Not that it matters a lot, Bob, but I've been teaching people to fly RC for 20-plus years. I know you use this "keyboard pilot" charge against everybody you disagree with, but without evidence it's meaningless. You are right in urging the OP to practice, but he should practice the right things. Do you really agree with the claim that, when not doing aerobatics, the best way to turn is with your controls crossed? That was the OP's question. Almost everyone who responded said "no." Are we all wrong?

I like that Pilatus porter in the video. I'll have to look for a foamie. I'm not into building currently.

When you first start out and you're on a buddy box, there's a safety net of sorts. When you get past that; I'm just glad these planes aren't real expensive and mistakes aren't so costly. It's not sky diving!!!. Anyone ever heard that saying "if at first you don't succeed-don't take up skydiving"!!!


Regards

LOL, no haven't heard that one but I like it.

I agree, practice does make perfect but practicing wrong technique? That only makes you perfectly wrong.

There was a story going around when I was learning to fly in the 80's about a pilot who would start his turns with rudder, he was never picked up on technique until getting his command on a 727.

After flights he would report an 'unknown vibration' during turns.

Maintenance would take a look find no problem and the plane would fly with another captain with no issue.

After this occurred several times the airline took a closer look at the captain and a check pilot flew with him on several flights.

It turns out he was leading turns with rudder, holding opposite aileron to prevent over banking (just like that vid) and occasionally applied enough aileron that the Roll Spoilers deployed on the wrong side for the turn, hence the vibration.

I think the OP did exactly the right thing, wants to learn, researched some videos and then asked others to comment on the validity of things he had seen.

Practice is good but it is important to practice the right technique.

I asked a lot of questions when first getting into electrics and then helicopters and the advice given was generally good and appreciated because it helped me a lot.

Excuse me but I don't understand why full size aircraft and professional practices are included here.
As far as RC air planes and the OP, a lot will depend on the airplane you are flying. Take it up high and practice rudder only, aileron only, (elevator will be needed), aileron & rudder the same side, aileron & rudder opposite. Normally, small heading changes involve small amounts of rudder, turns in general will be aileron and elevator, BUT depending largely upon the amount of dihedral, the airfoil, air speed, and whatever you feel comfortable with for any given model, just do it. Unless you are heading towards the goal of becoming a "pro" flyer, getting the plane up and down in one piece counts the most to start.

Just my 2 cents worth on this subject.

Model aircraft are actually just small aircraft that fly according to the same laws of aerodynamics as large aircraft.

Generally a pilot, RC or full size, should have a basic understanding of aerodynamics (I know it is not mandatory with RC but it does help)

The training of a pilot in full size aviation is no mystery, flying schools, military training schools use approved and proven syllabi.

If you are going to fly RC aircraft, why not understand correct aerodynamics and techniques? The correct techniques work in RC planes perfectly.

Yes you can "get away" with wrong techniques in RC planes but if you have a choice why not learn the difference between good and bad practice and do it properly?

I was a full size instructor, but I have been an RC pilot for longer.

Some RC pilots also learn to fly full size aircraft (and vice versa) In my experience, I probably trained a dozen students with previous RC experience, in virtually all cases that experience proved beneficial because they understood the jargon, and had a generally good understanding of the basics of flight controls.

Some knew about adverse yaw, and the use of rudder, and some didn't.

With every student I trained I would ensure they knew the difference between a skidding turn and a slipping turn and experienced a stall in a skidding turn situation (causing rapid spin entry). I wouldn't give them a licence unless they demonstrated this knowledge and how to identify dangerous situations and avoid them.

In real life, a lack of knowledge can kill you. In RC, you might lose a plane. How many times have you heard RC pilots say "the plane stalled on me"

No it didn't… A plane cannot stall by itself. It stalled as a result of the inputs to the controls by the RC pilot who lacked the knowledge or experience to recognise the aircraft was approaching a stall. Having a good understanding of aerodynamics can help RC pilots avoid crashes.

