Why are on-board computers allowed to change controls without notifying the pilots?Are 'human factor' specialists consulted during the UX design of cockpit controls and avionics?What improvements did Airbus make as a result of the Air France 447 accident?Why are critical flight computers redundant?Is A380's center of gravity really too far back?Would mechanical indicators have helped in the Air France 447 incident?At what point are the pilots allowed to communicate with the ground crew whilst they are still in the cockpit?Why are callouts of changes in the Flight Mode Annunciator not automated?On a modern Aircraft like the A320 or B737, is it possible to disable computer interference with the control inputs of the pilots?Could the autopilot have rectified the flight path without any crew input on the Aeroflot Flight 593?How difficult is it to simply disable/disengage the MCAS on Boeing 737 Max 8 & 9 Aircraft?
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Why are on-board computers allowed to change controls without notifying the pilots?
Are 'human factor' specialists consulted during the UX design of cockpit controls and avionics?What improvements did Airbus make as a result of the Air France 447 accident?Why are critical flight computers redundant?Is A380's center of gravity really too far back?Would mechanical indicators have helped in the Air France 447 incident?At what point are the pilots allowed to communicate with the ground crew whilst they are still in the cockpit?Why are callouts of changes in the Flight Mode Annunciator not automated?On a modern Aircraft like the A320 or B737, is it possible to disable computer interference with the control inputs of the pilots?Could the autopilot have rectified the flight path without any crew input on the Aeroflot Flight 593?How difficult is it to simply disable/disengage the MCAS on Boeing 737 Max 8 & 9 Aircraft?
$begingroup$
Recently we've had the 737-MAX debacle, where it increasingly appears that the MAX on-board MCAS system repeatedly would issue nose-down events, leading to the Lion Air crash, and possibly another
On the Lion Air flight, when the MCAS pushed the jet’s nose down, the captain pulled it back up, using thumb switches on the control column. Still operating under the false angle-of-attack reading, MCAS kicked in each time to swivel the horizontal tail and push the nose down again.
Apparently there is a notification light for MCAS that was an optional package but will now be required.
It reminds me of two other incidents that lead to crashes
Air France 447 A330 - A frozen pitot tube caused the computer to switch to Alternate Law 2, which meant that the computer would no longer prevent dangerous flight inputs. While not the same as the MCAS issue, it lead to confusion of the cockpit crew (who had been making maximum nose-up inputs while at TOGA power), and thus the plane crashed due to stall. It was noted that there was nothing direct to alert the pilots that the switch had occurred.
Scandanavian Air 751 MD81 - Ice accumulated on the wings. When the plane took off, the ice fell off, striking the engines. The pilots noted the engines were surging and reduced the throttle, but an auto-throttle system not disclosed to the pilots kept increasing power back to full, thus causing engine failure and a crash landing.
Has anyone ever stated why aircraft systems are allowed to make changes without notifying the pilots? Is it something that just hasn't been a large enough problem to address until now?
safety avionics autopilot
asked 4 hours ago
MachavityMachavity
2,4762834
$endgroup$
add a comment |
$begingroup$
Recently we've had the 737-MAX debacle, where it increasingly appears that the MAX on-board MCAS system repeatedly would issue nose-down events, leading to the Lion Air crash, and possibly another
On the Lion Air flight, when the MCAS pushed the jet’s nose down, the captain pulled it back up, using thumb switches on the control column. Still operating under the false angle-of-attack reading, MCAS kicked in each time to swivel the horizontal tail and push the nose down again.
Apparently there is a notification light for MCAS that was an optional package but will now be required.
It reminds me of two other incidents that lead to crashes
Air France 447 A330 - A frozen pitot tube caused the computer to switch to Alternate Law 2, which meant that the computer would no longer prevent dangerous flight inputs. While not the same as the MCAS issue, it lead to confusion of the cockpit crew (who had been making maximum nose-up inputs while at TOGA power), and thus the plane crashed due to stall. It was noted that there was nothing direct to alert the pilots that the switch had occurred.
