I am looking for learned input and lively conversation on why the various aileron designs are used. I spent some time with Abbott and von Doenhoff, and am happy with a slotted flap design with a below-wing pivot. We see lots of examples too. So I looked at a lot of ailerons while at OSH thinking that I might find ailerons applied similarly... Yeah right.
We hear about this airplane and that airplane having great aileron response right up into stall and good roll rates and nice control forces, while others do not. So what is it about the aileron design that makes them work well or not work well? There are so many designs out there. There are top surface hinges, foil center pivots, below wing pivots, Frise balance of various types, large balance areas on some, and none on others. And some aileron designs look like an afterthought too. Looking at factory built and experimentals there is tremendous variety. So which design type really works well both for gentleman aerobatics and at low speeds for landing and takeoff?
Notable among the many homebuilts is the RV design with the pivot just below the bottom surface at about 20% aileron chord, a slotted flap type arrangement, and Frise balance. Makes sense to me. In looking at them, and having done my flap homework, I kind of expected that the slot would open as the aileron goes down, but if the RV's do it, I could not detect it on the factory demo airplanes.
So, what are the basic thoughts on aileron and flap design?
Billski
We hear about this airplane and that airplane having great aileron response right up into stall and good roll rates and nice control forces, while others do not. So what is it about the aileron design that makes them work well or not work well? There are so many designs out there. There are top surface hinges, foil center pivots, below wing pivots, Frise balance of various types, large balance areas on some, and none on others. And some aileron designs look like an afterthought too. Looking at factory built and experimentals there is tremendous variety. So which design type really works well both for gentleman aerobatics and at low speeds for landing and takeoff?
Notable among the many homebuilts is the RV design with the pivot just below the bottom surface at about 20% aileron chord, a slotted flap type arrangement, and Frise balance. Makes sense to me. In looking at them, and having done my flap homework, I kind of expected that the slot would open as the aileron goes down, but if the RV's do it, I could not detect it on the factory demo airplanes.
So, what are the basic thoughts on aileron and flap design?
Billski
