actually tried flying it (even with test pilots). Interesting, no ?"
Can you explain? Connected controls aren't theoretical but merely a form of direct interface, sans intuition. They aren't 'flown', they are a direct cue, a blend of visual and potentially tactile cues, eg "follow me through".....
IF789.... If you read my opening, I specifically say they did addresss the pilot to pilot interface, and rejected it, as an engineering decision...
"I am reasonably convinced that the lack of Pilot/Pilot interface engineered into the Airbus cockpit was not arrogance , nor ignorance."
I also believe they rejected interconnectivity due to overconfidence in the flight test crew's ability to intuit commands from the other seat. Perhaps due to the implementation of test pilots with highly developed intuitive skillset in assessment of the p/p interface....should they have used more mediocre and perhaps more independent pilots?
You say....
"... Interconnection. Yes. Really. They had interconnection and they scrapped it after test flying it. Apparently it was great in theory but didn't work when you actually tried flying it (even with test pilots). Interesting, no ?"
Can you explain? Connected controls aren't theoretical but merely a form of direct interface, sans intuition. They aren't 'flown', they are a direct cue, a blend of visual and potentially tactile cues, eg "follow me through".....
Last edited by Lyman; 14th Oct 2012 at 23:38.
food for discussion
FAST03 Airbus, mini sidestick
FAST05 Airbus, Flight Control System
FAST09 Airbus Fly by Wire performance analysis
FAST14 Airbus Advanced technology and the pilot
Would you show your reference for that?
According to the documentation of Airbus the system was evaluated in flight by one SS on the left and one yoke on the right. The double SS and the linkage of those was tested only in the SIM and the linkage between SS was then discarded for reasons not like you describe them.
But please read yourself.
FAST05 Airbus, Flight Control System
FAST09 Airbus Fly by Wire performance analysis
FAST14 Airbus Advanced technology and the pilot
infrequentflyer789
they also rejected the first sidestick design after flight test (not sim, flight) and sent it back to the engineers not for a bit of tweaking but for radical design changes.
they also rejected the first sidestick design after flight test (not sim, flight) and sent it back to the engineers not for a bit of tweaking but for radical design changes.
According to the documentation of Airbus the system was evaluated in flight by one SS on the left and one yoke on the right. The double SS and the linkage of those was tested only in the SIM and the linkage between SS was then discarded for reasons not like you describe them.
But please read yourself.
Last edited by RetiredF4; 15th Oct 2012 at 22:19.
Join Date: Jun 2011
Location: france
Posts: 760
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by KBPsen
Watching these threads is like watching TV at 3 o'clock in the morning. You know it is going to be nothing but re-runs of stuff you've seen many times before. It does give you the benefit of being able to switch off for weeks at a time knowing that nothing have been missed, which is something I suppose.
(from a French poem from Nicolas Boileau (1636-1711) : Twenty times on the loom you will hand your work)@RetiredF4
Thank you for these links
Last edited by Jetdriver; 23rd Oct 2012 at 19:52.
Join Date: Jun 2011
Location: france
Posts: 760
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Lyman
Dans le visage du prejudice, repeter la verite......
or
Hasten slowly, and without losing heart, put your work twenty times upon the anvil
Join Date: Jan 2005
Location: W of 30W
Posts: 1,916
Likes: 0
Received 0 Likes
on
0 Posts
RF4,
according to FAST05, in 1983 Airbus had opted not to have a mechanical linkage between the sticks but an electronic mixage between signals emitted by the two sticks following a specific logic. But in 1988 that specific logic had already considerably changed. Are you aware of a FAST publication detailing the reasons for forgetting the logic of 1983 or the reasons for adopting the new logic as we know it today ?
Thanks
according to FAST05, in 1983 Airbus had opted not to have a mechanical linkage between the sticks but an electronic mixage between signals emitted by the two sticks following a specific logic. But in 1988 that specific logic had already considerably changed. Are you aware of a FAST publication detailing the reasons for forgetting the logic of 1983 or the reasons for adopting the new logic as we know it today ?
Thanks
Are you aware of a FAST publication detailing the reasons for forgetting the logic of 1983 or the reasons for adopting the new logic as we know it today ?
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 81
Posts: 1,330
Received 0 Likes
on
0 Posts
Fast 05 - bolding mine.
Then there are the HF effects that can skewer any perfected flight control system, that in the 447 case comprised a high level of abnormal noise, which was apparently ignored - with the exception of the SW after the aircraft had left the normal flight envelope.
The expectation of : control input equates to motion change, appears to have been missed in the case of longitudinal inputs. Likewise, assimilation of the "glass interface" data expected in a normal scan, didn't provide an answer. Similarly, the differences between pre-stall and post-stall lateral control, and the motion effects associated, didn't rattle any brain cells. The PF's sensed "over-speed" situation would, if it was true, have provided a good number of barrel rolls, based on his lateral inputs.