Scandanavian Air 751 MD81 - Ice accumulated on the wings. When the plane took off, the ice fell off, striking the engines. The pilots noted the engines were surging and reduced the throttle, but an auto-throttle system not disclosed to the pilots kept increasing power back to full, thus causing engine failure and a crash landing.
Has anyone ever stated why aircraft systems are allowed to make changes without notifying the pilots? Is it something that just hasn't been a large enough problem to address until now?
safety avionics autopilot
asked 4 hours ago
MachavityMachavity
2,4762834
$endgroup$
3
$begingroup$
The AF447 flight had an alternate law indication available to the pilots, as well as many other (too many in fact) warnings that caused further confusion. In automation systems, the key is to present the appropriate information without overwhelming the operator with too many conflicting or confusing warnings. AF447 showed that a pilot in the face of too much information will ignore everything the system is telling them and fly with how they think the aircraft should be flown.
$endgroup$
– Ron Beyer
4 hours ago
$begingroup$
For most modern aircraft, it is a design feature that some intervention is invisible to pilots. The rudder has automatically made invisible small adjustments to maintain symmetrical flight and dampen yaw oscillations for at least half a century, and more modern aircraft alleviate turbulence or other small disturbance from trimmed flight without announcing this either, as that would quite quickly become a nuisance...
$endgroup$
– Cpt Reynolds
2 hours ago
1
$begingroup$
I guess the question to ask is rather not “why don’t all automatic inputs get announced” (as quite often that’s actually OK) but “why would anyone design an automatic that is associated with a risky edge of the flight envelope and then not tell crew about its existence” (because that’s not OK).
$endgroup$
– Cpt Reynolds
2 hours ago
add a comment |
$begingroup$
Recently we've had the 737-MAX debacle, where it increasingly appears that the MAX on-board MCAS system repeatedly would issue nose-down events, leading to the Lion Air crash, and possibly another
On the Lion Air flight, when the MCAS pushed the jet’s nose down, the captain pulled it back up, using thumb switches on the control column. Still operating under the false angle-of-attack reading, MCAS kicked in each time to swivel the horizontal tail and push the nose down again.
Apparently there is a notification light for MCAS that was an optional package but will now be required.
It reminds me of two other incidents that lead to crashes
Air France 447 A330 - A frozen pitot tube caused the computer to switch to Alternate Law 2, which meant that the computer would no longer prevent dangerous flight inputs. While not the same as the MCAS issue, it lead to confusion of the cockpit crew (who had been making maximum nose-up inputs while at TOGA power), and thus the plane crashed due to stall. It was noted that there was nothing direct to alert the pilots that the switch had occurred.
Scandanavian Air 751 MD81 - Ice accumulated on the wings. When the plane took off, the ice fell off, striking the engines. The pilots noted the engines were surging and reduced the throttle, but an auto-throttle system not disclosed to the pilots kept increasing power back to full, thus causing engine failure and a crash landing.
Has anyone ever stated why aircraft systems are allowed to make changes without notifying the pilots? Is it something that just hasn't been a large enough problem to address until now?
safety avionics autopilot
asked 4 hours ago
MachavityMachavity
2,4762834
$endgroup$
Recently we've had the 737-MAX debacle, where it increasingly appears that the MAX on-board MCAS system repeatedly would issue nose-down events, leading to the Lion Air crash, and possibly another
On the Lion Air flight, when the MCAS pushed the jet’s nose down, the captain pulled it back up, using thumb switches on the control column. Still operating under the false angle-of-attack reading, MCAS kicked in each time to swivel the horizontal tail and push the nose down again.
Apparently there is a notification light for MCAS that was an optional package but will now be required.
It reminds me of two other incidents that lead to crashes
Air France 447 A330 - A frozen pitot tube caused the computer to switch to Alternate Law 2, which meant that the computer would no longer prevent dangerous flight inputs. While not the same as the MCAS issue, it lead to confusion of the cockpit crew (who had been making maximum nose-up inputs while at TOGA power), and thus the plane crashed due to stall. It was noted that there was nothing direct to alert the pilots that the switch had occurred.
