I hear a lot of warnings about not using the flapperon feature and I am not sure if that is just because they are tricky to set up well, or if they really do no good at all.

If set up correctly will they actually reduce stall speed and allow for slower and shorter landings? If so then I think they would be a good feature for my model.

People say flapperons will cause tip stalls, but obviously if they were flying faster their plane would not have stalled. I am not sure if people are stalling due to pilot error or if flapperons really make stalling more sudden?

If flapperons are useful feature I should I set them to go up like spoilers, or go down like flaps and how much up/down, should I try? I have a Phoenix Strega 40, basically a scale P-51 Mustang.

When deflected downwards they help let the plane fly slower down to around 20 degrees angle. At this point the adverse yaw they cause is managable if you use some rudder with your aileron inputs. Beyond 20 degrees things get real nasty in a hurry.

When delfected up they still have a yawing effect but now it works FOR you rather than against you so you can use more up "spoileron" angle than for the "flaperon" angle. But it'll make your plane descend like a gut shot duck from the drag and reduction in maximum lift possible and the touchdown speed may actually be higher.

Bruce thanks for the info. sounds like they are not always a bad idea.

when they are up like spoilers, I suppose the main wing has less lift, but I wonder if it could then maintain a higher angle of attack without stalling an allow a slower forward speed?

I have a 3-position switch on my tx, might try figuring out how to assign it and go try out a few different settings. I just wanted to make sure there was a realistic potential for success and this would not necessarly be a doomed experment.

I am of the opinion that inboard flaps and regular outboard ailerons are the way to go ,if you need flaps. I have an RCM Funster set up that way ,and believe me,it will come down steep and slow to,when the flaps are down all the way. And this model is not a lightweight by any means. Has no tendency to tip stall whatsoever.

Without flaperons, guys would still be just flying 2D instead of 3D. On the right plane they will flatten out your spins, tighten up the loops.......the plane needs to have a light wing loading for flaperons / spoilerons to enhance aerobatics without the stall tendencies.
The average lead sled type of plane might make good use of them for achieving slower flight like others have suggested.....just go easy on deflection.

Flapperons may have specialist applications, as alluded to in the previous post. But, for conventional flying, they are bad news. Best avoided, IMO.

Go the conventional route and you won't get any nasty surprises.

And as for ANY aero structure, whatever it is, it's not going to be adequately described for every airplane in just one short sentence. A one line sound byte isn't going to cover how flapperons work for every airplane. Cambered wings often respond differently than symmetrical ones to what's hanging back there on the TEs. Tapered planforms already tip stall naturally, and things like flaperons often just make that worse. High wings sometimes respond differently to flaps/flaperons/spoilerons quite differently than low wings.

Are flaperons "ever a good idea?" Yeah. Depends on a lot of things.

On a tapered planform, low wing Strega, they just might increase the tip stall a tapered wing often does naturally. Wing loading also affects things. Does that Strega already need a bit of extra speed landing to be comfortably safe? Does it stall out of harder looping maneuvers?

The real beauty of our hobby is that we can rig almost anything in our models with just an evening or two's work, and then go test at two mistakes high. And it greatly increases the fun we already have with those little suckers.

Are you going to have to rig something special on a Strega to get spoilerons? does it already have a setup for plain flaps? split flaps?

I think my main complaint is that my Strega just does not slow down as quickly as I would like when the engine is idling and am decenting into land.

It seems like if I am bringing in on a gentle decent then its speed is so fast that it is more willing to keep flying than actually land. To land it I kind of have to get it down a couple feet above the very begining of the runway and then hold it level for a 200 feet or so before it slows down enough to land and stay on the ground.

yes my Strega does stall out under hard looping when evelator is near max deflection, like near the top of a loop. It will also stall while doing a sharp turn if I ask for max elevator.

when is stalls under slow flight it does tend to tip-stall and drop a wing rather than just mush and drop the nose with wings level.

the Strega only has flaps or spoilers, but has individual servos for each aileron. I have a Futuba T7C programable tx. I would prefer to try softaware programming changes before really moding my aircraft.

