The wind won't get you too bad once you are up in the air. It's on takeoff and landing that it can bite you pretty fast. Use plenty of speed and learn to crab. When you come in to land, I always find it easier to come in a little fast. Just saw a guy last weekend bust his plane up coming in too slow, trying to harrier his yak with a cross wind. If he would have just greased it in instead of trying to float it down it probably wouldn't have gotten away from him. good luck.

Capo,

You are so right, but the ones who really benefits are people like me.
You can hear them all, try them on the sim and find what's best suited for you and your plane.

Things I learned that all opinions agree:

- Treat a cross wind like a head wind
- Add power for landing just like any head wind
- Use your ailerons but be careful with wind getting under the wing that can produce sudden rolls
- Need to learn to use rudder at the last seconds in order to land straight.

Am I right so far?

OK, to start with, I don't know what you mean by "the controls are reversed." Are you simply referring to the fact that the plane is heading toward you, so your right is the plane's left? I wouldn't ever let a beginner try a landing until he'd learned to deal with that problem. A lot of practice flying straight toward yourself is a good way to prepare for landing.

Next, if "the controls are reversed," why would it be better to use the "reversed" rudder than the "reversed" ailerons? Your apparent belief that it's easier to steer with rudder because of this reversal is why I assumed you thought the rudder wasn't reversed. "Move the stick toward the low wing to level t he plane" is usually one of the first things people learn about flying toward themselves, so it seems to me that aileron use would be easier.

There is no difference between full-scale aerodynamics and model aerodynamics; all airplanes are subject to the same laws of physics. I cited "Stick and Rudder" for a couple of basic propositions that are true of both models and full-scale planes, and which are often misunderstood by both model and full-scale pilots: (1) the plane feels no wind in a steady breeze, except for the relative wind caused by its own motion through the air, and (2) the rudder does not steer the plane (except indirectly, by inducing a bank in a plane with dihedral). Do you deny that these principles apply to models?

If you find slipping to land easier than crabbing, by all means slip. But few other people do.

Do I deny that R/C and full-scale are not different aerodynamically? No if flown in the same manner. But I have seen plenty of guys fly with a trainer that is over powered and it is nothing close to actual aerodynamics used in full-scale. Youre describing characteristics that maintain this thought. Thats why in this hobby there is such a thing as 3d where the power plant is far and away more powerful for the airframe in which it is flown. But again my post directs the question about the rudder. Do you agree that the rudder inputs vastly differ from the aileron input? The aileron input roll rate is much higher (at least in R/C) than that of the rudder so small adjustments can be made without the high rates as with ailerons. The plane "bites more" with rudder but orientates differently with ailerons. Why would you not teach a new pilot all and every aspect and allow him or her their own choosing?

Ask any IMAC pilot if they would rather make subtle changes in their position or have to correct the OVERCORRECT. If you are efficient then great! But we are talking about a beginner here. With aileron you can give a little right, but then what do you have to do? Give a little left especially if its a sport plane. And this type of thought with a beginner is harder to do with much more emphasis on being exact. With rudder input, especially over the threshold, you can make small adjustments to improve your nose position granted you keep your airspeed up.

Im not fighting you Top Gunn. I believe your very knowledgeable in aerospace eng. and aviation. I do, however, believe there is more than one way of doing things especially in R/C. This is our hobby. There are many like it but this one is MINE!!!

I do teach my students to use the rudder. For one thing, on some model planes the ailerons aren't very effective at low speeds, so it's good to have a backup. The SIG LT-40, wonderful as it is, is subject to this, especially if it's a little nose-heavy. And when people get good enough they will want to coordinate turns, especially with large models, and do things like stall turns and slips, all of which which require rudder.

What this thread was originally about, however, was crosswind landings, and for those I teach my students to crab. Telling people things like "just use your rudder instead of your ailerons" isn't going to help a beginner who has trouble with crosswind landings.

It would probably be a good thing if someone with better computer skills than mine could contribute some diagrams to illustrate crabbing. Diagrams with motion would help a lot. Picture is worth ....

The wind will only flip the plane if it is on the ground. Unless there is an obstruction causing low level turbulence you will not get flipped by the wind in the air. Keeping a little power is ok to avoid stalls if you encounter gusts or turbulence, not a steady wind. The extra power on a nice steady wind will make it harder to land, as it will want to float more, giving you even more time to get off center. Using rudder at the last second is the most popular menthod, but not the only method.

I got to say that while there has been some disagreements here this has been a very lively and informative thread! I have learned a few things that I guess I had never taken the time to learn. I enjoy a good informative debate anyway. HarryAngus it looks like you opened a can of worms here!!

This is where I'd be in minor disagreement because using rudder only in approach can allow the wings to not be level - and not having level wings on approach can throw the airplane dramatically off the runway center line.