Scandanavian Air 751 MD81 - Ice accumulated on the wings. When the plane took off, the ice fell off, striking the engines. The pilots noted the engines were surging and reduced the throttle, but an auto-throttle system not disclosed to the pilots kept increasing power back to full, thus causing engine failure and a crash landing.
Has anyone ever stated why aircraft systems are allowed to make changes without notifying the pilots? Is it something that just hasn't been a large enough problem to address until now?
safety avionics autopilot
safety avionics autopilot
asked 4 hours ago
MachavityMachavity
2,4762834
asked 4 hours ago
MachavityMachavity
2,4762834
asked 4 hours ago
MachavityMachavity
2,4762834
asked 4 hours ago
MachavityMachavity
2,4762834
asked 4 hours ago
MachavityMachavity
2,4762834
2,4762834
3
$begingroup$
The AF447 flight had an alternate law indication available to the pilots, as well as many other (too many in fact) warnings that caused further confusion. In automation systems, the key is to present the appropriate information without overwhelming the operator with too many conflicting or confusing warnings. AF447 showed that a pilot in the face of too much information will ignore everything the system is telling them and fly with how they think the aircraft should be flown.
$endgroup$
– Ron Beyer
4 hours ago
$begingroup$
For most modern aircraft, it is a design feature that some intervention is invisible to pilots. The rudder has automatically made invisible small adjustments to maintain symmetrical flight and dampen yaw oscillations for at least half a century, and more modern aircraft alleviate turbulence or other small disturbance from trimmed flight without announcing this either, as that would quite quickly become a nuisance...
$endgroup$
– Cpt Reynolds
2 hours ago
1
$begingroup$
I guess the question to ask is rather not “why don’t all automatic inputs get announced” (as quite often that’s actually OK) but “why would anyone design an automatic that is associated with a risky edge of the flight envelope and then not tell crew about its existence” (because that’s not OK).
$endgroup$
– Cpt Reynolds
2 hours ago
add a comment |
3
$begingroup$
The AF447 flight had an alternate law indication available to the pilots, as well as many other (too many in fact) warnings that caused further confusion. In automation systems, the key is to present the appropriate information without overwhelming the operator with too many conflicting or confusing warnings. AF447 showed that a pilot in the face of too much information will ignore everything the system is telling them and fly with how they think the aircraft should be flown.
$endgroup$
– Ron Beyer
4 hours ago
$begingroup$
For most modern aircraft, it is a design feature that some intervention is invisible to pilots. The rudder has automatically made invisible small adjustments to maintain symmetrical flight and dampen yaw oscillations for at least half a century, and more modern aircraft alleviate turbulence or other small disturbance from trimmed flight without announcing this either, as that would quite quickly become a nuisance...
$endgroup$
– Cpt Reynolds
2 hours ago
1
$begingroup$
I guess the question to ask is rather not “why don’t all automatic inputs get announced” (as quite often that’s actually OK) but “why would anyone design an automatic that is associated with a risky edge of the flight envelope and then not tell crew about its existence” (because that’s not OK).
$endgroup$
– Cpt Reynolds
2 hours ago
3
3
$begingroup$
The AF447 flight had an alternate law indication available to the pilots, as well as many other (too many in fact) warnings that caused further confusion. In automation systems, the key is to present the appropriate information without overwhelming the operator with too many conflicting or confusing warnings. AF447 showed that a pilot in the face of too much information will ignore everything the system is telling them and fly with how they think the aircraft should be flown.
$endgroup$
– Ron Beyer
4 hours ago
$begingroup$
The AF447 flight had an alternate law indication available to the pilots, as well as many other (too many in fact) warnings that caused further confusion. In automation systems, the key is to present the appropriate information without overwhelming the operator with too many conflicting or confusing warnings. AF447 showed that a pilot in the face of too much information will ignore everything the system is telling them and fly with how they think the aircraft should be flown.
$endgroup$
– Ron Beyer
4 hours ago
$begingroup$
For most modern aircraft, it is a design feature that some intervention is invisible to pilots. The rudder has automatically made invisible small adjustments to maintain symmetrical flight and dampen yaw oscillations for at least half a century, and more modern aircraft alleviate turbulence or other small disturbance from trimmed flight without announcing this either, as that would quite quickly become a nuisance...
