I´m begining to build my favorite plane. It´s a obscure 30's argentinian bomber called "AeMB2 Bombi".
Looking at ailerons photos, it is evident the hinge line isn´t paralell to that of aileron LE. I posted 2 images, one of uncovered aileron, and other of a finished Bombi.
At finihed airplane image, it´s very evident that when aileron goes UP, some part (inner) goes a little DOWN.
Really I don´t know why ...and if I build my 1/8 model in the same way ...how can this aileron setup influence flying characteristics.
Obviously I´m trying to build my model as scale as possible, and this includes ailerons setup.
Thanks in advance

I am not tracking on what you are saying.. from the image I see a tapered aileron.. But It looks like the LE of the aileron is straight.. Can you be more specific?

From the gaps at the root and tip for the aileron horns, there's a modest amount of "Frise aileron" effect, where the inner portion of the leading edge of the downward deflected surface projects below the surface of the wing proper, to provide a small amount of drag on that side offsetting the adverse yaw of the downward deflected aileorn on the other side.
Not commonly done, but not of any particular worry, if replicated 100% or not.

It was to combat adverse yaw just as Paul said. If you want true scale then copy it and it'll work for the model too. If you don't want to be THAT scale then just use regular aileron hinging but add in some differential travel where the up travel is about twice as much as the down travel.

This can be done either with the computer setup in the TX or with careful geometry in the control system.

With either it makes it a lot easier to do nice coordinated turns.

The RV series from Van's use a Frise style of aileron on the 3, 4, 6 series wings. Not sure what he's done on the later 7, 8, 9, and 10.

This seems to be more of an aerodynamic counter balance setup than a Frise aileron. Friese aileron sticks out the leading edge only when the aileron is moved up, but tucks it in when aileron moved down. From the picture, this looks like the leading edge of the aileron will protrude out of the wing in either direction of deflection. Kinda like modern Extra aerobatic airplanes - the ailerons are hinged at 25% of the chord and have mass counter balance in the leading edge (in addition to a spade that assists the movement and is used for trimming)

P.

Scott

May be this images explain better what I´m saying.

Daniel

looks normal to me man.. I see some aileron under the wing but it soesn't make me think that it was some aerodynamically improved design.. That aileron seems pretty normal to me..

It looks like an application of aero-balancing to lighten the control loads & perhaps prevent flutter (those are huge ailerons).

Hi Britbat...
I agree with you...and also may be it works as some differential....may be...
Daniel

You need to present something that shows the cross section of the aileron, wing cross section and the hinge location on the cross section. Then we can make some educated guesses as to what the designer had in mind.

That is a very interesting aileron.

My guess is that britbrat wins the cigar.

It makes sence to me that the greatest load would be inboard where the aileron's chord is the greatest. And so they made the hinge point further aft (there) to lighten the stick loads.

As the aileron tapers and the corresponding load is reduced, the need for the recessed hinge point is less.

So why slant the hinge line ? You have to. The chord of the aileron becomes to small not to.

Good luck modelling it !!

Actually who gets the cigar depends on the profile of the aileron. Paul's comment

"From the gaps at the root and tip for the aileron horns, there's a modest amount of "Frise aileron" effect, where the inner portion of the leading edge of the downward deflected surface projects below the surface of the wing proper, to provide a small amount of drag on that side offsetting the adverse yaw of the downward deflected aileorn on the other side. "

seems the most likely. That's the reason I asked about the profile, the Frise has a very definite look. There was a model in the early 1960's called the Orion that used them. It won the RC aerobatic nats I believe but no one else used them. For models it wasn't worth the effort.

Oh....my friends

Across wing sectio....it´s a dream. Forget it ! It took me 25 (YES!) years to find some photos and a decent 3 views set (unpublished in fact) ....
There are just very few info about this bomber.
Daniel

That makes it easy ------

My grandfather knew a man who dated the daughter of the designer - he told him from her as told by him that the ailerons were of the Frise design. It seems that they were all the rage at the time in the small town of Frise, Germany. All of the airplanes had to have them to be in style. It was a socially acceptable thing to do along with the fringes that were put around the bottom of the fuselage (they were supposed to reduce drag by half as a result of waving in the breeze, creating thrust vortexes).

Somebody actually tried to use a conventional aileron but soon found that the local air was so accustomed to reacting to the Frise type that the air didn't know what to do. Unfortunately they got so confused that they made the airplane pitch and it landed the unfortunate pilot into a hay loft.

To this day all of the airplanes in the town of Frise have always used the Frise aileron design.

Ben, for shame!
Bad Ben, bad, bad!!!!!
I use Frise ailerons on some Kadets... for their oddity, they're not any better than barn-doors.
Here's one showing the nose projecting below the wing surface..

May be this photo aswers some about airfoil. It seems lighten sticks load was a concern at overall design. Both tail surfaces have more conventional systems to do it.

Daniel

I couldn't help it, the doctor put me on some new anti-migraine medicine and it makes me do strange things.

That is a good shot of the field. Paul, why have you built so many Kadets? It isn't a very zzoooommmmyyy design.

baco, you might look up the date when the Friese aileron was first used and compare that to the date when your design was built. It would give you some idea.

The thing about Friese ailerons is that the benefits might show up when a real pilot is able to feel the benefits - I have to guess that a model is the worst place to try to see a difference. Maybe with instrumentation....

Ben, I'm not into zoomy any more. My personal speed limit is about 100 mph, I've found. I spend more time analyzing what the plane is doing, instead of flying it. This can lead to "the walk of shame"...
Kadets build so quickly and are so adaptable to almost anything...

First time posting!

Ben, I am a pilot who always wondered where the term "frise" came from. The explaination you gave of it's origins is interesting, but i cant seem to find a town called "frise" in Germany. Maybe Friedorf or Friesenheim?

IB

Frise is the last name of the inventor, Leslie George Frise... A Brit. worked for Bristol Aircraft (oops, Aerocraft)