do ailerons provide lift?
01-11-2013, 08:33 PM
#51
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RE: do ailerons provide lift?
But hey I only have a little over 15,000 hours of flight time. What would I know. 
That makes two of us. 
I'll muddy the waters. Ailerons change the camber of the wing which, when carried beyond a certain point, does spoil lift. I will agree the AOA changes also, so they go hand-in-hand.
I flew a Robertson STOL (short take-off and landing) Cessna 421 many years ago (thing nearly killed us one day, but that's another story), which had flaperons (!) and Fowler flaps. Ailerons were longer, thinner, and drooped with the first 5-degrees of flap. The first flap movement went straight aft about 20" and, when coupled with the drooped ailerons, added area (flaps) to the wing, and changed the camber (ailerons).
I think this horse is startin' to whinny (we've about beat it to death!). [8D]
01-11-2013, 08:38 PM
#52
RE: do ailerons provide lift?
ORIGINAL: eddieC
But hey I only have a little over 15,000 hours of flight time. What would I know. [img][/img]
That makes two of us.
I'll muddy the waters. Ailerons change the camber of the wing which, when carried beyond a certain point, does spoil lift. I will agree the AOA changes also, so they go hand-in-hand.
I flew a Robertson STOL (short take-off and landing) Cessna 421 many years ago (thing nearly killed us one day, but that's another story), which had flaperons (!) and Fowler flaps. Ailerons were longer, thinner, and drooped with the first 5-degrees of flap. The first flap movement went straight aft about 20'' and, when coupled with the drooped ailerons, added area (flaps) to the wing, and changed the camber (ailerons).
I think this horse is startin' to whinny (we've about beat it to death!). [8D]
NOW we can take it a step further and interject the MU-2 and Beechjet into the equation. They have no ailerons at all.
01-11-2013, 08:50 PM
#53
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RE: do ailerons provide lift?
ORIGINAL: sensei
Lets see here, it's about the aileron not the wing ha, try to get your head wrapped this, the aileron in fact becomes part of the wing, adding the aileron adds wing area and adding wing area adds lift.
Bob
ORIGINAL: brockettman
Probably won't work without a wing... It's about the aileron not the wing. Doesn't there have to be some kind of taper or airfoil to create a difference in air pressure? The variation in the tapered aileron might be miniscule, but it still matters, doesn't it?
OOPS! now I'm part of the fire drill!
Ben
Probably won't work without a wing...
It's about the aileron not the wing. Doesn't there have to be some kind of taper or airfoil to create a difference in air pressure? The variation in the tapered aileron might be miniscule, but it still matters, doesn't it?OOPS! now I'm part of the fire drill!
Ben
Bob
01-11-2013, 08:53 PM
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RE: do ailerons provide lift?
ORIGINAL: eddieC
Doesn't there have to be some kind of taper or airfoil to create a difference in air pressure? The variation in the tapered aileron might be miniscule, but it still matters, doesn't it?
If that were true, our flat-plate foamies and aircraft with symmetrical airfoils wouldn't fly. Fortunately they never got that memo. Bernoulli isn't everything. Angle of attack also has to be figured in. It's a combination of both.
Bernoulli isn't everything. Angle of attack also has to be figured in. It's a combination of both.
01-11-2013, 09:11 PM
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RE: do ailerons provide lift?
NOW we can take it a step further and interject the MU-2 and Beechjet into the equation. They have no ailerons at all.
[8D] And they're both scary, well, the MU-2 is!
Let's not forget some airliners that use ailerons and spoilers. And some Boeings where the whole wing looks like a Transformer on landing, the whole front & back shape-shift. [X(]
01-12-2013, 12:34 AM
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RE: do ailerons provide lift?
What are the leading-edge devices called? I always thought they were slats.
The Stinson 108 had slots, and the C177 Cardinal had them on the tail.
01-12-2013, 03:24 AM
#58
RE: do ailerons provide lift?
IMO ailerons will provide lift only if they are part of the airfoil of the wing, the chord would be then from the leading edge of the wing to the trailing edge of the aileron.
