Hibbitz

Hello all,

I have flown a high wing trainer and my brother and I are getting ready to build a low wing kit. I have a computer radio that I use with my helicopter and want to find out if I can set up this new low wing plane with flaprons if we have a servo for each aileron. I have seen different definitions of this function online so I am just trying to make sure I understand it properly. The kit that we are building uses a 40 size motor and does not have flaps, just the ailerons. Is the idea that with the computer radio you can program the ailerons to shift to a certain point of deflection (say 10% or whatever) to act a flaps slowing the plane down and then they would continue to move independently from there to provide the aileron function?

Sorry for the long explanation but I hope I was clear. Any insight into this would be greatly appreciated.

Kent

Lancair-RCU

You got it. BUT be careful using it on ailerons that are just on the outboard section of the wing, you can/will increase the possibilty of tip stall dramatically.

rockhouse

My Feedback: (5)

Also you have to use 2 separate channels for the ailerons & select the flaperon function from the radio menu.

Gringo Flyer

My Feedback: (18)

What model is it? There is bound to be someone that can give you advise on what flaperons do on that particular model.

The majority of the time flaperons are not necesarily needed for landing (otherwise the plane would come with flaps) but are used more for 3D. They can also be fun to play around with to see how the plane reacts (of course you do that a few mistakes high)

cstevenpeterson

My Feedback: (21)

Hi Kent,

You have that correct. Just take note that they behave a bit differently than when using flaps and ailerons separately. When using flaperons, you will be introducing some yaw. For example, if you input some % of down flaps and then you attempt to make a left turn using ailerons and elevator, the left aileron may be close to the neutral position while the right aileron is still down so this will introduce right yaw which results in the plane trying to turn (yaw) right somewhat while you are turning left. I am not an expert on this, but I am sure that it varies from plane to plane depending on many things. You need to be aware of this and be ready for it.

Steve

Rodney

I'll second the idea to watch out for tip stalls on landing if you use flaperons, they have the opposite effect of washout to prevent tip stall.

Hibbitz

Wow....thanks for all of the great information! My brother and I started with a .40 high wing trainer and then moved into helicopters. We love the helis but had a blast flying his plane the other weekend (it has been collecting dust for a year or so) and decided to order an AFR low wing kit. We ordered the Great Planes Super Sportster 40 ARF and I am going to put an OS .46 FX in it. Since I have a Futaba Super8 for my helis, I figured I would see if it was worth it to modify the Super Sportster for independent servos for each aileron and use the flapron function. I would mostly want it to slow the plane down for landings. If the general consensus is that this plane will fly slow enough and there isn't a real value to putting each aileron on its own servo, I won't bother.

Thanks again for all of the information......GREATLY appreciated!!

Kent

CRFlyer

I always use two servo's ( one for each) for the ailerons. I don't always enable flapperons though. I have the SS60 size, and it fly's great without flaps or flapperons. I don't think you will need them in the 40 size either. However, there is no harm in setting things up that way, and you can play around with the flapperons on high. after you get some experience as to how the plane performs with and without the flapperons, you can decide if you want to use them for landings, etc.

Another possiblity, though does add weight is to cut the ailerons and make functioning flaps out of the inward portions, leaving the outer portions to act as ailerons.

TexasAirBoss

My Feedback: (22)

Be careful. Flaps should be inboard. That way, the root of the wing is at a higher angle of attack than the outboard section of the wing. That way, the inboard stalls first. The nose drops a little, but that is all. And usually the sink rate just goes up.

But if you have flaps outboard, you aren't getting the washout effect of inboard flaps and the stalls can result in rolling over !!!


You might hold off on those flaperons for a while. Most sport kits will slow down just fine without flaps. It might take you a little time to learn how to slow it down, but thats OK.

And remember : Elevator controls attitude

Throttle controls rate of descent

MinnFlyer

My Feedback: (4)

If the plane is designed to use two torque rods at the center of the wing for aileron control, a better thing to do (Than Flapperons) is to cut the ailerons about 6 or 7" from the inboard side to use as flaps (Controlled by the aileron torque rods). then you can either add a servo to each wing for ailerons, or control them both from a single servo using flexible pushrods.