You don't have to know a thing about aerodynamics to bank and yank an RC aircraft around the sky and some people fly that way their entire RC career and have fun doing so.

That is totally cool, but in my opinion, if you want to be an experienced and knowledgable "RC" pilot, it helps to understand the whole gamut of techniques used in real aircraft.

Its up the individual of course because the FAA does not test the knowledge of RC pilots. I have never seen an RC club that requires students to pass a theory exam before being allowed to fly solo. At the end of the day, RC flying is all about having fun. So if bank and yank works for you then go for it.

+1

To add to it, I wish I had a dollar for every time I saw a plane spin in due to "interference" while they held full throttle, full opposite aileron and full up elevator, but it "just wouldn't respond." Yes you can learn to just point and go, but why would you when there is a world of free information out there.

So what exactly is "adverse yaw". I am imagining it must be yaw going the wrong way, ie, you are wanting to turn left; the plane is banked left (roll axis) and the nose is pointed right (the yaw axis).

So do some planes do that as part of their design; or is it a control issue?

Regards

Rob, I'm still going to disagree with you some here. While the same aerodynamic physics apply to our models, it is not a lateral crossover. I realize that I am repeating myself here but because of lower wing loadings and higher power to weight ratio models have a larger performance envelope. IMO getting hung up on all the full scale practices and or flight techniques means you are not exploring anywhere near your models potential nor yours. Now if that's your thing more power to you however some of us WANT to push that envelope. This means that we can and will do things that buck the full scale convention. Then again imagine if Art Schol or Leo Loudenslager didn't push the envelope? Am I correct when I bring up the fact that you did an aileron/rudder mix on your SE5? That's not full scale practice ( except Eurocoup ) I guess the point is that as R/C pilots we should not be held to the limitations of full scale aviation. To me it's irritating that when I instruct someone on a certain aspect of his R/C model just to have someone come along and say " that's not how we do it with real airplanes" well guess what I really don't care how YOU fly your full scale airplanes, I'm flying a MODEL and have zero interest in flying full scale. Name just about any R/C flying event and I have done it at the top level. Helicopters, sponsored pilot for GMP and then demo pilot/designer for Century. Sailplanes, 1996 US team selection finals. IMAC 2006 SW region runner up advanced class. Pylon 2012 Triangle series unlimited champion, 2013 Triangle series .46 modified Champion. I've had a few local pattern wins as well. Im not throwing all this out to brag. If that were my personality it would be reflected in my RCU profile, I'm just reinforcing the fact that when I offer someone advise it's because I have delt with the same issue as it applies to a MODEL. If you want to talk models then please do so I invite that conversation. If you want to talk about full scale piloting techniques then please take that conversation to the full scale forums.

Your explanation is correct. For most models it's an adjustment of having the aileron that travels upward have more travel then the aileron that travels down. This is because the downward aileron produced more drag then the aileron that moves up. The correct term is aileron differential. If your airplane has dual aileron servos you can mechanically offset your servo horns to do this mechanically or your transmitter most likely has an adjustment for aileron differential. If the airplane has a single aileron servo you must do it mechanically. Here is an example of mechanical differential, notice in the picture the ball links are positioned slightly aft from the servo arms center.

Speed, the issue I have with what you are proposing is not whether or not a plane can be operated in a manner inconsistent with full scale flight, but whether or not you need to understand how it works. Models and full scale alike will spin if you enter a Stall with enough yaw, and if you don't understand what is happening you will most likely use the wrong inputs to correct it. That is just one reason it is advisable to learn how and why aiplanes fly

The issue with that is you are assuming that I don't know how an airplane works. At least that is what I'm getting from your post. I assure you that I do otherwise I would not have been capable of designing the sailplane that took me to a team trials or the pylon airplanes that netted two championships. Most of my basic helicopter theory came directly from Stanley Hiller whom used to come into the hobby shop I worked as a young adult. I will agree that crossing controls on a Cessna is a bad deal however on a model with a fraction of the wing loading and a ton of power to get out of trouble it's a whole different ball game especially if the airplane is set up correctly as a model and not set up to fly in the same manner as a full scale aircraft. Remember I have been at this for a long time, 36 years to be exact. I have been in the retail end of the hobby when customer service meant something. I have seen countless models set up with full scale mentality thus leaving a ton of performance on the ground. IMO telling someone that our models fly the same as full scale is akin to telling someone that full scale Extra 330SC should be flown the same as a 737. Obviously that would be ridiculous just as telling someone that a model flys the same as a full scale aircraft.