If the ailerons are flat with no airfoil profile (as on some sports planes and fun fly's), the chord would then be from the leading edge of the wing to the hinge line as the aileron being parallel top and bottom would provide no lift.
When the ailerons are deflected, they alter the direction of airflow which causes the plane to roll. The reason the plane loses altitude is because the lift from the wing is no longer acting directly upwards but at an angle and their isn't sufficient lift acting upwards to maintain altitude. To turn, elevator must be applied which again, alters the direction of airflow moving the tail of the plane which in turn changes the direction of the plane. To prevent loss of altitude the elevator must be applied between the wings being level and at 90 degrees.
The stab will contribute very little to lift in most cases as the majority of models do not have airfoil sections on the stab. The stab/elevator and fin/rudder are primarily to steer the plane.
It was mentioned in an earlier post that if the model pulls to the canopy or belly in a vertical climb, adjust the ailerons up or down to achieve a straight vertical. This would most likely work, but the correct fix is to adjust down thrust on the engine.
If the ailerons are flat with no airfoil profile (as on some sports planes and fun fly's), the chord would then be from the leading edge of the wing to the hinge line as the aileron being parallel top and bottom would provide no lift.
When the ailerons are deflected, they alter the direction of airflow which causes the plane to roll. The reason the plane loses altitude is because the lift from the wing is no longer acting directly upwards but at an angle and their isn't sufficient lift acting upwards to maintain altitude. To turn, elevator must be applied which again, alters the direction of airflow moving the tail of the plane which in turn changes the direction of the plane. To prevent loss of altitude the elevator must be applied between the wings being level and at 90 degrees.
The stab will contribute very little to lift in most cases as the majority of models do not have airfoil sections on the stab. The stab/elevator and fin/rudder are primarily to steer the plane.
It was mentioned in an earlier post that if the model pulls to the canopy or belly in a vertical climb, adjust the ailerons up or down to achieve a straight vertical. This would most likely work, but the correct fix is to adjust down thrust on the engine.
01-12-2013, 05:12 AM
#59
RE: do ailerons provide lift?
ORIGINAL: eddieC
What are the leading-edge devices called? I always thought they were slats.
What are the leading-edge devices called? I always thought they were slats.
The Stinson 108 had slots, and the C177 Cardinal had them on the tail.
Bob
01-12-2013, 06:02 AM
#60
RE: do ailerons provide lift?
ORIGINAL: drac1
IMO ailerons will provide lift only if they are part of the airfoil of the wing, the chord would be then from the leading edge of the wing to the trailing edge of the aileron.
If the ailerons are flat with no airfoil profile (as on some sports planes and fun fly's), the chord would then be from the leading edge of the wing to the hinge line as the aileron being parallel top and bottom would provide no lift.
When the ailerons are deflected, they alter the direction of airflow which causes the plane to roll. The reason the plane loses altitude is because the lift from the wing is no longer acting directly upwards but at an angle and their isn't sufficient lift acting upwards to maintain altitude. To turn, elevator must be applied which again, alters the direction of airflow moving the tail of the plane which in turn changes the direction of the plane. To prevent loss of altitude the elevator must be applied between the wings being level and at 90 degrees.
The stab will contribute very little to lift in most cases as the majority of models do not have airfoil sections on the stab. The stab/elevator and fin/rudder are primarily to steer the plane.
It was mentioned in an earlier post that if the model pulls to the canopy or belly in a vertical climb, adjust the ailerons up or down to achieve a straight vertical. This would most likely work, but the correct fix is to adjust down thrust on the engine.
IMO ailerons will provide lift only if they are part of the airfoil of the wing, the chord would be then from the leading edge of the wing to the trailing edge of the aileron.
If the ailerons are flat with no airfoil profile (as on some sports planes and fun fly's), the chord would then be from the leading edge of the wing to the hinge line as the aileron being parallel top and bottom would provide no lift.
When the ailerons are deflected, they alter the direction of airflow which causes the plane to roll. The reason the plane loses altitude is because the lift from the wing is no longer acting directly upwards but at an angle and their isn't sufficient lift acting upwards to maintain altitude. To turn, elevator must be applied which again, alters the direction of airflow moving the tail of the plane which in turn changes the direction of the plane. To prevent loss of altitude the elevator must be applied between the wings being level and at 90 degrees.