$endgroup$
– Cpt Reynolds
2 hours ago
$begingroup$
For most modern aircraft, it is a design feature that some intervention is invisible to pilots. The rudder has automatically made invisible small adjustments to maintain symmetrical flight and dampen yaw oscillations for at least half a century, and more modern aircraft alleviate turbulence or other small disturbance from trimmed flight without announcing this either, as that would quite quickly become a nuisance...
$endgroup$
– Cpt Reynolds
2 hours ago
1
1
$begingroup$
I guess the question to ask is rather not “why don’t all automatic inputs get announced” (as quite often that’s actually OK) but “why would anyone design an automatic that is associated with a risky edge of the flight envelope and then not tell crew about its existence” (because that’s not OK).
$endgroup$
– Cpt Reynolds
2 hours ago
$begingroup$
I guess the question to ask is rather not “why don’t all automatic inputs get announced” (as quite often that’s actually OK) but “why would anyone design an automatic that is associated with a risky edge of the flight envelope and then not tell crew about its existence” (because that’s not OK).
$endgroup$
– Cpt Reynolds
2 hours ago
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
There is a general design principle, that some, but not all, of the behavior of the flight guidance system or autopilot should be visible to the pilot. That sounds simple and logical, but in reality it's a complex and tricky human factors issue. Displaying too much information to the pilots is just as bad as displaying too little, as too much information can cause them to ignore the most important indicators, like a stick shaker warning about a impending stall.
I know this isn't a very satisfying answer, but it's hard for anyone other than a human factors expert to answer a very general question like this with hard-and-fast rules.
For example, some autopilots will skip the aural warning about autopilot disengagement if the disengagement was directly caused by the pilot. The pilot only gets a visual indication AP has changed behavior. This sounds perfect, but on Aeroflot Flight 593 a pilot let his child into the cockpit, who then applied enough pressure on the yoke to disengage the automatic aileron control. There was no warning chime because the disengagement was considered intentional by the autopilot. This was unlike previous planes the pilot had flown, which contributed to the pilot's confusion when the plane began to turn.
The indicator light you mention for the 737 Max Lion Air crash is for "AoA disagreement", not MCAS engagment as you suggest. While these kinds of AoA indicators are generally considered good ideas, it's still an area of debate how much they'd help confused pilots like in the Lion Air crash or the Air France 447 crash.
Similarly, the quality of indication was not the biggest cause to the accidents you've listed. For example, the Scandinavian Airlines Flight 751 could probably have returned to the airport successfully, but a compressor stall due to ice striking both engines at low altitudes is a bad situation no matter the auto-thrust behavior. Bad sensors and confused pilots can crash a plane with perfectly designed indicators.
answered 2 hours ago
Cody PCody P
4,1741241
$endgroup$
$begingroup$
That's a good point. Information overload is a very real problem.
$endgroup$
– Machavity
1 hour ago
add a comment |
$begingroup$
In the case of MCAS and the stabilizer control, there is "notification" that the stabilizers are being automatically adjusted in the form of the two wheels on either side of the thrust controls. They spin, have markings, and are very noisy, so the pilots could not have been unaware of them acting. The problem was that the pilots were (apparently) unaware of the possibility of turning off the automatic stabilizer inputs from MCAS and kept trying to manual override the MCAS/stabilizer adjustments. The switches to turn off the stabilizer inputs are right in front of the thrust controls on the co-pilot side.
answered 19 mins ago
42-42-
1112
New contributor
42- is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
They were also unaware of that specific trim function sponsored by MCAS which probably wasn’t particularly helpful in fault diagnosis.
$endgroup$
– Cpt Reynolds
17 mins ago
add a comment |
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2 Answers
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active
oldest
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2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
There is a general design principle, that some, but not all, of the behavior of the flight guidance system or autopilot should be visible to the pilot. That sounds simple and logical, but in reality it's a complex and tricky human factors issue. Displaying too much information to the pilots is just as bad as displaying too little, as too much information can cause them to ignore the most important indicators, like a stick shaker warning about a impending stall.