Nothing wrong with pushing the envelope with advanced flying techniques and manoeuvres in models that are impossible in real aircraft. Heck that type of flying really does impress me (genuinely)

But this is the beginners forum and using rudder to compensate adverse yaw is a very basic concept taught to every student pilot in the early stages of flight training. I think it is very relevant to a beginners forum.

I think you might be surprised how many real aircraft do use an Aileron / Rudder interconnect of some type. Either a mechanical interconnect like some Piper, Grob, Beechcraft, CT4B air trainer aircraft or with a Yaw Damper on larger aircraft.

One of the functions of a Yaw Damper on virtually all turboprop, corporate jet and airliners is to correct for adverse yaw induced by ailerons.

So I have to disagree with you because an Aileron / Rudder "mix" of sorts is most certainly full scale practice.

As for my SE5a, if I was flying a real one, I would be the interconnect by coordinating rudder input with my aileron input to correct adverse yaw.

Perhaps I should be doing it manually with my RC models also and controlling the rudder myself to coordinate the turns, but as mentioned in a previous discussion, I am too lazy and the electronic mix in the radio does a superb job of providing exactly the rudder needed to compensate for adverse yaw. (after experimenting to get the right percentage mix for each aircraft - I only use it for lazy sport flying in my scale models and not in my aerobatic planes)

You are certainly free to fly your aircraft however you wish. As is anyone, but just because some of us fly full size does not mean we are not legitimate RC pilots also.

The question raised by the OP was using rudder to turn an aircraft and using aileron to reduce the bank. Even if I was an RC pilot with no full size experience, (which I was for 3 years) I would have jumped into this thread, based purely on my own experience as an RC pilot who was taught by a very good RC instructor (with no full size experience) never to turn that way.

So my argument in this thread would be identical if purely based on 35 years of flying RC aircraft.

To answer your question JPerrone, Adverse yaw comes from different drag on each wing when the ailerons are deflected.

The down going aileron changes the camber of the wing, producing more lift, but the penalty of lift is drag, so the down going aileron produces more drag.

The up going aileron reduces the camber (curvature) of the wing and this reduces lift and reduces drag, so you have different drag on each wing.

This will cause the aircraft to yaw, in the opposite direction to the roll. IE roll left, the aircraft will yaw right. Applying rudder in the direction of the roll will compensate for this adverse yaw. Adverse yaw is only there while ailerons are deflected. Not when they are neutral.

Speedracentrixie correctly states that adverse yaw can be minimised by the use of differential ailerons, and also by the use of Frise ailerons, where the up going aileron projects a portion of itself into the airstream under the wing to deliberately increase drag to balance the drag on the other wing.

These two design features work very well.

Here is a beautifully constructed Frise aileron, (on an RC model to keep it relevant to Models only)

http://www.youtube.com/watch?v=jtd9Bo7VW3U More reading on Adverse yaw here, with good explanations of how adverse yaw is corrected - I don't make this stuff up.

http://en.wikipedia.org/wiki/Adverse_yaw

Here is a beautiful statement from that article about how Adverse Yaw can be corrected.

The effect can be greatly minimized with ailerons or other mechanisms deliberately designed to create more drag when deflected upward than downward and/or mechanisms which automatically apply some amount of coordinated rudder.

If you still don't believe me, here is a NASA paper on the subject.

http://www.nasa.gov/centers/dryden/p...main_H-584.pdf

With some notable extracts.