The stab will contribute very little to lift in most cases as the majority of models do not have airfoil sections on the stab. The stab/elevator and fin/rudder are primarily to steer the plane.
It was mentioned in an earlier post that if the model pulls to the canopy or belly in a vertical climb, adjust the ailerons up or down to achieve a straight vertical. This would most likely work, but the correct fix is to adjust down thrust on the engine.
Bob
01-12-2013, 06:10 AM
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RE: do ailerons provide lift?
Hi!
Come on! It does'nt mean a thing what the ailerons look like...as long as they are firmly in place on the wing...they add lift! Simple as that!!!!
Come on! It does'nt mean a thing what the ailerons look like...as long as they are firmly in place on the wing...they add lift! Simple as that!!!!
01-12-2013, 07:14 AM
#62
RE: do ailerons provide lift?
IMHO, the discussion should not spin about removing or not the ailerons to prove their lifting capabilities.
Ailerons modify the lift for the section of the span that they cover by modifying the camber of the airfoil: higher camber = higher coefficient of lift (CL) = more lift = more drag.
In essence, they work on the same principle of the simplest flaps, only that for what they do, less variation of lift is needed.
Copied from http://www.americanflyers.net/aviati.../chapter_4.htm
"Ailerons control roll about the longitudinal axis. The ailerons are attached to the outboard trailing edge of each wing and move in the opposite direction from each other. Ailerons are connected by cables, bellcranks, pulleys or push-pull tubes to each other and to the control wheel.
Moving the control wheel to the right causes the right aileron to deflect upward and the left aileron to deflect downward. The upward deflection of the right aileron decreases the camber resulting in decreased lift on the right wing. The corresponding downward deflection of the left aileron increases the camber resulting in increased lift on the left wing. Thus, the increased lift on the left wing and the decreased lift on the right wing causes the airplane to roll to the right."
To roll a balanced airplane around its longitudinal axis requires much less force than to land slowly.
Whenever you travel in an airliner and have the opportunity to watch the ailerons working, you will see that a dramatic roll can be achieved with minimum ailerons deflection, specially at high speeds.
However, in order to sustain all those tons for landing at lower speeds, huge flaps are extended and deflected big angles.
Regarding the parallel discussion about the need for elevator when ailerons are deflected, I would say that it is not really a direct dependence.
All ailerons do is to induce a lift unbalance, moving the lift force (which keeps the same magnitude) along the wingspan and away from the central line of the fuselage.
Since a half wing lifts more than the other at that moment, a roll is started.
If the ailerons input is not removed, the roll continues all around as long as we keep the input.
If the aileron input is removed after certain angle of bank is achieved, the model remains at that bank (unless the plane has high dihedral, high wing, or any other form of pendulum type weight distribution).
Of course, during a bank or a roll, the lift will become less that the weight anytime that the wing is not parallel to the ground.
How do we keep a plane in level flight during a roll or a bank? - By increasing the AOA of the wing, either with up elevator, rudder or down elevator (depending on the angle of the roll being moderated, knife edge or inverted).
Any airplane in a leveled banked turn is following an horizontal conical trajectory; hence, it needs to have some nose up pitch attitude to follow that cone.
Ailerons modify the lift for the section of the span that they cover by modifying the camber of the airfoil: higher camber = higher coefficient of lift (CL) = more lift = more drag.
In essence, they work on the same principle of the simplest flaps, only that for what they do, less variation of lift is needed.
Copied from http://www.americanflyers.net/aviati.../chapter_4.htm
"Ailerons control roll about the longitudinal axis. The ailerons are attached to the outboard trailing edge of each wing and move in the opposite direction from each other. Ailerons are connected by cables, bellcranks, pulleys or push-pull tubes to each other and to the control wheel.
