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?

I confess to being the OP and therefore the instigator of this thread (!). It's been very interesting and I think I've learned a lot. Some of it I will probably think about and I'll probably come back to re-read some of the entries.

After all that's been said, I believe that I WON'T attempt cross controlling at this time, I'll use some other method to learn how to use rudder but not cross controlling.

The frise hinge was interesting, and the example looked like a work of art. It looked like at one extreme, the front of the aileron was exposed to the airflow and would have partially balanced the force on the control surface. Was that the intention? It only does that in one direction so I am assuming that was the desired effect.

Some people have made the point that the models fly just like their full scale brethren; however, there IS one big difference. That is the POV of the pilot. A full scale pilot perspective is always the same; he/she is looking out the windshield of the plane. The RC pilot is sometimes looking towards the plane coming at him/her, other times at the plane flying away, and also from the side. I'd say that is different... A full scale pilot also has instruments, the string thing, and lets not forget the seat of the pants thing.

Regards

Al, we would seem to have different definitions, The way I see it, holding a very slight amount of rudder to hold ground track is not a turn. I fail to see that if the airplane's ground track is strait regardless of the control input how it can be considered a turn. I suppose you would consider a knife edge pass a turn, after all the wings are banked and rudder is applied right?

In knife edge you are opposing the very real force of gravity being applied to the side of your aircraft. Holding rudder in this case effectively gives your fuselage an "angle of attack" to the airflow and this, plus a component of engine thrust balances the force of gravity.

In wings level flight, there is no such force acting sideways on the aircraft as it is flying within the moving air. Its a different scenario, there is no such thing as horizontal gravity. Let me ask a hypothetical question, how would you fly knife edge in a zero g environment? (Ie flying an RC aircraft inside a space craft) Would you need to hold rudder? and what would happen if you did?

Thanks for the laugh Rob but I do know the dynamics of knife edge flight, I was being sarcastic with Al. So now we are flying our models in space to prove out your point? This is getting a little on the silly side. All I'm saying is that you guys seem to have the pre disposition that if you can't do it with your full scale aircraft then you can't do it with the models either. All I'm saying.

Al seems to think that every time rudder is applied it's going to result in a turn.

Now that we are flying in the space station as it orbits the earth. Once air born does the model slam into the wall because it is no longer moving with the station? Or does it move with the air in which it is flying?

:) if you have a cargo airplane full of caged birds.... :D

(don't get me started on Flight Engineer stuff... now you're bringing back some memories! :) )

I have a question, if your plane is trimmed for straight and level and you hold rudder, even a little, won't it just continue to yaw? In my world when you apply a control force it will continue until it is released or an outside force acts upon it.

I'm pretty sure that was beaten to death errr I mean 'discussed' about 140 posts ago...
yes, if you hold rudder the airplane will continue to yaw. (on the planet earth, with the airplane (as defined by Miriam Webster) upright / essentially straight and level / in 99.9% of the cases)

cfircav8r, I think this is where the split in opinion is happening. I am of the opinion that the cross wind is the outside force and the applied rudder is to null the effects of flying in a drifting section of air. Remember the goal is maintain ground track. So essentially the guys are correct in that the airplane is constantly turning but at the same rate as the air is moving. kinda like walking the wrong direction on an escalator at the same speed the escalator is running. Sorry best example I could think of at the moment.

This is simply wrong. A steady crosswind carries the plane in the direction in which the wind is blowing, but it does not change the plane's heading. Applying rudder changes the plane's heading, and until the rudder is neutralized the heading will continue to change. It is therefore impossible for applying and holding rudder to "null" the effect of a crosswind, unless you do something else like using opposite aileron. Or neutralizing the rudder once you've reached a good crab angle.

I thought we had agreed on this quite a few posts back.

OK Al there is no way we are going to settle this at a keyboard. Next time you are out flying in a cross wind try flying passes back and forth 200 ft out using a 1/2 cuban at each end to turn around making rudder corrections only at the end and see how that works for you. I have coached enough beginning IMAC pilots to know the outcome but I realize you will need to see for yourself.

this thread needs to be longer and needs more input from " experts " on some of the most basic and easy flying functions ,

Speed,

I don't deny that you can keep your plane on a straight ground track in a crosswind with rudder corrections. I just deny that you can do it by applying rudder and keeping it applied, which is what I understand you to mean by "holding rudder.". What is your reasoning here? Is it that the crosswind changes the plane's heading? Or that applying rudder doesn't change the plane's heading? Unless one of those things is true, and neither of them is, applying rudder and keeping it there will not offset a crosswind.