Simulated feedback derived from standard inertial sources wouldn't have provided any additional tactile information once the airspeed had gone down the drain. Would have "stick shaker / ND inputs" induced into the SS provided further tactile feedback? In the 447 situation, I believe it wouldn't have changed anything, as the Microsoft "blue screen" effect accompanied by a "memory dump" seems to have claimed the day.
If AF447 is consigned as a "Black Swan" event, the major consideration with regard to safety needs to be focused on the Human Factors that contributed to the outcome. To do that, you start at the beginning with pilot selection, etc....
With standard flight control the aircraft may move significantly without flight control input and also a significant input of the flight control may have no apparent effect on the aircraft (i.e. when countering the flaps or engine change).
With the A320 Fly-by-Wire there is a consistant relationship between the aircraft movement and stick input at least in the normal flight envelope below minimized turbulence effect : no input, no motion change. Therefore, the natural detection of roll or load change gives an unmistakable warning that the other pilot (or the AP) is activating the flight control and the stick linkage is not necessary.
With the A320 Fly-by-Wire there is a consistant relationship between the aircraft movement and stick input at least in the normal flight envelope below minimized turbulence effect : no input, no motion change. Therefore, the natural detection of roll or load change gives an unmistakable warning that the other pilot (or the AP) is activating the flight control and the stick linkage is not necessary.
The expectation of : control input equates to motion change, appears to have been missed in the case of longitudinal inputs. Likewise, assimilation of the "glass interface" data expected in a normal scan, didn't provide an answer. Similarly, the differences between pre-stall and post-stall lateral control, and the motion effects associated, didn't rattle any brain cells. The PF's sensed "over-speed" situation would, if it was true, have provided a good number of barrel rolls, based on his lateral inputs.
Simulated feedback derived from standard inertial sources wouldn't have provided any additional tactile information once the airspeed had gone down the drain. Would have "stick shaker / ND inputs" induced into the SS provided further tactile feedback? In the 447 situation, I believe it wouldn't have changed anything, as the Microsoft "blue screen" effect accompanied by a "memory dump" seems to have claimed the day.
If AF447 is consigned as a "Black Swan" event, the major consideration with regard to safety needs to be focused on the Human Factors that contributed to the outcome. To do that, you start at the beginning with pilot selection, etc....
Join Date: Jun 2011
Location: france
Posts: 760
Likes: 0
Received 0 Likes
on
0 Posts
Selection !!!
Originally Posted by bold by mm43
Originally Posted by Fast5
at least in the normal flight envelope
Originally Posted by RetiredF4
Imho there is the behaviour in degraded law missing...........
agreed, but FAST05 is an old document (1985) and before 1988
Originally Posted by mm43
If AF447 is consigned as a "Black Swan" event, the major consideration with regard to safety needs to be focused on the Human Factors that contributed to the outcome. To do that, you start at the beginning with pilot selection, etc....
... but adding they were not able to distinguish rumours and facts and they would have to stop the investigation 
! Two years ago Gérard Feldzer confirmed the fact on a question I asked on a public radio 
. I listened during all these years trafic connected to other trafic was not finished. So is selection of ATPL in France.
Airbus fly by wire aircraft
Another read on the airbus FBW concept
FAST 20 Airbus
By the way, i now found the link to all FAST magazines on the airbus page
Publications | Airbus, a leading aircraft manufacturer
FAST 20 Airbus
By the way, i now found the link to all FAST magazines on the airbus page
Publications | Airbus, a leading aircraft manufacturer
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes
on
0 Posts
"Human Factor" ?! During 1980 I discovered a big trafic of French ATPL licenses.
Last edited by jcjeant; 24th Oct 2012 at 01:00.
Join Date: Jun 2011
Location: france
Posts: 760
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by jcjeant
Do you don't seen the same in 1988
rh
Last edited by roulishollandais; 24th Oct 2012 at 17:25.
Join Date: Dec 2010
Location: India
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
Automation surprises result from an imbalance between ‘autonomy’ and ‘authority’ of advanced systems and lurking gaps in operators' mental model of the system affecting the "human-automation interactions", rather the "man-machine interactions".
Thread Starter
Join Date: Feb 2011
Location: Nearby SBBR and SDAM
Posts: 875
Likes: 0
Received 0 Likes
on
0 Posts
HF or Interface?
AvMed.IN sez
“The accident resulted from the following succession of events: (I changed the sequence)
Temporary inconsistency between the measured airspeeds, likely following the obstruction of the Pitot probes by ice crystals that led in particular to autopilot disconnection and a reconfiguration to alternate law,
The crew not making the connection between the loss of indicated airspeeds and the appropriate procedure,
Inappropriate control inputs that destabilized the flight path,
The PNF’s late identification of the deviation in the flight path and insufficient correction by the PF,
The crew not identifying the approach to stall, the lack of an immediate reaction on its part and exit from the flight envelope,
The crew’s failure to diagnose the stall situation and, consequently, the lack of any actions that would have made recovery possible.”