Moving the control wheel to the right causes the right aileron to deflect upward and the left aileron to deflect downward. The upward deflection of the right aileron decreases the camber resulting in decreased lift on the right wing. The corresponding downward deflection of the left aileron increases the camber resulting in increased lift on the left wing. Thus, the increased lift on the left wing and the decreased lift on the right wing causes the airplane to roll to the right."
To roll a balanced airplane around its longitudinal axis requires much less force than to land slowly.
Whenever you travel in an airliner and have the opportunity to watch the ailerons working, you will see that a dramatic roll can be achieved with minimum ailerons deflection, specially at high speeds.
However, in order to sustain all those tons for landing at lower speeds, huge flaps are extended and deflected big angles.
Regarding the parallel discussion about the need for elevator when ailerons are deflected, I would say that it is not really a direct dependence.
All ailerons do is to induce a lift unbalance, moving the lift force (which keeps the same magnitude) along the wingspan and away from the central line of the fuselage.
Since a half wing lifts more than the other at that moment, a roll is started.
If the ailerons input is not removed, the roll continues all around as long as we keep the input.
If the aileron input is removed after certain angle of bank is achieved, the model remains at that bank (unless the plane has high dihedral, high wing, or any other form of pendulum type weight distribution).
Of course, during a bank or a roll, the lift will become less that the weight anytime that the wing is not parallel to the ground.
How do we keep a plane in level flight during a roll or a bank? - By increasing the AOA of the wing, either with up elevator, rudder or down elevator (depending on the angle of the roll being moderated, knife edge or inverted).
Any airplane in a leveled banked turn is following an horizontal conical trajectory; hence, it needs to have some nose up pitch attitude to follow that cone.
01-12-2013, 07:33 AM
#63
RE: do ailerons provide lift?
The initial question was: Do ailerons provide lift in the neutralposition? An aileron = more wing area, and more wing area = lift. Removing on aileron make the point, simple and to the point.
Bob
Bob
01-12-2013, 07:37 AM
#64
RE: do ailerons provide lift?
Interesting to see how we all evaluate "lift".
Basically, creating a pressure difference on a body will /can produce lift.
A difference in pressure is ALWAYS trying to equalize and the object seperating the different pressure regions, will be moved from higher pressure to lower pressure -
Your hand stuck out the window of a movingcar demonstrates lift.
Airfoils are shaped to provide efficient lift but a flat board also produces lift - very well.
You also do NOT need to bank to do a turn- - but it is an efficient way to do it for many aircraft.
Pushing air down -is a familiar and easily seen explanation .
Do ailerons provide lift?
sure -if you want them to .
but lift and drag are one and the same thing- air pressure at work
You have to decide which you are after .
tiled one way you get increased lift and drag
tilted the other way drag and reduced lift.
trailing evenly with flow over/under the wing, they add area which INCREASES lift.
and drag.
Basically, creating a pressure difference on a body will /can produce lift.
A difference in pressure is ALWAYS trying to equalize and the object seperating the different pressure regions, will be moved from higher pressure to lower pressure -
Your hand stuck out the window of a movingcar demonstrates lift.
Airfoils are shaped to provide efficient lift but a flat board also produces lift - very well.
You also do NOT need to bank to do a turn- - but it is an efficient way to do it for many aircraft.
Pushing air down -is a familiar and easily seen explanation .
Do ailerons provide lift?
sure -if you want them to .
but lift and drag are one and the same thing- air pressure at work
You have to decide which you are after .
tiled one way you get increased lift and drag
tilted the other way drag and reduced lift.
trailing evenly with flow over/under the wing, they add area which INCREASES lift.
and drag.
01-12-2013, 07:40 AM
#65
RE: do ailerons provide lift?
These discussions always remind me of the government making laws about things like fuel requirements and medical procedures. There are so many "experts" that confuse and obfuscate the subject to the point engineers and scientist don't get anything out of it except a good laugh.
01-12-2013, 07:48 AM
#66
RE: do ailerons provide lift?
ORIGINAL: rgburrill
These discussions always remind me of the government making laws about things like fuel requirements and medical procedures. There are so many ''experts'' that confuse and obfuscate the subject to the point engineers and scientist don't get anything out of it except a good laugh.