Deerslayer

If you are concerned about possible tip stalling and/or want to increase the flap effect, make your ailerons so that they are perhaps twice the width for about 1/3 of their span. For aesthetics, make a curved taper from the wide part to the narrow part over, say, a couple of inches. This works really well. When you have your flaperons (spoilerons) operating as flaps (spoilers), you will notice the flap (spoiler) effect and it will be where an airplane would normally have real flaps. Also, any forces created by having this flap or spoiler effect are being borne at the best location in the wing structure to avoid any twisting.

I have done this with some aircraft of my own design, having previously used uniform width ailerons on the same aircraft and the difference is rather dramatic. I also tend to taper the last few inches of my ailerons, this may help reduce flutter tendencies at high speed in a high performance sport aircraft.

Hibbitz

Ahhhh... this is one of the many reasons I love this hobby. Sharing information with people like yourselves is the ONLY reason I was able to build, UNDERSTAND, and fly helicopters. All of this information is of great help.

I will have ot see how much of a project we want to get into with this plane. Because it is ARF we may not want to fully open up the wing to install flex-pushrods for the ailerons but I LOVE that idea. Thanks for that one! As long as we have the space in the center of the wing, it sounds like a good idea to install dual servos for the ailerons. Maybe we can fool around (at high altitude) with the flaperon set up once we are confortable with the plane. Who knows, the fun of this hobby is finding out what works best for you. Maybe we will take on the project of cutting the ailerons and making flaps after a season of successful flying.

Thanks again for all the information and that is really important to understand that when using the flaperons, one aileron may just come up to neutral while the other is pointing down and this will cause yaw.

Cheers,

Kent

hebertjj

How about having the ailerons pop up for speed brakes to slow for landings? That should take care of the tip stall problem. I believe lots of pattern flyers do that; it doesn't take a lot of up to make a difference.

Deerslayer

" How about having the ailerons pop up for speed brakes to slow for landings? "

That's the technique I use mostly. It is what I picked up years ago from the "stick-it" type contest planes. Usually, I will have the flaperon configuration (ailerons go down as you add up elevator) programmed so that it can be either inhibited
or enabled from one switch on the TX. As well, I will have the spoileron (ailerons go up as throttle is pulled back) set so it can be enabled or inhibited on another switch. With both switches enabled, it is like having 3 hands available to control the aircraft. You can do really fast touch-an-goes - just hit the throttle (that dumps the spoilerons), yank the plane off the ground (flaperons will come down and help this), charge around your little circuit, cut the throttle (spoilerons come up, helping to bring the plane down quicker), arrest your descent with some elevator (the flaperon/aileron functions should be set to pretty much cancel each other out, leaving just a tad of droop when throttle is at idle and elevator is full up), touch and again hit the throttle. If you happen to mis-judge, or think you will hit hard, just nail the throttle and this combination of programming will sort things out for you much quicker than you could possibly do by flicking switches- that 3rd hand, remember? Even for less aggressive flying, the combination works to make for deadly accurate spot landings, if you wish.

The idea is to keep the 2 functions available, or not, at the flick of their respective switches. And, to experiment with
different amounts of each function. If you are careful, you can set up your plane so that the radical power on/off and associated spoileron function is blended in with some elevator trim such that the plane undergoes no noticeable pitch change. There's a lot of cool stuff you can do with this whole arrangement, and all it costs is to use 2 servos instead of 1 for your ailerons - a good idea in any case.

Depending upon your aircraft, you might find that the spoileron function doesn't really do a lot - sometimes, there just doesn't seem to be much additional drag from them and having the flaperon would actually make the plane come down quicker. High performance, full size, sailplanes typically have inboard flaps, linked to the ailerons, capable of 90 degree
deployment - but there you go, having to add the separate control surfaces, rather than just making the ailerons perform both duties. I still urge you to try the single aileron with the 2 different widths - I never see anyone else doing that, yet I know that it works very well.

Propwash in Pa

Sportster is a very good flying sportplane. My experience is that it does land a little fast. As you get comfortable, moving the CG back will help slow your landings. Only "issue" I ever had was the gear wires are weak. Normal landings caused them to bend back slightly, making plane "tippy".