Why do passenger jet manufacturers design their planes with stall prevention systems?Why do passenger jets accept input that will cause the aircraft to perform dangerous maneuvers it was not designed for?What climb rates can the Airbus A320-200 achieve and which climb rates are commonly used for normal flight operations?How can we recover from a tailplane stall?Does the expression “stall speed” have a definition?Why does Airbus suppress stall warnings in certain situations?Why disable stall warning based only on low airspeed, rather than multiple criteria?Why are the positive points in a V-n diagram associated with pitch maneuvers?Can computer imposed inputs be overridden on the Boeing 737-MAX?How do aircraft stall warning systems handle (or not) asymmetric-stall situations?Why is the A330/A340's angle-of-attack protection disabled in alternate law, even if the AoA vanes are operating normally?
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Why do passenger jet manufacturers design their planes with stall prevention systems?
Why do passenger jets accept input that will cause the aircraft to perform dangerous maneuvers it was not designed for?What climb rates can the Airbus A320-200 achieve and which climb rates are commonly used for normal flight operations?How can we recover from a tailplane stall?Does the expression “stall speed” have a definition?Why does Airbus suppress stall warnings in certain situations?Why disable stall warning based only on low airspeed, rather than multiple criteria?Why are the positive points in a V-n diagram associated with pitch maneuvers?Can computer imposed inputs be overridden on the Boeing 737-MAX?How do aircraft stall warning systems handle (or not) asymmetric-stall situations?Why is the A330/A340's angle-of-attack protection disabled in alternate law, even if the AoA vanes are operating normally?
$begingroup$
I understand why passenger jets use software that overrides pilot inputs that might cause the jet to exceed the flight envelope. But why do passenger jet manufacturers design their planes with stall prevention systems? Shouldn't professional pilots be well aware that a stall is possible when the airspeed is too low, or the angle of attack is too high?
aircraft-design stall
asked 21 hours ago
rclocher3rclocher3
26328
$endgroup$
add a comment |
$begingroup$
I understand why passenger jets use software that overrides pilot inputs that might cause the jet to exceed the flight envelope. But why do passenger jet manufacturers design their planes with stall prevention systems? Shouldn't professional pilots be well aware that a stall is possible when the airspeed is too low, or the angle of attack is too high?
aircraft-design stall
asked 21 hours ago
rclocher3rclocher3
26328
$endgroup$
3
$begingroup$
This isn't as simple as it sounds, and AF447 really set this in motion for the industry. The problem is that at differing altitudes your AoA between "flying" and "stall" can be extremely narrow. Couple that in with no visual references and a pilot may not know that the aircraft is stalling...
$endgroup$
– Ron Beyer
21 hours ago
$begingroup$
Be aware, especially on the more advanced, larger aircraft, although the anti-stall systems do pull and act largely on their own against pilot input, 20lb's of force is roughly the industry standard (I believe from personal experience) to override this.
$endgroup$
– Jihyun
19 hours ago
7
$begingroup$
@RonBeyer AF447 had such a system, but it had been disabled due to erroneous airspeed readings when the pitot tubes iced. If anything, AF447 is something of a cautionary tale of pilots becoming too reliant on such systems instead of knowing how to fly the airplane themselves.
$endgroup$
– reirab
18 hours ago
add a comment |
$begingroup$
I understand why passenger jets use software that overrides pilot inputs that might cause the jet to exceed the flight envelope. But why do passenger jet manufacturers design their planes with stall prevention systems? Shouldn't professional pilots be well aware that a stall is possible when the airspeed is too low, or the angle of attack is too high?
aircraft-design stall
asked 21 hours ago
rclocher3rclocher3
26328
$endgroup$
I understand why passenger jets use software that overrides pilot inputs that might cause the jet to exceed the flight envelope. But why do passenger jet manufacturers design their planes with stall prevention systems? Shouldn't professional pilots be well aware that a stall is possible when the airspeed is too low, or the angle of attack is too high?
aircraft-design stall
aircraft-design stall
asked 21 hours ago
rclocher3rclocher3
26328
asked 21 hours ago
rclocher3rclocher3
26328
asked 21 hours ago
rclocher3rclocher3
26328
asked 21 hours ago
rclocher3rclocher3
26328
asked 21 hours ago
rclocher3rclocher3
26328
26328
3
$begingroup$
This isn't as simple as it sounds, and AF447 really set this in motion for the industry. The problem is that at differing altitudes your AoA between "flying" and "stall" can be extremely narrow. Couple that in with no visual references and a pilot may not know that the aircraft is stalling...
$endgroup$
– Ron Beyer
21 hours ago
$begingroup$
Be aware, especially on the more advanced, larger aircraft, although the anti-stall systems do pull and act largely on their own against pilot input, 20lb's of force is roughly the industry standard (I believe from personal experience) to override this.
$endgroup$
– Jihyun
19 hours ago
7
$begingroup$
@RonBeyer AF447 had such a system, but it had been disabled due to erroneous airspeed readings when the pitot tubes iced. If anything, AF447 is something of a cautionary tale of pilots becoming too reliant on such systems instead of knowing how to fly the airplane themselves.
$endgroup$
– reirab
18 hours ago
add a comment |
3
$begingroup$
This isn't as simple as it sounds, and AF447 really set this in motion for the industry. The problem is that at differing altitudes your AoA between "flying" and "stall" can be extremely narrow. Couple that in with no visual references and a pilot may not know that the aircraft is stalling...
$endgroup$
– Ron Beyer
21 hours ago
$begingroup$
Be aware, especially on the more advanced, larger aircraft, although the anti-stall systems do pull and act largely on their own against pilot input, 20lb's of force is roughly the industry standard (I believe from personal experience) to override this.
$endgroup$
– Jihyun
19 hours ago
7
$begingroup$
@RonBeyer AF447 had such a system, but it had been disabled due to erroneous airspeed readings when the pitot tubes iced. If anything, AF447 is something of a cautionary tale of pilots becoming too reliant on such systems instead of knowing how to fly the airplane themselves.
$endgroup$
– reirab
18 hours ago
3
3
$begingroup$
This isn't as simple as it sounds, and AF447 really set this in motion for the industry. The problem is that at differing altitudes your AoA between "flying" and "stall" can be extremely narrow. Couple that in with no visual references and a pilot may not know that the aircraft is stalling...
$endgroup$
– Ron Beyer
21 hours ago
$begingroup$
This isn't as simple as it sounds, and AF447 really set this in motion for the industry. The problem is that at differing altitudes your AoA between "flying" and "stall" can be extremely narrow. Couple that in with no visual references and a pilot may not know that the aircraft is stalling...
