Why do gliders have bungee cords in the control systems and what do they do? Are they on all control surfaces? What about ultralights?What are the pros and cons of having canard control surfaces versus a horizontal tail control surface?What is the purpose of these odd “control surfaces” on the BAE Taranis?Why are trailing-edge control surfaces usually split?Does the size of control surfaces affect maneuverability, and if they are smaller, is it easier to stall?Do modern airplane controls provide force feedback of external forces on the control surfaces?What are the disadvantages of having vortex generators?What are the disadvantages of using just rudder to roll an airplane?Is aerodynamic flutter speed dependent?What are the takeoff and landing distances of motor gliders?
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Why do gliders have bungee cords in the control systems and what do they do? Are they on all control surfaces? What about ultralights?
What are the pros and cons of having canard control surfaces versus a horizontal tail control surface?What is the purpose of these odd “control surfaces” on the BAE Taranis?Why are trailing-edge control surfaces usually split?Does the size of control surfaces affect maneuverability, and if they are smaller, is it easier to stall?Do modern airplane controls provide force feedback of external forces on the control surfaces?What are the disadvantages of having vortex generators?What are the disadvantages of using just rudder to roll an airplane?Is aerodynamic flutter speed dependent?What are the takeoff and landing distances of motor gliders?
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$begingroup$
Why do gliders have bungee cords in the control systems and what do they do?
Are they on all control surfaces?
Why don't ultralights have them?
glider ultralight control-surfaces
edited 3 hours ago
Sean
8,3824 gold badges43 silver badges111 bronze badges
asked 8 hours ago
FredFred
3851 silver badge7 bronze badges
$endgroup$
add a comment |
$begingroup$
Why do gliders have bungee cords in the control systems and what do they do?
Are they on all control surfaces?
Why don't ultralights have them?
glider ultralight control-surfaces
edited 3 hours ago
Sean
8,3824 gold badges43 silver badges111 bronze badges
asked 8 hours ago
FredFred
3851 silver badge7 bronze badges
$endgroup$
3
$begingroup$
Could you add some more information about what you mean by bungee? A quick Google search finds Bungee Launch and Bungee Springs for trimming.
$endgroup$
– Bianfable
8 hours ago
add a comment |
$begingroup$
Why do gliders have bungee cords in the control systems and what do they do?
Are they on all control surfaces?
Why don't ultralights have them?
glider ultralight control-surfaces
edited 3 hours ago
Sean
8,3824 gold badges43 silver badges111 bronze badges
asked 8 hours ago
FredFred
3851 silver badge7 bronze badges
$endgroup$
Why do gliders have bungee cords in the control systems and what do they do?
Are they on all control surfaces?
Why don't ultralights have them?
glider ultralight control-surfaces
glider ultralight control-surfaces
edited 3 hours ago
Sean
8,3824 gold badges43 silver badges111 bronze badges
asked 8 hours ago
FredFred
3851 silver badge7 bronze badges
edited 3 hours ago
Sean
8,3824 gold badges43 silver badges111 bronze badges
asked 8 hours ago
FredFred
3851 silver badge7 bronze badges
edited 3 hours ago
Sean
8,3824 gold badges43 silver badges111 bronze badges
edited 3 hours ago
Sean
8,3824 gold badges43 silver badges111 bronze badges
edited 3 hours ago
Sean
8,3824 gold badges43 silver badges111 bronze badges
8,3824 gold badges43 silver badges111 bronze badges
asked 8 hours ago
FredFred
3851 silver badge7 bronze badges
asked 8 hours ago
FredFred
3851 silver badge7 bronze badges
asked 8 hours ago
FredFred
3851 silver badge7 bronze badges
3851 silver badge7 bronze badges
3
$begingroup$
Could you add some more information about what you mean by bungee? A quick Google search finds Bungee Launch and Bungee Springs for trimming.
$endgroup$
– Bianfable
8 hours ago
add a comment |
3
$begingroup$
Could you add some more information about what you mean by bungee? A quick Google search finds Bungee Launch and Bungee Springs for trimming.
$endgroup$
– Bianfable
8 hours ago
3
3
$begingroup$
Could you add some more information about what you mean by bungee? A quick Google search finds Bungee Launch and Bungee Springs for trimming.
$endgroup$
– Bianfable
8 hours ago
$begingroup$
Could you add some more information about what you mean by bungee? A quick Google search finds Bungee Launch and Bungee Springs for trimming.
$endgroup$
– Bianfable
8 hours ago
add a comment |
1 Answer
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$begingroup$
The bungee is just a bidirectional spring that tends to hold the elevator at position x, and if you move the stick you are stretching the spring in one direction or the other. They are used in the elevator control circuit to provide an adjustable centering force for trim purposes, and on gliders with all flying tails, a measure of stick free static stability (you don't get a lot - many gliders are mildly divergent in pitch if you aren't holding the stick, but this isn't a big deal since you are almost never flying hands off). The glider's pitch trim control adjusts the "at rest" or relaxed position of the spring so it will tend to fix the elevator at this position or that unless overcome by a control input.
