TedMo

Without going into a major discourse on aerodynamics ( which I'm not qualified to do) I would like to get some answers on something I have wondered about for years. Simply stated, why does it appear that beginners are steered to fly 3 ch aircraft, rudder for turns,not also ailerons? I know for a fact that is far easier to maintain control and execute a turn with use of ailerons. I'm not a beginner so just wish to know this for my own satisfaction.

Scar

My Feedback: (3)

Two things :
1. If you don't want a lengthy discourse, don't post in the Aerodynamics forum.
2. Tradition. Early radios only had one channel, so they chose Rudder & designed around that. I think it's a stretch to say that is still where newcomers are "steered."

Good luck,
Dave Olson

TedMo

Hopefully you did not interpret what I said as where newcomers are steered meaning single channel. Certainly not, but they do I think tend to be steered to trainers without ailerons. Since I have been flying RC for more than 50 years therefore began with single channel escapements, rudder only. Then progressed through all the various improvements with time. I do believe I have the experience to feel it far easier and better to fly useing ailerons along with rudder. Therefor my question is why start off without ailerons. There may be a good reason but I fail to see it. Yes I could go into a major dialog on aerodynamics to some degree but didn't think it necassary for a simple question?I really would like an answer just to satisfy my curiosity.

Rodney

One simple and dominant answer, it is less expensive for the manufacturer and he passes off some of the lower cost to the buyer; both save a tiny bit of money. One less servo, less current drain (smaller battery) and cheaper transmitter design for the packaged ready to fly packages.

Mode One

I don't espouse this idea and have to say I don't really hear it being recommended anymore. Any radio I would recommend a new person consider would have 4 channels, minimum. I also feel learning to deal with the three axis' of control is the right way to start.

TedMo

Thanks for that reply. Makes some sense but wondering if perhaps it makes more sense if by promoting 3 ch. planes the manufactures count on the likely upgrades that then provide additional revenue? Maybe?

pimmnz

Why 3 channels? The reasons go back to the mists of time, but for a beginner, having a limited number of control options makes sense. Why rudder over ailerons? Simply put, most learners models are high wing boxes, cambered ('flat bottom') sections and with a bit of dihedral the model is basically 'self righting'. Again, so long as the learner simply lets the stick go, the model will return to upright, straight flight. Unfortunately for ailerons, they don't work very well with sort of configuration, (adverse yaw, limited response etc) and rudder is usually much more powerful and immediate in response. It helps to think of the stick being waggled as the 'direction' stick, rather than 'aileron' or 'rudder'. Once the basic orientation and attitude responses have been learnt, then a model configured for aileron for direction control can be introduced, and now the beginner will only have to learn to roll back level afterwards, as most aileron models don't tend to return to 'S&L' after an attitude change. If you fly vintage, then ailerons are almost never used, as the yaw/roll couple on them can be quite fierce, and ailerons don't work at all. If you have ever flown a 'proper' rudder model, say something like a 'Headmaster', then you will understand that for many models, ailerons are simply not required, as these sorts of model will do consecutive rolls with rudder application alone. Actually, many of the so called 'trainers' don't fly very well at all, rudders are usually way to small to be effective, the ailerons don't and they need high speeds to fly cause they are way over-weight. An original 'Astro Hog' makes a superb '4 channel' trainer, and either a 'Tauri' or the previously mentioned 'Headmaster' make excellent 3 channel trainers with limited power and good fun machines when up-rated later. Is, then, providing a 3 channel model a marketing ploy? I doubt the manufacturers of the modern ARF trainer have that much (intelligence) forethought. They more likely hope that you break the thing and buy a couple more during the learning process, which is why they provide a poor product in the first place.
Evan, WB #12.

CrateCruncher

My Feedback: (1)

I haven't seen this question in a decade at least. My direct RC experience goes back to the early 80's when I learned to fly and I remember asking the EXACT same question then. At that time there were still a few trainers with no ailerons (like the Sig Kadet Sr.) and there were also a few kits called "Aileron Trainers". I never did get a straight answer ("I learned on a 3-channel so you should too" didn't cut it). Heck, why should I buy an airplane without ailerons if my goal is to fly a 4-channel plane! I learned out of the chute with a proper 4-channel system and never looked back.