$endgroup$
– Ron Beyer
21 hours ago
$begingroup$
Be aware, especially on the more advanced, larger aircraft, although the anti-stall systems do pull and act largely on their own against pilot input, 20lb's of force is roughly the industry standard (I believe from personal experience) to override this.
$endgroup$
– Jihyun
19 hours ago
$begingroup$
Be aware, especially on the more advanced, larger aircraft, although the anti-stall systems do pull and act largely on their own against pilot input, 20lb's of force is roughly the industry standard (I believe from personal experience) to override this.
$endgroup$
– Jihyun
19 hours ago
7
7
$begingroup$
@RonBeyer AF447 had such a system, but it had been disabled due to erroneous airspeed readings when the pitot tubes iced. If anything, AF447 is something of a cautionary tale of pilots becoming too reliant on such systems instead of knowing how to fly the airplane themselves.
$endgroup$
– reirab
18 hours ago
$begingroup$
@RonBeyer AF447 had such a system, but it had been disabled due to erroneous airspeed readings when the pitot tubes iced. If anything, AF447 is something of a cautionary tale of pilots becoming too reliant on such systems instead of knowing how to fly the airplane themselves.
$endgroup$
– reirab
18 hours ago
add a comment |
3 Answers
3
active
oldest
votes
$begingroup$
To be certifiable, airplanes have to have some kind of cues to warn when you are getting close to a stall, and have decent behaviour during the stall, because nobody is perfect. Airplanes with very strong physical cues prior to stall, like the whole airframe shaking, and good behaviour during a stall, like a good natural pitch over tendency with immediate unstalling of the wing, can get away without stall warning and prevention systems.
Transport aircraft with highly loaded wings and high performance airfoils may have poor behaviour before the stall (no buffeting or shaking), and poor recovery performance after, and need a little help. The airfoils used for airplanes that fly at near trans-sonic speeds tend to suffer from this because they tend to stall from the leading edge, at which point the wing stops lifting all at once, and there is often no prior buffeting or shaking.
The earlier supercritical (higher critical mach#) airfoils developed in the 70s were especially bad for this because they developed a flow separation bubble just aft of the leading edge at high angles of attack, due to the profile that was used to manage the formation of shock waves (the Challenger business jet and CRJ200 Regional Jet is typical). You do not want to experience the natural stall on such an aircraft and some kind of system has to be in place as a backup for mishandling of the airplane by the pilot.
For airplanes with mechanical/hydraulic controls, to provide a tactile warning as a substitute or supplement for the airplane shaking (pre-stall buffet), stick shakers are used, which is just a motor with an eccentric weight on the control column. If the post stall behaviour (not much natural pitch over, or worse, settling into an unrecoverable deep stall) is poor, a stick pusher is installed to give the control column a shove just before the natural stall occurs. The stall protection system calculates when to do all this.
Most high performance aircraft use shakers, and some use stick pushers. With FBW, the FBW computers intervene directly within the control loop to achieve the same end without having to shake or push the controls.
answered 20 hours ago
John KJohn K
21.5k13064
$endgroup$
$begingroup$
In the Air France 447 accident, the Airbus A330 only had a sound warning, with no physical warning, and the plane was clearly built so that it can't "get away" without a warning. Why is that?
$endgroup$
– gparyani
13 hours ago
2
$begingroup$
The last sentence in my post applies. It's a FBW airplane with side sticks and the computers control the airplane at the margins, only letting the pilot input go so far, with an aural warning when things are getting close, but the computers will simply not allow the pilot to go all the way into an aerodynamic stall. 447 wasn't stalled in the aerodynamic sense on its ride down, it was being held at the maximum attitude the computers would allow, not quite stalled, because the right seater was in a mental fog panic mode holding the right side stick fully aft the entire ride down.
$endgroup$
– John K
13 hours ago
2
$begingroup$
And the guy in the left seat was in a similar mentally saturated state and didn't think to hit the left seater's override button to pitch the plane over. He pushed his stick forward a few times but this only gets a 50% input because the two inputs are averaged, unless he overrides, and a 50% input wasn't enough to recover from the low speed mush descent.
$endgroup$
– John K
13 hours ago
1
$begingroup$
The cockpit recorded did record the sound of the audible stall warning for the entire decent, so I would agree that the pilots were in a mental fog and completely did not register what they needed to do.
$endgroup$
– Nelson
7 hours ago
add a comment |
$begingroup$
Why do car manufacturers install seat belts? Shouldn't licensed drivers be well aware that they should slow down when it's raining or snowing and that they shouldn't run through red lights or stop signs?
- Because accidents happen.
- Because pilots are human and make mistakes.
- Because when you're flying in the clouds with no visual references, it's easy to get confused.
- Because even with stall warning & prevention systems in place, confused pilots will fight the system. AF 447
answered 21 hours ago
FreeManFreeMan
7,3751057125
$endgroup$
$begingroup$
And because even with stall prevention systems, stalls are still a reality. That's how bad it is
$endgroup$
– Hanky Panky
8 hours ago
$begingroup$
To be fair the AF 447's stall prevention were disabled because of incorrect airspeed readings. In contrast, the Lion Air 737 crash was that it didn't get disabled... die if you do, die if you don't...
$endgroup$
– Nelson
7 hours ago
$begingroup$
I believe some planes have a nose wing set at a steeper angle than the main wing, causing the nose to stall first, thus bringing the nose down before a real stall is reached. (See ainonline.com/sites/default/files/uploads/2018/07/… for an example of a nose wing, though I don't know its purpose on the Piaggo.)
$endgroup$
– user3070485
2 hours ago
$begingroup$
@user3070485 that "nose wing" is called a canard, and yes, I believe you're correct. I would imagine that it's still possible to stall a canard winged aircraft, though that would make a good question of its own.
$endgroup$
– FreeMan
2 hours ago
$begingroup$
@FreeMan It is still possible to stall a canard aircraft but most are designed as @ user3070485 mentioned where the canard will stall first. However this becomes a more difficult situation when you introduce leading and trailing edge devices which alter the stall characteristics of the wing. You can get a situation where the canard will stall first under certain configurations and where the wing will stall first under others.
$endgroup$
– DJ319
1 hour ago
add a comment |
$begingroup$
You said you understand systems to prevent the airplane from exceeding the flight envelope. Stall is just another boundary of the flight envelope. The rest of the envelope limitations are listed in the flight manual as well. Shouldn't pilots know not to stall the airplane, just as they know not to over-stress it, or exceed other limitations? Of course.
But humans make mistakes, they can get distracted or disoriented. And just as there's little benefit to allowing a pilot to rip the wings off the plane by pitching too fast, there's little benefit from allowing the plane to stall.
Here is a selection of aircraft that have crashed due to stalls.
