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 1 hour ago
rclocher3rclocher3
22517
$endgroup$
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 1 hour ago
rclocher3rclocher3
22517
$endgroup$
$begingroup$
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
1 hour 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 1 hour ago
rclocher3rclocher3
22517
$endgroup$
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 1 hour ago
rclocher3rclocher3
22517
asked 1 hour ago
rclocher3rclocher3
22517
asked 1 hour ago
rclocher3rclocher3
22517
asked 1 hour ago
rclocher3rclocher3
22517
asked 1 hour ago
rclocher3rclocher3
22517
22517
$begingroup$
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
1 hour ago
add a comment |
$begingroup$
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
1 hour 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
1 hour 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
1 hour ago
add a comment |
2 Answers
2
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 28 mins ago
John KJohn K
21.2k13063
$endgroup$
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 59 mins ago
FreeManFreeMan
7,2101057124
$endgroup$
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
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 28 mins ago
John KJohn K
21.2k13063
$endgroup$
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 28 mins ago
John KJohn K
21.2k13063
$endgroup$
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 28 mins ago
John KJohn K
21.2k13063
$endgroup$
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 28 mins ago
John KJohn K
21.2k13063
answered 28 mins ago
John KJohn K
21.2k13063
answered 28 mins ago
John KJohn K
21.2k13063
answered 28 mins ago
John KJohn K
21.2k13063
21.2k13063
add a comment |
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 59 mins ago
FreeManFreeMan
7,2101057124
$endgroup$
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 59 mins ago
FreeManFreeMan
7,2101057124
$endgroup$
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 59 mins ago
FreeManFreeMan
7,2101057124
$endgroup$
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 59 mins ago
FreeManFreeMan
7,2101057124
answered 59 mins ago
FreeManFreeMan
7,2101057124
answered 59 mins ago
FreeManFreeMan
7,2101057124
answered 59 mins ago
FreeManFreeMan
7,2101057124
7,2101057124
add a comment |
add a comment |
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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...
$endgroup$
– Ron Beyer
1 hour ago