LOL.. It should actually be true on any planet with an atmosphere.. Try Austin Meyer's X-Plane - you can design aircraft and test them in an accurate Martian Atmosphere.

http://www.youtube.com/watch?v=-mKDbDO174I

Well I agree with you and so does my crutch. NASA.

https://www.grc.nasa.gov/www/k-12/airplane/move3.html

I'm probably late on the discussion but way too many modelers just fly bank and yank and never learn different then teach new people how to fly and the newbies learn the same and no one ever learn how to use rudder or even fly in a right hand turn because it was hard enough to learn to keep a plane in the air by bank and yank so once they learned that and were successful they never cared to learn anything else as far as pilotage and full controlling the plane.

This is is honestly dangerous and I don't let my students solo until they can taxi, take off in a strait line and land with a slip on the runway. If they don't learn to use the rudder takeoffs can go hard left and into the grass or people or crash the plane. Landings can be way off the runway. Crosswind operations are impossible and scary. Slow speed flight can turn ugly and aerobatics are always ugly without rudder not to mention your very limited in what you can do in the aerobatic box by ignoring the rudder.

I always suggest the first airplane should be a 3ch rudder/elev/throttle plane like a powered glider or slow stick or a simple cub like the PZ cub. This will teach the left thumb to work right off the bat and honestly you use the rudder and elevator in coordinated turns way more than the ailerons. Ailerons start and hold and end the bank. The rudder pulls the plane around the turn and the elevator controls altitude.

For those pilots who do not use rudder its never too late to learn and its nothing to be ashamed about not knowing yet.

Take ke a step back and get a trainer out and learn it. Practice using only rudder to turn.
The best trainer for this is a telemaster because they will not turn without rudder!

After er you can do a pattern in a coordinated faction practice figure 8s and then move on to forward slips to landing and knife edge slips that hold the slip but using throttle to hold altitude across the field.

Seriously, If you're holding in rudder you're doing it wrong. Now you may be doing it wrong better than those who are doing it right, but it's still wrong.

There's no way your plane won't change heading if your wings are level and you're holding in rudder, and if you're changing heading in a constant crosswind then your ground track isn't straight. You WILL have to lean on the rudder during each pass IF you start the pass slightly nose in and you need to hold it out by arcing the baseline.

The only way your plane won't change heading if you hold in rudder is if your opposite wing is low as it would be in a side slip case. Back in the day with skinny fuses you could get wonderfull (flatish) sideslips but now with modern F3A ships you need a 45deg opposite bank angle otherwise when you poke in the rudder your plane will just do a 180 and head back the way it came..

Are you saying that you set the transmitter up so that the typical aileron input (right stick in mode2) results in nothing?

Kurt

If you have a 4ch plane and really want to learn rudder control then you could setup a switch to turn the ailerons off, sure. Then flip it on if you get in trouble or an attitude where the rudder isn't enough to correct it and flip the aileron back "on".

But it for sure always use rudder on the rudder stick. I have to clarify that because a couple new pilots I've taught, after suggesting only useing rudder for a time, just unplugged the ailerons and plugged in the rudder on the aileron channel. This really doesn't teach anything other than the plane can be manipulated by rudder. It didn't teach them to use their left thumb.

Tough call on that one. Traditionally the rudder is operated from the aileron stick on a 3-channel plane but this has caused minor problems down the track when switching over to 4-channel planes and the "aileron" stick now won't keep the plane straight on takeoff or on a bungie/winch requiring the previously unused rudder stick to get some action. I can see the reason for having it "correct" from the start but it might be a mode I vs mode II human factor thing?

Now I'm experienced (?) I set up my 3 channel planes with the rudder on the correct stick BUT mix it over to the Aileron stick as well so I've got rudder on both sticks. Sometimes I find myself holding in a bit too much rudder and a bit of opposite "aileron" during a thermal turn like I do with the DLG ????

I thought that rudder on right stick for a 3ch was right; because you are mostly using aileron for turning, and the right stick becomes the "turn" stick, whether it is using the rudder (3ch) or aileron (4ch).
However, "thatplaneguy" (TPG) makes a good point. How will you learn rudder if you keep moving it around?