South Airlines Flight 8971
Air Algérie 5017
AirAsia QZ8501
Thai Airways International flight 261
Vladivostokavia Flight 352
N452DA
Yemenia Airways Flight 626
If stall protection systems are implemented and functioning properly, they can prevent issues. Here are just a few instances where stall protection worked as intended:
GoAir 338
Air France 7662
Jetstar 248
answered 19 hours ago
foootfooot
53.1k17168321
$endgroup$
1
$begingroup$
On the flip size, I'm curious what would have happened to Asiana 214 if it had had a stall prevention system. If I'm remembering correctly, they did stall (or at least very nearly stall) on very short final while trying to make the runway. If a stall prevention system had prevented them from raising the nose, would they have hit the nose on the seawall instead of the tail? That seems like it could have been a bad situation a whole lot worse.
$endgroup$
– reirab
18 hours ago
1
$begingroup$
@reirab True. On the other hand, if you allow the aircraft to run into two limits simultaneously (out of room and out of speed), there is not much anyone can do. You could argue the „opposite“ safety system, too, and say an automatic terrain escape manoeuvre would be fantastic, except with Asiana 214, it could have worsened the stall...
$endgroup$
– Cpt Reynolds
17 hours ago
2
$begingroup$
@CptReynolds Agreed. The root source of the problem was, of course, lack of energy on very short final, which was totally a result of pilot error. But, given that situation, they pretty much had to choose how they were going to crash rather than whether they were going to crash. In that sort of situation, I'd personally prefer a human pilot who can look out the window and make rapid judgments based on the exact situation in control. It's just not the sort of thing that's easy to account for when you're designing a computer program.
$endgroup$
– reirab
17 hours ago
$begingroup$
I suggest to add Colgan 3407 to the list.
$endgroup$
– Martin Argerami
3 hours ago
add a comment |
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3 Answers
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active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
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$begingroup$
To be certifiable, airplanes have to have some kind of cues to warn when you are getting close to a stall, and have decent behaviour during the stall, because nobody is perfect. Airplanes with very strong physical cues prior to stall, like the whole airframe shaking, and good behaviour during a stall, like a good natural pitch over tendency with immediate unstalling of the wing, can get away without stall warning and prevention systems.
Transport aircraft with highly loaded wings and high performance airfoils may have poor behaviour before the stall (no buffeting or shaking), and poor recovery performance after, and need a little help. The airfoils used for airplanes that fly at near trans-sonic speeds tend to suffer from this because they tend to stall from the leading edge, at which point the wing stops lifting all at once, and there is often no prior buffeting or shaking.
The earlier supercritical (higher critical mach#) airfoils developed in the 70s were especially bad for this because they developed a flow separation bubble just aft of the leading edge at high angles of attack, due to the profile that was used to manage the formation of shock waves (the Challenger business jet and CRJ200 Regional Jet is typical). You do not want to experience the natural stall on such an aircraft and some kind of system has to be in place as a backup for mishandling of the airplane by the pilot.
For airplanes with mechanical/hydraulic controls, to provide a tactile warning as a substitute or supplement for the airplane shaking (pre-stall buffet), stick shakers are used, which is just a motor with an eccentric weight on the control column. If the post stall behaviour (not much natural pitch over, or worse, settling into an unrecoverable deep stall) is poor, a stick pusher is installed to give the control column a shove just before the natural stall occurs. The stall protection system calculates when to do all this.
Most high performance aircraft use shakers, and some use stick pushers. With FBW, the FBW computers intervene directly within the control loop to achieve the same end without having to shake or push the controls.
answered 20 hours ago
John KJohn K
21.5k13064
$endgroup$
$begingroup$
In the Air France 447 accident, the Airbus A330 only had a sound warning, with no physical warning, and the plane was clearly built so that it can't "get away" without a warning. Why is that?
$endgroup$
– gparyani
13 hours ago
2
$begingroup$
The last sentence in my post applies. It's a FBW airplane with side sticks and the computers control the airplane at the margins, only letting the pilot input go so far, with an aural warning when things are getting close, but the computers will simply not allow the pilot to go all the way into an aerodynamic stall. 447 wasn't stalled in the aerodynamic sense on its ride down, it was being held at the maximum attitude the computers would allow, not quite stalled, because the right seater was in a mental fog panic mode holding the right side stick fully aft the entire ride down.
$endgroup$
– John K
13 hours ago
2
$begingroup$
And the guy in the left seat was in a similar mentally saturated state and didn't think to hit the left seater's override button to pitch the plane over. He pushed his stick forward a few times but this only gets a 50% input because the two inputs are averaged, unless he overrides, and a 50% input wasn't enough to recover from the low speed mush descent.
$endgroup$
– John K
13 hours ago
1
$begingroup$
The cockpit recorded did record the sound of the audible stall warning for the entire decent, so I would agree that the pilots were in a mental fog and completely did not register what they needed to do.
$endgroup$
– Nelson
7 hours ago
add a comment |
$begingroup$
To be certifiable, airplanes have to have some kind of cues to warn when you are getting close to a stall, and have decent behaviour during the stall, because nobody is perfect. Airplanes with very strong physical cues prior to stall, like the whole airframe shaking, and good behaviour during a stall, like a good natural pitch over tendency with immediate unstalling of the wing, can get away without stall warning and prevention systems.
Transport aircraft with highly loaded wings and high performance airfoils may have poor behaviour before the stall (no buffeting or shaking), and poor recovery performance after, and need a little help. The airfoils used for airplanes that fly at near trans-sonic speeds tend to suffer from this because they tend to stall from the leading edge, at which point the wing stops lifting all at once, and there is often no prior buffeting or shaking.
The earlier supercritical (higher critical mach#) airfoils developed in the 70s were especially bad for this because they developed a flow separation bubble just aft of the leading edge at high angles of attack, due to the profile that was used to manage the formation of shock waves (the Challenger business jet and CRJ200 Regional Jet is typical). You do not want to experience the natural stall on such an aircraft and some kind of system has to be in place as a backup for mishandling of the airplane by the pilot.
For airplanes with mechanical/hydraulic controls, to provide a tactile warning as a substitute or supplement for the airplane shaking (pre-stall buffet), stick shakers are used, which is just a motor with an eccentric weight on the control column. If the post stall behaviour (not much natural pitch over, or worse, settling into an unrecoverable deep stall) is poor, a stick pusher is installed to give the control column a shove just before the natural stall occurs. The stall protection system calculates when to do all this.
Most high performance aircraft use shakers, and some use stick pushers. With FBW, the FBW computers intervene directly within the control loop to achieve the same end without having to shake or push the controls.
answered 20 hours ago
John KJohn K
21.5k13064
$endgroup$
$begingroup$
In the Air France 447 accident, the Airbus A330 only had a sound warning, with no physical warning, and the plane was clearly built so that it can't "get away" without a warning. Why is that?