I know this isn't a very satisfying answer, but it's hard for anyone other than a human factors expert to answer a very general question like this with hard-and-fast rules.
For example, some autopilots will skip the aural warning about autopilot disengagement if the disengagement was directly caused by the pilot. The pilot only gets a visual indication AP has changed behavior. This sounds perfect, but on Aeroflot Flight 593 a pilot let his child into the cockpit, who then applied enough pressure on the yoke to disengage the automatic aileron control. There was no warning chime because the disengagement was considered intentional by the autopilot. This was unlike previous planes the pilot had flown, which contributed to the pilot's confusion when the plane began to turn.
The indicator light you mention for the 737 Max Lion Air crash is for "AoA disagreement", not MCAS engagment as you suggest. While these kinds of AoA indicators are generally considered good ideas, it's still an area of debate how much they'd help confused pilots like in the Lion Air crash or the Air France 447 crash.
Similarly, the quality of indication was not the biggest cause to the accidents you've listed. For example, the Scandinavian Airlines Flight 751 could probably have returned to the airport successfully, but a compressor stall due to ice striking both engines at low altitudes is a bad situation no matter the auto-thrust behavior. Bad sensors and confused pilots can crash a plane with perfectly designed indicators.
answered 2 hours ago
Cody PCody P
4,1741241
$endgroup$
$begingroup$
That's a good point. Information overload is a very real problem.
$endgroup$
– Machavity
1 hour ago
add a comment |
$begingroup$
There is a general design principle, that some, but not all, of the behavior of the flight guidance system or autopilot should be visible to the pilot. That sounds simple and logical, but in reality it's a complex and tricky human factors issue. Displaying too much information to the pilots is just as bad as displaying too little, as too much information can cause them to ignore the most important indicators, like a stick shaker warning about a impending stall.
I know this isn't a very satisfying answer, but it's hard for anyone other than a human factors expert to answer a very general question like this with hard-and-fast rules.
For example, some autopilots will skip the aural warning about autopilot disengagement if the disengagement was directly caused by the pilot. The pilot only gets a visual indication AP has changed behavior. This sounds perfect, but on Aeroflot Flight 593 a pilot let his child into the cockpit, who then applied enough pressure on the yoke to disengage the automatic aileron control. There was no warning chime because the disengagement was considered intentional by the autopilot. This was unlike previous planes the pilot had flown, which contributed to the pilot's confusion when the plane began to turn.
The indicator light you mention for the 737 Max Lion Air crash is for "AoA disagreement", not MCAS engagment as you suggest. While these kinds of AoA indicators are generally considered good ideas, it's still an area of debate how much they'd help confused pilots like in the Lion Air crash or the Air France 447 crash.
Similarly, the quality of indication was not the biggest cause to the accidents you've listed. For example, the Scandinavian Airlines Flight 751 could probably have returned to the airport successfully, but a compressor stall due to ice striking both engines at low altitudes is a bad situation no matter the auto-thrust behavior. Bad sensors and confused pilots can crash a plane with perfectly designed indicators.
answered 2 hours ago
Cody PCody P
4,1741241
$endgroup$
$begingroup$
That's a good point. Information overload is a very real problem.
$endgroup$
– Machavity
1 hour ago
add a comment |
$begingroup$
There is a general design principle, that some, but not all, of the behavior of the flight guidance system or autopilot should be visible to the pilot. That sounds simple and logical, but in reality it's a complex and tricky human factors issue. Displaying too much information to the pilots is just as bad as displaying too little, as too much information can cause them to ignore the most important indicators, like a stick shaker warning about a impending stall.
I know this isn't a very satisfying answer, but it's hard for anyone other than a human factors expert to answer a very general question like this with hard-and-fast rules.