Simply put:
The Interface should provide immediate and precise outputs to the crew even during anomalies
A brief cold in AS probes could and should be reported in the very beginning of the cascaded events. Surprises should be always reduced to a minimum and in AF447 case the uncertainties certainly played an import role to the outcome.
So, Human Factors emphasis or the need for better interface?
Clearly both are important and are closely related.
The vital factor at play in such cases could be low observability interfaces in novel (“nonroutine elements”) situations with operator caught in a bind while trying to track and anticipate the actions by the system in his hands! Simply put, when he (rather, they, being multi crew environment) is loosing the grip of the unfolding situation and finds himself inadequately prepared for the fast unwinding situation, which was chillingly evident in Air France Flight AF 447 as brought out in the final report [1]:-
“The accident resulted from the following succession of events: (I changed the sequence)
Temporary inconsistency between the measured airspeeds, likely following the obstruction of the Pitot probes by ice crystals that led in particular to autopilot disconnection and a reconfiguration to alternate law,
The crew not making the connection between the loss of indicated airspeeds and the appropriate procedure,
Inappropriate control inputs that destabilized the flight path,
The PNF’s late identification of the deviation in the flight path and insufficient correction by the PF,
The crew not identifying the approach to stall, the lack of an immediate reaction on its part and exit from the flight envelope,
The crew’s failure to diagnose the stall situation and, consequently, the lack of any actions that would have made recovery possible.”
Simply put:
The Interface should provide immediate and precise outputs to the crew even during anomalies
A brief cold in AS probes could and should be reported in the very beginning of the cascaded events. Surprises should be always reduced to a minimum and in AF447 case the uncertainties certainly played an import role to the outcome.
So, Human Factors emphasis or the need for better interface?
Clearly both are important and are closely related.
Join Date: Jul 2002
Location: UK
Posts: 3,093
Likes: 0
Received 0 Likes
on
0 Posts
Incorrect. The system was tripartite (engineering, management, pilot engineers), and the pilot engineer team led by Corps had veto power on the design specifics.
Thread Starter
Join Date: Feb 2011
Location: Nearby SBBR and SDAM
Posts: 875
Likes: 0
Received 0 Likes
on
0 Posts
Philosophy and specifics
DozyWannabe sez:
The "environment" at this time certainly was:
Management (overall philosophy, etc.)
Engineering (how to implement the overall philosophy, etc.)
And, Pilot engineers (As an important check of the above with veto power, etc.)
In this environment dealing with new frontiers it is very probable that:
Their (pilot engineers) influence in the design was reactive. The IT, automation, etc. as the "driving force", the top down "bias" that seems ultimately prevailed.
This obviously influential to marketing, sales, training, etc.
Veto power on specifics does not mean "enough power" to define the new philosophy. Not "coarse adjustments", just trim.
BTW:
I am motivated to address deeper some facts in this thread.
Could you tell me why not:
1) Inform assertively on the limitations being faced by the System
2) Orient crew clearly on proper procedure wrt to easily detectable UAS
I don´t like the "design approach" to delegate to the crew (creating "startling factors") both above issues.
This easily could generate a fatal "threshold effect" similar to the one observed in AF447 case.
And this not seems to me a "black swan" one as commented by mm43.
Graceful degradation is very important for survivability. Anomalies can be multiples. An the Interface is the "channel" in increasingly complex Systems.
...and the pilot engineer team led by Corps had veto power on the design specifics.
Management (overall philosophy, etc.)
Engineering (how to implement the overall philosophy, etc.)
And, Pilot engineers (As an important check of the above with veto power, etc.)
In this environment dealing with new frontiers it is very probable that:
Their (pilot engineers) influence in the design was reactive. The IT, automation, etc. as the "driving force", the top down "bias" that seems ultimately prevailed.
This obviously influential to marketing, sales, training, etc.
Veto power on specifics does not mean "enough power" to define the new philosophy. Not "coarse adjustments", just trim.
BTW:
I am motivated to address deeper some facts in this thread.
Could you tell me why not:
1) Inform assertively on the limitations being faced by the System
2) Orient crew clearly on proper procedure wrt to easily detectable UAS
I don´t like the "design approach" to delegate to the crew (creating "startling factors") both above issues.
This easily could generate a fatal "threshold effect" similar to the one observed in AF447 case.
And this not seems to me a "black swan" one as commented by mm43.
Graceful degradation is very important for survivability. Anomalies can be multiples. An the Interface is the "channel" in increasingly complex Systems.
Join Date: Jul 2002
Location: UK
Posts: 3,093
Likes: 0
Received 0 Likes
on
0 Posts
From what I was told, you've got it 180 degrees the wrong way. The original detailed specifications were drawn up by the pilot and aeronautical engineers. The systems engineers simply implemented those specifications.
Unfortunately I don't have any more detail than that, because sadly my source is no longer with us - but don't let the fact that you don't like aspects of the result on a personal or even professional level inform assumptions about how it was done.
Unfortunately I don't have any more detail than that, because sadly my source is no longer with us - but don't let the fact that you don't like aspects of the result on a personal or even professional level inform assumptions about how it was done.