Also: during takeoff whilst still on ground, I want to control heading with the rudder. Right now I have both 4 and 3 ch airplanes; and on my 3ch, "heading" is on the right, and on my 4ch, it's on the left!!! Wouldn't it be better in the long run FOR BEGINNERS to just keep the rudder on the left? The worst thing they would to then would be to try to turn with the rudder rather than the aileron. That's not always a fatal error; not like using down elevator to make a turn!!

I'll admit to knowing very little about how an airplane REALLY works, but I was going to weigh in on the holding rudder, on the basis of the resultant forces. Rob2160 found the perfect link to explain this. But here it is in my words

When you have cross wind, some of the wind is trying to push you to one side, some of it is along the path of the craft (this is breaking the wind into its vectors). In the absence of this force, the aircraft would have a vector parallel to the strip. However, the sum of these forces results in the airplane moving in the direction of the strip, plus a little bit to the side. The nature of this can be deceptive, as the aircraft HEADING is straight down the strip; but it's moving sideways!!

Now if you want the aircraft to follow a vector parallel to the strip, you need to introduce a force offsetting the sideways force. Some people think this is caused by the shape of the craft, some by the engine thrust vector. I think it's the thrust vector. You use the rudder to change the heading of the plane. It is just enough so that the thrust vector in the direction opposite of the wind is equalized. The aircraft will have a slight heading into the wind; but it's vector is parallel to the ground. This looks like all the crabbing videos although maybe crabbing is not the correct term.

Now if that is correct (I'm no expert right so maybe this is wrong. But the dynamics and vectors sound right, and agrees with NASA and they put people on the moon....) then if you release rudder; you take away the small component of force maintaining your heading and vector.

Did I miss something?

Regards

Yep you missed something.

Your plane is pretty much always flying aligned with the airflow until you poke the rudder in. Wind or no wind when you poke the rudder in you yaw the plane to one side, the fuse generates a sideways force which changes the flightpath and when you let go of the rudder the plane points back into the airflow again and your plane continues along the new flightpath. If the airmass is traveling across the ground at an angle to your flightpath (ground track), you won't be going to where your nose is pointing.

If in a "crosswind" you start out flying towards something with your nose pointing at it, you will drift to one side and need to apply rudder to keep the nose pointing where you want to go, but you're flying in an arcing groundtrack (your compass will be moving), NOT straight (compass not moving) which is why you need to hold the rudder in. Guys that fly long distances please ignore the compass moving/not moving references ;-)

Yes, NOW I understand. And this explains an observation I made, which is that my airplane only wants to go in one of 2 directions!

Let's say the wind is coming from North (call it 0 degrees). Let's say the airplane is heading towards the north. So, I am now aligned with the airflow. That direction, and the opposite one (south, 180 degrees, flying aligned with the airflow in the same direction as the wind) is the only OTHER direction my plane can wants to/can fly.

Oh, but that's not always true, I don't think. In fact there are times that I've been able to fly my plane at 30 degrees; 90 degrees; 270, and a lot in between. And most of the time, I got to that direction by turning (rudder, aileron, or combination) and once vector is established, I return surfaces to neutral. The plane seems like it is staying on that new heading, which is NOT the same direction as the wind. Unless there is a different definition of the term "aligned" then the airplane is actually flying in a different direction of the wind.

Just as in sailing, there is the "apparent wind" which is the wind direction that the aircraft experiences. This would be the resultant vector that is the summation of the wind vector, and the aircraft vector. This tends to make the apparent wind somewhere between the true wind and the aircraft vector. The nature of vector summation is that it is difficult for apparent wind to equal true wind.

Or is there something I'm missing?

Regards

It's that vector thing you spoke of. If a wind of 20 kn is coming from the north (say 0deg) while you want to fly east (say 90deg) with a groundspeed of 100kn then you'd need an airspeed of 101.98kn and your nose would be pointing 11.3 deg north of east (say 78.7deg).

Your plane would be flying straight and level and happy to stay that way and you'd still be pointing north by 11.3 degrees as you fly directly over the target tracking due east over the ground.

IF you started out pointing due east with 100kn airspeed, your ground track would be 101.98kn @11.3 deg south of east so you be leaning on the rudder all the way to not only fix the initital 11.3 deg error from the start but also to make up the lost ground from flying slightly south for a while..

What you described is exactly what I was thinking. Force diagrams are easier to explain this stuff; but I'm not good with computer stuff and applications.

Thanks!!!

Force/vector diagrams would explain things easier it but you're right about the computer graphics.

With a sailing boat you've got a moving airmass and moving water mass to worry about to get from point A to point B :-)