For example, some autopilots will skip the aural warning about autopilot disengagement if the disengagement was directly caused by the pilot. The pilot only gets a visual indication AP has changed behavior. This sounds perfect, but on Aeroflot Flight 593 a pilot let his child into the cockpit, who then applied enough pressure on the yoke to disengage the automatic aileron control. There was no warning chime because the disengagement was considered intentional by the autopilot. This was unlike previous planes the pilot had flown, which contributed to the pilot's confusion when the plane began to turn.
The indicator light you mention for the 737 Max Lion Air crash is for "AoA disagreement", not MCAS engagment as you suggest. While these kinds of AoA indicators are generally considered good ideas, it's still an area of debate how much they'd help confused pilots like in the Lion Air crash or the Air France 447 crash.
Similarly, the quality of indication was not the biggest cause to the accidents you've listed. For example, the Scandinavian Airlines Flight 751 could probably have returned to the airport successfully, but a compressor stall due to ice striking both engines at low altitudes is a bad situation no matter the auto-thrust behavior. Bad sensors and confused pilots can crash a plane with perfectly designed indicators.
answered 2 hours ago
Cody PCody P
4,1741241
$endgroup$
There is a general design principle, that some, but not all, of the behavior of the flight guidance system or autopilot should be visible to the pilot. That sounds simple and logical, but in reality it's a complex and tricky human factors issue. Displaying too much information to the pilots is just as bad as displaying too little, as too much information can cause them to ignore the most important indicators, like a stick shaker warning about a impending stall.
I know this isn't a very satisfying answer, but it's hard for anyone other than a human factors expert to answer a very general question like this with hard-and-fast rules.
For example, some autopilots will skip the aural warning about autopilot disengagement if the disengagement was directly caused by the pilot. The pilot only gets a visual indication AP has changed behavior. This sounds perfect, but on Aeroflot Flight 593 a pilot let his child into the cockpit, who then applied enough pressure on the yoke to disengage the automatic aileron control. There was no warning chime because the disengagement was considered intentional by the autopilot. This was unlike previous planes the pilot had flown, which contributed to the pilot's confusion when the plane began to turn.
The indicator light you mention for the 737 Max Lion Air crash is for "AoA disagreement", not MCAS engagment as you suggest. While these kinds of AoA indicators are generally considered good ideas, it's still an area of debate how much they'd help confused pilots like in the Lion Air crash or the Air France 447 crash.
Similarly, the quality of indication was not the biggest cause to the accidents you've listed. For example, the Scandinavian Airlines Flight 751 could probably have returned to the airport successfully, but a compressor stall due to ice striking both engines at low altitudes is a bad situation no matter the auto-thrust behavior. Bad sensors and confused pilots can crash a plane with perfectly designed indicators.
answered 2 hours ago
Cody PCody P
4,1741241
edited 2 hours ago
answered 2 hours ago
Cody PCody P
4,1741241
answered 2 hours ago
Cody PCody P
4,1741241
answered 2 hours ago
Cody PCody P
4,1741241
4,1741241
$begingroup$
That's a good point. Information overload is a very real problem.
$endgroup$
– Machavity
1 hour ago
add a comment |
$begingroup$
That's a good point. Information overload is a very real problem.
$endgroup$
– Machavity
1 hour ago
$begingroup$
That's a good point. Information overload is a very real problem.
$endgroup$
– Machavity
1 hour ago
$begingroup$
That's a good point. Information overload is a very real problem.
$endgroup$
– Machavity
1 hour ago
add a comment |
$begingroup$
In the case of MCAS and the stabilizer control, there is "notification" that the stabilizers are being automatically adjusted in the form of the two wheels on either side of the thrust controls. They spin, have markings, and are very noisy, so the pilots could not have been unaware of them acting. The problem was that the pilots were (apparently) unaware of the possibility of turning off the automatic stabilizer inputs from MCAS and kept trying to manual override the MCAS/stabilizer adjustments. The switches to turn off the stabilizer inputs are right in front of the thrust controls on the co-pilot side.
answered 19 mins ago
42-42-
1112
New contributor
42- is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
They were also unaware of that specific trim function sponsored by MCAS which probably wasn’t particularly helpful in fault diagnosis.