$endgroup$
– gparyani
13 hours ago
2
$begingroup$
The last sentence in my post applies. It's a FBW airplane with side sticks and the computers control the airplane at the margins, only letting the pilot input go so far, with an aural warning when things are getting close, but the computers will simply not allow the pilot to go all the way into an aerodynamic stall. 447 wasn't stalled in the aerodynamic sense on its ride down, it was being held at the maximum attitude the computers would allow, not quite stalled, because the right seater was in a mental fog panic mode holding the right side stick fully aft the entire ride down.
$endgroup$
– John K
13 hours ago
2
$begingroup$
And the guy in the left seat was in a similar mentally saturated state and didn't think to hit the left seater's override button to pitch the plane over. He pushed his stick forward a few times but this only gets a 50% input because the two inputs are averaged, unless he overrides, and a 50% input wasn't enough to recover from the low speed mush descent.
$endgroup$
– John K
13 hours ago
1
$begingroup$
The cockpit recorded did record the sound of the audible stall warning for the entire decent, so I would agree that the pilots were in a mental fog and completely did not register what they needed to do.
$endgroup$
– Nelson
7 hours ago
add a comment |
$begingroup$
To be certifiable, airplanes have to have some kind of cues to warn when you are getting close to a stall, and have decent behaviour during the stall, because nobody is perfect. Airplanes with very strong physical cues prior to stall, like the whole airframe shaking, and good behaviour during a stall, like a good natural pitch over tendency with immediate unstalling of the wing, can get away without stall warning and prevention systems.
Transport aircraft with highly loaded wings and high performance airfoils may have poor behaviour before the stall (no buffeting or shaking), and poor recovery performance after, and need a little help. The airfoils used for airplanes that fly at near trans-sonic speeds tend to suffer from this because they tend to stall from the leading edge, at which point the wing stops lifting all at once, and there is often no prior buffeting or shaking.
The earlier supercritical (higher critical mach#) airfoils developed in the 70s were especially bad for this because they developed a flow separation bubble just aft of the leading edge at high angles of attack, due to the profile that was used to manage the formation of shock waves (the Challenger business jet and CRJ200 Regional Jet is typical). You do not want to experience the natural stall on such an aircraft and some kind of system has to be in place as a backup for mishandling of the airplane by the pilot.
For airplanes with mechanical/hydraulic controls, to provide a tactile warning as a substitute or supplement for the airplane shaking (pre-stall buffet), stick shakers are used, which is just a motor with an eccentric weight on the control column. If the post stall behaviour (not much natural pitch over, or worse, settling into an unrecoverable deep stall) is poor, a stick pusher is installed to give the control column a shove just before the natural stall occurs. The stall protection system calculates when to do all this.
Most high performance aircraft use shakers, and some use stick pushers. With FBW, the FBW computers intervene directly within the control loop to achieve the same end without having to shake or push the controls.
answered 20 hours ago
John KJohn K
21.5k13064
$endgroup$
To be certifiable, airplanes have to have some kind of cues to warn when you are getting close to a stall, and have decent behaviour during the stall, because nobody is perfect. Airplanes with very strong physical cues prior to stall, like the whole airframe shaking, and good behaviour during a stall, like a good natural pitch over tendency with immediate unstalling of the wing, can get away without stall warning and prevention systems.
Transport aircraft with highly loaded wings and high performance airfoils may have poor behaviour before the stall (no buffeting or shaking), and poor recovery performance after, and need a little help. The airfoils used for airplanes that fly at near trans-sonic speeds tend to suffer from this because they tend to stall from the leading edge, at which point the wing stops lifting all at once, and there is often no prior buffeting or shaking.
The earlier supercritical (higher critical mach#) airfoils developed in the 70s were especially bad for this because they developed a flow separation bubble just aft of the leading edge at high angles of attack, due to the profile that was used to manage the formation of shock waves (the Challenger business jet and CRJ200 Regional Jet is typical). You do not want to experience the natural stall on such an aircraft and some kind of system has to be in place as a backup for mishandling of the airplane by the pilot.
For airplanes with mechanical/hydraulic controls, to provide a tactile warning as a substitute or supplement for the airplane shaking (pre-stall buffet), stick shakers are used, which is just a motor with an eccentric weight on the control column. If the post stall behaviour (not much natural pitch over, or worse, settling into an unrecoverable deep stall) is poor, a stick pusher is installed to give the control column a shove just before the natural stall occurs. The stall protection system calculates when to do all this.
Most high performance aircraft use shakers, and some use stick pushers. With FBW, the FBW computers intervene directly within the control loop to achieve the same end without having to shake or push the controls.
answered 20 hours ago
John KJohn K
21.5k13064
answered 20 hours ago
John KJohn K
21.5k13064
answered 20 hours ago
John KJohn K
21.5k13064
answered 20 hours ago
John KJohn K
21.5k13064
21.5k13064
$begingroup$
In the Air France 447 accident, the Airbus A330 only had a sound warning, with no physical warning, and the plane was clearly built so that it can't "get away" without a warning. Why is that?
$endgroup$
– gparyani
13 hours ago
2
$begingroup$
The last sentence in my post applies. It's a FBW airplane with side sticks and the computers control the airplane at the margins, only letting the pilot input go so far, with an aural warning when things are getting close, but the computers will simply not allow the pilot to go all the way into an aerodynamic stall. 447 wasn't stalled in the aerodynamic sense on its ride down, it was being held at the maximum attitude the computers would allow, not quite stalled, because the right seater was in a mental fog panic mode holding the right side stick fully aft the entire ride down.
$endgroup$
– John K
13 hours ago
2
$begingroup$
And the guy in the left seat was in a similar mentally saturated state and didn't think to hit the left seater's override button to pitch the plane over. He pushed his stick forward a few times but this only gets a 50% input because the two inputs are averaged, unless he overrides, and a 50% input wasn't enough to recover from the low speed mush descent.
$endgroup$
– John K
13 hours ago
1
$begingroup$
The cockpit recorded did record the sound of the audible stall warning for the entire decent, so I would agree that the pilots were in a mental fog and completely did not register what they needed to do.
$endgroup$
– Nelson
7 hours ago
add a comment |
$begingroup$
In the Air France 447 accident, the Airbus A330 only had a sound warning, with no physical warning, and the plane was clearly built so that it can't "get away" without a warning. Why is that?