The aileron-to-rudder interconnect was found to be effective in compensating for adverse aileron yaw, and turns could be made easier and more accurately

and

the preceding relationship implies that turn coordination can be achieved relatively simply by filtering a signal proportional to aileron position and applying it to the rudder.

That last one is exactly what an Aileron / Rudder mix does in an RC aircraft.

This is getting comical. So now you want to illustrate different hinging methods that the OPs airplane obviously doesn't have rather then just agree that the fix for most models with adverse yaw is aileron differential and has been for at least the 3.5 decades I have been flying. Worst case scenario would be to mix in some rudder but we seem to agree that's it's best to do manually, then you go right back to your crutch of throwing out published works on full scale flight again. Are you even capable of answering questions about models based on personal experience or just quoting what someone else wrote about full scale flight?

I did agree that differential aileron was an effective fix in most models, and so is a frise aileron. Do you disagree with that?

I found a few more articles on the subject, specifically written for beginners learning to fly RC aircraft.

http://www.rcflightschool.com/Basic_...lo_0B16-25.pdf

http://www.rcflightschool.com/SetupP...dderMixing.pdf

It is not the truth of your statements as much as the level of the audience. You can cross the controls in a Cessna and get away with it, and yes most of our aircraft are more than capable of flying well beyond a Cessna's envelope, but just as you know how an airplane flys it is necessary for a beginner to learn at some point if they are ever going to really progress. A beginner can learn by trial and error and sifting through the variety of good and bad advice on the internet, but why not just spend a little time at the start and learn it correctly so that they can go out with a good foundation to build on?

How many models do you see on a typical weekend out at the club site with frise hinging? As far as the articles you found about an R/C school advocating the use of aileron rudder mix is just wrong. But guess what, that guy is a full scale pilot and he is doing the same thing you are and that is convincing yourself that we should be piloting our models the same as we do full scale. I understand that you just don't get what I am saying here and maybe you will eventually get to the skill level as an R/C pilot where you can understand. I think this thread has gotten way off topic. My efforts have been to just point out to beginners that full scale principals and techniques need not always be applied with our models. If it were then 3D flying would never have happened. From my viewpoint you seem to have the opinion that if it does not work for full scale then it won't work for models and that is just plain wrong.

This I can agree with, I do feel that a beginner R/C pilot needs to learn how an airplane fly's but as it applies to his model and not a full scale aircraft. This is where we will disagree. I believe there are enough differences between full scale and models that if one is taught with full scale mentality then his models are going to be lacking proper trimming and he will be accepting a limited flight envelope. I have seen this many many times over the years. The most frequent example is full scale pilots teaching R/C pilots that different pitch trim is required at different air speeds. An R/C model properly flight trimmed will not need this and will hold pitch trim at all flight speeds.

JPerrone, to answer your question 'what is adverse yaw' :
(this example is specific to using ailerons to bank the airplane)
when a wing creates lift, (by moving through a relatively stationary air mass) that wing also creates drag,
but it does so at a different rate. in other words, if you double the amount of lift a wing is making, you increase the drag it's making by 4.
in the case of an airplane using it's ailerons to bank, (lets say to the left) the left aileron goes up, the right aileron goes down.
the right wing begins to make more lift that the left wing, therefore the right wing begins to make significantly more drag, while at the same time the left wing makes significantly LESS drag.
think about it: we're banking the airplane to the left, during a left turn, the left wing has a SHORTER distance to travel, yet the right wing is making much more drag than the left wing is.
and that at the end of the day is the 25 cent version of why rudder is (usually) needed during a banked turn in the first place.
the more adverse yaw created, the more rudder is needed.

by using differential aileron control, we make the ailerons move UP more than they do down.
the goal is to make it so the difference in the amount of drag each wing panel makes is not as drastic.

Speed, I am not trying to argue with you, I am simply posting information on aerodynamics. If any of my posts are technically inaccurate please identify the errors?