Here are some bullet points PRO and CON:

1)PRO: 3 channel radio is less expensive. CON: Do they still even sell 3 channel radio's?
2)PRO: Ailerons add complexity to the build. CON: Who still builds their trainer?
3)PRO: Rudder turns are easier than aileron turns. CON: Most students get their basic coordination training on simulators now.
4)PRO: Using "rudder only" forces student to learn rudder. CON: I agree with this but can't you just disconnect aileron servo?

RC planes and their designers tend to hang on to traditional "Rules" far past their operational effectiveness. Another example is the excessive dihedral still seen in many sport craft - what I think is a holdover from when a 3-channel relied on that roll couple mentioned in a previous post to turn the plane without ailerons.

Mode One

I learned to fly in the mid 70s, no one ever suggested to me to go with a three channel radio; or. Rudder, Elevator, Throttle trainer. Learning to fly rudder on the aileron stick does not help a person learn to use the rudder, because once you move to the next step, what was the rudder stick, now becomes the aileron stick and you have to re-learn rudder on the rudder stick. This is somewhat counter productive. I can see manufacturers possibly thinking selling a three channel radio would eventually lead to the R/Cer buying a 4, or, more; but, I would end up being mad I'd purchased the wrong rig to start with.

Suggesting three channels may be a localisms; thought a good idea by people of one club and not by another. I fly mode one, because the majority of members in my first club flew mode one.

UStik

In addition to what has been already said, there may be yet another aspect. Indeed recommending three-channel trainers might be a mere habit today, left over from the days when not even buddy boxes were available. But don't forget that simulators (especially the computers needed for them) were expensive and not common until recently. And I wonder how many beginners don't have an instructor on a buddy box, either. So maybe several people are more or less on their own whith their first airplane.

Attached is a remarkable page from a more than 40 years old catalog. Todays three-channel trainers are not that different from the old rudder-only model. They are still high-wingers with much dihedral and decalage, so they are "self-righting" both in the pitch and bank axes. In the 1960s we were told to leave the model alone as much as possible and if we had upset it, anyway, leave it alone again because it would recover on its own.

Most remarkable on the catalog page I find the statement "the more controls the more harm". I was baffled when I read it again after 40 years. Today, I find it harder to fly without ailerons, as supposedly you all as well. I tried out in a simulator and it's true, it's much harder. So the essence might be the self-righting capability of the model needed by a beginner who is on its own. With a buddy-box instructor or even a simulator you can just skip that learning phase and save you the hassle learning with a plane that is unnaturally/overly stable and later re-learn "real" flying.

After all, it's not only about replacing rudder by ailerons, it's about this unnatural stability. I remember a discussion of the Telemaster as a trainer. Of course the TM (designed by K.-H. Denzin) is a very good trainer, but I think a rank beginner needs an instructor on a buddy box. The TM is very slow and very well behaved and very stable but it is not self-righting. As long as the beginner is lacking the (unconscious) righting capability he needs some help, be it an instructor or a self-righting model.

One last aspect, looking at the old catalog page: Seems those people were quite clever (and honest) in rising sales. Obviously they thought that a beginner who crashes his first model would give up and never come back to buy another one. Therefore they tried to convince him of buying a suitable model so he would later come back and buy many more nicer (and more expensive) models. Is it really different today?

buzzard bait

I flew three channel for years before getting my first aileron plane. It really didn't matter. I didn't have anything to re-learn, I just turned with ailerons instead of rudder. Well, one exception: before I flew my first aileron plane I used my computer radio to work my three channel rudder from both the left and right sticks so I could get used to steering with left stick on the ground. Then switching to ailerons was effortless.

Starting three channel didn't teach me to use rudder on the aileron planes. On an aileron plane rudder is used for yaw. But three channel planes are designed to have strong yaw-roll coupling so they can do banked turns with just rudder - in effect, the rudder is actually used for roll, just like ailerons. It only really functions for yaw in a stall turn when the plane has no forward motion and the rudder is working on the prop blast.

I thought three channel trainers pretty much disappeared years ago, but now they are making a comeback in the form of small, cheap electrics. I think they are fine for starting out. Jim

dhal22

i built my kadet mk 2 back in the early 80's with rudder only. however it was plugged into the aileron channel and i learned to turn with the right stick that way. when i moved to an aileron controlled plane i was ready to go.

UStik

Well, of course I did the same. And maybe re-learn is wrong here. Obviously you acquired a lot of skills flying a r/e or even rudder-only model so moving to a three-axes plane was not a noticeable problem. But don't forget rudder against adverse yaw and top aileron, especially important when flying slow trainer-like models. That's all avoided using a r/e plane and has to be learned later unless you move directly to a fast and neutral pattern plane.