$endgroup$
– gparyani
13 hours ago
2
$begingroup$
The last sentence in my post applies. It's a FBW airplane with side sticks and the computers control the airplane at the margins, only letting the pilot input go so far, with an aural warning when things are getting close, but the computers will simply not allow the pilot to go all the way into an aerodynamic stall. 447 wasn't stalled in the aerodynamic sense on its ride down, it was being held at the maximum attitude the computers would allow, not quite stalled, because the right seater was in a mental fog panic mode holding the right side stick fully aft the entire ride down.
$endgroup$
– John K
13 hours ago
2
$begingroup$
And the guy in the left seat was in a similar mentally saturated state and didn't think to hit the left seater's override button to pitch the plane over. He pushed his stick forward a few times but this only gets a 50% input because the two inputs are averaged, unless he overrides, and a 50% input wasn't enough to recover from the low speed mush descent.
$endgroup$
– John K
13 hours ago
1
$begingroup$
The cockpit recorded did record the sound of the audible stall warning for the entire decent, so I would agree that the pilots were in a mental fog and completely did not register what they needed to do.
$endgroup$
– Nelson
7 hours ago
$begingroup$
In the Air France 447 accident, the Airbus A330 only had a sound warning, with no physical warning, and the plane was clearly built so that it can't "get away" without a warning. Why is that?
$endgroup$
– gparyani
13 hours ago
$begingroup$
In the Air France 447 accident, the Airbus A330 only had a sound warning, with no physical warning, and the plane was clearly built so that it can't "get away" without a warning. Why is that?
$endgroup$
– gparyani
13 hours ago
2
2
$begingroup$
The last sentence in my post applies. It's a FBW airplane with side sticks and the computers control the airplane at the margins, only letting the pilot input go so far, with an aural warning when things are getting close, but the computers will simply not allow the pilot to go all the way into an aerodynamic stall. 447 wasn't stalled in the aerodynamic sense on its ride down, it was being held at the maximum attitude the computers would allow, not quite stalled, because the right seater was in a mental fog panic mode holding the right side stick fully aft the entire ride down.
$endgroup$
– John K
13 hours ago
$begingroup$
The last sentence in my post applies. It's a FBW airplane with side sticks and the computers control the airplane at the margins, only letting the pilot input go so far, with an aural warning when things are getting close, but the computers will simply not allow the pilot to go all the way into an aerodynamic stall. 447 wasn't stalled in the aerodynamic sense on its ride down, it was being held at the maximum attitude the computers would allow, not quite stalled, because the right seater was in a mental fog panic mode holding the right side stick fully aft the entire ride down.
$endgroup$
– John K
13 hours ago
2
2
$begingroup$
And the guy in the left seat was in a similar mentally saturated state and didn't think to hit the left seater's override button to pitch the plane over. He pushed his stick forward a few times but this only gets a 50% input because the two inputs are averaged, unless he overrides, and a 50% input wasn't enough to recover from the low speed mush descent.
$endgroup$
– John K
13 hours ago
$begingroup$
And the guy in the left seat was in a similar mentally saturated state and didn't think to hit the left seater's override button to pitch the plane over. He pushed his stick forward a few times but this only gets a 50% input because the two inputs are averaged, unless he overrides, and a 50% input wasn't enough to recover from the low speed mush descent.
$endgroup$
– John K
13 hours ago
1
1
$begingroup$
The cockpit recorded did record the sound of the audible stall warning for the entire decent, so I would agree that the pilots were in a mental fog and completely did not register what they needed to do.
$endgroup$
– Nelson
7 hours ago
$begingroup$
The cockpit recorded did record the sound of the audible stall warning for the entire decent, so I would agree that the pilots were in a mental fog and completely did not register what they needed to do.
$endgroup$
– Nelson
7 hours ago
add a comment |
$begingroup$
Why do car manufacturers install seat belts? Shouldn't licensed drivers be well aware that they should slow down when it's raining or snowing and that they shouldn't run through red lights or stop signs?
- Because accidents happen.
- Because pilots are human and make mistakes.
- Because when you're flying in the clouds with no visual references, it's easy to get confused.
- Because even with stall warning & prevention systems in place, confused pilots will fight the system. AF 447
answered 21 hours ago
FreeManFreeMan
7,3751057125
$endgroup$
$begingroup$
And because even with stall prevention systems, stalls are still a reality. That's how bad it is
$endgroup$
– Hanky Panky
8 hours ago
$begingroup$
To be fair the AF 447's stall prevention were disabled because of incorrect airspeed readings. In contrast, the Lion Air 737 crash was that it didn't get disabled... die if you do, die if you don't...
$endgroup$
– Nelson
7 hours ago
$begingroup$
I believe some planes have a nose wing set at a steeper angle than the main wing, causing the nose to stall first, thus bringing the nose down before a real stall is reached. (See ainonline.com/sites/default/files/uploads/2018/07/… for an example of a nose wing, though I don't know its purpose on the Piaggo.)
$endgroup$
– user3070485
2 hours ago
$begingroup$
@user3070485 that "nose wing" is called a canard, and yes, I believe you're correct. I would imagine that it's still possible to stall a canard winged aircraft, though that would make a good question of its own.
$endgroup$
– FreeMan
2 hours ago
$begingroup$
@FreeMan It is still possible to stall a canard aircraft but most are designed as @ user3070485 mentioned where the canard will stall first. However this becomes a more difficult situation when you introduce leading and trailing edge devices which alter the stall characteristics of the wing. You can get a situation where the canard will stall first under certain configurations and where the wing will stall first under others.
$endgroup$
– DJ319
1 hour ago
add a comment |
$begingroup$
Why do car manufacturers install seat belts? Shouldn't licensed drivers be well aware that they should slow down when it's raining or snowing and that they shouldn't run through red lights or stop signs?
- Because accidents happen.
- Because pilots are human and make mistakes.
- Because when you're flying in the clouds with no visual references, it's easy to get confused.
- Because even with stall warning & prevention systems in place, confused pilots will fight the system. AF 447
answered 21 hours ago
FreeManFreeMan
7,3751057125
$endgroup$
$begingroup$
And because even with stall prevention systems, stalls are still a reality. That's how bad it is
$endgroup$
– Hanky Panky
8 hours ago
$begingroup$
To be fair the AF 447's stall prevention were disabled because of incorrect airspeed readings. In contrast, the Lion Air 737 crash was that it didn't get disabled... die if you do, die if you don't...
$endgroup$
– Nelson
7 hours ago
$begingroup$
I believe some planes have a nose wing set at a steeper angle than the main wing, causing the nose to stall first, thus bringing the nose down before a real stall is reached. (See ainonline.com/sites/default/files/uploads/2018/07/… for an example of a nose wing, though I don't know its purpose on the Piaggo.)