Normally you would have a trim tab on an elevator/stabilizer tail or a trim/anti-servo tab on an all flying tail, as regular airplanes do to provide speed-seeking trim and strong stick-free stability, but gliders operate with much lower loading and forces on the tail and can get away with a bungee spring that acts like a little man under the floor pushing on the stick, this way or that to try to hold it at a given position, so you don't have to. This does away with all the linkage, tab surface etc, which is a big deal when you are shooting for a 40:1 or more L/D.
You can put bungees in any control circuit if you want to be able to trim it with an adjustable centering force, or want to increase the forces. Some light aircraft use bungee springs in the rudder control circuit to provide rudder trim. The spring just replaces your foot by exerting a spring force so you don't have to. The downside is the spring loads are present when you move the controls out of the trimmed position, adding to the perceived rudder forces when maneuvering.
I'm pretty sure there are ultralights out there that use elevator bungees for trim purposes instead of a tab. However, driving the surface directly aerodynamically using a tab on the surface provides a more sensitive and robust solution and if I was designing an ultralight, where drag isn't that big a consideration, I'd use a tab for the elevator, and perhaps a bungee in the rudder and aileron circuits if I wanted rudder and roll trim.
answered 7 hours ago
John KJohn K
39k1 gold badge69 silver badges132 bronze badges
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The bungee is just a bidirectional spring that tends to hold the elevator at position x, and if you move the stick you are stretching the spring in one direction or the other. They are used in the elevator control circuit to provide an adjustable centering force for trim purposes, and on gliders with all flying tails, a measure of stick free static stability (you don't get a lot - many gliders are mildly divergent in pitch if you aren't holding the stick, but this isn't a big deal since you are almost never flying hands off). The glider's pitch trim control adjusts the "at rest" or relaxed position of the spring so it will tend to fix the elevator at this position or that unless overcome by a control input.
Normally you would have a trim tab on an elevator/stabilizer tail or a trim/anti-servo tab on an all flying tail, as regular airplanes do to provide speed-seeking trim and strong stick-free stability, but gliders operate with much lower loading and forces on the tail and can get away with a bungee spring that acts like a little man under the floor pushing on the stick, this way or that to try to hold it at a given position, so you don't have to. This does away with all the linkage, tab surface etc, which is a big deal when you are shooting for a 40:1 or more L/D.
You can put bungees in any control circuit if you want to be able to trim it with an adjustable centering force, or want to increase the forces. Some light aircraft use bungee springs in the rudder control circuit to provide rudder trim. The spring just replaces your foot by exerting a spring force so you don't have to. The downside is the spring loads are present when you move the controls out of the trimmed position, adding to the perceived rudder forces when maneuvering.
I'm pretty sure there are ultralights out there that use elevator bungees for trim purposes instead of a tab. However, driving the surface directly aerodynamically using a tab on the surface provides a more sensitive and robust solution and if I was designing an ultralight, where drag isn't that big a consideration, I'd use a tab for the elevator, and perhaps a bungee in the rudder and aileron circuits if I wanted rudder and roll trim.
answered 7 hours ago
John KJohn K
39k1 gold badge69 silver badges132 bronze badges
$endgroup$
add a comment |
$begingroup$
The bungee is just a bidirectional spring that tends to hold the elevator at position x, and if you move the stick you are stretching the spring in one direction or the other. They are used in the elevator control circuit to provide an adjustable centering force for trim purposes, and on gliders with all flying tails, a measure of stick free static stability (you don't get a lot - many gliders are mildly divergent in pitch if you aren't holding the stick, but this isn't a big deal since you are almost never flying hands off). The glider's pitch trim control adjusts the "at rest" or relaxed position of the spring so it will tend to fix the elevator at this position or that unless overcome by a control input.
Normally you would have a trim tab on an elevator/stabilizer tail or a trim/anti-servo tab on an all flying tail, as regular airplanes do to provide speed-seeking trim and strong stick-free stability, but gliders operate with much lower loading and forces on the tail and can get away with a bungee spring that acts like a little man under the floor pushing on the stick, this way or that to try to hold it at a given position, so you don't have to. This does away with all the linkage, tab surface etc, which is a big deal when you are shooting for a 40:1 or more L/D.
You can put bungees in any control circuit if you want to be able to trim it with an adjustable centering force, or want to increase the forces. Some light aircraft use bungee springs in the rudder control circuit to provide rudder trim. The spring just replaces your foot by exerting a spring force so you don't have to. The downside is the spring loads are present when you move the controls out of the trimmed position, adding to the perceived rudder forces when maneuvering.