From what I've seen most people attempt to use flaps when they really want spoilers. Flaps are used to allow a steeper glide angle without an increase in speed. What most people want is to fly with a constant "flare" or nose-high attitude. This is permitted by spoilers, not flaps. Flaps cause you to fly with a nose-down attitude up until the point of flare immediately before landing. I think the tip-stalling comes in with flaps when people attempt to flare too soon.

hmm interesting. I am really thinking spoilers or spoilerons might be what I am really looking for, because I do want to decend without carrying so much speed on the way down.

I tried out a few settings. They seemed to work quite well in my tx "Airbrake" mode where the ailerons both go up a bit. I think this enabled me to dive steeply and shorten my landings. I did not notice any undesirable affects.

they are not a susbstitue for lower wing loading that is they can NOT increase lift

But they will change lift to drag relationships ( very important) and the right one for your needs will take some careful experimenting.. some pattern guys use the flapperon feature to trim a model that is the EFFECTIVE airfoil shape can be tailored to setup a different wing to fuselage (the thing some call the main wing as opposed to the little wing on th e back of the body) relationship. the relative , effective AOA
The model will then fly tail high -or low- depending on the trim of the flapperon.
It's fun to futz with but the practical aspects of it are kinda iffy.
do your tests gently -a little at a time - like kissing a duck -it takes practice.

Not "quite" right Dick. When used with downward deflection they add camber and adding camber allows the wing to reach a higher lift coefficient before stalling so technically they do add lift. But I have to agree that a lower wing loading is better all around.

In the end it's also about adding drag if the goal is to steepen the approach glide. Adding lift does this but so does killing lift with upward deflection and thus requireing a higher angle of attack to restore the lift that was dumped.

- the semantics of it all
I stand by my statement
no lift increase - but - lift and drag relationships are varied and improved possibly when angle (up or down relative to fixed portion of the "main wing") for a particular speed and line of flight .
It's the same story with simple flaps - they can NOT increase overall lift - just maximize a given condition.

I've used flaperons, on two planes. One was a 'stik' type and the other a 'pattern' type. Not that impressed with them. Fun to play with, but, that's about it.

I'd agree that up to about 10-15 deg (depending on airfoil and wing shape) they work to modify the airfoil to give more lift by changing the camber of the airfoil, but, they also effectively change the incidence of the wing. This is similar to the 'take off' flap setting on many airplanes. There is a little bit of drag penalty due to the increased lift. That's where they can be like a flap for landing. A bit of increased lift (lower stall speed) and more drag (slows the airplane allowing a steeper descent).

At more deflection you are running into a situation where you probably have airflow separation over the control surface (at least that's what it seems like when flying). This is where things go bad in a hurry. You end up with big drag brakes on both wings and little aileron control. The airplane will come down in a hurry, and, if you aren't on top if it with the rudder, it will probably turn turtle on you (yes, been there, done that).

All of this is for 'normal' flight, where the wing is actually doing something, not 3D type stuff, which is a whole other category. In those cases flaperons can be great tools (as stated above somewhere) for maneuvers as well as descents/landings.

As for spoilerons, I've never tried them. I've been meaning to, just never got around to it. If what you want to do is come down faster, they are a way to go.

The best bet, if you have full length ailerons already, is to split them and have the inboard sections work as flaps. I've done that on two planes and it works VERY well. Turned a real 'floaty' plane into one that was pleasant to land.

charlie

If you are using ailerons as landing flaps, it depends on the plane too.
I use em on my pulse and it seems to kill aileron control, but as a mix to my elevator and dropping both ailerons when i pull full elevator up in a turn or loop they are really tight.

I wont fly my U can DO without the mix on at all times. reall makes it float and flatten.

With a split flap/aileron config I like the inner "flap" sections configured as flaperons on slow models. No air over the outboard ailerons can be a serious issue but inboard the prob flow provides enough. Having spoileron capability also allows my Tango (useless for much else) with Saito .82 to flat spin upwards Of course, you could just set up for CROW and mess around until you find combos you like

You basically stated what your difficulty is. You're flying too fast. What you need to do is get some altitude and play with airspeeds. Fly the model as slowly as possible so that you can learn the attitudes, control positions, and handling characteristics of your model. Once you find out slowly it can fly, you can then use that knowledge to increase the speed slightly to give you a bit more margin over the stall and learn to do your landing approaches at that speed.