$endgroup$
– user3070485
2 hours ago
$begingroup$
@user3070485 that "nose wing" is called a canard, and yes, I believe you're correct. I would imagine that it's still possible to stall a canard winged aircraft, though that would make a good question of its own.
$endgroup$
– FreeMan
2 hours ago
$begingroup$
@FreeMan It is still possible to stall a canard aircraft but most are designed as @ user3070485 mentioned where the canard will stall first. However this becomes a more difficult situation when you introduce leading and trailing edge devices which alter the stall characteristics of the wing. You can get a situation where the canard will stall first under certain configurations and where the wing will stall first under others.
$endgroup$
– DJ319
1 hour ago
add a comment |
$begingroup$
Why do car manufacturers install seat belts? Shouldn't licensed drivers be well aware that they should slow down when it's raining or snowing and that they shouldn't run through red lights or stop signs?
- Because accidents happen.
- Because pilots are human and make mistakes.
- Because when you're flying in the clouds with no visual references, it's easy to get confused.
- Because even with stall warning & prevention systems in place, confused pilots will fight the system. AF 447
answered 21 hours ago
FreeManFreeMan
7,3751057125
$endgroup$
Why do car manufacturers install seat belts? Shouldn't licensed drivers be well aware that they should slow down when it's raining or snowing and that they shouldn't run through red lights or stop signs?
- Because accidents happen.
- Because pilots are human and make mistakes.
- Because when you're flying in the clouds with no visual references, it's easy to get confused.
- Because even with stall warning & prevention systems in place, confused pilots will fight the system. AF 447
answered 21 hours ago
FreeManFreeMan
7,3751057125
answered 21 hours ago
FreeManFreeMan
7,3751057125
answered 21 hours ago
FreeManFreeMan
7,3751057125
answered 21 hours ago
FreeManFreeMan
7,3751057125
7,3751057125
$begingroup$
And because even with stall prevention systems, stalls are still a reality. That's how bad it is
$endgroup$
– Hanky Panky
8 hours ago
$begingroup$
To be fair the AF 447's stall prevention were disabled because of incorrect airspeed readings. In contrast, the Lion Air 737 crash was that it didn't get disabled... die if you do, die if you don't...
$endgroup$
– Nelson
7 hours ago
$begingroup$
I believe some planes have a nose wing set at a steeper angle than the main wing, causing the nose to stall first, thus bringing the nose down before a real stall is reached. (See ainonline.com/sites/default/files/uploads/2018/07/… for an example of a nose wing, though I don't know its purpose on the Piaggo.)
$endgroup$
– user3070485
2 hours ago
$begingroup$
@user3070485 that "nose wing" is called a canard, and yes, I believe you're correct. I would imagine that it's still possible to stall a canard winged aircraft, though that would make a good question of its own.
$endgroup$
– FreeMan
2 hours ago
$begingroup$
@FreeMan It is still possible to stall a canard aircraft but most are designed as @ user3070485 mentioned where the canard will stall first. However this becomes a more difficult situation when you introduce leading and trailing edge devices which alter the stall characteristics of the wing. You can get a situation where the canard will stall first under certain configurations and where the wing will stall first under others.
$endgroup$
– DJ319
1 hour ago
add a comment |
$begingroup$
And because even with stall prevention systems, stalls are still a reality. That's how bad it is
$endgroup$
– Hanky Panky
8 hours ago
$begingroup$
To be fair the AF 447's stall prevention were disabled because of incorrect airspeed readings. In contrast, the Lion Air 737 crash was that it didn't get disabled... die if you do, die if you don't...
$endgroup$
– Nelson
7 hours ago
$begingroup$
I believe some planes have a nose wing set at a steeper angle than the main wing, causing the nose to stall first, thus bringing the nose down before a real stall is reached. (See ainonline.com/sites/default/files/uploads/2018/07/… for an example of a nose wing, though I don't know its purpose on the Piaggo.)
$endgroup$
– user3070485
2 hours ago
$begingroup$
@user3070485 that "nose wing" is called a canard, and yes, I believe you're correct. I would imagine that it's still possible to stall a canard winged aircraft, though that would make a good question of its own.
$endgroup$
– FreeMan
2 hours ago
$begingroup$
@FreeMan It is still possible to stall a canard aircraft but most are designed as @ user3070485 mentioned where the canard will stall first. However this becomes a more difficult situation when you introduce leading and trailing edge devices which alter the stall characteristics of the wing. You can get a situation where the canard will stall first under certain configurations and where the wing will stall first under others.
$endgroup$
– DJ319
1 hour ago
$begingroup$
And because even with stall prevention systems, stalls are still a reality. That's how bad it is
$endgroup$
– Hanky Panky
8 hours ago
$begingroup$
And because even with stall prevention systems, stalls are still a reality. That's how bad it is
$endgroup$
– Hanky Panky
8 hours ago
$begingroup$
To be fair the AF 447's stall prevention were disabled because of incorrect airspeed readings. In contrast, the Lion Air 737 crash was that it didn't get disabled... die if you do, die if you don't...
$endgroup$
– Nelson
7 hours ago
$begingroup$
To be fair the AF 447's stall prevention were disabled because of incorrect airspeed readings. In contrast, the Lion Air 737 crash was that it didn't get disabled... die if you do, die if you don't...
$endgroup$
– Nelson
7 hours ago
$begingroup$
I believe some planes have a nose wing set at a steeper angle than the main wing, causing the nose to stall first, thus bringing the nose down before a real stall is reached. (See ainonline.com/sites/default/files/uploads/2018/07/… for an example of a nose wing, though I don't know its purpose on the Piaggo.)
$endgroup$
– user3070485
2 hours ago
$begingroup$
I believe some planes have a nose wing set at a steeper angle than the main wing, causing the nose to stall first, thus bringing the nose down before a real stall is reached. (See ainonline.com/sites/default/files/uploads/2018/07/… for an example of a nose wing, though I don't know its purpose on the Piaggo.)
$endgroup$
– user3070485
2 hours ago
$begingroup$
@user3070485 that "nose wing" is called a canard, and yes, I believe you're correct. I would imagine that it's still possible to stall a canard winged aircraft, though that would make a good question of its own.
$endgroup$
– FreeMan
2 hours ago
$begingroup$
@user3070485 that "nose wing" is called a canard, and yes, I believe you're correct. I would imagine that it's still possible to stall a canard winged aircraft, though that would make a good question of its own.
$endgroup$
– FreeMan
2 hours ago
$begingroup$
@FreeMan It is still possible to stall a canard aircraft but most are designed as @ user3070485 mentioned where the canard will stall first. However this becomes a more difficult situation when you introduce leading and trailing edge devices which alter the stall characteristics of the wing. You can get a situation where the canard will stall first under certain configurations and where the wing will stall first under others.