These discussions always remind me of the government making laws about things like fuel requirements and medical procedures. There are so many ''experts'' that confuse and obfuscate the subject to the point engineers and scientist don't get anything out of it except a good laugh.
Bob
01-12-2013, 08:30 AM
#67
RE: do ailerons provide lift?
ORIGINAL: rmh
Interesting to see how we all evaluate ''lift''.
.......
but lift and drag are one and the same thing- air pressure at work
Interesting to see how we all evaluate ''lift''.
.......
but lift and drag are one and the same thing- air pressure at work
Any deflected control surface generates one productive force (lift, rudder yaw, roll, loop, etc.) and a non-productive force (drag).
That productive force, whatever name we give it, cannot exist without the associated non-productive force.
As drag always consumes energy, each control input consumes energy, in form of speed or height.
A good pylon pilot avoids control inputs as much as possible.
You modify the pressure value on both sides of the surface and the airstream reacts against the airframe (re-locating it or re-adjusting its attitude) in order to re-establish balance of pressure.
01-12-2013, 08:39 AM
#68
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RE: do ailerons provide lift?
ORIGINAL: Lnewqban
Exactly !!
Any deflected control surface generates one productive force (lift, rudder yaw, roll, loop, etc.) and a non-productive force (drag).
That productive force, whatever name we give it, cannot exist without the associated non-productive force.
As drag always consumes energy, each control input consumes energy, in form of speed or height.
A good pylon pilot avoids control inputs as much as possible.
You modify the pressure value on both sides of the surface and the airstream reacts against the airframe (re-locating it or re-adjusting its attitude) in order to re-establish balance of pressure.
ORIGINAL: rmh
Interesting to see how we all evaluate ''lift''.
.......
but lift and drag are one and the same thing- air pressure at work
Interesting to see how we all evaluate ''lift''.
.......
but lift and drag are one and the same thing- air pressure at work
Any deflected control surface generates one productive force (lift, rudder yaw, roll, loop, etc.) and a non-productive force (drag).
That productive force, whatever name we give it, cannot exist without the associated non-productive force.
As drag always consumes energy, each control input consumes energy, in form of speed or height.
A good pylon pilot avoids control inputs as much as possible.
You modify the pressure value on both sides of the surface and the airstream reacts against the airframe (re-locating it or re-adjusting its attitude) in order to re-establish balance of pressure.
01-12-2013, 08:49 AM
#69
RE: do ailerons provide lift?
ORIGINAL: brockettman
Excellent. Would it be true to say that an aileron that is symmetrical and is at zero degrees incidence (or angle of attack), produces no lift? Just asking, because I don't know.
Excellent. Would it be true to say that an aileron that is symmetrical and is at zero degrees incidence (or angle of attack), produces no lift? Just asking, because I don't know.
That is the case of the rudder in normal position: a symmetrical (or flat) airfoil, flying with zero AOA and producing no lateral force in any direction (only drag force due to skin friction).
01-12-2013, 09:11 AM
#71
RE: do ailerons provide lift?
01-12-2013, 09:25 AM
#72
RE: do ailerons provide lift?
ORIGINAL: brockettman
Thanks. I think I get it now.
Ben
Thanks. I think I get it now.
Ben
It is information helpful if one is interested in dissecting the laws of flowing fluids but oft times confusing in determining the basics
Many writers are paid by the column and the info can become quite daunting -unless you speak techno babble
A lot of it is simply the result of a self styed expert trying to ferret out the obvious.
Birds figure it out with out instruction - how hard can it be ?
01-12-2013, 09:30 AM
#73
RE: do ailerons provide lift?
Guys this is not rocket science, unless you are using a semi symmetrical airfoil then a positive AOA is required to produce lift and that is certainly no front page news.
Now with that understood, less wing area of lets say a neutralized aileron in this case, I know back to his original question before all the semantics of the so called experts, means simply a less available lift component to work with for any given speed or AOA.
Bob
Now with that understood, less wing area of lets say a neutralized aileron in this case, I know back to his original question before all the semantics of the so called experts, means simply a less available lift component to work with for any given speed or AOA.
Bob