$endgroup$
– Cpt Reynolds
17 mins ago
add a comment |
$begingroup$
In the case of MCAS and the stabilizer control, there is "notification" that the stabilizers are being automatically adjusted in the form of the two wheels on either side of the thrust controls. They spin, have markings, and are very noisy, so the pilots could not have been unaware of them acting. The problem was that the pilots were (apparently) unaware of the possibility of turning off the automatic stabilizer inputs from MCAS and kept trying to manual override the MCAS/stabilizer adjustments. The switches to turn off the stabilizer inputs are right in front of the thrust controls on the co-pilot side.
answered 19 mins ago
42-42-
1112
New contributor
42- is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
They were also unaware of that specific trim function sponsored by MCAS which probably wasn’t particularly helpful in fault diagnosis.
$endgroup$
– Cpt Reynolds
17 mins ago
add a comment |
$begingroup$
In the case of MCAS and the stabilizer control, there is "notification" that the stabilizers are being automatically adjusted in the form of the two wheels on either side of the thrust controls. They spin, have markings, and are very noisy, so the pilots could not have been unaware of them acting. The problem was that the pilots were (apparently) unaware of the possibility of turning off the automatic stabilizer inputs from MCAS and kept trying to manual override the MCAS/stabilizer adjustments. The switches to turn off the stabilizer inputs are right in front of the thrust controls on the co-pilot side.
answered 19 mins ago
42-42-
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$endgroup$
In the case of MCAS and the stabilizer control, there is "notification" that the stabilizers are being automatically adjusted in the form of the two wheels on either side of the thrust controls. They spin, have markings, and are very noisy, so the pilots could not have been unaware of them acting. The problem was that the pilots were (apparently) unaware of the possibility of turning off the automatic stabilizer inputs from MCAS and kept trying to manual override the MCAS/stabilizer adjustments. The switches to turn off the stabilizer inputs are right in front of the thrust controls on the co-pilot side.
answered 19 mins ago
42-42-
1112
New contributor
42- is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 19 mins ago
42-42-
1112
New contributor
42- is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 19 mins ago
42-42-
1112
answered 19 mins ago
42-42-
1112
1112
New contributor
42- is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
42- is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
42- is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$begingroup$
They were also unaware of that specific trim function sponsored by MCAS which probably wasn’t particularly helpful in fault diagnosis.
$endgroup$
– Cpt Reynolds
17 mins ago
add a comment |
$begingroup$
They were also unaware of that specific trim function sponsored by MCAS which probably wasn’t particularly helpful in fault diagnosis.
$endgroup$
– Cpt Reynolds
17 mins ago
$begingroup$
They were also unaware of that specific trim function sponsored by MCAS which probably wasn’t particularly helpful in fault diagnosis.
$endgroup$
– Cpt Reynolds
17 mins ago
$begingroup$
They were also unaware of that specific trim function sponsored by MCAS which probably wasn’t particularly helpful in fault diagnosis.
$endgroup$
– Cpt Reynolds
17 mins ago
add a comment |
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$begingroup$
The AF447 flight had an alternate law indication available to the pilots, as well as many other (too many in fact) warnings that caused further confusion. In automation systems, the key is to present the appropriate information without overwhelming the operator with too many conflicting or confusing warnings. AF447 showed that a pilot in the face of too much information will ignore everything the system is telling them and fly with how they think the aircraft should be flown.
$endgroup$
– Ron Beyer
4 hours ago
$begingroup$
For most modern aircraft, it is a design feature that some intervention is invisible to pilots. The rudder has automatically made invisible small adjustments to maintain symmetrical flight and dampen yaw oscillations for at least half a century, and more modern aircraft alleviate turbulence or other small disturbance from trimmed flight without announcing this either, as that would quite quickly become a nuisance...
$endgroup$
– Cpt Reynolds
2 hours ago
1
$begingroup$
I guess the question to ask is rather not “why don’t all automatic inputs get announced” (as quite often that’s actually OK) but “why would anyone design an automatic that is associated with a risky edge of the flight envelope and then not tell crew about its existence” (because that’s not OK).
$endgroup$
– Cpt Reynolds
2 hours ago