My point was that a "normal" airplane is not self-righting, both in bank and pitch, and has to be flown habitually. Once you've acquired these "habits" there's no problem at all. But before you can do that you have to acquire the reflexes to steer a model, and that's where you need help. Maybe that's why they said "the more controls the more harm" and didn't even mention "re-learning". Sorry for that.

Lafayette

"2)PRO: Ailerons add complexity to the build. CON: Who still builds their trainer? "



Hey! I build my planes still. In fact, I am trying out RC now after reading loads of books on aerodynamics. I am currently building my trainer. You may think that I am close to 50 right now, going the old way, but I haven't even reached my 20s yet . ARFs I just don'
t appreciate, or RTFs. Sorry.

TruBlu02

I have seen a large increase in the number of three channels showing in the market. Really it is only in the small cheap electrics that I have seen. I have flown a couple of them and even those planes have the stick on the right so really it does not make much of s difference. I learned to fly back in the late 90's When the ARF's first started being so mainstream. I got a Thunder Tiger Trainer to learn on and had a buddy box. For me learning with a high wing 4-channel trainer was really no big deal. As far as I know none of the larger trainers available on the market today are three channels anymore. About 6 months ago I wanted to get a new trainer for letting friends fly. I got a Tower Hobbies trainer for $80 and sl;apped a TT Pro .46 in it and called it a day! You really couldn't ask for an easier plane to fly. I would never reccomend a newbie to use three channels anymore. There is just really to many great 4 Channel ARF trainers out there.

rmh

The model a person uses as a primary trainer ,is typically thought of as the "best" .
If you try to design a primary trainer which works best for most beginners - the selection changes .
I learned on a model I designed - and it worked just fine.
The catch is that I was a free flighter and a control line stunt competitive flyer- first - So I had a background in what works and why and how it works.
In teaching newcomers -i used a number of types and settled on the type which worked for th emost flyers .
A slow 3 channel type. The Seniorita by Sig I still thingk was the best.
It was not a beginner's building model .-
I thought it was too difficult for rank beginners.
But setup properly and using a ruddr/aileron mix. -It prooved to be a good model for training purposes
The model was very controllable at even very slow speeds and could be trimmed easily to demonstrate low power flight and reasonably faster flight.

Also the model was self righting. and could also be used to demonstrate stalls/ trimming for various speeds and other typical mustakes, all very easily

Most importantly, it could easily be flown in close and in a "box" , in order to practice exercizes like figure 8 and looping.
landing approaches could be botched with no damage as the wire gear simply splayed and would recover or could be re bent by hand.
Easy to see and flyover a very wide speed range.
Bad learning habits were easy to avoid as the fear of "messing up " were greatly reduced
All in all, the confidence level acheived with this type model was very good.

Now, a beginner can learn basics on a computer program and if desired , go directly to a foam. electric model for actual flight practice with no fear of costly damages .
It just gets easier n easier.

TFF

I like 3 channel planes. Many of the new flyers show up at the field are not airplane people(yet), so they really dont know what they are getting into. Kids are easy but the older people who dont know how a plane works have motor skill challenges that require reprograming. Everyone is showing up with these electric T-28s; neat plane, but they are too scared to mess it up and they panic because they worry about the plane instead of work through the problem so you have to take over from them all the time. I can slap them on my sons 3 channel Kadet and it does everything slow enough for the "other left" to be found. I built my sons Kadet as a 3 channel as he is not really into the plane thing, but makes the success easy enough for him to not mind being out there and not get discouraged. The new simulators are great but the question is for the ones who learned without it, would you give up all you learned along the way for the quick new way?

Tall Paul

For 3-channel planes, I mix the aileron to the rudder.
This gives steering on the ground, and steering in the air.
Upgrading channel wise doesn't require re-educating the thumbs.

TFF

I wish I put an extra servo in my sons plane for steering no mixing on his radio. That is for my retraining.

Falsifly

Anyone remember the Ercoupe? A full size plane that had the ailerons and rudder coupled on the control wheel. No rudder peddles!

Any way, IMHO if you are learning to fly why not start with all the control surfaces working? One less thing to worry about, less confusing, easier to fly? Come on! I did it. I think the most important thing is the A/C itself. A slow stable trainer properly powered and rigged is the key. And come on guys, you my steer an airplain on the ground but you don't steer it in the air you fly it.