Most R/C flyers just approach and land too fast. What is a good practice is to find out what speed is good and then find out if a trim setting will give it to you. I used to have a model that would set up a perfect approach speed when I rolled in full "up" elevator trim. I'd retard the throttle, and as the model slowed down, slowly roll in full "up" trim. Then I'd mainly use throttle to keep the approach angle as I wanted. For that airplane, it worked out very well. Other models needed more or less trim. It's a "find and see" type of thing. Regardless, you need to learn to use a slower approach speed. Once you've achieved that, you'll find that your model will set down quite close to the point where you round out into the landing flare.

Adding to the above category of thought from BAX, using the standard " landing pattern" is very helpful.

Begin slowing (Throttle) on the Downwind Leg, when the model is midfield. Fly Downwind Leg out for a good distance. If you maintain a slight Nose Down attitude through Downwind, Crosswind and Final ... as you continue to reduce power, you will keep enough airspeed for control AND bleed off ground speed(so to speak).

Arrive at landing field threshold, then level / flare to touchdown.

also make sure the idle is as low as it will go, if that doesnt work then get set for a long low aproach and then kill he engine close to the end of run way then try to fly it 1 foot off till it come down on its own. If that doesnt work then give a slight wing rock at that foot and she will come down. the wing rock should be no more that 15 degrees or so. work for all our pylon planes.

I would like to elaborate on Bax's response. At slow speed, elevator controls speed and throttle controls altitude/ glide slope.
Set the trim for a safe airspeed. If you don't pull up elevator, you will not stall on a down wind turn regardless of the wind speed. Cut throttle and let it slow down. A 60 deg bank turn will require 2gs to maintain altitude. If you cut throttle and start a 2g turn you can bleed of a lot of speed by maintaining altitude. This will help in entering the landing pattern at the desired speed.
Experiment with altitude, throttle setting, and bank angle these will determine the distance needed to descend.
Don't apply elevator until you are ready for the flare, and you will never stall.

If you want to have fun, you can slip to loose altitude. Full scale planse such as Citabrias that don't have flaps use this often. Basically if is opposite aileron and rudder. This creates a lot of drag as the airflow nor strines the fuse from the side. This drag will reduce airspeed which will require down elevator to maintain speed. You will loose a lot of altitude quickly without gaining speed.

Like everything practice makes better. If you practice enough, you are bound to have one that is perfect even if it is by accident.

Interesting post. I think flaperons are not really suited to slow an airplane for landing. If you look at a cross section of a wing and draw a line from the leading edge to the trailing edge you will get an angle of attack (AOA) as compared to the relative wind. When you employ flaperons (both ailerons down) you are increasing the AOA across the whole wing. If there is no wing washout (where the wingtips are twisted to lower the AOA) you can stall the whole wing or tip stall even though the airplane appears straight and level. Flaps are designed to slow an airplane for landing. They increase the AOA only on the inboard section of the wing while the outboard sections (where the ailerons are) have a lower AOA and therefore remain in control.

Spoilerons might be a better way to slow for a landing because by bringing both ailerons up you are lowering the AOA on the whole wing. This would allow you to fly nose high and thereby increasing your induced drag. A harrier approach if you will.

Not quite a harrier approach, but they are extremely useful to land my Falcon 1.20 and Bobcat .50's.

They permit me to keep the nose high exactly as you mentioned, slowing the plane, and preventing it from overshooting.

Without the flaperons the planes decend with too much airspeed and you cannot hold the nose high.

The flaperons also prevent tip stalling tendancies.

Spoilerons are used to spoil the lift on the wing. Mainly used in aerobatics to cause a drastic loss of altitude with a nose high attitude such as in a maneuver called the elevator or on gliders when caught in an updraft to spoil the lift on the wing

And to ease landings on the Bobcats & Falcon's.