On crosswind landings without gusts you need level wings. The rudder alone will not keep your wings level. Ailerons keep your wings level. But with heavy gusts you may need to roll the airplane and side slip, which is where the rudder would come in.

Fly the airplane with ailerons on line with the runway in a crab. Straighten the airplane on landing with the rudder.

For a steady wind you can do a forward slip to landing all the way to touch down. This is a standard technique taught at many flight schools. You touch down with the windward wing low and that wheel will touch down first. You use the rudder to keep the nose pointed down the runway and use ailerons to stay over the centerline. If done properly you will have a slight bank into the wind and the nose will be pointed straight down the runway. It is a very stable maneuver and requires no timing like the last minute rudder kick. Only a slightly higher airspeed is recommended. Now this can be a lot harder with a model then it is with a full scale, which is why I didn't bring it up before. The point I was trying to make though, is the wind will not get under the wing while in the air and flip the plane, so don't be afraid to use a little aileron as long as you have enough speed.

It is actually not a can of worms, but one of resources.
This weekend I will print the whole thread and try to absorb and undestand it.
Controversy is good and help understand there no magic formula for all occasions.
I do like to start with the basics. I woul hate to have bad habits.
I know some guys at the field who have been flying for years but can only land on one side. This is bad.
At this time, I will only fly with high winds on the sim.

Thank you all

Cfircav8r, very true in my experience regarding slipping an RC. Side slipping an RC model (banking using rudder on approach) is very difficult as a practiced maneuver. I've tried and never come close to accomplishing it.

It's infinitely easier to keep the wings level and "steer" the airplane in with ailerons - while using the throttle to keep the centerline of the runway.

As you alluded to in your post, side slipping RC is more difficult than side slipping full scale. I believe this is true.

I don't yet have my Private Pilot License. I know from personal experience it's tremendously easier to fly a full scale airplane than flying RC.

I am just having a hard time understanding how you steer with ailerons while keeping the wings level and how does throttle keep you on centerline. If you are saying use more throttle during the crab to stop the drift or allow more drift then that would be very counter productive. The best way to fly an approch is to establish a safe airspeed with trim and use throttle to adjust the glideslope. Use small heading changes with coordinated turns (aileron, and rudder if needed) to maintain your approach path on the centerline.

All I can say is you'll have to come over to Oregon and fly with me because I can't explain it better than that. The only other thing I'd say is there's drift on turn to final.

Yes, crab is set to counter the drift and crab is just a heading change to compensate for that drift. There should be no different control input than is needed for a normal turn. You just turn more or less, than you would without wind, to establish the crab angle. As you get lower the wind speed can vary somewhat and therfore your crab angle may need to change, and you do this again with small normal turns to adjust heading. When you reach the runway start the flare and just before touchdown use rudder to straighten the nose to align it with the runway. At this point you should also be adding a small amount of aileron into the wind to keep from drifting, and increase it after the plane is on the runway. Again trim for a good approach speed and throttle for glide slope.

In my experience, I agree 100% with this post. Yes, crab is a heading change to compensate for drift. And I will say again, with a strong crosswind and using only ailerons, I keep a sport airplane on the centerline of a runway on approach without using rudder.

Allright I made another video demonstrating the forward slip method mentioned by cfircav8r and myself earlier in the thread.

This is the first video I made using the most commn method of crabing almost to the runway then using rudder at the last second to correct:
[youtube]http://www.youtube.com/watch?v=_Y9hoVxVeD0[/youtube]

Here is the second one showing a side slip to landing. You see I straightened out the airplane much ealier and flew it in with a wing low attitude. It is much more difficult but it sure looks cool!!
[youtube]http://www.youtube.com/watch?v=mz6UcwbOanA[/youtube]

And this one I made just for fun. This is a technique I invented myself and took a few tries to get right!! This is still with a 15 knot crosswind as in the other videos.
[youtube]http://www.youtube.com/watch?v=wPIod6aJtG0[/youtube]

Assuming I am below average in learning, how long do you guys think it will take me to fly like that????

By the way, I have three 5-minutes solo flights under my belt. 

LOL

Learn as much as you can, fly as often as you can, don't be afraid to push yourself and it will come quickly.

I am gratified to see that all those who mention the sideslip approach got it the right way around! So often I read people advocating doing it in the wrong direction. The wing lift is very powerful, so if you want to do a sidelip you bank the wing into the crosswind so that the angled lift force counteracts the crosswind force. Of course the plane would then start to turn that way so you apply opposite rudder to stop it. For example, wind from the plane's right, bank right and hold on left rudder. Where so many people get it wrong is they believe they apply rudder first into wind because they think thats what counteracts the drift, and then bank away from the wind, e.g. wind from plane's right, they rudder right and bank left. Always bank into wind for a sideslip.

