aurora

My Feedback: (1)

What are the advantages and disadvantages of both? Is one better than the other? If one was building and flying his first DF model, what method would be best suited for that indivdual? Field is no a problem, several to choose from with length being no problem. This question pertains to the BVM Viper and BVM Aggressor. The majority of the Vipers I've seen use flaperons and the Aggressors I've seen have separate controls for each functions. I guess if you read into my questions, I'm siding particular to BVM jets BUT understanding and learning how to use both functions are just as important as chossing which model to fly and build. Hope I haven't confuse anyone - thanks, Steve

RampRat

I don't have any experience with flaperons on jets, but after trying it on other models i came to the decision that i'll never use flaperons on an expensive model... Although flaperons help to reduce the stall-speed, the flaperons give the model some very odd roll-characterisitcs when aileron is used at low speed, and it might even flip your model over if you fly really slow.

It's ok for very small aileron-inputs, but larger inputs both look odd in the air, and might do some damage when you land with the wheels pointing to the sky.

I do however love spoilerons since these usually are applied on established final or on touchdown, and they're very effective...

Flaperons on the other hand is usually deployed on the downwind-leg, and that still leaves you with two funny looking turns before you land...

My opinion anyway...

JohnMac

Flaps & ailerons seperate is the way to go. Dropping the flaperons increases the local angle of attack at the wingtip. (=washin) This is bad! Tip stalling as you turn onto finals will be a piece of cake.
Conversly, flaps increase the local angle of attack at the root, the wingtip in comparison will be at a low angle of attack (=washout). This is good! Tip stalling is delayed, full flap is available, no adverse yaw problems, its a no-brainer really.
How many full size aircraft have flaperons?
Have fun,
John Mac.

RampRat

Well... The Airbus A330 has Flaperons...
...and the Twin Otter has them...

JohnMac

Ramprat,
My point precisely, you could only name two!

Terry Holston

My Feedback: (1)

Full scale F-16 uses Flaperons, too!! Thats three, Ha Ha

WreckRman2

My Feedback: (5)

I like to use an elevator to flaperons mix setup on a switch. The more elevator input the more the ailerons go down as flaps.

Rojeck

My Feedback: (22)

Hate to bud in on this, but my question is similar. I am preparing the Yellow F18 twin for it first flight and wondering if I should use flaperons as well. The previous owner had set it up with flaperons , once the flaps came down to 30 degrees. This plane right now is setup with tailerons, ailerons and flaps. It is powered by a P160 and weighs around 40 lbs.

Sung

ryanvu

My Feedback: (3)

So does the F-18 - although airlerons, and flaps are separate - they all set to down for take off and landing.

Flaperon = greater flap area = require more power on landing = also mean that the plane might also get airborne sooner if you use them on take-off.

I like it actually - give you more airleron authority at slow speed because of the close to full span airleron...just gotta watch that speed that's all.

JohnMac

Yeah, I guess you're right. F-16 and F18 etc do use flaperons. If you are planning to have your CG on your trailing edge and have a computer fly your plane, then I would also use flaperons. Otherwise I suggess you use Tailerons for steering and flaps as flaps. I fly my F-16 with tailerons and it works just fine right down to touchdown.
Regards,
JohnMac.

Jackjet

My Feedback: (1)

The full size F-18 drops the ailerons with the flaps...........


Jackjet

JohnMac

Jack Jet,
I know. The point is that the pilot doesn't fly the F18, a computer does. The pilot demands a control input from the computer and the computer works out if this is safe to do. If the pilot is on his final turn with flaps and ailerons down and he then commands an input which would create a spin, the computer will not provide the output he commands, but will provide the maximum safe output.
Now if I am flying the F18 model in the same configuration I am relying on Mk 1 eyeball and if I get it wrong I am going to destroy this model as it will tip stall easily in this configuration. Now these are the facts of aerodynamics. The choice is yours. but if you must depress your ailerons for landing, I suggest that you depress your flaps about 4 degrees more than your ailerons. This will ensure that the wingtip is washed out and much less likely to tips stall. I speak from bitter experience BTW.
Regards,
John Mac.

Bandito

My Feedback: (5)

If you have not used flaparons before.... I strongly suggest that you Dont use them on a plane you really are fond of for the first time.... They are difficult to set up properly and add a higher degree of Stall tendency to most planes. The planes you mentioned, Vipers and aggresors have already have a higher degree of stall characteristics than many planes, for example Mavericks and Bandits..the planes you are referring to being ducted fans does not help you either especially if your engine loads up on final. I have flown flaparons a few years ago on a ducted fan aggressor. I personally dont like them because split flaps are so simple and predictable . Dont get me wrong, flaparons ARE effective, they just change the characteristics of the plane too much. ( for me at least )... Ray Blair

Jackjet

My Feedback: (1)

JohnMac,

I know what you mean - but I have had no problems flying with the ailerons and flaps working together - when I land that Tom Cook F-4 (30lbs.) - I drop aileron and flaps - slows it down to 35 mph. - no tip stall or anything like it - but each plane is different - as far as the F-18 - just move the C/G 1" further forward - that will tame the stall and then you can use flaps and ailerons together.

God bless,
Jackjet

Ralph Morris

Jack; Are you the same Jack who used to fly DF at Mile Square Park with Harry Wood?

JohnMac; I received an email notice that you replied to the "Larger Electrics" thread, but I didn't find your post. Funny, the subject of flaperons came up recently in the "Open Design" thread. These threads are in the "Aerodynamics" forum.

My experience with flaperons is similar to yours, and I advised "Q" to use only about 20 degrees flap deflection with full-span flaperons. First time I tried flaperons on my larger electric-powered plane I found they would cause a tip stall if you tried to turn. Fortunately I tried them with enough altitude to recover. Now I only deploy them on final.

My newest plane has flaperons with tip plates ("tipplets"). We'll see if the tipplets affect the flaperon characteristics. I've flown it twice, and used only a little flap deflection on final. Soon I'll try a turn with flaps down, but you can be sure I'll do that about three mistakes high.

Here's a link to a photo of my "M3-E":

http://www.rcuniverse.com/gallery/sh...t=1&thecat=500

Jackjet

My Feedback: (1)

[QUOTE]Originally posted by Ralph Morris
[B]Jack; Are you the same Jack who used to fly DF at Mile Square Park with Harry Wood?

Ralph ,
yes - it is me .

Jackjet


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