I'm pretty sure there are ultralights out there that use elevator bungees for trim purposes instead of a tab. However, driving the surface directly aerodynamically using a tab on the surface provides a more sensitive and robust solution and if I was designing an ultralight, where drag isn't that big a consideration, I'd use a tab for the elevator, and perhaps a bungee in the rudder and aileron circuits if I wanted rudder and roll trim.
answered 7 hours ago
John KJohn K
39k1 gold badge69 silver badges132 bronze badges
$endgroup$
add a comment |
$begingroup$
The bungee is just a bidirectional spring that tends to hold the elevator at position x, and if you move the stick you are stretching the spring in one direction or the other. They are used in the elevator control circuit to provide an adjustable centering force for trim purposes, and on gliders with all flying tails, a measure of stick free static stability (you don't get a lot - many gliders are mildly divergent in pitch if you aren't holding the stick, but this isn't a big deal since you are almost never flying hands off). The glider's pitch trim control adjusts the "at rest" or relaxed position of the spring so it will tend to fix the elevator at this position or that unless overcome by a control input.
Normally you would have a trim tab on an elevator/stabilizer tail or a trim/anti-servo tab on an all flying tail, as regular airplanes do to provide speed-seeking trim and strong stick-free stability, but gliders operate with much lower loading and forces on the tail and can get away with a bungee spring that acts like a little man under the floor pushing on the stick, this way or that to try to hold it at a given position, so you don't have to. This does away with all the linkage, tab surface etc, which is a big deal when you are shooting for a 40:1 or more L/D.
You can put bungees in any control circuit if you want to be able to trim it with an adjustable centering force, or want to increase the forces. Some light aircraft use bungee springs in the rudder control circuit to provide rudder trim. The spring just replaces your foot by exerting a spring force so you don't have to. The downside is the spring loads are present when you move the controls out of the trimmed position, adding to the perceived rudder forces when maneuvering.
I'm pretty sure there are ultralights out there that use elevator bungees for trim purposes instead of a tab. However, driving the surface directly aerodynamically using a tab on the surface provides a more sensitive and robust solution and if I was designing an ultralight, where drag isn't that big a consideration, I'd use a tab for the elevator, and perhaps a bungee in the rudder and aileron circuits if I wanted rudder and roll trim.
answered 7 hours ago
John KJohn K
39k1 gold badge69 silver badges132 bronze badges
$endgroup$
The bungee is just a bidirectional spring that tends to hold the elevator at position x, and if you move the stick you are stretching the spring in one direction or the other. They are used in the elevator control circuit to provide an adjustable centering force for trim purposes, and on gliders with all flying tails, a measure of stick free static stability (you don't get a lot - many gliders are mildly divergent in pitch if you aren't holding the stick, but this isn't a big deal since you are almost never flying hands off). The glider's pitch trim control adjusts the "at rest" or relaxed position of the spring so it will tend to fix the elevator at this position or that unless overcome by a control input.
Normally you would have a trim tab on an elevator/stabilizer tail or a trim/anti-servo tab on an all flying tail, as regular airplanes do to provide speed-seeking trim and strong stick-free stability, but gliders operate with much lower loading and forces on the tail and can get away with a bungee spring that acts like a little man under the floor pushing on the stick, this way or that to try to hold it at a given position, so you don't have to. This does away with all the linkage, tab surface etc, which is a big deal when you are shooting for a 40:1 or more L/D.
You can put bungees in any control circuit if you want to be able to trim it with an adjustable centering force, or want to increase the forces. Some light aircraft use bungee springs in the rudder control circuit to provide rudder trim. The spring just replaces your foot by exerting a spring force so you don't have to. The downside is the spring loads are present when you move the controls out of the trimmed position, adding to the perceived rudder forces when maneuvering.
I'm pretty sure there are ultralights out there that use elevator bungees for trim purposes instead of a tab. However, driving the surface directly aerodynamically using a tab on the surface provides a more sensitive and robust solution and if I was designing an ultralight, where drag isn't that big a consideration, I'd use a tab for the elevator, and perhaps a bungee in the rudder and aileron circuits if I wanted rudder and roll trim.
answered 7 hours ago
John KJohn K
39k1 gold badge69 silver badges132 bronze badges
answered 7 hours ago
John KJohn K
39k1 gold badge69 silver badges132 bronze badges
answered 7 hours ago
John KJohn K
39k1 gold badge69 silver badges132 bronze badges
answered 7 hours ago
John KJohn K
39k1 gold badge69 silver badges132 bronze badges
39k1 gold badge69 silver badges132 bronze badges
add a comment |
add a comment |
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Could you add some more information about what you mean by bungee? A quick Google search finds Bungee Launch and Bungee Springs for trimming.
$endgroup$
– Bianfable
8 hours ago