Now we can see that whichever approach you use, crab or sideslip, the rudder is applied away from, not towards the wind. In the sideslip it is applied away from the wind all the way down the approach, and in the crab it is applied for a moment away from the wind to straighten the plane along the runway.

Which approach should you choose? Unless you have a special need to sideslip, always choose the crab for the following reasons:

Crab: controls are at their normal neutral position. That makes it easy to hold attitude, and after correcting bumps and gust control sticks go straight back to neutral position. Airspeed is normal, allowing for headwind component. Airflow over wings is normal. Stall speed is normal. Any stall will be the normal for that plane. Small rudder kick at touchdown and land normally. In full-size, passengers feel everything normal.

Sideslip: controls have to be held at some non-neutral position. That position takes time to find as amount of bank is proportional to side wind component. Not easy to maintain smooth path either mentally or physically. Takes time to re-find correct control position after correcting for turbulence. Airflow over wings not normal and stall speed is raised so it is very important that you fly faster. If stall occurs it is not normal but is extremely likely to flick and spin viciously into the applied rudder direction. Have to touchdown still in sideslip on one wheel, then lower other wheel and reduce yaw. In full-size passengers feel aircraft leaning over uncomfortably all the way down approach. Can't be used as a landing in gliders as the lower wingtip will reach ground before the wheels do! The raised drag of the sideslip is its one advantage allowing you to get down a steeper path if you are too high on approach but remember you are, or should be, going faster because the stall speed is raised so it is not a short field technique but a steep approach technique!

In any wind from head on to 90 degree cross runway, you will either have to make a steeper approach, or use more throttle to make a normal angle approach, the throttle being used to reduce rate of descent, not increase airspeed. The reason is that the plane flies through the air, not by reference to the ground. You may turn finals say 50 yards away from the runway and on a calm day the plane flies 50 air yards to the runway, but in a headwind the plane must fly 60 or 70 or... air yards to get the 50 ground yards to the runway. Thus it takes longer to do so the rate of descent must be less. What about in a 90 degree cross wind? Remember that crabbing means pointing ever so slightly into wind so the plane will still have to fly say 55 or 60 air yards to cover the 50 ground yards, so even with no wind component along the runway the plane still has further air distance to fly.
H

PS beware of r/c simulators, they have their uses but they are not accurate. for example I can't fly helis, but in AFPD I can fly helis using the keyboard. Is that like real life? I think not! So beware of using sims as validation for anything.

So, on strong or cross-wind, I take it that crabing is definetly the second choice for beginners.

The first choice beeing to sit down and watch experts fly their RC models.

I would replace the word "wind" with "turbulence and gusts". If you have a very smooth and steady side wind you can fly easily up to very high wind speeds. When turbulence or gusts are strong, sit down and watch the fools fly, experts know when to give up! (competitions excepted, there you have a bad choice to compete or lose if the turbulence is high)

H

I made one last video on this subject to kind of clear up a common wording mistake when it comes to slipping. HarryC actually reminded me about the proper terminology for using a SIDE slip for landing in a crosswind. I always get the the term sideslip mixed up with forward slip. They have similar control inputs but they are used for different reasons. A sideslip is exactly how HarryC and several others have described so I wont go into that. A forward slip on the other hand is a cross control maneuver used to drastically increase drag and therefore is useful for increasing descent rate without increasing airspeed dramatically. This very useful if you have a field where you need to make a steep descent over an obstacle or you lose an engine to high to make a normal descent. I found a good article describing the difference.

http://en.wikipedia.org/wiki/Slip_(aerodynamic) I am sure there are better sources but this was just a quick internet search.

And of course a video demonstrating a forward slip with an engine out.
[youtube]http://www.youtube.com/watch?v=AQQNjIDeq5M[/youtube]

I wold agree with you that Sims have their limitations especially with helicopters. But to be honest I had hit a serious plateau with my flying skills till I got a simulator. Sims help you develop the required muscle memory required for alot of difficult situations with no fear of crashing. Now flying in the real world is more dificult but at least you can master the basics before risking an expensive model trying something crazy. Most 3D stuff I can do I learned on the sim then transferred to real life.

I fully agree, one good use I found was just as you describe, building the muscle memory for things like slow rolls, so that when transferred to the real world all i had to do was adjust to suit the plane, my thumbs were already moving the right directions at the right times. What I would be wary of is using the sim as a proof of some things like how planes behave in winds

I am not aware of any fundamental difference and have never heard the term "forward slip" in the 30 years I have been full-size flying! It is always sideslip, whether to approach in cross wind or to lose height rapidly because you have messed up a glide/engine failure approach! One requires more power to prevent that rapid loss of height, in the other situation you actually want that rpaid loss, but that apart they are the same!
H