Let me ask you a question. Do you have a full size pilot licence? How many hours do you have flying real aircraft?

No doubt you are an accomplished RC pilot with a wall full of trophies. But without any real flying experience in real aircraft, how do you know full scale aerodynamics and techniques don't work in RC aircraft?

You missed my point in mentioning Frise ailerons, The OP asked "What is adverse yaw" I explained it and also described ways it could be minimised in any aircraft, full size or models, IE Differential, (where I agreed with you) and Frise ailerons.

Sure you are right that not many RC models have Frise ailerons, but that does not negate the fact that they are a valid design feature to reduce adverse yaw. Again, am I technically incorrect in saying so?

Remember this is a beginners forum, how many beginners do you see on a typical weekend learning to fly in a perfectly set up aircraft with no roll / yaw coupling?

We are talking about learning the foundations correctly, once that knowledge is in place, then the pilots can experiment with aircraft and piloting techniques that expand the flight envelope beyond anything a real aircraft is capable of.

Not everybody is in this hobby to win 3D trophies, I know many RC pilots who only fly scale models and want to fly them as accurately as possible to the full size example. For them (and me) the biggest satisfaction in this hobby comes from watching scale models flying like a real aircraft.

I'm not saying that full scale techniques don't work, I'm saying that they work differently and can't always be laterally applied. You are correct, I am not a full scale pilot, I do have a few hours in a C152 but that's about it. I grew up around airplanes, my father was career air force and I took all available aviation classes I could all through high school. Still I admit that my full scale knowledge is limited. My comments are based on years of seeing full scale pilots getting into R/C and then setting up the airplanes to operate much the same as full scale and then struggle with a model that could be made much easier to fly. That brings me to your last sentence. Shouldn't that foundation include teaching a beginner to to trim flight his airplane to be as easy to fly as possible? Correct me if I'm wrong but my perspective is that with full scale you simply accept that it has certain characteristics because there is really nothing you can do to change them. A good example is that full scale aircraft has to have slightly forward CG to accommodate passengers and/or cargo. Our models CG should be more or less a fixed position so we can adjust it to more a neutral position and reduce the need for pitch trim adjustments considerably. I'm simply saying that taking a different approach to models as opposed to full scale will lead to a better model pilot in the long run.

IMAC which has been what I have invested most time in is actually modeled after the full scale IAC and shares the same maneuver catalog. The judging criteria is the same as well so in fact we do try to emulate full scale aerobatics as closely as we can. That doesn't mean that I should put up with the same pitch couple when rudder is applied that the full scale Extra 300 exhibits. 3D is a different animal all together then IMAC

Speed,

The OP is a beginner, flying a trainer. He asked whether the best way to turn that trainer is with his controls crossed. Several of us have said no, and given reasons, such as the risk of spinning if he stalls with the controls that way (not likely with a trainer, but some other kinds of models get wiped out when people do that). And trying to turn a giant scale cub with the controls crossed would get you something really ugly, even if the plane survives.You have told him he should cross his controls when turning. But you give no reason except for saying that pattern judges insist on flat turns and that he can probably get away with that. Why do you think he should do that? He isn't asking about how to fly pattern planes.

Al go back and read all my posts, not once had I suggested that he make turns with crossed controls. Nor have I said anything about flat turns in pattern in fact if you knew what you were talking about you would realiz that a pattern sequence has no" turns " at all. I simply stated to the OP how it was that I dealt with a cross wind. Then I got the barrage of " Thats not how we do it in full scale " Guess what guys, we aren't flying full scale. If you can't make the distinction then IMO you will only reach a certain level of skill as an R/C pilot. If your OK with that then who am I to judge? In the end this hobby should be about having fun.

In post 139 you told him to deal with a crosswind this way: "rudder slightly into the wind to keep your ground track. Your trainer will have a roll couple so you will want to counter that with opposite aileron." If that isn't turning with crossed controls, what is? Turning to set up a crab is turning, isn't it?