$endgroup$
– DJ319
1 hour ago
$begingroup$
@FreeMan It is still possible to stall a canard aircraft but most are designed as @ user3070485 mentioned where the canard will stall first. However this becomes a more difficult situation when you introduce leading and trailing edge devices which alter the stall characteristics of the wing. You can get a situation where the canard will stall first under certain configurations and where the wing will stall first under others.
$endgroup$
– DJ319
1 hour ago
add a comment |
$begingroup$
You said you understand systems to prevent the airplane from exceeding the flight envelope. Stall is just another boundary of the flight envelope. The rest of the envelope limitations are listed in the flight manual as well. Shouldn't pilots know not to stall the airplane, just as they know not to over-stress it, or exceed other limitations? Of course.
But humans make mistakes, they can get distracted or disoriented. And just as there's little benefit to allowing a pilot to rip the wings off the plane by pitching too fast, there's little benefit from allowing the plane to stall.
Here is a selection of aircraft that have crashed due to stalls.
South Airlines Flight 8971
Air Algérie 5017
AirAsia QZ8501
Thai Airways International flight 261
Vladivostokavia Flight 352
N452DA
Yemenia Airways Flight 626
If stall protection systems are implemented and functioning properly, they can prevent issues. Here are just a few instances where stall protection worked as intended:
GoAir 338
Air France 7662
Jetstar 248
answered 19 hours ago
foootfooot
53.1k17168321
$endgroup$
1
$begingroup$
On the flip size, I'm curious what would have happened to Asiana 214 if it had had a stall prevention system. If I'm remembering correctly, they did stall (or at least very nearly stall) on very short final while trying to make the runway. If a stall prevention system had prevented them from raising the nose, would they have hit the nose on the seawall instead of the tail? That seems like it could have been a bad situation a whole lot worse.
$endgroup$
– reirab
18 hours ago
1
$begingroup$
@reirab True. On the other hand, if you allow the aircraft to run into two limits simultaneously (out of room and out of speed), there is not much anyone can do. You could argue the „opposite“ safety system, too, and say an automatic terrain escape manoeuvre would be fantastic, except with Asiana 214, it could have worsened the stall...
$endgroup$
– Cpt Reynolds
17 hours ago
2
$begingroup$
@CptReynolds Agreed. The root source of the problem was, of course, lack of energy on very short final, which was totally a result of pilot error. But, given that situation, they pretty much had to choose how they were going to crash rather than whether they were going to crash. In that sort of situation, I'd personally prefer a human pilot who can look out the window and make rapid judgments based on the exact situation in control. It's just not the sort of thing that's easy to account for when you're designing a computer program.
$endgroup$
– reirab
17 hours ago
$begingroup$
I suggest to add Colgan 3407 to the list.
$endgroup$
– Martin Argerami
3 hours ago
add a comment |
$begingroup$
You said you understand systems to prevent the airplane from exceeding the flight envelope. Stall is just another boundary of the flight envelope. The rest of the envelope limitations are listed in the flight manual as well. Shouldn't pilots know not to stall the airplane, just as they know not to over-stress it, or exceed other limitations? Of course.
But humans make mistakes, they can get distracted or disoriented. And just as there's little benefit to allowing a pilot to rip the wings off the plane by pitching too fast, there's little benefit from allowing the plane to stall.
Here is a selection of aircraft that have crashed due to stalls.
South Airlines Flight 8971
Air Algérie 5017
AirAsia QZ8501
Thai Airways International flight 261
Vladivostokavia Flight 352
N452DA
Yemenia Airways Flight 626
If stall protection systems are implemented and functioning properly, they can prevent issues. Here are just a few instances where stall protection worked as intended:
GoAir 338
Air France 7662
Jetstar 248
answered 19 hours ago
foootfooot
53.1k17168321
$endgroup$
1
$begingroup$
On the flip size, I'm curious what would have happened to Asiana 214 if it had had a stall prevention system. If I'm remembering correctly, they did stall (or at least very nearly stall) on very short final while trying to make the runway. If a stall prevention system had prevented them from raising the nose, would they have hit the nose on the seawall instead of the tail? That seems like it could have been a bad situation a whole lot worse.
$endgroup$
– reirab
18 hours ago
1
$begingroup$
@reirab True. On the other hand, if you allow the aircraft to run into two limits simultaneously (out of room and out of speed), there is not much anyone can do. You could argue the „opposite“ safety system, too, and say an automatic terrain escape manoeuvre would be fantastic, except with Asiana 214, it could have worsened the stall...
$endgroup$
– Cpt Reynolds
17 hours ago
2
$begingroup$
@CptReynolds Agreed. The root source of the problem was, of course, lack of energy on very short final, which was totally a result of pilot error. But, given that situation, they pretty much had to choose how they were going to crash rather than whether they were going to crash. In that sort of situation, I'd personally prefer a human pilot who can look out the window and make rapid judgments based on the exact situation in control. It's just not the sort of thing that's easy to account for when you're designing a computer program.
$endgroup$
– reirab
17 hours ago
$begingroup$
I suggest to add Colgan 3407 to the list.
$endgroup$
– Martin Argerami
3 hours ago
add a comment |
$begingroup$
You said you understand systems to prevent the airplane from exceeding the flight envelope. Stall is just another boundary of the flight envelope. The rest of the envelope limitations are listed in the flight manual as well. Shouldn't pilots know not to stall the airplane, just as they know not to over-stress it, or exceed other limitations? Of course.
But humans make mistakes, they can get distracted or disoriented. And just as there's little benefit to allowing a pilot to rip the wings off the plane by pitching too fast, there's little benefit from allowing the plane to stall.
Here is a selection of aircraft that have crashed due to stalls.
South Airlines Flight 8971
Air Algérie 5017
AirAsia QZ8501
Thai Airways International flight 261
Vladivostokavia Flight 352
N452DA
Yemenia Airways Flight 626
If stall protection systems are implemented and functioning properly, they can prevent issues. Here are just a few instances where stall protection worked as intended:
GoAir 338
Air France 7662
Jetstar 248
answered 19 hours ago
foootfooot
53.1k17168321
$endgroup$
You said you understand systems to prevent the airplane from exceeding the flight envelope. Stall is just another boundary of the flight envelope. The rest of the envelope limitations are listed in the flight manual as well. Shouldn't pilots know not to stall the airplane, just as they know not to over-stress it, or exceed other limitations? Of course.
But humans make mistakes, they can get distracted or disoriented. And just as there's little benefit to allowing a pilot to rip the wings off the plane by pitching too fast, there's little benefit from allowing the plane to stall.
Here is a selection of aircraft that have crashed due to stalls.
