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Control surfaces chord percentage

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stanislavz

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It may not be necessary...my craft will have considerable flaps increasing the wing area by 7%. Goal is to be able to reduce the motor glider landing speed to 45 km/h niveau.
Ok, but still - i have seen live example of one fuselage, different wngs on LAK-16. From simple rag and tube (and it was biggest one), then Composite nose D cell and fabric covered rear part. And fully composite wing... Last one was smallest of course. No-one was perfect, but they do fly.

So - If you may use 70% of span for high efficiency flaps, like fowler or slotted ones, and use thicker ailerons on last 30% span you may have smaller wing for same stall speed. But better performance.. Yes, it will be "hotter" on handling side.. So why not ?
 

Speedboat100

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My only worry are the customers...I want them to land safely in any occasion...and keeping the plane right side up even in the gabbage field.
 

stanislavz

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Got some call to friends, regarding of blanik. With same airfoil and smaller aileron chord of 25% - ailerons was not as effective as on blanik. And blanik ailerons have little deflections, in ~10 degree region, not 20, as he said.

So - it may be an to turbulent/separate flow to cause this effect..
 

wsimpso1

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Having read about aircraft with one aileron, I muddy the waters of this thread with the preposterous notion: Just use one aileron.

Weighs less. Builds faster. Sparks conversation wherever you fly.
Increased and asymmetric aileron control forces. Ailerons in normal unaccelerated flight are loaded trailing edge up by the wing airflow. With two ailerons, the control circuit hooking them together makes them require no force in level flight. Put in aileron, and the control moment decreases on one, increases on the other, and the forces are still frequently high. Take away that opposite moving aileron, and the forces will be asymmetric and will require control inputs to go straight. This can all be solved with enough effort in control linkage design, spades or other aero balance design, etc. And after all of that effort and risk, you will still be short on control authority because you have less aileron area.
 
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wsimpso1

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Go for wing warping. The Wright brothers' patent has lapsed now...
The Bishop's boys (and his daughter too) did not have enough airspeed for twist mode flutter to interfere with human level roll axis control forces. Most of us do have to make the wings stiff enough in twist to keep flutter at bay, which precludes that mode for control.
 

Andy_RR

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The Bishop's boys (and his daughter too) did not have enough airspeed for twist mode flutter to interfere with human level roll axis control forces. Most of us do have to make the wings stiff enough in twist to keep flutter at bay, which precludes that mode for control.
It kind of depends on how you do your morphing doesn't it? Morphing doesn't necessarily imply non-rigid structures in totality. I know parts of the structure will need to be flexible but not all. Flexible and morphable are two separate ideas.

Having written this, I do conceed that warping/continuously morphing structures are not commonplace.
 

BBerson

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Don't see many wide chord ailerons. The reason is because the 40% chord aileron is hardly more effective than a 25% flap. (ailerons are same as flaps). Look up figure 115 in Theory of Wing Sections.
Ailerons change the camber of a wing, so they must span across a large part of the wing, not just the tip.
If you do put short wide chord ailerons just at the tip so you can use large span flaps like a Helio Courier, you will then need to add spoiler blades in front of the nearly useless ailerons, same as the Helio.
 

Riggerrob

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Increased and asymmetric aileron control forces. Ailerons in normal unaccelerated flight are loaded trailing edge up by the wing airflow. With two ailerons, the control circuit hooking them together makes them require no force in level flight. Put in aileron, and the control moment decreases on one, increases on the other, and the forces are still frequently high. Take away that opposite moving aileron, and the forces will be asymmetric and will require control inputs to go straight. This can all be solved with enough effort in control linkage design, spades or other aero balance design, etc. And after all of that effort and risk, you will still be short on control authority because you have less aileron area.
 

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