South Airlines Flight 8971
Air Algérie 5017
AirAsia QZ8501
Thai Airways International flight 261
Vladivostokavia Flight 352
N452DA
Yemenia Airways Flight 626
If stall protection systems are implemented and functioning properly, they can prevent issues. Here are just a few instances where stall protection worked as intended:
GoAir 338
Air France 7662
Jetstar 248
answered 19 hours ago
foootfooot
53.1k17168321
answered 19 hours ago
foootfooot
53.1k17168321
answered 19 hours ago
foootfooot
53.1k17168321
answered 19 hours ago
foootfooot
53.1k17168321
53.1k17168321
1
$begingroup$
On the flip size, I'm curious what would have happened to Asiana 214 if it had had a stall prevention system. If I'm remembering correctly, they did stall (or at least very nearly stall) on very short final while trying to make the runway. If a stall prevention system had prevented them from raising the nose, would they have hit the nose on the seawall instead of the tail? That seems like it could have been a bad situation a whole lot worse.
$endgroup$
– reirab
18 hours ago
1
$begingroup$
@reirab True. On the other hand, if you allow the aircraft to run into two limits simultaneously (out of room and out of speed), there is not much anyone can do. You could argue the „opposite“ safety system, too, and say an automatic terrain escape manoeuvre would be fantastic, except with Asiana 214, it could have worsened the stall...
$endgroup$
– Cpt Reynolds
17 hours ago
2
$begingroup$
@CptReynolds Agreed. The root source of the problem was, of course, lack of energy on very short final, which was totally a result of pilot error. But, given that situation, they pretty much had to choose how they were going to crash rather than whether they were going to crash. In that sort of situation, I'd personally prefer a human pilot who can look out the window and make rapid judgments based on the exact situation in control. It's just not the sort of thing that's easy to account for when you're designing a computer program.
$endgroup$
– reirab
17 hours ago
$begingroup$
I suggest to add Colgan 3407 to the list.
$endgroup$
– Martin Argerami
3 hours ago
add a comment |
1
$begingroup$
On the flip size, I'm curious what would have happened to Asiana 214 if it had had a stall prevention system. If I'm remembering correctly, they did stall (or at least very nearly stall) on very short final while trying to make the runway. If a stall prevention system had prevented them from raising the nose, would they have hit the nose on the seawall instead of the tail? That seems like it could have been a bad situation a whole lot worse.
$endgroup$
– reirab
18 hours ago
1
$begingroup$
@reirab True. On the other hand, if you allow the aircraft to run into two limits simultaneously (out of room and out of speed), there is not much anyone can do. You could argue the „opposite“ safety system, too, and say an automatic terrain escape manoeuvre would be fantastic, except with Asiana 214, it could have worsened the stall...
$endgroup$
– Cpt Reynolds
17 hours ago
2
$begingroup$
@CptReynolds Agreed. The root source of the problem was, of course, lack of energy on very short final, which was totally a result of pilot error. But, given that situation, they pretty much had to choose how they were going to crash rather than whether they were going to crash. In that sort of situation, I'd personally prefer a human pilot who can look out the window and make rapid judgments based on the exact situation in control. It's just not the sort of thing that's easy to account for when you're designing a computer program.
$endgroup$
– reirab
17 hours ago
$begingroup$
I suggest to add Colgan 3407 to the list.
$endgroup$
– Martin Argerami
3 hours ago
1
1
$begingroup$
On the flip size, I'm curious what would have happened to Asiana 214 if it had had a stall prevention system. If I'm remembering correctly, they did stall (or at least very nearly stall) on very short final while trying to make the runway. If a stall prevention system had prevented them from raising the nose, would they have hit the nose on the seawall instead of the tail? That seems like it could have been a bad situation a whole lot worse.
$endgroup$
– reirab
18 hours ago
$begingroup$
On the flip size, I'm curious what would have happened to Asiana 214 if it had had a stall prevention system. If I'm remembering correctly, they did stall (or at least very nearly stall) on very short final while trying to make the runway. If a stall prevention system had prevented them from raising the nose, would they have hit the nose on the seawall instead of the tail? That seems like it could have been a bad situation a whole lot worse.
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– reirab
18 hours ago
1
1
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@reirab True. On the other hand, if you allow the aircraft to run into two limits simultaneously (out of room and out of speed), there is not much anyone can do. You could argue the „opposite“ safety system, too, and say an automatic terrain escape manoeuvre would be fantastic, except with Asiana 214, it could have worsened the stall...
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– Cpt Reynolds
17 hours ago
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@reirab True. On the other hand, if you allow the aircraft to run into two limits simultaneously (out of room and out of speed), there is not much anyone can do. You could argue the „opposite“ safety system, too, and say an automatic terrain escape manoeuvre would be fantastic, except with Asiana 214, it could have worsened the stall...
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– Cpt Reynolds
17 hours ago
2
2
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@CptReynolds Agreed. The root source of the problem was, of course, lack of energy on very short final, which was totally a result of pilot error. But, given that situation, they pretty much had to choose how they were going to crash rather than whether they were going to crash. In that sort of situation, I'd personally prefer a human pilot who can look out the window and make rapid judgments based on the exact situation in control. It's just not the sort of thing that's easy to account for when you're designing a computer program.
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– reirab
17 hours ago
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@CptReynolds Agreed. The root source of the problem was, of course, lack of energy on very short final, which was totally a result of pilot error. But, given that situation, they pretty much had to choose how they were going to crash rather than whether they were going to crash. In that sort of situation, I'd personally prefer a human pilot who can look out the window and make rapid judgments based on the exact situation in control. It's just not the sort of thing that's easy to account for when you're designing a computer program.
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– reirab
17 hours ago
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I suggest to add Colgan 3407 to the list.
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– Martin Argerami
3 hours ago
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I suggest to add Colgan 3407 to the list.
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– Martin Argerami
3 hours ago
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$begingroup$
This isn't as simple as it sounds, and AF447 really set this in motion for the industry. The problem is that at differing altitudes your AoA between "flying" and "stall" can be extremely narrow. Couple that in with no visual references and a pilot may not know that the aircraft is stalling...
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– Ron Beyer
21 hours ago
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Be aware, especially on the more advanced, larger aircraft, although the anti-stall systems do pull and act largely on their own against pilot input, 20lb's of force is roughly the industry standard (I believe from personal experience) to override this.
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– Jihyun
19 hours ago
7
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@RonBeyer AF447 had such a system, but it had been disabled due to erroneous airspeed readings when the pitot tubes iced. If anything, AF447 is something of a cautionary tale of pilots becoming too reliant on such systems instead of knowing how to fly the airplane themselves.
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– reirab
18 hours ago